Hekla

Hekla (), or Hecla, is a stratovolcano in the south of Iceland with a height of . Hekla is one of Iceland's most active volcanoes; over 20 eruptions have occurred in and around the volcano since 874. During the Middle Ages, Europeans called the volcano the "Gateway to Hell".
Hekla is part of a volcanic ridge, long. The most active part of this ridge, a fissure about long named "Heklugjá", is considered to be within Hekla proper. Hekla looks rather like an overturned boat, with its keel being a series of craters, two of which are generally the most active.
The volcano's frequent large eruptions have covered much of Iceland with tephra, and these layers can be used to date eruptions of Iceland's other volcanoes. Approximately 10% of the tephra created in Iceland in the last thousand years has come from Hekla, amounting to 5 km3. Cumulatively, the volcano has produced one of the largest volumes of lava of any in the world in the last millennium, around 8 km3.
Etymology.
In Icelandic "Hekla" is the word for a short hooded cloak, which may relate to the frequent cloud cover on the summit. An early Latin source refers to the mountain as "Mons Casule".
Reputation.
After the eruption of 1104, stories, probably spread deliberately through Europe by Cistercian monks, told that Hekla was the gateway to Hell. The Cistercian monk Herbert of Clairvaux wrote in his "De Miraculis" (without naming Hekla): A poem by the monk Benedeit from circa 1120 about the voyages of Saint Brendan mentions Hekla as the prison of Judas.
In the "Flatey Book Annal" it was recorded that during the 1341 eruption, people saw large and small birds flying in the mountain's fire which were taken to be souls.
In the 16th century Caspar Peucer wrote that the Gates of Hell could be found in "the bottomless abyss of Hekla Fell". The belief that Hekla was the gate to Hell persisted until the 19th century. There is still a legend that witches gather on Hekla during Easter.
Geology.
Hekla has a morphological type between that of a crater row and stratovolcano (built from mixed lava and tephra eruptions) sited at a rift-transform junction in the area where the south Iceland seismic zone and eastern volcanic zone meet. The unusual form of Hekla is found on very few volcanoes around the world, notably Callaqui in Chile. Hekla is situated on a long volcanic ridge of which the 5.5 km "Heklugjá" fissure is considered Hekla proper. This fissure opens along its entire length during major eruptions and is fed by a magma reservoir estimated to have a top 4 km below the surface with centroid 2.5 km lower.
The tephra produced by its eruptions is high in fluorine, which is poisonous to animals. Hekla's basaltic andesite lava generally has a SiO2 content of over 54%, compared to the 45–50% of other nearby transitional alkaline basalt eruptions (see TAS classification).
It is the only Icelandic volcano to produce calc-alkaline lavas.
Phenocrysts in Hekla's lava can contain plagioclase, pyroxene, titanomagnetite, olivine, and apatite.
When not erupting Hekla is often covered with snow and small glaciers; it is also unusually aseismic with activity only starting 30–80 minutes before an eruption. Hekla is located on the mid-ocean ridge, a diverging plate boundary.
Hekla is closely studied today for parameters such as strain, tilt, deformation and other movement and seismic activity. Earthquakes in the volcano's vicinity are generally below magnitude 2 while it is dormant and magnitude 3 when erupting.
Eruption history.
The earliest recorded eruption of Hekla took place in 1104. Since then there have been between twenty and thirty considerable eruptions, with the mountain sometimes remaining active for periods of six years with little pause. Eruptions in Hekla are varied and difficult to predict. Some are very short (a week to ten days) whereas others can stretch into months and years (the 1947 eruption started 29 March 1947 and ended April 1948). But there is a general correlation: the longer Hekla goes dormant, the larger and more catastrophic its opening eruption will be. The most recent eruption was on 26 February 2000.
Prehistoric eruptions.
One of the largest Holocene eruptions in Iceland was the Hekla 3 (or H3) eruption circa 1000 BC, which threw about 7.3 km3 of volcanic rock into the atmosphere, placing its Volcanic Explosivity Index (VEI) at 5. This would have cooled temperatures in the northern parts of the globe for a few years afterwards. Traces of this eruption have been identified in Scottish peat bogs, and in Ireland a study of tree rings dating from this period has shown negligible tree ring growth for a decade.
Unless otherwise stated eruption dates are from Global Volcanism Program, other sources disagree.
Hekla 3, 4, and 5 produced huge amounts of rhyolitic ash and tephra, covering 80% of Iceland and providing useful date markers in soil profiles in other parts of Europe such as Orkney, Scandinavia, and elsewhere. H3 and H4 produced the largest layers of tephra in Iceland since the last Ice Age. During the last 7,000 years, one third of the volcanic ash deposited in Scandinavia, Germany, Ireland, and the United Kingdom originated from Hekla.
1104 to 1878.
Hekla had been dormant for at least 250 years when it erupted explosively in 1104 (probably in the autumn), covering over half of Iceland (55,000 km2) with 1.2 km3 / 2.5 km3 of rhyodacitic tephra. This was the second largest tephra eruption in the country in historical times with a VEI of 5. Farms upwind of the volcano in Þjórsárdalur valley (15 km away), Hrunamannaafréttur (50 km away) and Lake Hvítárvatn (70 km away) were abandoned because of the damage. The eruption caused Hekla to become famous throughout Europe.
A VEI 4 eruption began on 19 January 1158 producing over 0.15 km3 of lava and 0.2 km3 of tephra. It is likely to be the source of the "Efrahvolshraun" lava on Hekla's west.
The VEI 3 eruption began on 4 December.
The VEI 2 eruption and the 1206 eruption distributed around 0.24 km3 of tephra mainly to the northeast.
This VEI 4 eruption, which started on 11 July and lasted for a year, was the second largest tephra eruption of Hekla since Iceland was settled, covering 30,000 km2
of land with 0.31 km3 of tephra. Over 0.5 km3 of lava was also expelled. The tephra caused significant damage to the settlements of Skagafjörður and Fljót, leading to over 500 deaths that winter.
The material output from this eruption had SiO2 levels of between 56% and 64%, and apart from a slight abundance of olivine the lava, was typical of Hekla eruptions.
A small eruption (VEI 3) started on 19 May and deposited around 5×107 m3 of tephra over the areas west and southwest of Hekla, leading to many cattle deaths, probably mainly from fluorosis.
In late 1389 Hekla erupted again (VEI 3), starting with a large ejection of tephra to the southeast. Later "the eruption fissure moved itself out of the mountain proper and into the woods a little above Skard". Skard and another nearby farm were destroyed by a large lava flow that now forms the 12.5 km2 "Nordurhraun". In total around 0.3 km3 of lava and 5×107 m3 of tephra were produced.
An eruption may have occurred around 1440 at Raudölder; despite being close to Hekla this is not classed as an eruption of Hekla based on the SiO2 content of the lava.
Details of the 1510 eruption were not recorded until a century later. It started on 25 July and was particularly violent (VEI 4), firing volcanic bombs as far as Vördufell, 40 km west. Tephra was deposited over Rangárvellir, Holt and Landeyjar, 0.2 km3 in total. A man in Landsveit was killed.
A VEI 4 eruption began on 3 January and lasted for over 6 months, with 0.15 km3 of tephra being deposited to the south-southeast, damaging Mýrdalur.
A small (VEI 3) eruption began on 8 May 1636 and lasted for over a year. The 5×107 m3 of tephra from the eruption damaged pasture to the northeast causing death of livestock.
Starting 13 January and lasting for over 7 months the eruption was one of Hekla's most destructive (VEI 4). Initially tephra was produced at 60,000 m3·s−1, 0.18 km3 during the entire eruption, which also caused lahars and tsunami. The tephra was deposited to the northwest, destroying and damaging farms and woodland in Þjórsárdalur, Land, Hreppar and Biskupstungur. Fine ash from the eruption reached Norway. There was damage to wildlife with significant numbers of trout, salmon, ptarmigan and farm animals dying.
A very small eruption, possibly only VEI 1, took place on 2 April 1725, producing flows of lava from locations around Hekla which have since been covered by later lava flows. These eruptions are not classed as of Hekla itself based on the SiO2 content of the lava.
The eruption of 1766 was large (VEI 4) and produced the second largest lava flow, 1.3 km3 covering 65 km2, and third largest tephra volume, 0.24 km3, of any Icelandic volcano during the inhabited era. The eruption started at around 3:30 am on 5 April 1766 and ceased in May 1768. Initially a 2–4 cm layer of tephra was deposited over Austur-Húnavatnssýsla and Skagafjördur, resulting in the deaths of both fish and livestock. Rangárvellir, Land and Hreppar also suffered damage. During the eruption up to 0.5 m lava bombs were thrown 15–20 km away, and flooding was caused by the sudden melting of snow and ice on Hekla's slopes.
Hekla was dormant for more than sixty years before 1845, when it suddenly burst forth on 2 September at 9 am:
The eruption ceased around 5 April 1846. Initially in this VEI 4 eruption tephra was produced at 20,000 m3·s−1. The tephra deposition (0.17 km3) was mainly to the east-southeast; immediately to the east of Hekla the layer was 20–40 cm deep. Fine ash was carried to the Faroes, Shetland and Orkney. Lava flows to the west and northwest covered an area of 25 km2 with 0.63 km3 of lava. Large quantities of dark ash were deposited over pasture in the same directions leading to many livestock deaths through fluorosis for the next two years.
A small eruption (VEI 2) occurred between 27 February 1878 and April 1878, around 10 km east of Hekla, and produced 0.2 km3 of lava from two parallel fissures covering 15.5 km2.
1913 to 1948.
A small eruption (VEI 2) occurred between 25 April 1913 and 18 May 1913, around 10 km east of Hekla, and caused large fissures at Mundafell and Lambafit which produced 3.8 and 6.3 km2 of lava respectively.
The VEI 4 eruption started on 29 March 1947 and ended on 21 April 1948. It is likely that this was both the second greatest lava eruption of Hekla whilst Iceland was inhabited and the second greatest lava eruption in the world in the period 1900–1970. A total lava volume 0.8 km3 was produced with 0.21 km3 of tephra. The height of Hekla was 1,447 m before the eruption, increasing to a maximum of 1,503 m, before dropping to 1,491 m subsequently.
The eruption occurred over a century after the last eruption of Hekla proper, the longest dormant period since 1104. Before the eruption the volcano had been visible from the surrounding area but nothing remarkable was noticed. The eruption occurred at 6:41 am ± 3 min with a loud roar; later eruptions could be heard throughout Iceland. An earthquake at 6:50 am measured 6 on the Mercalli intensity scale and increased the eruption intensity until it covered a 4 km fissure on the ridge. The cloud from the eruption had ascended to a height of 30 km by 7:08 am, the wind then carried it southwards towards Eyjafjallajökull, turning it black. Pumice first landed on Fljótshlíð at around 7:10 am, and tephra and ash continued falling until it formed a 3–10 cm layer. A lava bomb that landed 32 km from Hekla was 0.5 m across and weighed 20 kg. Between Vatnafjöll and Hekla, a layer of tephra up to a metre thick was deposited, including bombs with a diameter larger than 0.5 m. Bombs with areas of 50 m2 were dropped onto the slopes of Hekla, up to 1 km away. 51 hours after the eruption had started, ash fell on Helsinki, Finland, having covered 2,860 km in this time.
The initial tephra production rate in the first 30 minutes of the eruption was 75,000 m3·s−1, dropping to 22,000 m3·s−1 for the next half-hour. The initial phase produced 0.18 km3 of tephra, equating to 4.5×107 m3 of solid rock, covering 3,130 km2 of land and sea. 98 farms were damaged by the eruption, but only 2 were no longer farmed in 1970. A large volunteer effort was mobilized to clear the tephra – around 1000 man-days by the end of July. The eruption produced around 3 ML of water (snowmelt and directly from the fissure) which caused flooding of the Ytri Rangá river.
In the first 20 hours of the eruption approximately 3,500 m3·s−1 of lava was produced from the fissure, dividing into various branches and covering 12–15 km2. On the second day, 8 distinct eruption columns were discernible. A crater formed at 860 m called the Lava Crater ("Hraungígur"), producing a constant flow of lava. Another crater named the Shoulder Crater ("Axlargígur") produced a column of smoke every 10 seconds together with loud explosions that created visible compression waves in the smoke. By the fourth, fifth, and sixth days, the eruption was greatly diminished, and only the shoulder and summit craters were erupting explosively.
The explosive eruption increased in strength from 9–12 April and then from 28 April it reduced again. On 3 May, the volcano stopped throwing out lava in sudden explosions from its craters and changed to continuously ejecting tephra and ash for long periods, until early June when this reduced. On 2 September, the Shoulder Crater had a 960 m circumference at its top and the Summit Crater a 700 m circumference at its highest point, 90 m above the ridge. Sandy tephra and ash fell over Iceland in May and June, sometimes making it dark in the daytime near Hekla. The tephra caused fluorine poisoning of grazing sheep, making them unable to walk. That winter more craters formed, building up cones. Explosive activity had ceased six months after the first eruption. Lava flowed from the Lava Crater continuously during the eruption, starting at a rate of over 100 m3·s−1, dropping to 5–10 m3·s−1 in April and early May at a speed of around 20 cm·s−1 before increasing, eventually reaching 150 m3·s−1 at the end of June and at similar levels until mid-July with a peak flow speed of 2–2.5 m·s−1. From there it gradually decreased to under 10 m3·s−1 in November. Initially the lava comprised 57–58% SiO2 and 11% Fe2O3, from the time of peak flow onwards this changed to 54% SiO2 and 13.5% Fe2O3.
The lava river sometimes ran through lava tubes before emerging again. The lava front had a height of up to 15 m. On 15 and 16 June, a branch of lava flow to the south of Melfell traveled over 1 km in 30 hours before slowing and stopping by 21 June, 7.8 km from the Lava Crater. The longest lava stream produced was 8 km long and stopped in Stóraskógsbotnar. A scientist filming one of the lava streams on 2 November was hit by a block of lava and was killed.
The lava flow stopped after 13 months on 21 April, having covered 40 km2 and with a maximum depth of 100 m. The lava beds produced were mainly the ʻAʻā lava type with Pāhoehoe and "lava a budella" (lava tubes) areas. In April and May 1948 CO2 emitted from cracks in the ground pooled in hollows near to Hekla, killing 15 sheep and some wild animals and birds. In total 24,000 tonnes of CO2 was emitted. Ditches were dug by farmers to drain these hollows, and the CO2 emission had stopped by the end of the year.
1970 to 1991.
The 1970 eruption of Hekla started at 9:23 pm on 5 May 1970 and lasted until 5 July. It had a VEI of 3 and produced 0.2 km³ of lava covering an area of 18.5 km² and 6.6×10 7 m³ of tephra, deposited over an area of 40,000 km², mainly to the northwest of the volcano.
The main Hekla fissure only erupted at its far southwest end, most of the eruption was from other fissures nearby. The eruption stopped in the south-southwest on 10 May and in Hlídargígar on 20 May, but a new fissure opened on the same day and lava flowed from this until 5 July. The lava was andesite containing olivine, similar to the lava produced later in the eruption of 1947.
Before the eruption, a greater than normal amount of snow melting had occurred, indicating the volcano was heating up. Earth tremors began at 8:48 pm on the evening of the eruption; the largest had a magnitude of 4. The eruption started weakly at 9:23 pm IMT ± 2 min before increasing in power. The first pumice fell on Búrfell power station, 15 km away, at 9:35 pm causing people to evacuate. The eruption seems to have started in two locations at the same time – to the Shoulder crater's south-southwest and below the Lava Crater. At 10:30 pm a crater at 780 m was producing a lava column which reached an altitude of around 1000 m. During the night a 700 m high lava fountain was thrown up from the main crater. A 500 m long fissure starting below the Lava Crater opened and lava fountains and other lava flows emanated from it. One hour into the eruption, a new 400 m fissure opened to the northeast, producing two main lava fountains, and shortly after another adjoining fissure opened producing lava fountains to a height of 500 m. At around midnight, another fissure opened northwest of the Lava Crater, later hurling an over 300 m long lava fountain, 200–300 m into the air. By midnight lava had already covered over 1 km² and this extended to 7.5 km² by next morning implying a flow rate of around 1500 m³/s.
For the first two hours, tephra was produced at the rate of 10,000 m³/s. The cloud from the eruption, which had reached by 10:10 pm, caused a lightning storm. The tephra was transported northwards by the wind, causing the sky to turn black in places – 190 km away at Blönduós tephra fell from midnight until 2 am, and ash fell on a trawler 330 km away at 2 am. Icelanders sampled the tephra fall in their locality by putting a plate outside to capture everything that fell onto it. This, and other measurements, showed the area covered was long and narrow with the 1 mm contour (an equivalent of 8 tonnes per hectare) extending to the north coast.
By 5:30 on 6 May, the lava flow measured 4 km long. Many lava bombs were found near the main crater, one had an area of 6 m² and a likely weight of 12 tons. Xenoliths formed around 2% of the material produced by the craters. These were of rock types including basalt, andesite, ignimbrite and sedimentary rock.
The eruption became stronger at Skjólkvíar on 12 May, with columns of steam attaining a height of 2500 m. The eruption intensity then gradually reduced until it stopped on 20 May. The lava field then had an area of 5.8 km². Later that day a 900 m long fissure opened 1 km north of the main Hlídargígar crater. That night it contained 17 lava fountains, each 20–50 m in height. By the evening of the next day, 10–12 craters had formed, each throwing pieces of lava 50–100 m in the air. This row of craters was named Öldugígar. Gradually the number of active craters decreased, the most active of these built a cone 100 m higher than the level of the ridge. Lava flowed from its base until mid-June when the lava cut through the north crater wall. The larger cones produced more tephra, occasionally with lightning within the tephra cloud. By 5 July, the eruption had stopped.
During eruptions of Hekla, fluorine is produced and sticks to the surfaces of the grains of tephra. Fine grains can have a fluorine content of 350 ppm, and fluorine poisoning can start in sheep at a diet with fluorine content of 25 ppm. At 250 ppm, death can occur within a few days. In 1783, 79% of the Icelandic sheep stock were killed, probably as a result of fluorosis caused by the eruption of Lakagígar. Some of the ash produced in this eruption had a fluorine content of 0.2%, and two days after the eruption contaminated grass had a dry weight content of up to 0.4% fluorine. 450 farms and 95,000 sheep were affected by the eruption. Some sheep were kept inside and fed on hay or moved, but other farmers were forced to graze their flocks outside.
This VEI 3 eruption started at 13:28 on 17 August 1980 and lasted until 20 August 1980. It was a mixed eruption producing a lava volume of 0.12 km³ and a tephra volume of 5.8×107 m³. The fissure opened along a 7 km length. Shortly before the eruption started a steam column was produced; eventually the eruption column reached a height of 15 km. The main tephra deposits were to the north-northeast and lasted for around 2 hours. Deposits were 20 cm thick 10 km from the summit, decreasing to less than 1 mm at the coast 230 km away.
Lava was initially produced from close to the summit, spreading to other parts of the fissure and covering an area of 22 km² in around 24 hours. The last scoria were seen on the morning of 20 August. This was an unusual eruption both in the short time since the previous eruption – the shortest since 1104, and the length – previous eruptions had lasted from 2 months to 2 years rather than just 3 days.
The 1981 eruption, which is regarded as being a continuation of the previous year's eruption, began at 3 am on 9 April 1981, had a VEI of 2 and produced 3×107 m³ of lava, lasting until 16 April 1981. The eruption threw ash to a height of 6.6 km, and a new crater formed at the summit from which 3 lava flows originated. These extended to a maximum of 4.5 km from the volcano, covering 5–6 km².
A VEI 3 eruption occurred from 17 January 1991 to 11 March 1991, producing 0.15 km³ of lava and 2×107 m³ of tephra. The eruption, which was preceded by sulphurous smells and earthquakes, started as a Plinian eruption, producing an ash cloud reaching an altitude of 11.5 km within 10 minutes which had travelled over 200 km north-northeast to the coast within 3 hours. The eruption then began producing andesitic lava, the flows eventually covering an area of 23 km² to an average depth of 6–7 m. Initially, part of the Heklugja fissure and other fissures erupted with lava fountains reaching 300 m in height. By the second day, the activity stopped in all but one fissure where the main crater formed. During these 2 days, 800 m³/s of lava were produced, slowing to between 1 m³/s and 14 m³/s for most of the eruption. This low viscosity lava had a SiO2 content of approximately 54%.
2000.
The most recent eruption was relatively short; it started at 18:18 on 26 February 2000 and lasted until 8 March. It was a VEI 3 eruption producing a lava volume of 0.189 km3 DRE / 0.29 km3 and 107 m3 of tephra. The eruption went through four phases:
Eruption activity was at a maximum in the first hour, and by the first night the fissure on Hekla had opened to a length of 6–7 km. The steam column rose to a height of almost 15 km, and ash was transported to Grímsey. During this eruption, a NASA DC-8 aeroplane accidentally flew through the plume with all instruments switched on, resulting in unprecedented measurement of a young volcanic plume.
Up until this eruption, it had been assumed that Hekla was incapable of producing the most dangerous of volcanic phenomena, the pyroclastic flow. In January 2003, however, a team from the Norvol Institute in Reykjavík, under the leadership of Dr. Ármann Höskuldsson, reported that they found traces of a pyroclastic flow, roughly 5 km long, stretching down the side of the mountain. This will call for a reappraisal of volcanic eruptions of the basic rock type, which up to now were generally thought not to produce large pyroclastic flows. It will also require that the public and curious spectators who always rush to the scene at the start of a new outbreak, be kept much further away from the volcanic activity than was thought necessary during previous outbreaks.
Flora and fauna.
The Hekla area was once forested. Forest and some grasses are much more resilient to ash and pumice fall than low vegetation, but the combined effect of human habitation and the volcanic activity has left an unstable surface very susceptible to erosion. Hekluskógar, a 90,000 ha reforesting project is attempting to restore the birch and willow woodland to the slopes of Hekla, starting with soil fertilisation and grass sowing. This would stabilize the large areas of volcanic ash, help to reduce wind erosion of the frost heaved surface, slow drainage rates and hence water erosion, and ultimately increase biodiversity. It is the largest reforestation of its type in Europe. After an eruption, almost all of the 'safe sites' on new lava flows are colonised by mosses within 20 years expanding to a homogeneous layer up to 20 cm thick within 50 years.
Sport and recreation.
Hekla is a popular destination for hiking. Following the most recent eruption the path goes most of the way to the summit; the walk takes 3 to 4 hours.
In spring, skiing is possible on short routes around the rim of the crater. In summer, there are easy (F) mountaineering routes also around the crater rim, and it is possible to snowcat to the top in winter. The volcano can be reached using the buses to Landmannalaugar 30 km further east, and it is possible to stay or camp at farms in the area. A visitor centre, The Hekla Center at Leirubakki Farm, opened in 2007.
In popular culture.
Hekla has featured in artistic works since the time of its medieval infamy.
Films.
In the Spanish apocalyptic science fiction film, "Los Últimos Días" (2013), some news reporters speculate that three recent eruptions of Mount Hekla could have caused the spreading form of agoraphobia that kills affected people who go outside.
Food.
In the Boston, Massachusetts area, Hekla pastries can be found – large, upside-down cinnamon rolls with white sugar icing spooned over the top to look like the snow-topped volcano.
Literature.
The British poet William Blake showed Winter being banished to Hekla in "To Winter", one of the works from his "Poetical Sketches".
In "To Lie With Lions", by Dorothy Dunnett, a party of merchants visiting Iceland in the year 1471 is threatened by an imminent eruption of both Hekla and Katla.
Mt. Hekla is referenced in the third chapter of Herman Melville's novel "Moby Dick", in EE Ryan's "The Odd Saga of the American and a Curious Icelandic Flock", and in the final chapters of Joan Aiken's novel "Is".
The Hekla 3 eruption and the ensuing volcanic winter play a large role in Stephen Baxter's alternate-history novel "Bronze Winter".
Music.
The piece "Hekla", Op 52 (1964) by Icelandic composer Jón Leifs, has been called the "loudest classical music of all time". The requirements for a performance of "Hekla" include four sets of rocks hit with hammers, steel plates, anvils, sirens, cannons, metal chains, choir, a large orchestra, and organ.
Transportation.
A small Danish cruiser launched in 1890 was named ""; it was scrapped in 1955.
A Danish steamer called also saw combat in the First Schleswig War.
Icelandair named one of their aircraft after Hekla.
There have been several ships of the Royal Navy named HMS "Hecla"
Organizations.
In October 2011 a German left-wing militant group called the " (Hekla Reception Committee) set at least 17 incendiary devices on railways in the Berlin area, with 2 of them going off.
The DBU Copenhagen football club " play at Hekla Park.


Adamantas

Adamantas (, older form Αδάμας, from the Greek αδάμας= "diamond") is the harbor town of Milos island. It has a population of 1,347 people (2011).
Highlights:
Adamantas is the cultural and commercial center of the island.


Huehuecanauhtlus

Huehuecanauhtlus is an extinct genus of hadrosauroid dinosaur known from the Late Cretaceous (Santonian stage) of Michoacán, western Mexico. It contains a single species, Huehuecanauhtlus tiquichensis.
Etymology.
"Huehuecanauhtlus" was first described and named by Angel Alejandro Ramírez-Velasco, Mouloud Benammi, Albert Prieto-Márquez, Jesús Alvarado Ortega and René Hernández-Rivera in 2012 and the type species is "Huehuecanauhtlus tiquichensis". The generic name is derived from Náhuatl (group of dialects related to the Aztecan languages) "huehuetl", meaning "ancient" and "canauhtli", meaning "duck" in reference to its hadrosauroid affinities. The correct pronunciation of the generic name is "UEUE-CANA-UHh-TLUS". The specific name, "tiquichensis", honors the town of Tiquicheo, for the generosity and hospitality of its people during the fieldwork season.
Discovery.
"Huehuecanauhtlus" is known only from two individuals. The holotype IGM 6253 represented by fragmentary skull (partial left maxilla and dentary fragment) and postcranial skeleton including four cervical vertebrae, nine dorsal vertebrae, four dorsal neural spines, one dorsal diapophysis, five right dorsal ribs, seven left dorsal ribs, seven sacral neural spines, seven sacral diapophyses, one caudal diapophysis, three caudal vertebrae, two caudal neural spine, eight fragmentary ossified tendons, left and right partial ilium, and left and right partial pubis. The smaller paratype, IGM 6254, is represented by fragment of left dentary, two teeth, and one cervical prezygapophysis.
Both specimens were collected at the Barranca Los Bonetes locality in Tuzantla, Michoacán. The holotype came from the sixth fossiliferous spot, whereas the paratype came from the third spot, of an unnamed formation, dating to the Santonian stage of the Late Cretaceous period, about 85.8-83.5 million years ago.
Description.
Ramírez-Velasco "et al." (2012) diagnosed "Huehuecanauhtlus" by a unique combination of characters. For example, two teeth exposed on the occlusal plane of the rostral third and the posterior third of the dentary and maxilla, respectively. It had seven sacral vertebrae and tall neural spines of posterior vertebrae, being between 3.5 and 4 times taller than their corresponding centra. As in "Claosaurus", its supraacetabular process is as long as 75% of the length of the central iliac plate, with an apex located above the posteroventral corner of the ischiac tuberosity. It differs from other hadrosauroids in possessing an extremely deflected preacetabular process of the ilium, so that the bisecting long axis of the process forms an angle less than 130° with the horizontal plane defined by the ischiac and pubic peduncles. It can be differentiated from basal hadrosauroids in having a very deep concave profile of the dorsomedial margin of the iliac plate, adjacent to the supraacetabular process. A phylogenetic analysis performed by Ramírez-Velasco "et al." (2012) found a big polytomy of all hadrosauroids which are more derived than "Probactrosaurus" but less derived than Hadrosauridae. The exclusion of "Claosaurus", "Jeyawati", "Levnesovia", "Nanyangosaurus", "Shuangmiaosaurus" and "Telmatosaurus" from the polytomy resulted in a more resolved topology. The cladogram below shows "Huehuecanauhtlus" phylogenetic position among other hadrosauroids following this topology (the relationships within Hadrosauridae are not shown).


Hueicolla

Hueicolla is a beach and hamlet () at the sparsely populated coast of La Unión commune, southern Chile. Hueicolla is located south of Colún Beach, west of Alerce Costero National Park and Cordillera Pelada and north of the mouth of Bueno River.


Ksar Metlili Formation

The Ksar Metlili Formation is a geological formation in eastern High Atlas of Morocco, it is late Tithonian to Berriasian in age. It is approximately thick and primarily consists of mudstone and sandstone, with thin calcareous beds. One of these calcareous beds near the middle of the sequence is an important microvertebrate locality. Subsequent to the original site, several other localities have been sampled. The depositional environment is thought to be near shore deltaic.


Klusenberg

The Klusenberg is, at , the highest elevation on the territory of the city of Dortmund.
The Klusenberg part of the Ardey Hills lies west of the Hohensyburg. To the south its slopes fall away into the Hengsteysee lake. The Klusenberg is wooded with just a few residential houses.


Illaenula

Illaenula is a genus of trilobites in the order Phacopida (family Phacopidae), that existed during the middle Devonian in what is now the Czech Republic. It was described by Chlupac in 1977, and the type species is "Illaenula illaenoides", which was originally described under the genus "Ductina". The type locality was the Stínava-Chabicov Formation, in Moravia.


Austrosaurus

Austrosaurus (meaning "Southern lizard") was an extinct genus of titanosaurian sauropod dinosaur from the Allaru Formation and Winton Formation, from the early Cretaceous (110-105 million years ago) of Central-Western Queensland in Australia.
Discovery and species.
The remains were discovered by Mr. H.B. Wade on Clutha Station near Maxwelton in north Queensland in 1932, who alerted the station manager H. Mackillop, who showed his brother who sent them to the Queensland Museum. "Austrosaurus" was described by Heber Longman in 1933.
Paleobiology.
Originally it was thought that sauropods spent time near or in water to relieve weight from their legs. However, this theory is now rejected and it is believed that "Austrosaurus" like all sauropods lived on dry land. Fossil finds suggest a height of approximately 3.9 metres at the hip and 4.1 metres at the shoulder, which would have given it an almost level back. According to Gregory S. Paul, it was 20 meters long and weighed about 16, 000 kg.
Classification.
Initially, "Austrosaurus" was considered a cetiosaurid, like "Patagosaurus" or "Shunosaurus". Hocknull et al. (2009) described the new sauropod "Wintonotitan" from material that originally assigned to "Austrosaurus" by Coombs and Molnar in 1981. Hocknull suggested that "Austrosaurus mckillopi" differed only slightly from the QMF 7292, the holotype of "Wintonotitan wattsii", and should be considered a "nomen dubium". Recently, Poropat et al. (2017) reported additional sauropod material from the "Austrosaurus" type locality and assigned them to the "Austrosaurus" holotype, finding the genus to be a valid titanosauriform tentatively assignable to Somphospondyli.


Emausaurus

Emausaurus is a genus of thyreophoran or armored dinosaur from the Early Jurassic (Toarcian). Its fossils have been found in Mecklenburg-Vorpommern, northern Germany. "Emausaurus" is the only known Toarcian thyreorphoran and it is also the only dinosaur from the zone of the same age with a formal name.
Discovery and naming.
The type and only species, "E. ernsti", was named and described by Harmut Haubold in 1990. The generic name is composed of an acronym of Ernst Moritz Arndt University of Greifswald and Greek "/" (lizard). The specific name is derived from the name of geologist Werner Ernst, who acquired the fossil, holotype SGWG 85, in the summer of 1963 from foreman Werner Wollin at a loampit near Grimmen, in strata dating from the Toarcian. It is known by the right side of the skull, the right lower jaw, caudal vertebrae, neural arches, a radius, a metatarsal, a claw, fragments of ribs, scutes and plates, known as EMAU SGWG 85.
Description.
"Emausaurus" was probably a semibipedal to quadrupedal animal, being covered on a armor of osteoderms across the body. Like other thyreorphora, probably was hervivore, concretely a low dwelling one, with a diet more related with ground flora, such as Cycads and Bennnetitales. The body length of the holotype of "Emausaurus" has been estimated at around 2.5 m, with a weight of 70–90 kg. This was based on a juvenile individual though; adult length has been estimated at three to four metres, with a weight up to 240 kg. Most of the reconstruction has been based on "Scelidosaurus", although it is possible that "Emausaurus" was a more bipedal animal, as some of the young specimens of "Scelidosaurus" were thought to be. Adult forms probably where more quadrupedal. Armor includes three conical scutes and one tall, spiny element. David Norman in 2019 examined the morphology of "Scelidosaurus", comparing it with "Emausaurus". In "Emausaurus" the maxilla has, overall, a similar morphology to that seen in "Scelidosaurus". The disarticulated maxilla of "Emausaurus" exhibits an anteromedially directed robust process with which it met its counterpart in the midline, creating a wedge-like structure, with no obvious offset between the alveolar margins. In "Emausaurus" the structure of the frontals is not well preserved. In outline, its proportions resemble those of "Scelidosaurus", but the same is true of many Ornithischia. The lacrimal bone of "Emausaurus" is incomplete, but includes a long, curved jugal process that evidently wrapped itself around the anterior tip of the jugal.
So little is known of the postcranium "Emausaurus", recovering parts like a multipartite odontoid (sutured to the axis centrum), similar to that of "Scelidosaurus".
"Emausaurus" has a series of assigned Osteoderms, but lacks like "Scutellosaurus" ‘scapular osteoderms’. The major series of osteoderms foun appear to come from the tail or the dorsal section.
Classification.
Cladistic analyses showed that "Emausaurus" was a basal member of the Thyreophora, more derived than "Scutellosaurus", but less than "Scelidosaurus". "Scelidosaurus", "Emausaurus" and "Scutellosaurus" cluster at the base of most trees because they can be scored for only a restricted number of anatomical characters.
The cladistic status of the specimen is relatively controversial due to its young nature. Clearly it is a member of the Thyreophora, but its position can change by the time, if an adult specimen is found. "Emausaurus" can be more derived than "Scelidosaurus", or even be a sister taxon to Stegosauria. The major consensus has put "Emausaurus" as a non-eurypodan stem thyreophoran, along with Scutellosaurus and "Scelidosaurus" reinforced by almost all subsequent systematic reviews of ornithischian–thyreophoran relationships. Being "Emausaurus" and "Scutellosaurus" more basal than "Scelidosaurus". "Emausaurus" has been put on an outgroup to Ankylosauria, with "Scelidosaurus" and the basal stegosaur "Huayangosaurus". 7. Vickaryous et al. (2004), did the default phylogenetic analysis for ingroup ankylosaurs, due to including cranial and postcranial characters, a wide range of taxa and made no in-group relationships, although this analysis used the holotype "Lesothosaurus" and "Huayangosaurus" as outgroups, ignoring "Scelidosaurus" and "Emausaurus". On 2020, Norman et al. by studying "Scelidosaurus" found that along "Scutellosaurus" and "Emausaurus" both are positioned on the stem of Ankylosauria, rather than on the stem of Thyreophora, with "Emausaurus" as the basal sister-taxon to "Scelidosaurus". This is because "Emausaurus" possesses a dorsal margin of the dentary sinuous in lateral view and neither elongated nor squat proportions of metacarpal 1 ‘medium’. Alternatively, Emausaurus can be basal sister-taxon to "Scutellosaurus", but taking the similarities between "Emausaurus" and "Scelidosaurus" is more unlikely. The Norman study is resumed on:
Paleoecology.
"Emausaurus" has a sinuous jaw profile, more advanced in ankylosauromorphans, unlike the rectilinear morphology seen in the more basal genus "Scutellosaurus". The changes on the jaw is considered a series of modifications due to changes on the Diet and evolution of the food procesation of this dinosaurs, where it seems to be adapted to eat Coriaceous flora, such as Bennetites and Cycads, abundant on the coeval "Ciechocinek Formation" Lublin Coal Basin and specially on the Sorthat Formation. The rest of the skeleton of this genus is poorly presented, with for example the vertebrae showing no evidence of the proportional changes in the height of the neural arches and spines seen on stegosaurs. The animal was covered on Osteoderms, altrougth the few found give no indication of how extensively they were distributed across the torso. "Emausaurus", based on the proportions of the preserved metacarpals that the forelimb shows adaptations for weight support, rather than grasping, having ungulal phalanges that are conical and only slightly decurved.
The partial known proximal pedal phalanges are short and block-like, with near the same proportions seen in the pes of "Scelidosaurus". A series of characters that together are suggestive of graviportality and quadrupedality, maling "Emausaurus" a low roaming herbivore. Pseudo-Bipedality isn't discarded, with the genus able to reach slightly taller flora.
Paleoenvironment.
The holotype of "Emausaurus" was found on the so-called "Emausaurus type site", that represents a shale ingression from the Ciechocinek Formation, dated from the Lower Toarcian (Tenuicostatum). Is is a boundary composed by bituminous shale, It represents an ancient seashore-influenced environment, probably lagoonal, and it is contemporaneous of the Posidonia Shale and specially the Sorthat Formation of the same region. Fossil wood has been found on the same location, including driftwood and other related to the Araucariaceae, present in other European environments of Toarcian age. Of the invertebrate fauna insects, bivalves, sea snails and ammonites (Genus "Tiltoniceras", "Eleganticeras" and "Lobolytoceras") have been found. The vertebrate fauna is also varied, with fossils of the fish genus "Saurorhynchus", and the new genus "Grimmenichthys" and "Grimmenodon". Reptile fossils include Ichthyosauria indet., indeterminate Plesiosauria, rhomaleosaurid plesiosaurs, indeterminate Mesoeucrocodylia (probably Goniopholididae), indeterminate Thalattosuchia and at least two gravisaurian sauropods.


Ypresiosirex

Ypresiosirex is an extinct genus of sawfly in the horntail family Siricidae. The genus is solely known from a single Eocene fossil found in North America. At the time of its description the new genus was composed of a single species named Ypresiosirex orthosemos.
History and classification.
"Y. orthosemos" is known only from one fossil, a part and counterpart holotype, specimen number RBCM.EH2015.004.0001.001A&B, which is housed in the collections of the Royal British Columbia Museum in Victoria, British Columbia. "Ypresiosirex" was described from a specimen which was recovered from outcrops of the early Eocene, Ypresian McAbee Fossil Beds near Cache Creek, British Columbia. The unnamed formation outcropping at the McAbee Fossil Beds preserve an upland temperate flora that was first interpreted as being Microthermal, although further study has shown them to be more mesothermal in nature. The plant community preserved in the McAbee Fossil Beds site is mostly broadleaf pollen with alder and elm dominating, and may represent a successional forest involving multiple volcanic ash eruptions.
"Ypresiosirex" was first studied by the paleoentomologists S. Bruce Archibald from Simon Fraser University in Burnaby, British Columbia and Alexandr Rasnitsyn of the A. A. Borissiak Paleontological Institute. Their 2015 type description of the new genus and species was published in the journal "Canadian Entomologist". The genus name "Ypresiosirex" was coined by the researchers as a combination of Ypresian, the age of the fossil, and "Sirex" a horntail genus name. The specific epithet "orthosemos" is derived from Greek meaning "with vertical stipes", alluding to the corrugated texture of the wing membrane at its base.
"Ypresiosirex orthosemos" was one of three sawfly species described in Archibald & Rasnitsyn's 2015 paper, the other two being "Ulteramus republicensis" and "Cuspilongus cachecreekensis", from the Klondike Mountain Formation and the McAbee fossil beds respectively.
Description.
The single described female of "Ypresiosirex" is mostly complete, missing the very apical section of the ovipositor. The female has a body length of approximately and an overall preserved length of with the partially preserved ovipositor included. The body is dark in coloration overall, with an area of the mid-abdomen possibly lighter, though the change in color may be the result of preservation showing the ventral color and not the dorsal color. The fore-wings show darkening near the base which grades to hyaline for the rest of the membrane. In some areas of the head and thorax preservation is detailed enough to show the surfaces had a patterning of shallow densely spaced pits. Placement of the genus into Siricidae was based on the modified abdomen tip which forms a cornus. The basal area of the wings shows distinct corrugation running from the leading edge to the rear edge, which is not seen in any other hymenopterans.


Albert Heber Longman

Albert Heber Longman (24 June 1880 – 16 February 1954), also often referred to as Heber Longman or Heber Albert Longman, was an Australian newspaper publisher and museum director of British origin.
Early years.
Longman was born at Heytesbury in Wiltshire, England, and educated at Emwell House School at Warminster. Because of a chest weakness, in 1902 he emigrated to Australia and settled in Toowoomba, Queensland. There he, with support from local businesses, established a newspaper first called the "Rag", and later the "Citizen". In 1904 he married Irene Maud Bayley, who was to be the first woman elected to the Queensland Parliament. Interested in the natural history of the area, Longman collected botanical specimens and helped establish the local field naturalists club. In 1911 he published a book – "The Religion of a Naturalist" – expressing his philosophical position as an agnostic.
Queensland Museum.
In 1911 Longman moved to Brisbane to take up a position as a member of the staff of the Queensland Museum, rising to become Acting Director in 1917 and Director in 1918. There the main focus of his interests turned from botany to zoology, especially vertebrate paleontology, describing new genera of fish, marine reptiles, dinosaurs and a marsupial. He wished to make the Museum more of an educational institution, rather than a repository of fossils. He acquired for the Museum several dinosaur skeletons, including the Rhoesaurus Brownei.
He published approximately 70 papers which appeared in the "Memoirs of the Queensland Museum". He also wrote a popular column – "Nature’s ways" – in the Brisbane "Courier-Mail". He retired from the museum in 1945 and died at his home in Brisbane in 1954. He was survived by his wife Irene Longman.


Chequiaraju

Chequiaraju, Chequiarajo"," or Checquiacraju (possibly from Quechua, "chiqlla" green, "rahu" snow, ice, mountain with snow) is a mountain in the Cordillera Blanca in the Andes of Peru, about high. It is situated in the Ancash Region, Carhuaz Province, Shilla District. Chequiaraju lies northwest of Hualcán and the lake Chiqllaqucha.


Oryctorhynchus

Oryctorhynchus is an extinct genus of rhynchosaur from the Late Triassic (Carnian-Norian)-aged Wolfville Formation of Nova Scotia, Canada. The type species, O. bairdi, was named and described in 2020. It was originally seen as a species of "Hyperodapedon" until 2020.
Discovery and naming.
The holotype was discovered in the Wolfville Formation; its earliest known mention is by Baird (1963). Shortly after, it was informally named the "Nova Scotia "Hyperodapedon"" ("H". sp.) by Robin Whatley. It was briefly described by Michael Benton (1983) also as a species of "Hyperodapedon". The genus was not recognised as a distinct taxon until it was named in 2020.
The holotype, NSM018GFF009.003, consists of a partial jaw and several skull fragments including the rostrum and skull roof.
Etymology.
The genus name consists of the "orycto" prefix, which means "burrow", and the "rhynchus" suffix, meaning "snout"; the full genus name means "burrowed snout". The epithet honours David Baird, for his work on Triassic tetrapods from Nova Scotia.
Classification.
Sues "et al." (2020) placed "Oryctorhynchus" as the sister species to "Hyperodapedon" and an unnamed hyperodapedontine taxon from Wyoming.
Paleoecology.
"Ornithorhynchus" is from the Wolfville Formation (Upper Wolfville Member; Fundy Basin), which probably corresponds to the Popo Agie Formation. The age of the Upper Wolfville Member is unclear; it either dates from the latest Carnian? - earliest Norian? or the late Carnian (~230 Ma).
It would have coexisted with "Acadiella", "Arctotraversodon", ""Arctosuchus buceros" (?)", "Haligonia", "Scoloparia" and "Teraterpeton".


Wyonycteris

Wyonycteris is a genus of small mammals that existed in the late Paleocene and early Eocene epochs. The type species is "Wyonycteris chalix", which lived in Wyoming during the Clarkforkian North American Land Mammal Age of the Paleocene and was originally proposed to be an early form of insectivorous bat. Later re-examination of the material has put this alliance in doubt, and the genus has instead been proposed as belonging to the subfamily Placentidentinae, within the family Nyctitheriidae. Similar fossil material of the same time period found in Europe was later discovered and described as new species, "Wyonycteris richardi".
Secord (2008) described the first known species of "Wyonycteris" from the Tiffanian NALMA, "Wyonycteris galensis" and "W. microtis", although the status of both species as members of "Wyonycteris" has been questioned. The two largest species, "W. primitivus" and "W. kingi", are known from the early Eocene of Mississippi and England, respectively.
Evolutionary relationships.
"Wyonycteris" is only known from dental remains. It is characterized by W-shaped crests on the outer side of the upper molars, a trait that it shares with most insectivorous bats. However, "Wyonycteris" possesses a number of additional cusps on the upper molars that are not present in bats leading many researchers to conclude that it is more closely related to the extinct insectivorous family Nyctitheriidae. A recent phylogenetic analysis found most species of "Wyonycteris" to be within the family Nyctitheriidae, most closely related to the genus "Pontifactor." "Wyonycteris microtis" was found to be very distantly related to the other species of "Wyonycteris" and outside the family Nyctitheriidae.
Rose et al. (2012) compared "Wyonycteris" to the genus "Plagioctenoides" and concluded that the two may in fact belong to the same genus. If this is the case, the correct genus name would be "Plagioctenoides" since it was formally named first.


Eleutherocercus

Eleutherocercus was a genus of glyptodonts that lived during the Late Miocene and Early Pliocene in South America. Fossils of the genus have been found in the Huayquerian Ituzaingó Formation ("E. paranensis") and the Montehermosan Monte Hermoso Formation ("E. antiquus") in Argentina.


Daouitherium

Daouitherium ("Sidi Daoui beast" from the name of the site where it was discovered) is an extinct genus of early proboscideans (a group including modern elephants and their extinct relatives) that lived during the early Eocene (Ypresian stage) some 55 million years ago in North Africa.
Remains of this animal, fragments of jaws and teeth, have been found in the Ouled Abdoun Basin in Morocco. It is estimated to have weighed between , making it one of the earliest large mammals known from Africa and one of the oldest known proboscideans. Another estimate gives a weight of .
Description.
"Daouitherium" is known only from lower jaws and associated cheek teeth. It had lophodont and bilophodont molars, i.e. molars with large ridges. The second and third premolars had a notably large cusp called the hypoconid. Gheerbrant et al. described the teeth as similar to those of other early proboscideans "Phosphatherium", "Numidotherium", and "Barytherium".


Acanthopyge

Acanthopyge is an extinct genus of lichid trilobite that lived during the Devonian. Very few "A. consanguinea" from the Devonian of Oklahoma have been found, and only a handful of complete specimens from Morocco, and many so-called "Acanthopyge"-specimens from Morocco are fake.


Lissodus

Lissodus is an extinct genus of freshwater shark. It lived from the Early Carboniferous stage to the Albian age of the Cretaceous. It was about long and had flat teeth that it used for eating clams.


Gassi Touil

Gassi Touil is a large natural gas field in the Sahara Desert region of Grand Erg Oriental of Algeria, within the commune of Hassi Messaoud. It is an outlying part of the Berkine Basin, itself a region of the Ghadames Basin that extends into Tunisia. The land surface is dominated by extensive sand dune fields.
Gassi Touil is the site of a major liquefied natural gas development project, in which natural gas extracted from the Gassi Touil field will be piped to a liquefaction plant at Djedid. The project was initially developed by Spanish firms Repsol and Gas Natural, but their contract was terminated in 2007 by the Algerian state oil company Sonatrach, which elected to pursue the project on its own.
On November 6, 1961 a gas well fire broke out at Gassi Touil, becoming known as the Devil's Cigarette Lighter. It was finally extinguished on April 28, 1962 by well fire specialist Red Adair.
The field also produces oil, first discovered in 1961, from 38 wells as of 2008.


Pronymphes

Pronymphes is an extinct genus of lacewing which existed during the Eocene period. It contains two species, "Pronymphes mengeana" and "P. hoffeinsorum".


Paratoceras

Paratoceras is an extinct genus of Artiodactyla, of the family Protoceratidae, endemic to North America. They lived during the Early to Middle Miocene, 20.4—10.3 Ma, existing for approximately . "Paratoceras" resembled deer, but were more closely related to camels. In addition to having horns on the top of the head, they had a third horn on the snout.
Fossil distribution.
Fossils have been recovered from:


Gorman Creek Formation

The Gorman Creek Formation is a geologic formation of Early Cretaceous (Valanginian) age in the Western Canada Sedimentary Basin that consists primarily of nonmarine sediments. It is present in the northern foothills of the Canadian Rockies and the adjacent plains in northeastern British Columbia. Plant fossils and dinosaur tracks have been described from its strata.
Lithology.
The Gorman Creek Formation consists of repetitive successions of argillaceous sandstone, siltstone, coaly mudstone, and coal beds. Beds of conglomeratic sandstone are present in some areas, particularly in the upper part of the formation .
Depositional environment.
The Gorman Creek Formation was deposited in primarily nonmarine environments adjacent to the Western Interior Seaway. Depositional settings include deltaic, coastal plain, floodplain, and swamp environments.
Fossil content.
A variety of plant fossils, palynomorph and microfossils have been described from the Gorman Creek Formation, and dinosaur track-ways are present on bedding surfaces near the Narraway River:
"More than 200 fossil footprints are preserved in at least 8 trackways... The majority of the footprints were made by small theropods, but the most dramatic track-way was made by a large biped whose feet were more than a half meter in length."
Thickness and distribution.
The Gorman Creek Formation is present in the foothills of the Canadian Rockies and the adjacent plains from the Sukunka River in northeastern British Columbia to the Berland River in west-central Alberta. It attains a maximum thickness of roughly in the foothills near the Kakwa River in Alberta, and it thins to zero beyond the eastern edge of the foothills where it was removed by erosion prior to the deposition of the Cadomin Formation.
Relationship to other units.
The Gorman Creek Formation forms the upper part of the Minnes Group. It conformably overlies the Monteith Formation and is unconformably overlain by the Cadomin Formation. To the north it grades into the Beattie Peaks, Monach and Bickford Formations which comprise the upper part of the Minnes Group in that area.


Clermont-Ferrand

Clermont-Ferrand (, ; ; ; ) is a city and commune of France, in the Auvergne-Rhône-Alpes region, with a population of 143,886 (2017). Its metropolitan area ("aire urbaine") had 485,315 inhabitants at the 2017 census. It is the prefecture (capital) of the Puy-de-Dôme department. is its current mayor.
Clermont-Ferrand sits on the plain of Limagne in the Massif Central and is surrounded by a major industrial area. The city known for the chain of volcanoes, the Chaîne des Puys surrounding it, including the dormant volcano Puy de Dôme (), one of the highest, topped by communications towers, and visible from the city, which is inscribed since July 2018 as a "tectonic hotspot" on the UNESCO World Heritage List.
One of the oldest French cities, it has been known by Greeks as the capital of the Arvernie Tribe before developing under the Gallo-Roman era under the name of Augustonemetum in the 1st century BC. The forum of the Roman city was located on the top of the Clermont mound, on the site of the present cathedral. The High Middle Ages were marked by the looting it was subjected to by the peoples who invaded Gaul and would not have been spared by the Vikings during the weakening of the Carolingian Empire. Growing in importance under the Capetian dynasty, it hosted in 1095 the Council of Clermont that included the call to arms that would result in the First Crusade, and eventually the capture of Jerusalem. In 1551, Clermont became a royal town, and further made in 1610, inseparable property of the Crown.
Today Clermont-Ferrand hosts the Clermont-Ferrand International Short Film Festival (Festival du Court-Métrage de Clermont-Ferrand), one of the world's leading international festivals for short films. It is also home to the corporate headquarters of Michelin, the global tyre company founded there more than 100 years ago. With a quarter of the municipal population being students, and 6,000 researchers, Clermont-Ferrand is the first city in France to join the UNESCO Learning City Network.
Along with its highly distinctive black lava stone Gothic Cathedral, Clermont-Ferrand's most famous site includes the public square Place de Jaude, on which stands a grand statue of Vercingetorix astride a warhorse and brandishing a sword. The inscription reads: "J'ai pris les armes pour la liberté de tous" ("I took up arms for the liberty of all"). This statue was sculpted by Frédéric Bartholdi, who also created the Statue of Liberty.
History.
Name.
Clermont-Ferrand's first name was Augusta Nemetum. It was born on the central knoll where the cathedral is situated today, known then as Nemossos. It overlooked the capital of Gaulish Avernie. The fortified castle of Clarus Mons gave its name to the whole town in 848, to which the small episcopal town of Montferrand was attached in 1731, together taking the name of Clermont-Ferrand. The old part of Clermont is delimited by the route of the ramparts, as they existed at the end of the Middle Ages. The town of Clermont-Ferrand came about with the joining together of two separate towns, Clermont and Montferrand, which was decreed by Louis XIII and confirmed by Louis XV.
Prehistoric and Roman.
Clermont ranks among the oldest cities of France. The first known mention was by the Greek geographer Strabo, who called it the "metropolis of the Arverni" (meaning their oppidum, civitas or tribal capital). The city was at that time called "Nemessos" – a Gaulish word for a sacred forest, and was situated on the mound where the cathedral of Clermont-Ferrand stands today. Somewhere in the area around Nemossos the Arverni chieftain Vercingetorix (later to head a unified Gallic resistance to the Roman invasion led by Julius Caesar) was born around 72 BC. Also, Nemossos was situated not far from the plateau of Gergovia, where Vercingetorix repulsed the Roman assault at the Battle of Gergovia in 52 BC. After the Roman conquest, the city became known as "Augustonemetum" sometime in the 1st century, a name which combined its original Gallic name with that of the Emperor Augustus. Its population was estimated at 15,000–30,000 in the 2nd century, making it one of the largest cities of Roman Gaul. It then became "Arvernis" in the 3rd century, taking its name, like other Gallic cities in this era, from the people who lived within its walls.
Early Middle Ages.
The city became the seat of a bishop in the 5th century, at the time of the bishop Namatius or Saint Namace, who built a cathedral here described by Gregory of Tours. Clermont went through a dark period after the disappearance of the Roman Empire and during the whole High Middle Ages, marked by pillaging by the peoples who invaded Gaul. Between 471 and 475, Auvergne was often the target of Visigothic expansion, and the city was frequently besieged, including once by Euric. Although defended by Sidonius Apollinaris, at the head of the diocese from 468 to 486, and the patrician Ecdicius, the city was ceded to the Visigoths by emperor Julius Nepos in 475 and became part of the Visigothic kingdom until 507. A generation later, it became part of the Kingdom of the Franks. On 8 November 535 the first Council of Clermont opened at Arvernis (Clermont), with fifteen bishops participating, including Caesarius of Arles, Nizier of Lyons, Bishop of Trier, and Saint Hilarius, Bishop of Mende. The Council issued 16 decrees. The second canon reiterated the principle that the granting of episcopal dignity must be according to merit and not as a result of intrigues.
In 570, Bishop Avitus ordered the Jews of the city, who numbered over 500, to accept Christian baptism or be expelled.
In 848, the city was renamed "Clairmont", after the castle Clarus Mons. During this era, it was an episcopal city ruled by its bishop. Clermont was not spared by the Vikings at the time of the weakening of the Carolingian Empire: it was ravaged by the Normans under Hastein or Hastingen in 862 and 864 and, while its bishop Sigon carried out reconstruction work, again in 898 (or 910, according to some sources). Bishop Étienne II built a new Romanesque cathedral which was consecrated in 946. It was almost entirely replaced by the current Gothic cathedral, though the crypt survives and the towers were only replaced in the 19th century.
Middle Ages.
Clermont was the starting point of the First Crusade, in which Christendom sought to free Jerusalem from Muslim domination. Pope Urban II preached the crusade in 1095, at the Second Council of Clermont. In 1120, following repeated crises between the counts of Auvergne and the bishops of Clermont and in order to counteract the clergy's power, the counts founded the rival city of Montferrand on a mound next to the fortifications of Clermont, on the model of the new cities of the Midi that appeared in the 12th and 13th centuries. Until the early modern period, the two remained separate cities: Clermont, an episcopal city; Montferrand, a comital one.
Early Modern and Modern eras.
Clermont became a royal city in 1551, and in 1610, the inseparable property of the French Crown. On 15 April 1630 the Edict of Troyes (the First Edict of Union) joined the two cities of Clermont and Montferrand. This union was confirmed in 1731 by Louis XV with the Second Edict of Union. At this time, Montferrand was no more than a satellite city of Clermont, and it remained so until the beginning of the 20th century. Wishing to retain its independence, Montferrand made three demands for independence, in 1789, 1848, and 1863.
In the 20th century, construction of the Michelin factories and of city gardens, which shaped modern Clermont-Ferrand, united the two cities, although two distinct downtowns survive and Montferrand retains a strong identity.
Geography.
Climate.
The city is in the rain shadow of the Chaîne des Puys, giving it one of the driest climates in metropolitan France, except for a few places around the Mediterranean Sea.
The mountains also block most of the oceanic influence of the Atlantic, which creates a climate much more continental than nearby cities west or north of the mountains, like Limoges and Montluçon. Thus the city has comparatively cold winters and hot summers. From November to March, frost is very frequent, and the city, being at the bottom of a valley, is frequently subject to temperature inversion, in which the mountains are sunny and warm, and the plain is freezing cold and cloudy. Snow is quite common, although usually short-lived and light. Summer temperatures often exceed , with sometimes violent thunderstorms. The highest temperature was reached in 2019 of 40.9 °C (105.6 °F) while the lowest was -29.0 °C (-20.2 °F).
Main sights.
Religious architecture.
Clermont-Ferrand has two famous churches. One is Notre-Dame du Port, a Romanesque church which was built during the 11th and 12th centuries (the bell tower and was rebuilt during the 19th century). It was nominated as a World Heritage Site by UNESCO in 1998. The other is Clermont-Ferrand Cathedral ("Cathédrale Notre-Dame-de-l'Assomption de Clermont-Ferrand"), built in Gothic style between the 13th and the 19th centuries.
Economy and infrastructure.
Food production and processing as well as engineering are major employers in the area, as are the many research facilities of major computer software and pharmaceutical companies.
The city's industry was for a long time linked to the French tyre manufacturer Michelin, which created the radial tyre and grew up from Clermont-Ferrand to become a worldwide leader in its industry. For most of the 20th century, it had extensive factories throughout the city, employing up to 30,000 workers. While the company has maintained its headquarters in the city, most of the manufacturing is now done in foreign countries. This downsizing took place gradually, allowing the city to court new investment in other industries, avoiding the fate of many post-industrial cities and keeping it a very wealthy and prosperous area home of many high-income executives.
Transport.
The main railway station has connections to Paris and several regional destinations: Lyon, Moulins via Vichy, Le Puy-en-Velay, Aurillac, Nîmes, Issoire, Montluçon and Thiers.
The motorway A71 connects Clermont-Ferrand with Orléans and Bourges, the A75 with Montpellier and the A89 with Bordeaux, Lyon and Saint-Étienne (A72). The airport offers flights within France.
Recently, Clermont-Ferrand was France's first city to get a new Translohr transit system, the Clermont-Ferrand Tramway, thereby linking the city's north and south neighbourhoods.
The TGV will arrive in Auvergne after 2030. It will be one of the last regions to not have a TGV stop.
Culture.
Clermont-Ferrand was the home of mathematician and philosopher Blaise Pascal who tested Evangelista Torricelli's hypothesis concerning the influence of gas pressure on liquid equilibrium. This is the experiment where a vacuum is created in a mercury tube: Pascal's experiment had his brother-in-law carry a barometer to the top of the Puy-de-Dôme. The Université Blaise-Pascal (or Clermont-Ferrand II) is located primarily in the city and is named after him.
Clermont-Ferrand also hosts the Clermont-Ferrand International Short Film Festival, the world's first international short film festival which originated in 1979. This festival, which brings thousands of people every year (137,000 in 2008) to the city, is the second French film Festival after Cannes in term of visitors, but the first one regarding the number of spectators (in Cannes visitors are not allowed in theatres, only professionals). This festival has revealed many young talented directors now well known in France and internationally such as Mathieu Kassovitz, Cédric Klapisch and Éric Zonka.
Beside the short film festival, Clermont-Ferrand hosts more than twenty music, film, dance, theatre and video and digital art festivals every year. With more than 800 artistic groups from dance to music, Clermont-Ferrand and the Auvergne region's cultural life is important in France. One of the city's nicknames is "France's Liverpool". Groups such as The Elderberries and Cocoon were formed there.
Additionally, the city was the subject of the acclaimed documentary "The Sorrow and the Pity", which used Clermont-Ferrand as the basis of the film, which told the story of France under Nazi occupation and the Vichy regime of Marshal Pétain. Pierre Laval, Pétain's "handman," was an "Auvergnat".
"My Night at Maud's" (), a 1969 French drama film by Éric Rohmer, was set and filmed in Clermont-Ferrand in and around Christmas Eve. It is the third film (fourth in order of release) in his series of "Six Moral Tales". One of the main themes of the film concerns Pascal's Wager whose author was born in the city in 1623.
The city also hosts "L'Aventure Michelin", the museum dedicated to the history of Michelin group.
Sport.
A racing circuit, the Charade Circuit, close to the city, using closed-off public roads held the French Grand Prix in 1965, 1969, 1970 and 1972. It was a daunting circuit, with such harsh elevation changes that caused some drivers to be ill as they drove. Winners included Jim Clark, Jackie Stewart (twice), and Jochen Rindt.
Clermont-Ferrand has some experience in hosting major international sports tournaments such as the FIBA EuroBasket 1999.
The city is also host to a rugby union club competing at international level, ASM Clermont Auvergne, as well as Clermont Foot Auvergne, a football club that has competed in France's second division, Ligue 2, since the 2007–08 season.
In the sevens version of rugby union, Clermont-Ferrand has hosted the France Women's Sevens, the final event in each season's World Rugby Women's Sevens Series, since 2016.
Education.
Education is also an important factor in the economy of Clermont-Ferrand. The University of Clermont Auvergne (formed from a merger of Université Blaise Pascal and Université d'Auvergne) is located there and has a total student population of over 37,000, along with university faculty and staff.
With around 1,000 students SIGMA Clermont is the biggest engineering graduate school in the city.
A division of Polytech (an engineering school) located in Clermont-Ferrand made the news because two of its students, Laurent Bonomo and Gabriel Ferez, were murdered in June 2008 while enrolled in a program at Imperial College in London in what was to be known as the New Cross double murder.
The ESC Clermont Business School, created in 1919, is also located in the city.
Twin towns - sister cities.
Clermont-Ferrand is twinned with:


Trapa-Trapa Formation

Trapa-Trapa Formation () is a volcano-sedimentary formation of Miocene age in south-central Chile and nearby parts of Argentina. The largest outcrops lie in the Andes, while the Chilean Central Valley host some of the smaller outcrops. The volcanic rocks of the formation are of calc-alkaline character, and are less silicic than contemporary volcanic rocks found further north in the Farellones Formation.


Bothriceps

Bothriceps is an extinct genus of stereospondyl temnospondyl. It is a member of the infraorder Trematosauria and is the most basal brachyopomorph known. It is one of the only brachyopomorph that lies outside the superfamily Brachyopoidea, which includes the families Brachyopidae and Chigutisauridae. It shares several similarities to "Keratobrachyops", another basal brachyopomorph, and may be closely related to or even synonymous with it.
The genus was named in 1859 by Thomas Henry Huxley with the description of its type species "B. australis" from the Early Triassic Upper Parmeener Group of Tasmania, Australia. It was originally assigned to the family Brachyopidae and was not reassigned to a more basal position until 2000, when the clade Brachyopomorpha was constructed to accommodate for it. The genus "Bothriceps" once included several species, but the only species assigned to it now is the type. "Bothriceps major", named in 1909, was reassigned to the family Rhytidosteidae as the type species the genus "Trucheosaurus" in 1998. The brachyopid "Platycepsion wilkinsoni" (then referred to as "Platyceps wilkinsoni") was reassigned to "Bothriceps" in 1890 and in 1969, but was placed back within the original genus in 1973.


Eoprephasma

Eoprephasma is an extinct genus of stick insect in the superfamily Susumanioidea known from a group of Eocene fossils found in North America. When first described there was a single named species, E. hichensi.
History and classification.
When described, "Eoprephasma" was known from two isolated wings which are compression-impression fossils preserved in a layer of soft sedimentary rock. Along with other well preserved insect fossils, the "Eoprephasma" specimens were collected from layers of Ypresian age Lagerstätte lake sediments Washington, USA, and an additional three partial Susumanioidea fossils were recovered from British Columbia, Canada. The partial Susumanioidea specimens were found in an unnamed formation belonging to the Kamloops group that outcrops at the McAbee Fossil Beds near Cache Creek, BC. The two "E. hichensi" wing were recovered from the Tom Thumb Tuff member of the Klondike Mountain Formation in Republic, Washington which is designated the type locality for the species, with the holotype recovered from the "Boot hill" site #B4131, and the paratype from the "Corner lot" site #A0307.
At the time of description, the species type series consisted of the holotype specimen, SR 12-004-007 and paratype specimen SR 93-10-02 were preserved in the Stonerose Interpretive Center fossil collections. The three Susumanioidea fossils, part/counterpart F-846 and F-951 plus F-1392 and F-1393 are deposited in the Thompson Rivers University. The counterpart specimen F-1099 is also in the Thompson Rivers University collections, while the part side, PB-3825 is at the Burke Museum of Natural History and Culture. All the insects were first studied by Canadian entomologist S Bruce Archibald and German entomologist Sven Bradler, with their 2015 type description of the new genus and species being published in the journal "Canadian Entomology". Archibald and Bradler noted the genus name to be a combination of "eo", from Eocene, "pre" and "Phasma", referencing the status of the genus as a stem group phasmatodean. The specific epithet "hichensi" is in honor of Keir Hichens, who first found the specimen in 2012 and donated it to the Stonerose Interpretive Center.
The fossils were described by Archibald and Bradler as the youngest members of the Phasmatodea stem group lineage Susumanioidea. Prior to the 2015 paper, Susumanioidea had been known from Chinese fossils dating to the Jurassic. The youngest member of the superfamily dated to the Paleocene Paskapoo Formation in Alberta, Canada. Due to the incomplete nature of the McAbee fossils, it was not possible for Archibald and Bradler to distinguish them from the Canadian fossils, which are also incomplete.
Description.
The "Eoprephasma hichensi" specimens are both well preserved, though partial, forewings. The overall length of the holotype forewing is long and has an estimated width of . The paratype is notably smaller, being approximately and only about wide. Both wings have a dark coloration, light veins of varying width, and numerous cross-veins. The wings are distinguished from other Susumanioidea members by both the CuA, apical cubitus vein, and the CuPα, posterior cubitus alpha vein, being forked.


Pycnonemosaurus

Pycnonemosaurus (meaning 'dense forest lizard') is a genus of carnivorous theropod dinosaur that belonged to the family Abelisauridae. It was found in the Upper Cretaceous red conglomerate sandstones of the "Cabembe Unit", Mato Grosso, Brazil, and it lived about 70 million years ago during the Late Cretaceous (Maastrichtian stage).
Discovery and naming.
The type species, "Pycnonemosaurus nevesi", was formally described by Kellner and Campos in 2002. The only known specimen was found in a red conglomeratic sandstone at the Fazenda Roncador locality, in Mato Grosso State that is exposed close to Paulo Creek, which is referred to an unidentified formation of the Upper Cretaceous Bauru Group. During 1952-1953, Llewellyn Ivor Price visited a farm named "Roncador" in the state of Mato Grosso and collected several dinosaur bones. These remains were found by the owner of the farm, Max de Barros Erhart, and his hired workers at the Paulo Creek site. The most important specimen found was the incomplete skeleton of a large abelisaurid theropod, which was found near several titanosaurid sauropod bones.
"Pycnonemosaurus nevesi" was named from the Greek word "pycnós" meaning dense, "némos" meaning pastures and woods, and "saûrus" meaning reptile or lizard. This naming was an allusion to Mato Grosso State, where the remains were found. The specific name was named after the late Dr. Iedo Batista Neves, who passed in 2000, who encouraged the pursuit of paleontological studies, particularly of Alexander Kellner.
Description.
Thus far, the remains of "Pycnonemosaurus" have been fragmentary. No elements were well preserved, and the bone surface is well abraded that indicates the elements were partially exposed at the discovery location before being collected. The type specimen (DGM 859-R), housed at the Earth Sciences Museum, Rio de Janeiro, consists of five incomplete teeth, parts of seven caudal vertebrae, the distal part of a right pubis, a right tibia, and the distal articulation of the right fibula. The small pubic foot and hatchet-shaped cnemial crest of the tibia distinguishes this species within the abelisaurs. The caudal vertebra has distinct abelisaurid features, such as a fan-shaped transverse process and a cranial projection. However, these awl-like projections are somewhat unlike related abelisaurids, such as "Aucasaurus", in that they diminish more towards the distal caudals. All remains were found associated and are presently regarded as belonging to the same individual.
Initial size estimates put the animal at in length and 1.2 tonnes in weight (1.3 short tons), but later analyses have found that it was likely larger, being about long. This new size estimate currently makes "Pycnonemosaurus" the largest formally described member of the Abelisauridae thus far. Another estimation gave a length of 9.3 meters (30.5 feet) and a weight of 3.6 tonnes (~4 short tons).
"Pycnonemosaurus" is the best known abelisaurid from Brazil, where most theropod material is presently rare besides preserved teeth and footprints. Even though only a few species are known from Brazil, it is one of the most informative countries concerning the Lower Cretaceous period. "Pycnonemosaurus" was a predator, preying on mid-sized sauropodomorphs, small crocodylomorphs, and dromaeosaurs. Its teeth were small yet sharp, and were used to get a hold of struggling prey as the abelisaur shook and tore them apart.


Sven Axel Tullberg

Sven Axel Theodore Tullberg (27 February 1852 – 15 December 1886) was a Swedish botanist, palaeontologist and geologist.
The subgenus Svenax derived its name from a contraction of Sven Axel, the given names of Tullberg.
Biography.
Tullberg was born at Landskrona in Skåne County, Sweden.
Tullberg studied geology at Lund University from 1871 and became a professor in 1880. He worked as an assistant geologist from 1879 and as geologist and palaeontologist at the Geological Survey of Sweden from 1881. Initially, he focused on botanical subjects including the genus Ranunculus and published "Öfversigt af de skandinaviska arterna af slägtet Ranunculus" (1873). Together with J. Eriksson, he contributed to the Skåne flora in "Bidrag till Skånes flora" (1873) and wrote about the genus Primula in "Om några på Möen förekommande Primulaformer" (1876).
Then he focused on palaeontology and geology, especially the Silurian deposits in Skåne. His first palaeontological work was about the species of the genus " Agnostus " near Andrarum. Later he studied graptolites from both paleontological and stratigraphic perspective.
Selected works.
Publications included: "Some Didymograplus Species in Lower Graptolite Crime at Kivik's Esperöd" (1880), "Trenne New Graptolisms" (1880), "On The Graptolites Described by Hisinger and the Older Swedish Authors" (1882), "Skåne's Graptolites: I. General overcrowding of the Silurian foundations in Skåne etc. " (1882), "II. Graptolite faunas in the Cordiolaskiffern and Cyrtograptusskiffrarna" (1883) and the "Schichtfolge des Silur in Schonen" in Zeitschrift der Deutschen geologischen Gesellschaft " '35' " (1883). Other works of stratigraphic and palaeontological content describe the layeredness in Cambodia and Silure at Rostanga (1880) and reports of geological tours on Öland (1882). He further described the fossils of the Jurassic collected by Adolf Erik Nordenskiöld on Nova Zembla in "Über Versteinerangen aus den Aucellschichten Noraja Zemljas" (1881), describing marine molluscs from the Hörs sandstone and depicting the geological charts (with Gustaf Linnarsson).


Charruodon

Charruodon is an extinct genus of cynodonts which existed in the "Hyperodapedon" Assemblage Zone of the Santa Maria Formation in the Paraná Basin in southeastern Brazil during the Late Triassic. The genus contains only the type species Charruodon tetracuspidatus, which is known from a single specimen of uncertain provenance. Upon its first description, "Charruodon" was tentatively placed within the family Therioherpetidae, but a 2017 study by Agustín G. Martinelli and colleagues instead recovered it as a more basal member of Probainognathia.


Cardabiodon

Cardabiodon (; meaning 'Cardabia tooth') is an extinct genus of large mackerel shark that lived about 95 to 91 million years ago (Ma) during the Cenomanian to Turonian of the Late Cretaceous. It is a member of the Cardabiodontidae, a family unique among mackerel sharks due to differing dental structures, and contains the two species "C. ricki" and "C. venator". "Cardabiodon" fossils have been found in Australia, North America, England, and Kazakhstan. It was likely an antitropical shark that inhabited temperate neritic and offshore oceans between 40° and 60° paleolatitude, similar to the modern porbeagle shark.
One of the largest sharks of its time, "Cardabiodon" has been estimated to measure up to in length. It may have been an apex predator in its ecosystem and likely used its large, robust teeth and fast swimming capabilities to prey on a variety of marine animals including plesiosaurs, ichthyosaurs, and other large fish. "Cardabiodon" also had a very heavy and stocky body. Scientists have been partially successful in calculating the life history of the shark. At birth, "Cardabiodon" individuals measured between in length and reached sexual maturity at around five to seven years of age, but no conclusive estimates on the maximum lifespan of "Cardabiodon" have been made.
Taxonomy.
Discovery and naming.
"Cardabiodon" was described from an associated fossil discovered in the Southern Carnarvon Basin of the Gearle Siltstone which is located within Cardabia, a cattle station in West Australia, by paleontologist Mikael Siverson, who published his findings in 1999. This locality is dated in the Cenomanian age of the Late Cretaceous around 96 to 94.7 million years ago. This specimen, which is cataloged as WAM 96.4.45, originally consisted of an association of one hundred teeth and fifteen vertebrae and represented a subadult shark; later expeditions to the same locality recovered four more teeth belonging to the same specimen. Siverson recognized the specimen as a holotype for a new genus and assigned to it the scientific name "Cardabiodon ricki". The generic name "Cardabiodon" is an assemblage of the location name Cardabia and the Ancient Greek ὀδών ("odṓn", "tooth"); when put together, they mean "Cardabia tooth". The species' specific epithet, "ricki" translates to "of Rick", in honor of Rick French, the owner of the Cardabia station. In 2005, the second species "C. venator" was described from type specimens consisting of a total of 37 teeth recovered from a locality of the Fairport Member of the Carlile Shale near Mosby, Montana, a formation dated around 92-91 million years ago. This species' specific epithet "venator" is a Latin word translating as "hunter" referring to "C. venator"s presumed position as an apex predator at or near the top of the food chain.
Before Siverson's description of "Cardabiodon", its teeth have been described in the past under two now-synonymous taxa. The original description was made in 1957 by Soviet paleontologist Leonid Glickman, where he described the taxon "Pseudoisurus tomosus" based on four teeth from the Saratov Oblast. Earlier in 1894, Sir Arthur Smith Woodward described an association of twenty-five teeth from Cretaceous chalk around Maidstone, England under the taxon" 'Lamna appendiculata"' ("Cretalamna appendiculata"), which in 1977 paleontologist Jaques Herman found actually pertain to a new species and erected the taxon "Cretolamna woodwardi". In 1996, Siverson synonymized "Cretolamna woodwardi" with "Pseudoisurus tomosus" after finding that their referred type specimens pertained to the same species. Later in 1999, Siverson reassessed the taxonomy of "Pseudoisurus tomosus" and concluded that its syntypes are lost, making it a "nomen dubium". He also found that the former "Cretalamna woodwardi" actually represents two distinct genera of sharks, which was also the likely case for "Pseudoisurus tomosus"- The first was "C. ricki" (which he already described using WAM.96.4.45), and the other was assigned the taxon "Dwardius woodwardi".
Classification and evolution.
"Cardabiodon" was a unique shark set apart due to a unique dental structure. Nevertheless, it is still placed within the order Lamniformes as a mackerel shark due to its possession of mackerel shark-exclusive vertebral and basic dental features. To reflect the unique dental structure of "Cardabiodon", Siverson erected the family Cardabiodontidae and placed the taxon, along with an extinct Cenozoic shark, "Parotodus", in it. However, he would later express a weakening of the rationale for placing "Parotodus" into the family, mainly citing a ~60 million-year fossil gap between it and "Cardabiodon". Another Late Cretaceous shark, "Dwardius", whose teeth are very similar with those of "Cardabiodon", would also be placed within the family. There has been a proposal of a close relationship between the two, and the possibility of them being synonymous genera has been raised by a 2010 study led by paleontologist Todd D. Cook. However, Siverson expressed the unlikeliness of the latter proposal by noting contradictory evolutionary trends such as the gradual decrease of lateral cusplets in "Cardabiodon" over time in comparison to the gradual increase of such in "Dwardius" but agreed that the two genera were still closely related. The phylogenetic placement of the Cardabiodontidae is uncertain and yet to be established. A "C. ricki" tooth recovered from Alberta deposits dating about 93 Ma was discovered to contain features usually found in "C. venator", suggesting a chronospecific relationship between the two species with the tooth representing a transitional morphotype.
Although the Cardabiodontidae contains only the two genera "Cardabiodon" and "Dwardius", several fossils of undescribed cardabiodonts from earlier periods are known. The most notable of them includes an associated set of teeth and very large vertebrae dated in the Albian age of 105 Ma from the Toolebuc Formation in Queensland that belonged to an individual that was estimated to measure in length. In a blog discussion, Siverson noted the Albian specimen's teeth are less robust than other Cretaceous apex sharks such as "Cretoxyrhina". He suggested an evolutionary trend of the Cardabiodontidae being marked by a reduction in body size and length, a reduction in the number of teeth per jawline, an increase in the robustness of teeth (including an increased robustness of the root and widening of the crown), and a reduction of lateral cusplets (small enameled cusps that appear at the base of the tooth's main crown).
Description.
"C. ricki" was estimated to measure up to via vertebral comparisons with that of a modern great white shark of the same length, while "C. venator" was estimated to be up to based on dental analysis, making "Cardabiodon" one of the largest sharks known. The fossil record is very sparse but currently consists of teeth, vertebrae, and scales, which is usual as the cartilage in sharks do not preserve well during fossilization, although vertebrae may sometimes be preserved if hardened via calcification.
The skin of "Cardabiodon" was covered by teardrop-shaped enameloid placoid scales clad with 6–8 parallel grooves that each possessed kneels. In an individual measuring in length, these scales would range from in maximum dimensions. Scales with grooves and kneels are efficient in hydrodynamic drag-reduction and are correlated with the swimming ability of the shark possessing them, being common in fast-swimming sharks like lamnids. This means it is likely that "Cardabiodon" too was capable of fast swimming and thus pursuit of lively prey.
The vertebrae were robust. The "corpus calcareum" and "radial lamellae", the two outermost layers of a mackerel shark vertebra, which are associated with the relationship between length and weight, were thicker than those of other large predatory mackerel sharks, suggesting that "Cardabiodon" was significantly heavier and stockier, although no estimation of its weight has been attempted yet. The vertebral column was rigid and spindle-shaped, which would be poorly flexible but efficient for fast swimming. "Cardabiodon" also had a larger body relative to its teeth.
Dentition.
"Cardabiodon" possessed the basic dental characteristics for a mackerel shark. Its dental structure was heterodontic, meaning that there were many tooth morphologies present. Diagnostic features of "Cardabiodon" teeth include strongly bilabial roots, robust crowns that is either near-symmetrically erect or distally curved, visible and large tooth necks (bourlette), nonserrated cutting edges, and lateral cusplets. The lingual side, the side that faces towards the mouth, shows a massively convex root with small nutritive pores. The crown on the labial side, which faces outwards, shows protuberance.
"Cardabiodon" teeth are moderately sized. The largest tooth examples of "C. ricki" come from the holotype. Its anterior teeth measure up to in maximum slant height, while the first few lower lateroposteriors are larger and measure up to in maximum slant height. "C. venator" teeth are slightly smaller, with the largest known tooth discovered being an anterior measuring in maximum slant height but are much more bulky and thicker instead. "C. venator" also has significantly shorter lateral cusplets compared to "C. ricki".
Siverson reconstructed an artificial dental formula based on the 104 teeth from the "C. ricki" holotype, which he revised in a 2015 paper after concluding that he overestimated the number of missing teeth in the lower jaw. The dental formula based on these studies is . This means that "Cardabiodon" had mainly four types of teeth in its dentition ordered from front to back- symphysial, anteriors, intermediates, and lateroposteriors. The dental structure of "Cardabiodon" is unique and incomparable with any other known extant or extinct shark. In the lower jaw, tooth size abruptly increases and peaks at the first lateroposterior tooth. This is contrary to more generic mackerel shark dental structures where tooth size gradually decreases as it transitions from anterior to posterior (with the exception of the smaller symphysial and intermediate teeth). The lower teeth are also wider than the teeth in the upper jaw, whereas the upper teeth are wider for generic mackerel sharks. The lower jaw bite circumference of the "C. ricki" holotype was measured to be .
An alternative dental formula was reconstructed from an associated disarticulated tooth set identified as "Cardabiodon sp." from the Carlile Shale in Kansas, which is . The study that created the formula aimed to be more consistent with generic structure of mackerel sharks, unlike the one reconstructed by Siverson, which the scientists who made the reconstruction expressed with some caution due inconsistencies towards the generic mackerel shark dental structure. However, both are still hypothetical due to the disarticulated nature of the fossil teeth used.
Paleobiology.
Life history.
Like all mackerel sharks, "Cardabiodon" grew a growth ring in its vertebrae every year and is aged through measuring each band. However, few "Cardabiodon" individuals were aged due to the rarity of well-preserved vertebrae. The ontogenetics of "C. ricki" was calculated using the vertebrae of three different preadult individuals as well as an isolated tooth of a newborn. When compared with the ontogenetic records of "Cretoxyrhina mantelli" and "Archaeolamna kopingensis", the vertebrae of "C. ricki" suggested that total length at birth was smaller than the two sharks at between . It grew at an average rate of per year compared to the much quicker average growth rate of "C. mantelli" at per year and the slower rate of "A. kopingensis" at per year. All three vertebral specimens showed thirteen growth rings, meaning that the individuals lived to around 13 years of age. However, a growth rate slower than "C. mantelli" suggested an indeterminable maximum lifespan greater than 13 years, and that the ages found in the specimens were a result of premature death. Around the 5th to 7th growth ring in the three specimens there exists a change in growth, suggesting that "C. ricki" reached sexual maturity around 5–7 years of age.
Paleoecology.
Antitropical distribution.
"Cardabiodon" fossils have been found in Canada, the midwestern United States, England, West Australia, and Kazakhstan. It had been implied in the past that "Cardabiodon" may have had an antitropical distribution as these localities were between 40° and 60° paleolatitude, mimicking the range of the confirmed antitropical porbeagle shark, which only exists between 30° and 60° latitude. This was confirmed by a 2010 study that found the latitudinal, and sea surface temperature ranges between the two were nearly the same. The study also found that the highest latitudinal fossils of "Cardabiodon" were dated just before the warmest period in the Late Cretaceous about 93 Ma known as the Cenomanian-Turonian Thermal Optimum, suggesting a shift in distribution farther north due to increasing temperatures and tropical environments. It has been determined that "Cardabiodon"s sea surface temperature range was . It has been proposed that "Cardabiodon" may have been able to move from one hemisphere to the other by crossing deeper and thus cooler waters. This has been observed with modern basking sharks, another antitropical shark, which migrates between hemispheres by following cooler isothermic paths into deep tropical waters where temperatures are similar to the basking shark's normal range. Although no "Cardabiodon" fossils have been found outside its inferred range, this proposal is supported by the occurrence of "Cardabiodon" teeth in deep-water deposits around its lowest paleolatitudinal range.
Habitat.
The antitropical distribution of "Cardabiodon" suggests it lived mainly in temperate and offshore, but moderately deep, inner to mid-neritic waters. The majority of its fossils are from North America. In North America, "C. venator" fossils are found mostly in the southern half of the Western Interior Seaway, which had a warmer temperate climate; they are seldom found in the northern half. Although having lived in the colder sea temperatures of , "Cardabiodon" was contemporaneous with the Cenomanian-Turonian Thermal Optimum, which led to a change in biodiversity and appearance and radiation of new fauna like mosasaurs. Cenomanian localities in the Western Interior Seaway have yielded several marine vertebrates that coexisted with "Cardabiodon", which the shark, presumably as an apex predator, may have preyed upon. These include many sharks including mackerel sharks like "Cretodus", "Cretalamna", "Protolamna", and "Cretoxyrhina"; anacoracids like "Squalicorax"; and hybodonts like "Ptychodus" and "Hybodus"; large bony fish such as "Protosphyraena", "Pachyrhizodus", "Enchodus" and "Xiphactinus"; seabirds like "Pasquiaornis" and "Ichthyornis"; marine reptiles such as elasmosaurid and polycotylid plesiosaurs; the pliosaur "Brachauchenius lucasi", protostegid sea turtles, and dolichosaurids like "Coniasaurus crassidens". The Gearle Siltstone in West Australia was mainly dominated by "Cretalamna", but other sharks such as "Squalicorax", "Archaeolamna", "Paraisurus", "Notorhynchus", "Leptostyrax", and "Carcharias" were present. Fragmentary remains of pliosaurs are also known from the formation. Other parts of West Australia were also inhabited during the Cenomanian by ichthyosaurs like "Platypterygius". Benthic faunae were rare around this time, especially in the more northern waters "Cardabiodon" inhabited. This was due mostly to lower oxygen levels caused by the Cenomanian-Turonian anoxic event which led to the extinction of as much as 27% of all marine invertebrates.
Nursery areas.
Like many modern sharks, "Cardabiodon" made use of nursery areas to give birth to and raise young, which would ideally be shallow waters that provides protection from natural predators. An area of the Carlile Shale near Mosby, Montana, has been identified as a nursery site due to the rich prevalence of juvenile "Cardabiodon" fossils. Other localities in the Western Interior Seaway region of North America including the Kaskapau Formation in northwestern Alberta and the Greenhorn Limestone in central Kansas have also reported fossils of juveniles. Because such fossils are largely absent elsewhere, this has led to the suggestion the Western Interior Seaway as a whole may have served as a nursery area for "Cardabiodon".