new zealand was a part of the new zealand continent supercontinent until the jurassic period.
new zealand was a part of the new zealand continent supercontinent until the jurassic period.
new zealand was a part of what supercontinent until the jurassic period?
new zealand continent
the jurassic () was important in the development of birds, one of the insects' major predators. during the early jurassic period, the supercontinent pangaea broke up into the northern supercontinent laurasia and the southern supercontinent gondwana; the gulf of mexico opened in the new rift between north america and what is now mexico's yucatan peninsula. the jurassic north atlantic ocean was relatively narrow, while the south atlantic did not open until the following cretaceous period, when gondwana itself rifted apart.
evolution of insects
a new series of tropical islands emerged during the triassic period, formed by the merging of the state's older volcanic chains. the only plant fossil from oregon's triassic formations is "diplopora oregonensis". as in the paleozoic, shallow water invertebrates made up oregon's triassic fauna. these include sponges, ammonites, radiolarians, brachiopods, and the belemnite "aulacoceras". the trace fossil "chondrites", a species of fodinichnid, has been found in the same formations. although corals have also been found in these assemblages, paleontologists debate the presence of true coral reefs in the region during the triassic. the oldest vertebrate fossils in oregon's fossil record appear in triassic-aged limestones in the wallowa mountains. these fossils, including vertebrae, ribs, and a partial skull, have been assigned to the early ichthyosaur genus "shastasaurus." the breakup of the pangaean supercontinent during the transition to the jurassic period created a subduction zone in oregon's ancient seaway, burying older rock formations and giving way to new volcanic island chains. oregon's jurassic invertebrates, such as the reef-building clam "lithiolus problematicus" and the mussel-like "buchia piochii," indicate shallow sea environments similar to those of the state's late triassic. among oregon's jurassic-aged vertebrate fossils are the remains of marine crocodiles, tentatively identified in the genus "metriorhynchus." these crocodiles likely shared oregon's jurassic seaways with ichthyosaurs. plant fossils from oregon's jurassic period show that the terrestrial environment became warmer and wetter, creating swampy conditions. these fossils, from the coon hollow formation and others of similar age, include ferns, quillworts, cycads, and conifers.
paleontology in oregon