Seabird in the Cretaceous, with a species called "Tytthostonyx glauconiticus", which seems allied to the Procellariiformes and Pelecaniformes. In the Paleogene both pterosaurs and marine reptiles became extinct, allowing seabirds to expand ecologically. These post-extinction seas were dominated by early Procellariidae, giant penguins and two extinct families, the Pelagornithidae and the Plotopteridae (a group of large seabirds that looked like the penguins). Modern genera began their wide radiation in the Miocene, although the genus "Puffinus" (which includes today's Manx shearwater and sooty shearwater) might date back to the Oligocene. The highest diversity of seabirds apparently existed during the Late Miocene and
Gwennap Head 15 October each year and most of the recording was by volunteers who spent up to twelve hours a day on seawatch. The main targeted species were Balearic shearwater ("Puffinus mauretanicus") and basking shark, along with the ocean sunfish (or common mola). Marine mammals such as whales, dolphins and grey seal ("Halichoerus grypus") were additional main targets. During a seawatch on 28 August 2015 a red-billed tropicbird ("Phaethon aethereus") was seen over the Runnel Stone, a bird that usually frequents tropical areas. Gwennap Head is part of the Land’s End granite massif with shallow, free-draining and acidic soils. The dominant