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
Black-vented shearwater central and southern California during the country's colder months. The black-vented shearwater is thought to feed on mainly small fish. This bird nests in burrows and caves; it is a colonial nester. In the past, this bird had been threatened by feral cats and other predators on its breeding islands, but the problem seems to have been largely eliminated. There is some loss of birds from commercial gill netting, and the species is classified as near threatened by the IUCN mainly due to the uncertain impact on it by the expanding fishing industry. Black-vented shearwater The black-vented shearwater ("Puffinus opisthomelas")