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
Saba (IBA AN006 "Saba Coastline") by BirdLife International. Saba is home to about sixty species of birds, many of which are sea birds that use the holes and crevices of the steep cliffs and two small islands for breeding and feed in the waters around the island. Saba’s shoreline is home to the Caribbean’s largest breeding colony of Red-billed tropicbird ("Phaethon aethereus"). The Audubon's Shearwater ("Puffinus lherminieri") is another common bird, and is the national bird of Saba as well as being featured on their coat of arms. Being an island, Saba is home to a number of endemic species including