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
Summerland Peninsula Bird Area. It is home to one of the largest Little Penguin ("Eudyptula minor") breeding colonies in Australia, the second largest breeding colony of Australian Fur Seals ("Arctocephalus pusillus doriferus") in the world, one of the largest breeding colonies of Greater crested terns ("Sterna bergii") in Victoria and an important breeding ground for Short-tailed shearwaters ("Puffinus tenuirostris"). Several plants regarded as rare or threatened in either Victoria or Australia have been recorded on the peninsula, including River Swamp Wallaby-grass ("Amphibromus fluitans") listed as vulnerable in Australia. The peninsula was significantly modified by agricultural, residential and recreational developments until the 1980s