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
Flinders Island provided by many small streams, few of them permanently flowing directly leading to the waters of Bass Strait or such a lagoon. The coastal areas are mainly covered in scrub or shrubs, whereas the vegetation at a higher elevation consists of woodland, mainly eucalyptus species. The total number of plant species in the Furneaux Group well exceeds 800, showing the great biodiversity of its ecosystem. Native bird species include the Cape Barren goose ("Cereopsis novaehollandiae") and the short-tailed shearwater ("Puffinus tenuirostris"). Marsupial mammals are represented by Bennett's wallaby ("Macropus rufogriseus"), brushtail possum ("Trichosurus vulpecula"), eastern pygmy possum ("Cercartetus nanus"), potoroo