Plotopteridae they became extinct. That they became extinct at the same time as the giant penguins of the Southern Hemisphere, which also coincided with the radiation of the seals and dolphins, has led to speculation that the expansion of marine mammals was responsible for the extinction of the Plotopteridae, though this has not been formally tested. Plotopteridae Plotopteridae is the name of an extinct family of flightless seabirds from the order Suliformes. Related to the gannets and boobies, they exhibited remarkable convergent evolution with the penguins, particularly with the now extinct giant penguins. That they lived in the North Pacific, the
Cuban flightless crane Cuban flightless crane The Cuban flightless crane ("Grus cubensis") is a large, extinct species of crane that was endemic to the island of Cuba in the Caribbean. The remains were found in Pleistocene deposits in Pinar del Rio. Probably derived from an early invasion of sandhill cranes from North America, it differed from that species by, as well as larger size, having a proportionately broader bill, stockier legs, and with reduced wings and pectoral girdle indicating that it may have been flightless. Currently, the only extant Caribbean crane is the Cuban sandhill crane, "Antigone canadensis nesiotes", an endangered subspecies of