Mekosuchinae

Mekosuchinae is an extinct clade of crocodilians from the Cenozoic of Australasia. They represented the dominant group of crocodilians in the region during most of the Cenozoic, first appearing in the fossil record in the Eocene of Australia, and surviving until the arrival of humans: the Late Pleistocene on the Australian continent and during the Holocene in the Pacific islands of Fiji, New Caledonia and Vanuatu.

Mekosuchine crocodiles are a diverse group displaying a great variety of shapes and sizes. Some taxa, like Baru and Paludirex, were large semi-aquatic ambush hunters, though the two genera likely differed significantly in their hunting methods. The medium-sized Australosuchus may have been relatively cold-resistant and taxa like Trilophosuchus and Mekosuchus are renowned for their small size. One of the most distinct mekosuchines was Quinkana, with its altirostral (deep) skull and blade-like serrated teeth.

There is some question around the lifestyle of mekosuchines. Based on skull shape, many taxa are semi-aquatic and most mekosuchines have relatively conservative hip morphology, although other factors might indicate greater terrestrial capabilities. The humeri are straighter than in modern crocodiles, allowing them to perform the so-called "highwalk" more easily. Mekosuchus and Trilophosuchus are commonly regarded as more terrestrial, perhaps similar to dwarf caimans and dwarf crocodiles, while Quinkana displays a skull shape very similar to terrestrial crocodylomorphs like sebecids and planocraniids.