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. They first appear in the fossil record in the Eocene in Australia, and survived until the arrival of humans: in the Pleistocene in Australia and within the Holocene in the Pacific islands of Fiji, New Caledonia and Vanuatu.
Deinosuchus is an extinct genus of alligatoroid crocodilian, related to modern alligators and caimans, that lived 82 to 73 million years ago (Ma), during the late Cretaceous period. The name translates as "terrible crocodile" and is derived from the Greek deinos (δεινός), "terrible", and soukhos (σοῦχος), "crocodile". The first remains were discovered in North Carolina in the 1850s; the genus was named and described in 1909. Additional fragments were discovered in the 1940s and were later incorporated into an influential, though inaccurate, skull reconstruction at the American Museum of Natural History. Knowledge of Deinosuchus remains incomplete, but better cranial material found in recent years has expanded scientific understanding of this massive predator.
Baru, sometimes referred to as the cleaver-headed crocodile, is an extinct genus of Australian mekosuchine crocodilian. Its fossils have been found from various Late Oligocene and Miocene localities from across the Northern Territory and Queensland, indicating that Baru was a common species during the late Paleogene and early Neogene. Three species are recognized, B. darrowi, B. iylwenpeny, and B. wickeni.
Mekosuchus is a genus of extinct Australasian mekosuchine crocodilian. Species of Mekosuchus were generally small-sized, terrestrial animals with short, blunt-snouted heads and strong limbs. Four species are currently recognized, M. inexpectatus, M. whitehunterensis, M. sanderi and M. kalpokasi, all known primarily from fragmentary remains.
Trilophosuchus is an extinct genus of mekosuchine crocodilian from Australia. Its fossils have been found at the Ringtail Site in the Riversleigh World Heritage Area and date to the Miocene epoch. Additional remains have also been found at the older Hiatus Site and extend its range into the Oligocene. Like the closely related Mekosuchus, it is thought to have had a short and blunt snout and large eyes that generally resembles today's dwarf crocodiles. It also shares similarities with several much older crocodylomorph groups and is commonly thought to have been more terrestrial than any crocodilian living today. Only a single species has been described, the type species T. rackhami.
Quinkana is an extinct genus of mekosuchine crocodylians that lived in Australia from about 28 million to about 10,000 years ago. Most attributed specimens have been found in Queensland. It is speculated to have been one of the top predators of Pleistocene Australia.
Australosuchus is an extinct monospecific genus of crocodylian belonging to the subfamily Mekosuchinae. The type and only known species Australosuchus clarkae lived during the Late Oligocene and the Early Miocene in the Lake Eyre Basin of South Australia. It was described in 1991 by Paul Willis and Ralph Molnar from fossil material discovered at Lake Palankarinna.
Paludirex is an extinct genus of mekosuchine crocodylian from the Pliocene and Pleistocene of Australia. A large and robust semi-aquatic ambush hunter capable of attaining lengths of up to 5 m (16 ft), it was likely the top predator of Australia's waterways prior to the appearance of modern saltwater crocodiles. Two species are known, the smaller Paludirex gracilis and the larger Paludirex vincenti. A third as of yet unnamed species may have also existed.
Kambara is an extinct genus of mekosuchine crocodylian that lived during the Eocene epoch in Australia. It is generally thought to have been a semi-aquatic generalist, living a lifestyle similar to many of today's crocodiles. Four species are currently recognized, the sympatric Kambara murgonensis and Kambara implexidens from sediments near Murgon, the poorly preserved Kambara molnari from the Rundle Formation and the youngest of the four, Kambara taraina, also from the Rundle Formation. Kambara was a medium-sized crocodilians, with mature specimens generally reaching lengths from 3–4 m (9.8–13.1 ft).
Harpacochampsa is a poorly known Early Miocene crocodilian from the Bullock Creek lagerstätte of the Northern Territory, Australia. The current specimen consists of a partial skull and fragments of a long, slender snout reminiscent of that of a false gharial, demonstrating that it was a piscivore in life.
Aldabrachampsus is an extinct genus of small horned crocodile known from fragmentary remains. It lived during the Pleistocene on Aldabra Atoll, Seychelles in the western Indian Ocean. The name Aldabrachampsus dilophus means "Two-crested crocodile from Aldabra". It was a small animal, reaching a length of 2–2.5 m, comparable in size to the smallest extant crocodilians.
Asiatosuchus is an extinct genus of crocodyloid crocodilians that lived in Eurasia during the Paleogene. Many Paleogene crocodilians from Europe and Asia have been attributed to Asiatosuchus since the genus was named in 1940. These species have a generalized crocodilian morphology typified by flat, triangular skulls. The feature that traditionally united these species under the genus Asiatosuchus is a broad connection or symphysis between the two halves of the lower jaw. Recent studies of the evolutionary relationships of early crocodilians along with closer examinations of the morphology of fossil specimens suggest that only the first named species of Asiatosuchus, A. grangeri from the Eocene of Mongolia, belongs in the genus. Most species are now regarded as nomina dubia or "dubious names", meaning that their type specimens lack the unique anatomical features necessary to justify their classification as distinct species. Other species such as "A." germanicus and "A." depressifrons are still considered valid species, but they do not form an evolutionary grouping with A. grangeri that would warrant them being placed together in the genus Asiatosuchus.
Armadillosuchus is an extinct genus of sphagesaurid crocodylomorph. It was described in February 2009 from the late Campanian to early Maastrichtian Adamantina Formation of the Bauru Basin in Brazil, dating to approximately 70 Ma. Armadillosuchus was among the larger and more robust sphagesaurids, with a total length of approximately 2 metres (6.6 ft).
Bergisuchus is an extinct genus of small sebecosuchian mesoeucrocodylian known primarily from the Eocene Messel Pit in Germany. Few fossils of Bergisuchus have been discovered, only a single incomplete snout, a few partial lower jaws and some teeth. Despite being fragmentary, the jaw bones are enough to indicate that Bergisuchus had a short, deep, narrow snout and serrated teeth, quite unlike the broad flat snouts of modern crocodylians.
Megavitiornis altirostris is an extinct, flightless, giant stem-galliform bird that was endemic to Fiji, it is the only known species in the genus Megavitiornis. Originally thought to be a megapode, more recent morphological studies indicate a close relationship with Sylviornis of New Caledonia, with both genera belonging to the family Sylviornithidae outside of the Galliformes crown group. It is likely that it became extinct through overhunting shortly after the colonisation of the Fiji Islands by humans.
Diabolotherium is an extinct genus of megatheriine ground sloth, known from the Late Pleistocene of Peru. Unlike most other extinct mainland sloths, it seems to have been a climber, similar to extinct sloths from the Caribbean. Fossils of the genus were found at the coastal Piedra Escrita site and the Andean Casa del Diablo cave.
"Baru" huberi is a species of mekosuchine Crocodilian from the Miocene of Australia. Although initially named as a member of the genus Baru, both phylogenetic analysis and additional discoveries of related forms have shown that this species belonged to a distinct mekosuchine lineage more closely related to Mekosuchus and Trilophosuchus. Consequently, several researchers have argued that it should be placed in its own genus, which has yet to be named.
Ultrastenos is an extinct genus of Australian mekosuchine crocodilian first described in 2016. The type species Ultrastenos willisi was discovered at Riversleigh in northwestern Queensland, Australia, and lived during the Late Oligocene era. Following its discovery, it was speculated that Ultrastenos was a slender-snouted animal similar to modern gharials or freshwater crocodiles and that it may have inhabited forest pools and fed on small vertebrates like frogs and lizards. This is based on the peculiar shape of its mandible, which is wide towards the base of the head but constricts rapidly, leading into a narrow and gracile rostrum. Assuming that the holotype skull belonged to an adult individual, Ultrastenos may have been a rather small animal, approximately the size of a modern freshwater crocodile. However, Ultrastenos is only known from very fragmentary remains and thus among the most enigmatic mekosuchines. In a 2023 study multiple authors argue that the fragmentary nature of the animal means that further studies are required to truly test the hypothesis proposed in its original description, especially following the discovery of what is thought to have been a close relative.
Kalthifrons is an extinct monospecific genus of mekosuchine crocodylian known from the Pliocene Tirari Formation of Australia. More specifically, Kalthifrons was recovered from the Mampuwordu Sand Member, which underlies the younger sediments of the Pompapillina Member. This is significant, as the latter preserves some of the earliest records of the genus Crocodylus in Australia, which would eventually go on to replace mekosuchines. It is currently unclear whether or not the Tirari Crocodylus directly outcompeted Kalthifrons or simply moved into the region after the niche was left empty by the extinction of the local mekosuchines. Should the later be the case, then Kalthifrons may have simply been the victim of global cooling and aridification. A point in favour of the competition hypothesis is that both Kalthifrons and the Tirari Crocodylus have broadly similar skull forms, with both being interpreted as generalist semi-aquatic predators much like many of today's crocodiles. Though far from large, Kalthifrons was nonetheless bigger than many other mekosuchines such as Trilophosuchus and Mekosuchus. The genus is monotypic, meaning it contains only a single species, Kalthifrons aurivellensis.
Confractosuchus is a genus of extinct eusuchian crocodyliform from the Cretaceous Winton Formation of Australia. Described as a macro-generalist, Confractosuchus was found with the bones of a juvenile ornithopod dinosaur in its abdomen. It currently contains a single species, Confractosuchus sauroktonos, which literally means "broken dinosaur killer."
