''Mekosuchus'' is a genus of

extinct Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...

Australasian

crocodile Crocodiles (family (biology), family Crocodylidae) or true crocodiles are large semiaquatic reptiles that live throughout the tropics in Africa, Asia, the Americas and Australia. The term crocodile is sometimes used even more loosely to inclu ...

s within the subfamily Mekosuchinae. They are believed to have been made extinct by the arrival of humans on the

South Pacific The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the continen ...

islands where they lived. The species of this genus were small in size, 2 m in maximum length, and terrestrial, making them the last surviving group of fully terrestrial crocodilians, leaving only semi-terrestrial species such as the Cuban crocodile and the dwarves ''

Osteolaemus ''Osteolaemus'' is a genus of crocodiles. They are small, secretive crocodiles that occur in wetlands of West and Middle Africa. They are commonly known as the African dwarf crocodiles. Unlike other crocodiles, ''Osteolaemus'' are strictly noctur ...

'' and ''

Paleosuchus ''Paleosuchus'' is a South American genus of reptiles in the subfamily Caimaninae of the family (biology), family Alligatoridae. They are the smallest members of the order Crocodilia in the Americas. The genus contains two extant species and a ye ...

''. Fossils of related mekosuchines, such as '' Trilophosuchus'', have been found from Miocene Australia (the earliest known mekosuchine is the Eocene genus '' Kambara''), while '' Quinkana'' survived until the arrival of humans.Roberts, R.G., Flannery, T.F., Ayliffe, L.K., Yoshida, H., Olley J.M., Prideaux, G.J., Laslett, G.M., Baynes, A., Smith, M.A., Jones, R., Smith, B.L. (2001). New Ages for the Last Australian Megafauna: Continent-Wide Extinction About 46,000 Years Ago. ''Science'' 292 (5523): 1888–1892
DOI: 10.1126/science.1060264
/ref> ''Mekosuchus'' survived until the Holocene, and their sub-fossils have been found in

New Caledonia ) , anthem = "" , image_map = New Caledonia on the globe (small islands magnified) (Polynesia centered).svg , map_alt = Location of New Caledonia , map_caption = Location of New Caledonia , mapsize = 290px , subdivision_type = Sovereign st ...

and Vanuatu.

Species

There are currently four species of ''Mekosuchus'' recognised. The first discovered (and youngest) is the type species ''M. inexpectatus'' from the Holocene of

which became extinct at some point in the last 4,000 years, most likely with the arrival of humans in the archipelago. ''Mekosuchus'' had specialized back teeth for cracking mollusk shells and arthropod carapaces, an adaptation in response to the lack of large ground-dwelling prey in

; although it was likely also an opportunistic hunter that went after lizards and various-sized birds when possible. Another Holocene species is known, ''M. kalpokasi'' which lived on the island of

Éfaté Efate (french: Éfaté) is an island in the Pacific Ocean which is part of the Shefa Province in Vanuatu. It is also known as Île Vate. Geography It is the most populous (approx. 66,000) island in Vanuatu. Efate's land area of makes it Vanua ...

of Vanuatu approximately 3,000 years ago and likewise disappeared with the arrival of humans. ''M. whitehunterensis'', the oldest known species, lived during the late

Oligocene The Oligocene ( ) is a geologic epoch of the Paleogene Period and extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that define the epoch are well identified but the ...

in Queensland,

Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...

. ''M. sanderi'' also lived in Queensland but later, during the Miocene.

Phylogeny

A 2018 tip dating study by Lee & Yates simultaneously using morphological, molecular (

DNA sequencing DNA sequencing is the process of determining the nucleic acid sequence – the order of nucleotides in DNA. It includes any method or technology that is used to determine the order of the four bases: adenine, guanine, cytosine, and thymine. Th ...

), and stratigraphic ( fossil age) data established the inter-relationships within Crocodylia. The cladogram below shows the placement of ''Mekosuchus'' within Mekosuchinae:

References

{{Taxonbar, from=Q604542, from2=Q371172, from3=Q1918871 Mekosuchinae Neogene crocodylomorphs Oligocene crocodylomorphs Miocene crocodylomorphs Terrestrial crocodylomorphs New Caledonia Holocene fauna Holocene extinctions Pliocene crocodylomorphs Pleistocene crocodylomorphs Taxa named by Jean-Christophe Balouet Prehistoric pseudosuchian genera

Species

Phylogeny

See also

References