Paludirex vincenti: Fossils of Large-Bodied Crocodile Found in Australia

Wednesday, December 23, 2020

Paludirex vincenti belongs to Mekosuchinae, an extinct subfamily of crocodylids from Australia and the South Pacific. Image credit: University of Queensland.

A new genus and species of prehistoric crocodile, Paludirex vincenti, has been identified from fossils unearthed in Queensland, Australia.

Paludirex vincenti roamed Earth during the Pliocene Epoch, between 5 and 2.5 million years ago.

Nicknamed the ‘swamp king,’ it grew up to 5 m (16.4 feet) long and was capable of preying on giant prehistoric marsupials.

“Crocs have been an important component of Australia’s fauna for millions of years,” said senior author Dr. Steve Salisbury, a paleontologist in the School of Biological Sciences at the University of Queensland, Brisbane.

“But the two species we have today — Crocodylus porosus and Crocodylus johnstoni — are only recent arrivals, and were not part of the endemic croc fauna that existed here from about 55 million years ago.”

“Whether Paludirex vincenti went extinct as a result of competition with species like Crocodylus porosus is hard to say.”

“The alternative is that it went extinct as the climate dried, and the river systems it once inhabited contracted — we’re currently investigating both scenarios.”

Paludirex vincenti, partial skull in ventral view: (A) non-annotated photograph of the specimen as embedded in a concrete slab, and (B) annotated photograph, with the concrete slab digitally removed. Abbreviations: enfen – external narial fenestra, fro – frontal, if – incisive foramen, jug – jugal, lac – lacrimal, max – maxilla, nas – nasals, or – orbit, par – parietal, pmx – premaxilla, po – postorbital, prf – prefrontal, so – supraoccipital, sq – squamosal, stfen – supratemporal fenestra. Image credit: Ristevski et al., doi: 10.7717/peerj.10466.

Several fossilized specimens of Paludirex vincenti were discovered near the town of Chinchilla in south-eastern Queensland.

“The largest crocodylian today is the Indo-Pacific crocodile, Crocodylus porosus, which grows to about the same size,” said lead author Jorgo Ristevski, a Ph.D. candidate in the School of Biological Sciences at the University of Queensland, Brisbane.

“But Paludirex vincenti had a broader, more heavy-set skull so it would’ve resembled an Indo-Pacific crocodile on steroids.”

The study was published in the journal PeerJ.


J. Ristevski et al. 2020. Australia’s prehistoric ‘swamp king:’ revision of the Plio-Pleistocene crocodylian genus Pallimnarchus de Vis, 1886. PeerJ 8: e10466; doi: 10.7717/peerj.10466