Ancient croc had cat-like features, scientists say

Published on Wednesday 4 August 2010 17:40

SCIENTISTS have unearthed the 100 million-year-old fossilised remains of an African creature that resembled a cross between a crocodile and a cat.

Pakasuchus kapilimai had the scaly amoured body of a crocodile but also cat-like features, including canine teeth, slender limbs and a flexible backbone that would have helped it move with agility and grace.

Unlike modern crocodiles, it probably hunted on land, at a time when the world was dominated by the dinosaurs.

Experts believe it occupied an ecological niche in the southern hemisphere that was chiefly filled by small mammals in the north during the mid-Cretaceous period.

The house cat-sized fossil skull and skeleton of Pakasuchus was discovered encased in sandstone on a river bank in the Rukwa Rift Basin of Tanzania.

Paka is Swahili for cat, while suchus is derived from the Greek word for crocodile.

The creature's most distinctive feature was its jaw and teeth, said scientists writing in the journal Nature.

A CT scan, of the kind more commonly seen in hospitals, was used to peer through the stone and reveal hidden details of the animal's teeth and skull.

Dr Patrick O'Connor, from the University of Ohio in the United States, who led the international team of scientists, said: "At first glance this croc is trying very hard to be a mammal.

"A number of characteristics of this new species, including a reduction in its total number of teeth and a dentition specialised into ones similar to canines, premolars and occluding molars, are very similar to features that were critical during the course of mammalian evolution."

Like other crocodiles, Pakasuchus kapilimai had a heavily armoured tail protected by bony plates. However, the plates were far less pronounced around the animal's back and sides. Combined with an extremely flexible backbone, this would have aided its mobility.

When the creature was alive the area where its remains were found, near Lake Rukwa in south-western Tanzania, was criss-crossed by waterways and covered in low-lying vegetation. Other fossil finds from the region dating to the same period include plant- and meat-eating dinosaurs, as well as different types of crocodile.