Creature named Pakasuchus kapilimai lived 105m years ago and had agile body and teeth like those of a mammal. The fossilised remains of an ancient crocodile with cat-like features that feasted on insects and other small animals have been recovered from a riverbank in south-western Tanzania.
The short, agile creature lived 105m years ago, alongsidedinosaurs, on a landscape dominated by a large river system and vast floodplains rich with vegetation.
The animal had a small, broad skull, a robust lower jaw and bony protective plates on its back and tail. Unlike modern crocodiles it had fewer armoured plates on its body, making it more nimble.
Fossil hunters discovered a complete skeleton of the animal in red sandstone sediments while working along a riverbank in what is now the Rukwa Rift Basin in the Mbeya region of Tanzania.
Because the specimen was encased in rock with its jaws tightly clamped shut, the team used an x-ray scanner to reveal details of the skull and dentition.
The most curious feature of the animal was its teeth, which were more like those of a mammal than a reptile. While the teeth of modern crocodiles tend to be cone-shaped and pointed at the end to seize and tear prey, the ancient crocodile had a variety, including primitive canines, premolars and molars.
"Once we were able to get a close look at the teeth, we knew we had something new and very exciting," said Patrick O'Connor at Ohio University.
The new species has been named Pakasuchus kapilimai, where Paka means cat in Swahili, and suchus comes from the Greek for crocodile. The latter part of the name, kapilimai, honours a late researcher, Saidi Kapilimai at the University of Dar es Salaam, who led the project.
The animal lived at a time when the southern supercontinent of Gondwana was breaking up into Africa, India, Australia, Madagascar and Antarctica.
Relatively few mammals of a similar age have been uncovered from this part of the world, and it is possible that Pakasuchus occupied a mammalian niche in the Gondwana ecosystem during the period.
The creature is not a close relative of modern crocodiles, but belonged to a successful sidebranch of the lineage, according to details published in the journal Nature. Previous fossil finds show that ancient crocodiles were once more varied in shape and size than those alive today.
http://www.guardian.co.uk/science/2010/aug/04/ancient-crocodile-fossil-found-tanzania
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