Wits expert discovered new croc
Johannesburg - The international journal, Nature, published an article on Thursday about Johannesburg-based scientist Zubair Jinnah, who discovered the holotype of a new species in Tanzania - an ancient crocodile with mammal-like teeth.
"The unusual creature is changing the picture of animal life at 100 million years ago in sub-Saharan Africa," said Wits University in Johannesburg in a statement. The fossils were discovered in the Rukwa Rift Basin of Tanzania in 2008.
"I discovered the specimen which has an articulated skull, vertebrae and limb elements, whereas previously discovered material found by our research team of the same species in previous years was of isolated or incomplete elements," said Jinnah, who is a sedimentologist and an associate lecturer in the Wits School of Geosciences.
Sedimentology is the study of modern sediments such as sand, mud and clay. Jinnah's research focuses on fossil-bearing sedimentary rocks.
"This specimen will now form the holotype (reference material) of the new species," said Jinnah.
Patrick O'Connor, associate professor of anatomy at the Ohio University College of Osteopathic Medicine, said the specimen's teeth made the discovery very interesting.
"If you only looked at the teeth, you would not think this was a crocodile. You would wonder at whether it is a strange mammal or mammal-like reptile."
The new species, named Pakasuchus (Paka is the Ki-Swahili name for cat and souchos is Greek for crocodile), is a small animal whose head would fit into the palm of a person's hand.
"It was not as heavily armoured as other crocodiles, except along the tail and its gracile limbs suggests that the creatures were quite mobile. Other aspects of its anatomy suggest that it was a land-dwelling creature (unlike water-dwelling crocodiles) that likely feasted on insects and other small animals to survive," said the Wits statement.
"The new species is not a close relative of modern crocodilians, but is a member of a very successful side branch of the crocodyliform lineage that lived during the Mesozoic Era."
Pakasuchus lived alongside large, plant-eating sauropod and predatory theropod dinosaurs, other types of crocodiles, turtles and various kinds of fish.
It is believed that the Pakasuchus were abundant during the middle Cretaceous period, from around 110 million until 80 million years ago.
Former Wits scientist Eric Roberts, who was the lead geologist on the Tanzanian project, said the discovery was important in understanding past eco-systems.
"Understanding the African fossil record from the Cretaceous (145 to 90 million years ago) is important for a number of reasons," Jinnah said.
"Gondwana (South America, Africa, Australia, Antarctica, India) had begun breaking up at that time and the types of animals we find in Cretaceous ecosystems help us hypothesise about how the continents broke up."
Jinnah said it would help scientists understand how African landscapes evolved over time.
"Africa's records of sedimentary rocks and fossils are relatively poorly understood and documented," added Jinnah.