Fossil hunters unearth galloping, dinosaur-eating crocodiles in Sahara

Fossil hunters have uncovered the remains of primitive crocodiles that "galloped" on land and patrolled the broad rivers that coursed through north Africa one hundred million years ago.

A flesh model of the head of BoarCroc and the fossil skull discovered in the Sahara. 
BoarCroc was a 6m-long meat eater with three sets of dagger-shaped fangs 
[Credit: National Geographic/Mike Hettwer]

Artist’s conception of BoarCroc [Credit: National Geographic/
Todd Marshall]

The skeletons of five creatures that walked with dinosaurs – and ate them – were unearthed in remote and rocky regions of what are now Morocco and Niger during a series of expeditions in the Sahara desert.

Three of the crocodiles are new species and include Kaprosuchus saharicus, a 6.5m-long beast with three sets of dagger-like tusks and an armoured snout for ramming its prey.

A flesh model of the head of RatCroc and its fossil lower jaw. RatCroc 
used its pair of buckteeth to dig for plant roots and grubs 
[Credit: National Geographic/Mike Hettwer]

Artist’s conception of RatCroc, a metre-long, upright plant and grub-eater 
[Credit: National Geographic/Todd Marshall]

Another species, Laganosuchus thaumastos, was of similar length but had a pancake-flat head and is thought to have lurked in rivers with its jaws open, waiting for unsuspecting fish to pass.

The most striking feature the beasts have in common was revealed by their bone structure, which suggests they were efficient swimmers but that when they clambered ashore they were also capable of galloping across the plains. Modern crocodiles crawl on their bellies because their legs sprawl out to the side.

A flesh model of the head of PancakeCroc and its fossil lower jaw. 
PancakeCroc was a fish eater with a metre-long, pancake-flat skull 
[Credit: National Geographic/Mike Hettwer]

PancakeCroc probably remained motionless for hours, its open jaws waiting 
for prey [Credit: National Geographic/Todd Marshall]

"My African crocs appeared to have had both upright, agile legs for bounding overland and a versatile tail for paddling in water," writes Paul Sereno, a palaeontologist at the University of Chicago, in National Geographic Magazine. "These species open a window on a croc world completely foreign to what was living on northern continents."

The third new species, Araripesuchus rattoides, was only a metre long and probably used a pair of buckteeth in its lower jaw to dig for grubs.

A flesh model of the head of DogCroc and its fossil skull. DogCroc had a soft, 
doglike nose and would have been an agile galloper and swimmer 
[Credit: National Geographic/Mike Hettwer]

Artist's conception of DogCroc, an agile galloper and capable swimmer 
[Credit: National Geographic/Todd Marshall]

The other two crocodiles unearthed during the expedition are known species. One had a wide, overhanging snout containing sensory areas that it used to sniff out prey in shallow waters. The other had a soft, dog-like nose and is thought to have been extremely agile.

Most of the fossils were found near the site where, in 2001, Sereno uncovered a 12m-long crocodile that lived 110m years ago. The beast, nicknamed SuperCroc, weighed around eight tonnes. The latest fossils are described in the journal ZooKeys.

A flesh model of the head of DuckCroc and its fossil skull. DuckCroc 
had a broad, overhanging snout and a long, pointed nose 
[Credit: National Geographic/Mike Hettwer]

DuckCroc was around a metre long. In common with the other ancient crocs, 
but unlike modern crocodiles, it walked upright with its legs extended 
[Credit: National Geographic/Todd Marshall]

"We were surprised to find so many species from the same time in the same place," said Hans Larsson, a palaeontologist at the University of Montreal, who took part in the expedition. "Each of the crocs apparently had different diets, different behaviours. It appears they had divided up the ecosystem, each species taking advantage of it in its own way."

Author: Ian Sample | Source: The Guardian [December 03, 2015]

TANN

Newer Post Older Post