BoarCroc, RatCroc, DogCroc, DuckCroc and PancakeCroc

Nov 19, 2009
On the cusp of discovery, Paul Sereno, a National Geographic Explorer-in-Residence, closes in on the remains of "BoarCroc," a 20-foot-long meat eater with an armored snout for ramming and three sets of dagger-shaped fangs used for slicing. Credit: Photo by Mike Hettwer, courtesy National Geographic

A suite of five ancient crocs, including one with teeth like boar tusks and another with a snout like a duck's bill, have been discovered in the Sahara by National Geographic Explorer-in-Residence Paul Sereno. The five fossil crocs, three of them newly named species, are remains of a bizarre world of crocs that inhabited the southern land mass known as Gondwana some 100 million years ago.

Sereno, a professor at the University of Chicago, and his team unearthed the strange crocs in a series of expeditions beginning in 2000 in the Sahara. Many of the fossils were found lying on the surface of a remote, windswept stretch of rock and dunes. The crocs galloped and swam across present-day Niger and Morocco when broad rivers coursed over lush plains and ruled.

This video is not supported by your browser at this time.
National Geographic Explorer-in-Residence Paul Sereno uncovers new species of crocs that lived in the Sahara 100 million years ago. Credit: National Geographic Channel

"These species open a window on a croc world completely foreign to what was living on northern continents," Sereno said. The five crocs, along with a closely related sixth species, will be detailed in a paper published in the journal ZooKeys and appear in the November 2009 issue of National Geographic magazine. The crocs also will star in a documentary, "When Crocs Ate Dinosaurs," to premiere at 9 p.m. ET/PT Saturday, Nov. 21, on the National Geographic Channel.

At 40 feet in length and weighing 8 tons, Sarcosuchus imperator, popularly known as SuperCroc, was the first and largest of the crocs Sereno found in the Sahara, but it was not the strangest, Sereno said. He and his teams soon discovered key fossils of five previously unknown or poorly understood species, most of them walking "upright" with their arms and legs under the body like a land mammal instead of sprawled out to the sides, bellies touching the ground.

The crocs and their nicknames:

  • BoarCroc: New species, Kaprosuchus saharicus; fossils found in Niger. Twenty-foot-long upright meat eater with an armored snout for ramming and three sets of dagger-shaped fangs for slicing. Closest relative found in Madagascar.
  • RatCroc: New species, Araripesuchus rattoides; fossils found in Morocco. Three-foot-long, upright plant and grub eater. Pair of buckteeth in lower jaw used to dig for food. Closest relative in South America.
  • PancakeCroc: New species, Laganosuchus thaumastos; fossils found in Niger and Morocco. Twenty-foot-long, squat fish eater with a three-foot pancake-flat head. Spike-shaped teeth on slender jaws. Likely rested motionless for hours, its jaws open and waiting for prey. Closest relative from Egypt. The scientific paper also names a close relative discovered by the team in Morocco, Laganosuchus maghrebensis.
  • DuckCroc: New fossils of previously named species, Anatosuchus minor. Fossils found in Niger. Three-foot-long upright fish-, frog- and grub-eater. Broad, overhanging snout and Pinocchio-like nose. Special sensory areas on the snout end allowed it to root around on the shore and in shallow water for prey. Closest relative in Madagascar.
  • DogCroc: New fossils of named species, Araripesuchus wegeneri. Fossils found in Niger include five skeletons, all next to each other on a single block of rock. Three-foot-long upright plant and grub eater with a soft, doglike nose pointing forward. Likely an agile galloper, but also a capable swimmer. Closest relative in Argentina.
"We were surprised to find so many species from the same time in the same place," said paleontologist Hans Larsson, associate professor at McGill University in Montreal and a team member who discovered the bones of BoarCroc and PancakeCroc. "Each of the crocs apparently had different diets, different behaviors. It appears they had divided up the ecosystem, each species taking advantage of it in its own way."

To better understand how these ancient crocs — mostly upright and agile — might have moved and lived, Sereno traveled to northern Australia, where he observed and captured freshwater crocs. Realizing while there that he may have stumbled onto one of the keys to crocodilian success, Sereno saw freshwater crocs galloping at full speed on land and then, at water's edge, diving in and swimming away like fish. On land they moved much like running mammals, yet in a flash turned fishlike, their bodies and tails moving side to side, propelling them in water.

Paleontologist Paul Sereno with his Saharan discoveries -- SuperCroc, BoarCroc (upper right), PancakeCroc (lower right), RatCroc, DogCroc and DuckCroc. The fossil crocs were unearthed in a series of expeditions to the Sahara beginning in 2000, supported by the National Geographic Society. Credit: Photo by Mike Hettwer, courtesy National Geographic

Based on interpretation of the fossils, Sereno and Larsson hypothesize that these early crocs were small, upright gallopers. In the scientific paper, they suggest that the more agile of their new croc menagerie could not only gallop on land but also evolved a swimming tail for agility and speed in water, two modes of locomotion suggested to be evolutionary hallmarks for the past 200 million years.

"My African crocs appeared to have had both upright, agile legs for bounding overland and a versatile tail for paddling in water," Sereno writes in the National Geographic magazine article. "Their amphibious talents in the past may be the key to understanding how they flourished in, and ultimately survived, the dinosaur era."

To study the crocs' brains, Sereno CT-scanned the skulls of DuckCroc and DogCroc and then created digital and physical casts of the brains. The result: Both DogCroc and DuckCroc had broad, spade-shaped forebrains that look different from those of living crocs. "They may have had slightly more sophisticated brain function than living crocs," Larsson said, "because active hunting on land usually requires more brain power than merely waiting for prey to show up."

To collect the croc fossils, Sereno and his teams endured temperatures topping 125 degrees F, living for months on dehydrated food. Logistics were challenging: For the 2000 expedition, they transported trucks, tools, tents, five tons of plaster, 600 pounds of water and four months' worth of other supplies.

More information: The scientific paper can be access at: pensoftonline.net/zookeys/index.php/journal/index

Source: National Geographic Society (news : web)

Explore further: Ancient clay seals may shed light on biblical era

add to favorites email to friend print save as pdf

Related Stories

Dinosaur from Sahara ate like a 'Mesozoic cow'

Nov 15, 2007

A 110 million-year-old dinosaur that had a mouth that worked like a vacuum cleaner, hundreds of tiny teeth and nearly translucent skull bones will be unveiled Thursday, Nov. 15, at the National Geographic ...

Student identifies enormous new dinosaur

Dec 12, 2007

The remains of one of the largest meat-eating dinosaurs ever found have recently been recognized as representing a new species by a student working at the University of Bristol.

Researchers find new giant amphibian fossils in Africa

Apr 18, 2005

Two new 250-million-year-old species of large, meat-eating amphibians have been discovered by researchers, including investigators from McGill University. Their findings, published in the last issue of Nature, describe the ...

Recommended for you

Ancient clay seals may shed light on biblical era

10 hours ago

Impressions from ancient clay seals found at a small site in Israel east of Gaza are signs of government in an area thought to be entirely rural during the 10th century B.C., says Mississippi State University archaeologist ...

Digging up the 'Spanish Vikings'

Dec 19, 2014

The fearsome reputation of the Vikings has made them the subject of countless exhibitions, books and films - however, surprisingly little is known about their more southerly exploits in Spain.

Short-necked Triassic marine reptile discovered in China

Dec 17, 2014

A new species of short-necked marine reptile from the Triassic period has been discovered in China, according to a study published December 17, 2014 in the open-access journal PLOS ONE by Xiao-hong Chen f ...

Gothic cathedrals blend iron and stone

Dec 17, 2014

Using radiocarbon dating on metal found in Gothic cathedrals, an interdisciplinary team has shown, for the first time through absolute dating, that iron was used to reinforce stone from the construction phase. ...

User comments : 2

Adjust slider to filter visible comments by rank

Display comments: newest first

fossilator
Nov 19, 2009
This comment has been removed by a moderator.
nonoice
not rated yet Nov 20, 2009
Aah reality is so much more fun than imagination.

Rarely seen except in the hands of certain fundamental evangelicals, the elusive "Crocoduck" has been fabled to be the theological deal-breaker Christians demand to prove evolution is legitimate.

http://freethough...rocoduck
fossilator
not rated yet Nov 20, 2009
Sorry, my comment was meant to show that the naming could be unfortunate. Will someone now claim that evil evolutionists are trying to recover from the blows inflicted by "Banana Man" and company, by inventing transitional forms?

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.