March 1, 2013
Newly Discovered Dinosaur Species Was Lunch For Crocodiles
WATCH VIDEO: [Ancient Crocs And Their Prey]
Brett Smith for redOrbit.com - Your Universe OnlineBy catching an ancient reptile with its ℠hand in the cookie jar,´ paleontologists were able to identify a relationship between a predator and a previously unknown species of dinosaur that it preyed upon.
According to a report in the open-access journal PLoS ONE, a group of American researchers has discovered a new species of herbivorous dinosaur that was preyed upon by prehistoric crocodyliforms, relative of today´s crocodiles.
The team was able to positively identify that the juveniles of the yet-to-be-named dinosaur were prey for the ancient reptiles by spotting a crocodyliform tooth still embedded in a dinosaur femur fossil.
“The traditional ideas you see in popular literature are that when little baby dinosaurs are either coming out of a nesting grounds or out somewhere on their own, they are normally having to worry about the theropod dinosaurs, the things like raptors or, on bigger scales, the T. rex,” said the report´s co-author Clint Boyd, from the South Dakota School of Mines & Technology (SDSMT).
“So this kind of adds a new dimension,” he said. “You had your dominant riverine carnivores, the crocodyliforms, attacking these herbivores as well, so they kind of had it coming from all sides."
The paleontologists said that the small dinosaurs were about 3 to 6 feet in length. Based on tooth and bone evidence, the paleontologists found that the crocodyliforms were also fairly small, less than 7 feet long, as a larger reptile would have likely eaten its prey in one or two big gulps. The discovery is also notable because paleontologists had only direct evidence of giant crocodyliforms interacting with large dinosaurs.
“It´s not often that you get events from the fossil record that are action-related,” Boyd said. “While you generally assume there was probably a lot more interaction going on, we didn´t have any of that preserved in the fossil record yet.”
“This is the first time that we have definitive evidence that you had this kind of partitioning, of your smaller crocodyliforms attacking the smaller herbivorous dinosaurs,” he said in a statement.
“A lot of times you find material in close association or you can find some feeding marks or traces on the outside of the bone and you can hypothesize that maybe it was a certain animal doing this, but this was only the second time we have really good definitive evidence of a crocodyliform feeding on a prey animal and in this case an ornithischian dinosaur,” Boyd added.
The tiny dinosaur bones were found in the Grand Staircase Escalante-National Monument, a park in southern Utah. The arrangement and concentration to the bone fossils led scientists to believe that the crocodilyforms selectively fed on these juveniles.
“Maybe it was closer to a nesting ground where baby dinosaurs would have been more abundant, and so the smaller crocodyliforms were hanging out there getting a lunch,” Boyd said.
Through diagnostic cranial material, the team discovered that these baby prey are a new, yet-to-be-named dinosaur species. They said that the new species will soon be described and published in another paper to be published soon.