'Sarahsaurus' discovery shows opportunistic nature of dinosaurs
By Randy Boswell, Postmedia News
Synopsis: discovery indicates sauropods migrated further north than previously believed.
A new dinosaur species is forcing a major rethink about the early evolution of the species, suggesting they were more opportunistic in their northward migrations as they spread to North America some 200 million years ago.Click to read more.
Robert Reisz, a biology professor at the University of Toronto, has co-authored a paper about the discovery with University of Texas paleontologist Tim Rowe and Hans-Dieter Sues, curator of vertebrate paleontology at the National Museum of Natural History in Washington, D.C.
Rowe's research had been stymied because the bones he collected didn't include anything from the specimen's head. Remarkably, the fossils Reisz and Sues were studying included a sarahsaurus skull.
The combined remains revealed a creature about 4.3 metres long and weighing about 110 kilograms. Sarahsaurus is classified as a small, early member of the sauropod.
The sarahsaurus discovery shows the animals moved from their original southerly habitats into the future North America in "several separate dispersal events" rather than in the "sweepstake" style rush of an unstoppable competitor, Reisz told Postmedia News.
"Until recently, we've viewed dinosaurs as very successful animals that outcompeted other species wherever they went," Reisz stated in a summary of the team's findings. "But this study puts dinosaurs in a very different light — that they were more opportunistic creatures that moved into North America only when a mass extinction event made eco-space available to them."
New Strong-Handed Dinosaur May Shatter Assumptions
Were gentle, plant-eating giants also scavengers and opportunists?
Brian Handwerk for National Geographic News
Synopsis: Sarahsaurus might also indicate that some sauropods were omnivorous scavengers.
The discovery of Sarahsaurus aurifontanalis, which roamed North America about 190 million years ago, boosts the idea that at least some dinosaurs became masters of their domain by opportunistic behavior and a bit of good luck.Click to read more.
The newly identified creature boasted strong teeth and an unusual clawed hand, that, while only human size, was clearly built for enormous power and leverage, according to paleontologists.
"The dogma is that these animals were herbivores, but these hands and massive claws reopen the door to what they might have been doing with them," said study leader Tim Rowe, a paleontologist at the University of Texas.
"Looking at the teeth, I think they could have eaten anything that they wanted, so they may have also been scavengers and not pure herbivores."
Oldest-Ever Footprints Scrambles Dinosaur Origin Theory
Posted by CBSNews.com staff
Synopsis: Polish tracks indicate dinosaurs are 9 million years older than believed.
Walking through mud in what is now Poland, a dinosaur thought to be about the size of a domestic cat left behind footprints that paleontologists believe constitute the oldest footprints on Earth.Click to read more.
The footprints date back 250 million years. If the findings hold up, that would mean dinosaurs existed about 9 million years earlier than previously believed.
The researchers who made the discovery in the Holy Cross Mountains of central Poland - Grzegorz Nied?wiedzki, Stephen Brusatte, and Richard Butler - detailed their findings.
The footprints left behind approximate a period in the Earth's history in which most life had been wiped out during the so-called Permian-Triassic extinction event. it was generally believed that dinosaurs made their appearance on the world's stage some 15 million years after that tumultuous event. But the footprints date to only a couple of million years after that mass extinction.
"The biggest crisis in the history of life also created one of the greatest opportunities in the history of life by emptying the landscape and making it possible for dinosaurs to evolve," said Brusatte.
Dinosaur jawbone found in Laurel
By Washington Post editors
Synoposis:Child finds earliest carnivorous predator in Maryland.
A 7-year-old boy from Elkridge has found a fossil at a dinosaur park in Laurel that appears to date back about 116 million years.Click to read more.
Aidan Isenstadt found the approximately 1 1/2 inch jawbone fragment last month while fossil hunting.
Curator of dinosaurs at the Smithsonian’s National Museum of Natural History Matthew Carrano says the fragment is part of a juvenile meat-eating dinosaur. He believes the find is the first jawbone from a meat-eating dinosaur ever found in Maryland.