The discovery of a single anatomical difference between males and females of a species of Stegosaurus provides some of the most conclusive evidence that some dinosaurs looked different based on sex, according to new research.
Princeton University research published in the journal PLoS ONE found that the back plates of the species Stegosaurus mjosi came in two varieties that indicated the animal’s sex — short and wide, and tall and narrow. Females had one type of plate and males donned the other. The lack of a particular female-specific bone tissue found in birds and some dinosaurs, however, made it difficult to determine which sex had which plate type.(more…)
*Some Dinosaurs Were as Warm as Most Modern Mammals*
PASADENA, Calif.—Were dinosaurs slow and lumbering, or quick and agile? It depends largely on whether they were cold or warm blooded. When dinosaurs were first discovered in the mid-19th century, paleontologists thought the y were plodding beasts that had to rely on their environments to keep warm, like modern-day reptiles. But research during the last few decades suggests that they were faster creatures, nimble like the velociraptors or T. rex depicted in the movie Jurassic Park, requiring warmer, regulated body temperatures like in mammals.
Now, a team of researchers led by the California Institute of Technology (Caltech) has developed a new approach to take body temperatures of dinosaurs for the first time, providing new insights into whether dinosaurs were cold or warm blooded. By analyzing isotopic concentrations in teeth of sauropods, the long-tailed, long-necked dinosaurs that were the biggest land animals to have ever lived—think Apatosaurus (also known as Brontosaurus)—the team found that the dinosaurs were about as warm as most modern mammals. (more…)
