![]() Adult triceratops grew to be up to 30 feet long and 10 feet tall. Triceratops also had a big bony frill on its head like a huge collar. Instead it charged them with its three sharp horns. Since triceratops walked so slowly, it couldn't run from predators. The smaller horn was right above its nose. The two biggest horns were on the top of the triceratops' head above its eyes. It walked on four legs and had three horns on its face. The research was published in the journal Evolutionary Biology.Triceratops was a plant eating-dinosaur that looked a lot like a rhinoceros. In our view, that hypothesis is not yet the best explanation.” Other sources of variation – changes with growth, with region, with sex, and with good old-fashioned individual differences – have to be rejected before one accepts the hypothesis that two sets of specimens are in fact separate species. “It becomes much more difficult when the species involved are ancient and only known from a fairly small number of specimens. “The boundaries of even living species are very hard to define: for instance, zoologists disagree over the number of living species of giraffe,” said Thomas Holtz, co-author of the study. The team acknowledges that it is possible that there could be multiple species of Tyrannosaurus, but as the old adage goes, extraordinary claims require extraordinary evidence. This line of evidence for proposed multiple species doesn’t hold up.” rex is less variable than most living theropod dinosaurs. When compared to data from hundreds of living birds, we actually found that T. “But this claim was based on a very small comparative sample. rex specimens was so high that they were probably from multiple closely related species of giant meat-eating dinosaur,” said James Napoli, co-lead author of the new study. “Their study claimed that the variation in T. rex bones was consistent with natural differences between individuals of a single species. To rectify that, the researchers compared them to measurements from 112 species of living birds, and found that the level of variation in the T. The team also says that the original study only compared the Tyrannosaurus features to other similar dinosaurs, which are obviously also extinct and as such impossible to verify their own species status. ![]() They found no statistical significance in the clustering of the physical features that clearly indicated multiple species. In the new study, the researchers revisited the original data, performing their own measurements and analysis of the same specimens. This team, made up of scientists from the American Museum of Natural History and Carthage College, concluded that there isn’t enough evidence to make such a bold claim. However, other scientists were quick to question the validity of the findings, and now some of those critics have hit back with their own study. Examining the ratio of femur length to circumference, some skeletons have “robust” femurs, while others are more “gracile.” The groupings of these characteristics, as well as the layers of sediment they were found in, apparently suggested the presence of three species. Some have a single slender incisor tooth on either side of the front of their jaw, while others have two on each side. ![]() Their reasoning for this split was based on differences in physical characteristics between specimens. rex was actually one of three species of Tyrannosaurus, along with two new ones the scientists named the T. ![]() But in March, a team of paleontologists proposed that the T. Since it was first discovered over a century ago, Tyrannosaurus rex has been the sole species in its genus. Earlier this year a study proposed that the iconic Tyrannosaurus rex should be split into three distinct species, but a new analysis says there isn’t enough evidence for such a drastic shake-up. The dinosaur king may yet retain its crown.
0 Comments
Leave a Reply. |
Details
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |