How to Identify Inaccuracies About Dinosaurs

Reposted from: http://perpetualartistsblock.tumblr.com/post/7795344449/how-to-identify-inaccuracies-about-dinosaurs

I’m a stickler for accuracy when it comes to dinosaurs, so I felt like making a quick list of inaccuracies. Obviously, no one cares, but it makes me feel better, so yeah.


Pronated Hands - If you see a theropod dinosaur like Tyrannosaurus or Velociraptor with its hands parallel to the ground, that’s inaccurate! All theropod dinosaurs (along with their close relatives, sauropodomorphs like Plateosaurus and Massospondylus) could not rotate their arms to have their palms face the ground, and thus always kept them facing each other.


Tripod Stance - Next up on the list of inaccuracies with theropods is the tripod stance, in which the tail is dragging on the floor, and the dinosaur’s body is held vertically. It’s now known that dinosaurs always held their tails up in the air, and kept their backs horizontal. (Thus, this also applies to sauropods who have their tails dragging on the ground behind them, but this obviously isn’t tripod stance) It is thought, however, that diplodocid sauropods and stegosaurs may have gone into a tripod-like stance to reach higher vegetation, so an image depicting this shouldn’t be thought as inaccurate.


Vertical Neck Sauropods - Now, to clarify, this only really applies to diplodocid sauropods like Diplodocus and Apatosaurus, as macronarians like Brachiosaurus and Camarasaurus definitely held their necks higher up, so as not to compete with diplodocids. Diplodocid sauropods usually held their necks horizontal, which, along with their tail being held up, would help in balance. Now, this isn’t to say that they couldn’t raise their neck up and down, but they didn’t hold them up completely vertical like say, a giraffe.


Dromaeosaur Tail Flexibility - Dromaeosaurs like Deinonychus and Velociraptor had tails supported by what are called “ossified tendons”, which act as stiff rods that kept the tail straight for the most part. Thus, they could not perform any serpentine wiggling or curling. Now, this isn’t to say that they were completely inflexible, but they couldn’t curl to a very great degree.
Theropod Digits - Basically, most theropods have three digits. Some, like tyrannosaurs, only had two (although more basal species had three). So any “Tyrannosaurus” depicted with three fingers is inaccurate. No theropods had any number greater than three (some older species had a small protrusion where the fourth digit was, and Carnotaurus had a spur-like fourth digit)


Non-Dinosaurs - One of the most wide-spread of inaccuracies is basically just mistaking other ancient reptiles for dinosaurs. Dinosaurs are purely terrestrial (unless of course you bring birds into the equation) archosaurs (Archosauria being the group which contains dinosaurs, crocodiles, pterosaurs, and birds, as well as some others) that lived solely in the Mesozoic (again, unless you count birds). This means that pterosaurs (or pterodactyls) are not dinosaurs, since although they are also mesozoic archosaurs, they were capable of flight, and thus not fully terrestrial. Even farther from dinosaurs are ichthyosaurs, plesiosaurs, mosasaurs, and pliosaurs, groups of marine reptiles that lived in the Mesozoic, since these aren’t even in Archosauria. Ichthyosaurs are off by themselves, while plesiosaurs, pliosaurs, and mosasaurs are in Lepidosauromorpha, plesiosaurs and pliosaurs being in their own group of Sauropterygia while mosasaurs are in Squamata. These groups were completely marine, and most likely never came ashore, and thus, are not dinosaurs. Another group confused with dinosaurs are the reptiles of the Permian, like Dimetrodon (a quadrupedal sail-backed reptile). There were no dinosaurs in the Permian, since dinosaurs only appeared in the Mesozoic, while the Permian is in the Paleozoic.