Pterosaurs were prehistoric winged reptiles distantly related to the dinosaurs – they were NOT actually flying dinosaurs, despite what some people might tell you. Pterosaurs are broadly catergorized into two biological groups called “sub-orders”: the pterodactyloids (this is where the word “pterodactyl” comes from) and the rhamphorhynchoids. They came in all shapes and sizes, from sparrow-sized ones to creatures as large as fighter jets.
The Mesozoic Era, the geologic time frame when dinosaurs lived, is divided up into three “periods”: the Triassic Period, the Jurassic Period, and the Cretaceous Period. Pterosaurs first appeared towards the end of the Triassic Period, and likely evolved from small tree-dwelling gliding reptiles.
The pterosaur depicted in this blog post’s associated image comes from the late Jurassic Period. One of the best places to find fossils dated to this time is in western North America, and it is referred to as the Morrison Formation – a layer of rock stretching throughout much of Utah, Wyoming, and Colorado where fossils of dinosaurs and other prehistoric creatures have been found dated to the late Jurassic, spanning from 155-145 MYA.
The pterosaur that you see here is named Dermodactylus montanus. It was a small pterodactyloid pterosaur with a 3-foot wingspan, about the size of a hawk. So far, the only fossil collected of this species was a single finger bone found in 1878. No other pterosaur fossils found within the Morrison Formation have been ascribed to this genus since then. Many paleontologists today classify Dermodactylus as a nomen dubium – a classification used when scientists aren’t sure if a certain species or genus actually existed. The finger bone in question might have come from another pterosaur, and was misidentified.
If you want to know more about pterosaurs, I highly suggest you check out the WordPress blog “Archosaur Musings”, run by British paleontologist Dave Hone.
Also, check out Mark Witton’s (another British pterosaur expert) blog: