DINOSAUR: The Pterodactyl

Apologies for the mis-representative title as Pterodactyls are clearly not true dinosaurs. Also, I have used the term Pterodactyl when I should have more accurately used the word 'Pterosaur'. However, most people will understand where I am coming from and as I am not a paleontologist I don't feel need to let the specific science get in the way of the interesting facts! You know what I mean, and let's be honest - everyone knows what a pterodactyl is!

History of the Pterodactyl

The first pterosaur fossil was described by the Italian naturalist Cosimo Collini in 1784. Collini misinterpreted his specimen as a seagoing creature that used its long front limbs as paddles. However, it was Georges Cuvier who first suggested that pterosaurs were flying creatures in 1801, and coined the name 'Pterodactyl' 1809 for the specimen recovered in Germany.

As touched on earlier, due to the standardization of scientific names, the official name for this genus became Pterodactylus, though the name 'pterodactyl' continues to be popularly and incorrectly applied to all members of Pterosaur. Paleontologists now avoid using 'pterodactyl' and prefer the term 'pterosaur'. The term 'pterodactyl' is now used specifically for members of the genus Pterodactylus or more broadly for members of the suborder Pterodactyloidea. I hope that this makes it a little more clearer.

So, just what is a Pterodactyl/Pterosaur?

Because pterosaur anatomy has been so heavily modified for flight, and immediate "missing link" predecessors have not so far been described, the ancestors of pterosaurs is not well understood - but this is what we know:

Pterosaurs existed from the late Triassic to the end of the Cretaceous Period (220 to 65.5 million years ago), and are the earliest vertebrates known to have evolved powered flight. Their wings were formed by a membrane of skin, muscle, and other tissues stretching from the legs to a dramatically lengthened fourth finger. Early species had long, fully toothed jaws and long tails, while later forms had a highly reduced tail, and some lacked teeth. Many sported furry coats made up of hair-like filaments known as pycnofibres, which covered their bodies and parts of their wings. Pterosaurs spanned a wide range of adult sizes, from the very small Nemicolopterus to the largest known flying creatures of all time, including Quetzalcoatlus and Hatzegopteryx.

It was once thought that competition with early bird species may have resulted in the extinction of many of the pterosaurs. By the end of the Cretaceous, only large species of pterosaurs are known. The smaller species seem to have become extinct, their niche filled by birds. However, pterosaur decline (if actually present) seems unrelated to bird diversity. At the end of the Cretaceous period, the Cretaceous–Tertiary extinction event which wiped out all non-avian dinosaurs and most avian dinosaurs as well, and many other animals, seemed to also take the pterosaurs. Alternatively, most pterosaurs may have been specialised for an ocean-going lifestyle. Consequently, when the Cretaceous–Tertiary extinction event severely affected marine life that most pterosaurs fed on, they went extinct.

How did Pterodactyls fly?

The problem is that the mechanics of pterosaur flight are not completely understood or modeled at this time. In fact, Katsufumi Sato - a Japanese scientist - published calculations using modern birds and decided that it is impossible for a pterosaur to stay aloft!

However, in the book Posture, Locomotion, and Paleoecology of Pterosaurs, it is theorized that they were able to fly due to the oxygen-rich, dense atmosphere of the Late Cretaceous period. However, one must note both Katsufumi and the authors of Posture, Locomotion, and Paleoecology of Pterosaurs based their research on the now outdated theories of pterosaurs being seabird-like, and the size limit doesn't apply to terrestrial pterosaurs like azhdarchids and tapejarids. Furthermore, Darren Naish concluded that atmospheric differences between the present and the Mesozoic weren't needed for the giant size of pterosaurs.

However, Mark Witton and Mike Habib, of the University of Portsmouth and Johns Hopkins University, respectively, argue that pterosaurs used a vaulting mechanism to obtain flight. Once in air, pterosaurs could reach speeds up to 120 kilometres per hour (75 mph) and travel thousands of kilometres.

For related articles click onto the following links:
DINOSAUR: Archaeopteryx
DINOSAUR: Did Pterosaurs hang upside down?
DINOSAUR: The Pterodactyl
TERRA NOVA - Dinosaur trailer

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