Evolution Of The Pterosaurs

Pterosaurs were discovered many years before the term dinosaur became a household word. The first scientific description of a pterosaur fossil was written in 1784 for a specimen discovered in Germany. The specimen was found in the limestone quarries of Solnhofen, the same general area in which Archaeopteryx, the first bird, was discovered more than 75 years later. The pterosaur in question was Pterodactylus (Late Jurassic, Germany); however, it was not named until 1812, when French anatomist Georges Cuvier (1769-1832) ascertained that the fossil represented a form of extinct reptile that was previously unknown. Cuvier named it Pterodactylus ("wing finger") after the long fourth finger that made up much of the length of the wing. The animal had a long, toothed snout and a wingspan of about 30 inches (76 cm).

The wonderfully preserved fossils from the limestone quarries of Solnhofen continued to reveal new specimens of pterosaurs. By 1847, with the discovery of the first known pterosaur with a long tail—Rhamphorhynchus ("beak snout")—it was clear that two basic forms of pterosaur existed. Some had short tails and some had long tails. Pterosaurs with long tails were part of an informal group called Rhamphorhynchoidea, and they reigned from the Late Trias-sic Epoch to the Late Jurassic Epoch. The short-tailed variety were part of a group called Pterodactyloidea, and they existed from the Late Jurassic to the Late Cretaceous and were the last pterosaurs to become extinct. The remains of pterosaurs have been discovered on every continent.

Many pterosaurs evidently did not compete directly with dinosaurs for either food or living space. Studies of their habitats and feeding specializations suggest that pterosaurs typically filled a role in the environment as fish-eaters or possible scavengers, living on cliffs and other out-of-the-way places where dinosaurs did not tread. This is not to say that the dinosaurs and pterosaurs did not ultimately compete for survival. The extinction of the smaller

Pterodactylus and Rhamphorynchus

pterosaurs may have been catalyzed by a new kind of dinosaur that arose near the end of the Age of Dinosaurs: the smaller, quicker, and probably smarter birds. There is also fossil evidence that some pterosaurs suffered the attacks of predatory dinosaurs. In 2004, paleontologist Eric Buffetaut described the remains of a pterosaur from Africa that included a broken tooth of a spinosaur embedded in the neck.

Because pterosaur remains are typically rare and fragmentary, the taxa we know about are probably only a fraction of those that existed. This lack of information also leads to an oversimplification of pterosaur ecology. While it is true that many pterosaurs seem to have been seagoing or lake-dwelling fish-eaters, there were also small, insectivorous, forest-dwelling pterosaurs (Anurognathus, Jeholopterus, Nemicolopterus); shellfish-eating pterosaurs (Dsungar-ipterus); and filter-feeding pterosaurs (Ctenochasma, Pterodaustro).

Paleontologist Matt Lamanna says that he would not be surprised if, one day, "somebody found flightless pterosaurs, and herbivorous pterosaurs."

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