Fossil of the Extict Flying Reptile

Many people might be familiar with pterosaurs, the extinct flying reptiles that lived alongside the dinosaurs, through science-fiction films. But the real pterosaurs made their mark quite nicely many eons ago without the help of filmmakers with active imaginations.

Pterosaurs (pronounced TER-oh-sawrs) were the first vertebrates to conquer flight. They thrived for 160 million years before perishing along with their cousins the dinosaurs when a big extraterrestrial rock slammed into Earth 65 million years ago.

The spotlight was cast anew on those long-ago winged creatures when Brazilian scientists Alexander Kellner and Diogenes de Almeida Campos announced on July 18 the discovery of one of the strangest ones of them all.

The head of their pterosaur, Thalassodromeus, was topped with a huge bony crest. Similarities between its beak and that of a modern-day type of bird offered good clues about how this flying reptile caught its dinner.

"There is, unfortunately, very little that we know about pterosaurs," Kellner said in an interview, noting their lightly built and fragile bones only rarely left behind fossils. Sites in Brazil, Germany, England and Kansas have yielded many of the known specimens.

"Normally, those specimens tend to be very crushed and fragmentary," Kellner said.

The earliest pterosaurs appeared at about the same time as the first dinosaurs, about 225 million years ago. Those pterosaurs in the Triassic period were modest in size next to those that lived later in the Jurassic and Cretaceous periods.

Scientists are debating whether pterosaurs and dinosaurs, both of which arose from earlier forms of reptiles, are closely or more distantly related.

Thalassodromeus, which lived 110 million years ago and had a wingspan of nearly 5 meters, was among the larger pterosaurs, but far from the largest. The wingspan of the smallest pterosaurs was about 20 centimeters. But Pteranodon had a wingspan of 11 meters. The behemoth Quetzalcoatlus had a wingspan of 12 meters.

Pterosaurs were the Orville and Wilbur Wright of prehistoric animals -- in other words, the first to fly. While insects already had gone airborne, no vertebrate -- an animal with a backbone such as fish, amphibians, reptiles, birds and mammals -- developed the ability to fly before pterosaurs.

Birds, which first appeared about 150 million years ago, and bats, flying mammals that arose about 55 million years ago, are the other members of the vertebrate flight club. The wing structure of the three differs in interesting ways.

Many pterosaurs lived near the sea and probably fed on fish, scientists say.

Based on the similarities to modern skimmer birds, Kellner theorized that Thalassodromeus glided low over the water in an inland lagoon near the sea, with its lower jaw skimming the surface, poised to nab any fish or crustaceans.

Khorsheed.com - August 2002