The pterosaur might have achieved flight by jumping off cliffs and riding
the updrafts, by climbing trees and diving into the wind, or by gliding across the
tops of wave crests like modern albatrosses.The animal could have trotted along
the ground flapping its wings and taking off gooney bird fashion. It could have
simply stood on its hind legs, caught a strong breeze, and with a single flap of its
huge wings and a kick of its powerful legs became airborne. It probably spent
most of its time aloft riding air currents like present-day condors.
When landing, it simply stalled near the ground, gently touching down on
its hind legs like a hang glider does.While on the ground, pterosaurs might have
been ungainly walkers, sprawling about on all fours similar to the way a bat does.
However, fossil pterosaur pelvises seem to indicate that the hind legs extended
straight down from the body, enabling the reptiles to walk upright on two feet.
They could then trot along for short bursts to gather speed for takeoff.
Pterosaurs living in North America about 75 million years ago were
thought to be toothless, until the first evidence of a flying reptile with teeth
approximately an inch long was discovered in Texas. The fossil record of
pterosaurs is sketchy because their delicate bones were easily destroyed. The
only remains found of the Texas specimen was its bill, which had a distinctive
crest that apparently helped stabilize the pterosaur’s head like a keel as it
dipped into the sea to catch fish.
The discovery of the 100-million-year-old Texas pterosaur proves that
teeth-bearing flying reptiles similar to those in South America and Eurasia
migrated to North America.The pterosaur had a wingspan of about 5 feet and
a slender body about 1.5 feet long. It resembled a species that lived in Great
Britain about 140 million years ago. Whether any connection exists between
this toothy North American pterosaur and the toothless variety that came later
is still unclear.
The largest pterosaur was about the size of a small airplane, with a
wingspan of 30 feet. Fossils of the huge flier were unearthed in Big Ben
National Park in southwest Texas. Originally thought to feed on carrion such
as dead dinosaurs, it was most likely a fish eater resembling a giant pelican even
though the deposits where the animal was found were far from the sea.Their
extremely large size enabled them to fly long distances to the ocean, where
they could find plentiful fish to catch.That the animals could actually fly leaves
little doubt, and they went on to become the world’s greatest aviators.THE GIANT DINOSAURS
Dinosaurs attained their largest sizes and longest life spans during the Jurassic.
The biggest dinosaurs occupied Gondwana, which included all the southern
continents. The Jurassic Morrison Formation, a famous bed of sediments inHistorical Geology