Pterosauria: I’m not a “flying dinosaur”
In our cognition, dinosaurs were the overlords of the earth in ancient times. We take it for granted that similar animals at that time are all classified into the category of dinosaurs. So, the Pterosauria became “flying dinosaurs”. In fact, Pterosauria were not dinosaurs!
Dinosaurs refer to certain land reptiles that can adopt an upright gait, excluding pterosaurs. Pterosauria are just flying reptiles, together with dinosaurs are both belong to the evolutionary tributaries of Ornithodira. That is to say, pterosauria and dinosaurs are like “cousins”. They are close relatives, and they are two evolutionary directions that lived in the same era, and their most recent ancestor is called Ornithischiosaurus.
Wing development
The land was dominated by dinosaurs, and the sky was dominated by pterosaurs. They are a family, how come one is in the sky and the other is on the ground?
In the western of Liaoning Province of China, a pterosauria egg was found which was squashed but showed no signs of breaking. It had been observed that the wing membranes of the embryos inside have developed well, which means that pterosauria can fly soon after birth.
Research by many experts has shown that the earliest pterosauria evolved from small, insectivorous, long-legged land runners such as Scleromochlus, which had membranes on their hind legs , extending to the body or tail. Perhaps because of the need for survival and predation, the skin of them became larger and gradually developed into a shape similar to wings. So they could also be driven up and slowly developed into flying reptiles.
Fossils show that first these little guys were not only small, but also that the bone structure in the wings was not obvious. But slowly, they evolved toward the sky, and the larger wing, short-tailed flying Pterosauria gradually replaced the “dwarfs”, and eventually became the air dominance.
In 2001, a pterosauria fossil was discovered in Germany. The wings of the fossil were partially preserved. Scientists irradiated it with ultraviolet light and detected that its wings were a skin membrane with blood vessels, muscles and long fibers. Fibers can support the wings, and the skin membrane can be pulled tight, or folded like a fan. And in 2018, two pterosauria fossils discovered in China showed that they also had primitive feathers, but unlike the feathers of birds, their feathers were smaller and more fluffy which may be used to maintain body temperature.
Difficult to fly
Do you know? Among the fossils found, the wingspan of large pterosauria can expand 10 meters. Therefore, some experts believe that even if they have two wings, some large pterosauria cannot fly as long-term and long-distance as birds, and some people even think that they may never fly at all! Because they are too heavy!
However, the way pterosauria flew is still inconclusive. Some scientists also speculate that perhaps pterosauria did not use gliding like birds, but their wings evolved independently, forming a unique aerodynamic structure. Although large pterosauria needed strong limbs to get off the ground, but thick bones made them too heavy. Soon, they figured out a way! The wing bones of pterosauria evolved into hollow tubes with thin walls, which allowed them to “lose weight” successfully, becoming more flexible and lightweight, and can fly much easier.
Others say that pterosauria could not only fly, but swooped down like eagles to prey on fish from the surface of oceans, lakes, and rivers. Flight allowed pterosauria to travel long distances, escape predators and develop new habitats.
Kawah Dinosaur Official Website: www.kawahdinosaur.com
Post time: Nov-18-2019