In the reality around us, only birds, insects and bats can fly, the size of which usually does not exceed one meter. Therefore, it can be difficult for us to imagine giant flying lizards, the size of an antelope or a giraffe, fluttering freely in the air. However, archaeological finds suggest that such animals really existed and lived for more than one million years.
Flying reptiles
Ancient flying lizards, or pterosaurs, appeared in the Mesozoic era about 200 million years ago. It was so long ago that, despite all the efforts of scientists, it is not possible to unravel all the secrets of their life even now. Researchers still cannot say from which ancestors the lizards appeared, why they disappeared and how exactly they could fly, sometimes having incredible dimensions.
At the same time, it is known that these were the first vertebrates that managed to master the airspace of the planet. According to the internal structure, they had a lotin common with birds, outwardly they resembled a mixture of birds and bats. Pterosaurs are often identified with dinosaurs, but this is a mistake. They represent two different groups of prehistoric creatures that belonged to a subclass of diapsid reptiles, or archosaurs. It included many animals, but only crocodiles have survived to this day. The last pterosaurs lived about a million years ago and disappeared from the face of the Earth during the Cretaceous-Paleogene extinction period, along with dinosaurs and some marine reptiles.
Fly or swim?
The first pterosaur in history was discovered in 1784, but this event did not become a sensation, and the scale of the find was estimated only after almost 20 years. The fact is that the fossils of an unknown fossil were attributed to an aquatic creature. The Italian naturalist Cosimo Collini believed that the elongated forelimbs served as flippers and helped him move in the sea. In systematics, he was given a place between birds and mammals.
In the early 19th century, naturalists John German and Georges Cuvier suggested that the creature could fly. They decided that it supported large wings with long fingers of the forelimbs, so the specimen was named pterodactyl, which literally translates as “wing + finger”. Thus, the pterodactyl found in Bavaria became the first official evidence of the existence of flying pangolins.
Species diversity
Since the beginning of the 19th century, about 200 genera of pterosaurs have been discovered, whichsubdivided into two large suborders. The first and more primitive flying lizards were the Rhamphorhynchus. Their remains were found on the territory of Tanzania, Portugal, Germany, Great Britain, Kazakhstan and the countries of South America. Rhamphorhynchus were much smaller in size than later species, had a large head, long tail and short neck. They had narrow wings and a jaw with well-developed teeth.
For a long time Rhamphorhynchus coexisted with representatives of the second group - pterodactyls, but, unlike them, died out at the beginning of the Cretaceous period. It is assumed that their disappearance occurred gradually and completely naturally. Pterodactyls appeared only in the Jurassic period and lived until the end of the Mesozoic era. Much more mysteries are associated with their extinction, because at the same time 30% of all marine and land animals died on Earth.
Pterodactyls were rather large creatures with a large elongated head, wide wingspan, short tail. Compared to early forms of pterosaurs, they had a more elongated and mobile neck, and most later species had no teeth at all.
Appearance
There have been many attempts to visualize pterosaurs in print and film, but all depictions of prehistoric flying pangolins remain very approximate. From the remains found, it is known that they had beaks of various sizes and shapes, reminiscent of birds. The body of animals was covered with filamentous hairs of pinnofibre, the origin of which differs from that of wool.mammals. Researcher Alexander Kellner suggested that they are more similar to the shields on the body of crocodiles and bird feathers.
Many flying lizards had ridges on their heads made of keratin and other relatively soft substances. They could reach quite large sizes and, most likely, served as the main distinguishing features between males and females. Perhaps they also performed the function of thermoregulation. They were peculiar outgrowths on the beak and head of the animal and could have the most bizarre shapes.
In representatives of the genus Thalassodromeus, the crest accounted for almost three-quarters of the surface of the entire skull, which could reach 1.5 meters in length. In animals of the genus Tapejara, the crest was bony and consisted of several teeth on the back of the head and at the base of the beak.
Wings of pterosaurs are skin membranes that were attached to the front and rear limbs. Inside the membranes were thin muscles, as well as blood vessels. Due to this structure, for a long time they were considered ancient bats and were even classified as mammals.
Sizes
The order of pterosaurs included creatures completely different in structure and size. It is believed that the early Rhamphorhynchus did not exceed the size of modern birds. Some of them were no more than a titmouse, while they had developed and rather long wings. For example, the body of anurognathas grew only 9-10 centimeters in length, but in the wingspan they reached almost 50 centimeters. The smallest of the lizards discovered by archaeologists wasNemicolopterus with a wingspan of 25 centimeters. True, there is a possibility that this is a cub, and not an adult form of a separate species of pterosaurs.
Over time, these animals grew larger until they turned into real giants. Already in the middle of the Jurassic period, flying lizards reached 5-8 meters in wingspan, and presumably weighed about a hundred kilograms. The largest creatures of the Earth capable of flight are still considered to be Quetzalcoatl and Hatzegopteryx. They had relatively short bodies and strongly elongated necks, and in size they can be compared with adult giraffes. Their skulls could reach 2-3 meters in length, and their wingspan was approximately 10-11 meters.
Flying lizards and birds
The ability to actively fly and some features of the anatomy made pterosaurs the first contenders for the role of the ancestors of birds. Like birds, they had a keel, to which the muscles responsible for the wing flap were attached; their bones also had air-filled voids; and later species even fused the thoracic vertebrae to provide more rigid support for the wings.
Despite all these similarities, scientists believe that birds evolved parallel to pangolins and most likely evolved from dinosaurs. There are dozens of finds of feathered reptiles that could theoretically be their ancestors. This list includes: maniraptors, archeopteryxes, protoavis and others. Feathers close to modern species appeared only in the Jurassic period, at a time when pterosaurs were already in full swing.used airspace.
For millions of years, ancient birds and flying lizards lived side by side. They led a similar lifestyle and competed for food. According to one hypothesis, it was the birds that caused the increase in the size of pterosaurs and the complete extinction of their small species.
Methods of transportation
Research on the skulls of pterosaurs showed that they had highly developed brain regions closely associated with flight. They accounted for 7-8% of the brain mass, while in modern birds they occupy only 2%. But flying was not the only way to get around. The lizards had well-developed limbs that allowed them to run fast and walk confidently on the ground. Many of them moved with all four legs like mammals.
It is still unknown exactly how pterosaurs flew. Today, the largest birds - the Andean condor and the wandering albatross - reach a maximum of 3 meters in wingspan and weigh no more than 15 kilograms. Pterosaurs, on the other hand, were several times larger and it is not clear how, in general, they could rise into the air. According to one version, powerful hind limbs helped them take off, with which they pushed off the ground. According to another version, for the initial jerk, they swung their heads strongly to create resonance and set the rest of the body in motion.
Lifestyle
Judging by the presence of many teeth, pterosaurs were mostly carnivores or omnivores. Ornithocheirids, pteranodontids fed mainly on fish. Ramphorhynchus and tapeyarids were eaten assmall vertebrates and insects, and fruits of plants. Large species of azhdarchids could prey on even medium-sized dinosaurs.
Pterosaurs caught their prey on the ground or in flight. Among them were both day and night representatives. Animals such as the Tapejars could remain active at any time of the day, but only for short periods of time.
Most likely, young pterosaurs needed parental care for some time. However, they were not completely helpless. It is known that they had the ability to fly much earlier than the chicks of modern birds.
