Ancient reptiles: the origin and extinction
Dinosaurs, brontosaurs, ichthyosaurs, pterosaurs - these and many other of their relatives are known to modern people due to archaeological excavations. At different times, in different regions, some fragments of the skeletons of ancient reptiles were found, by which scientists meticulously restored the appearance and lifestyle of archaic animals. Today, the remains of reptiles can be admired in many museums around the world.
General characteristics of the ancient reptiles
Archaic reptiles - the second stage in the ontogenesis of the animal world after amphibians. Ancient reptiles are pioneers among vertebrates who are adapted to life on land.
A common feature of ancient reptiles is the skin covering of the trunk, covered with a dense layer of horn formations. Such a “protection” made it possible for animals not to fear the scorching rays of the sun and freely disperse over the entire surface of the Earth.
The apogee of the development of ancient reptiles in the Mesozoic era. Archaic lizards - the largest vertebrates living on our planet. Over time, they adapted to fly and swim under water. In short, animals reigned supreme in all earthly elements.
The history of the ancient reptiles
The cause of the archaic lizards was the change of climatic conditions. Due to the cooling and drying of many water bodies, amphibians were forced to get out of the usual aquatic habitat on dry land. As a result of evolution, the ancient reptiles appeared, as a more perfect link of the lower vertebrates.
Climate change has caused large mountain-building processes. Ancient amphibians had a thin skin without a protective coating, insufficiently developed internal organs, imperfect lungs. Creatures multiplied mainly by spawning. This method of procreation could not be carried out on land due to the fragility of future offspring. Lizards laid eggs that have a hard shell and endurance in changing climatic conditions.
The ability to adapt to any habitat has led to the emergence of various species of ancient reptiles. The most famous of them are:
- land animals (dinosaurs, fur-toothed lizards, theriodonts, tyrannosaurs, brontosaurs);
- swimming fish lashes (ichthyosaurs and plesiosaurs);
- flying (pterosaurs).
Types of ancient lizards
Depending on the habitat and feeding habits, archaic reptiles are divided into the following types:
- Flying dinosaurs - pterodactyls, ramphorinha, etc. The most enormous planning dinosaur was the pteranodon, whose wingspan reached 16 meters. A rather fragile body deftly moved through the air even in weak winds due to the natural rudder - the bone ridge on the back of the head.
- Water reptiles - ichthyosaur, mesozavr, plesiosaurus. Cephalopods, fish and other sea creatures served as food for lizard fish. The length of the body of aquatic reptiles ranged from 2 to 12 meters.
- Herbivorous chordates.
- Carnivorous dinosaurs.
- Fur-toothed lizards are reptiles, whose teeth were not the same, but were divided into fangs, incisors, and molars. The most famous periododonts are pterosaurs, dinosaurs, etc.d.
Many ancient reptiles were herbivorous creatures - sauropods. Climatic conditions contributed to the development of plants suitable for pangal lizards.
The lizards who ate grass were:
- Apatosaurus and others.
The teeth of the found remains of reptiles were not developed enough to eat carnal food. The skeleton structure indicates the adaptation of archaic animals to pluck leaves located on the crown of tall trees: almost all herbivorous lizards had a long neck and a rather small head. The body of "vegetarians", on the contrary, was huge and sometimes reached 24 meters in length (for example, brachiosaurus). Herbivores moved exclusively on four strong legs, and also relied on a powerful tail for reliability.
The most ancient predatory reptiles, unlike their herbivorous congeners, were relatively small in size. The largest representative of the archaic carnivores is the Tyrannosaurus, whose torso reaches 10 meters in length. Predators had strong, big teeth and a rather awesome look. Reptiles carnivores include:
Causes of extinction of the ancient reptiles
Adapting to the conditions of the Mesozoic, dinosaurs inhabited almost all habitats. Over time, the climate on Earth began to harden. Gradual cooling did not contribute to the comfort of heat-loving animals. As a result, the Mesozoic era became the heyday and disappearance of archaic dinosaurs.
Another reason for the extinction of the ancient reptiles is considered to be the distribution of a large number of plants that are not suitable for dinosaurs. Poisonous grass has destroyed many species of lizards, most of which were herbivorous.
It did not contribute to the further development of ancient vertebrates and the natural struggle for survival. The place of reptiles began to occupy more powerful animals - mammals and birds, warm-blooded and with higher brain development.