In the late Permian period - the early Triassic on Earth lived a large group of beast-shaped reptiles - theromorphs. Typical representatives of this group are Dicynodonts or “two-canine”. In the structure of their body, they had a number of progressive features and this greatly distinguished them from other reptiles.

Species: Dicinodont - the precursor of mammals

The appearance of the Dicynodonts can be described as follows: a beak of a turtle, a hippo body and two walrus fangs.

Scientists describe Dicinodont as a small - no more than one meter in length, herbivore with a kind of hooked skull and a short thick tail. Paleontologists suggest that he could live in holes. Scientists also believe that Dicynodonts belong to a group of animals described as a species of reptile mammal, from which mammals originated.

Dicinodont (lat.Dicynodontia)

Researchers believe that the earliest evidence of the appearance of distinctive signs of sexual dimorphism in land animals is the large fangs of Dicinodont, who lived on Earth long before the dinosaurs. Of the animals living in the Permian period, Dicynodonts are the most long-lived reptiles. According to the researchers, Dicynodonts appeared on our planet at the end of the Permian period of the Paleozoic, about 30 million years before the heyday of the dinosaur era.

Some species of Dicynodonts lasted until the end of the Upper Triassic and lived on the territory of modern Australia 105 million years ago. It was of this age that the fossilized remains of an ancient reptile were discovered - the jaw, canine and beak. Although it was previously believed that the Dicynodonts died out about 220 million years ago. At one time, this fanged lizard was the dominant animal on Earth, according to Australian paleontologist Talbourne.

Dicinodont Placerias hesternus

Other researchers disagree with Talbourne's findings and believe that parts of the fossilized skull could belong to a horned dinosaur. For example, Fraser, a paleontologist at Virginia's American Museum of Natural History, questions the claim that dicynodonts survived the mass extinction of animals 200 million years ago (as suggested by the collision of our planet with a giant asteroid). However, Talbourne claims that the Dicynodonts could be hiding in the east of the Gondwana supercontinent, in the area that over the centuries has become Australia.

Types of dicynodonts.

The largest accumulation of fossil remains of Ditsinodontov was discovered near Kotelnich. Studying the find, scientists came to the conclusion that the ancient reptiles underwent enormous evolutionary changes. the most recent representatives of this pangolin were the size of a modern elephant. Dicynodonts in their heyday spread flesh to all continents of the Earth to Australia, where their remains were found.

Dicinodont listozavr.

Over the past twenty years, excavations have been carried out in South Africa and a detailed analysis of almost all the found skeletons of Dicinodonts has been made. The results of scientific research give a clear idea of ​​the presence of these ancient reptiles of complex social behavior. It was found that the Dicinodonts led a herd life, lived near ponds, and were apparently herbivorous. The animal could move well on the ground, but led a predominantly aquatic lifestyle.

Dicinodont Hundezahn.

With the evolutionary changes, according to a well-founded assumption by scientists, the late Dicynodonts had a constant body temperature, had a hair coat, and even were viviparous.

In the same species of Dicynodonts, the presence of sexual demorphism was found, which manifests itself in different physiological features between different sexes (in size, shape and color), which researchers found convincing evidence. The first manifestation of sexual demorphism in Dicynodonts appeared 252-260 million years ago. The male Dicinodont, unlike the female, had two large fangs growing down from the upper jaw.

Primitive dicinodont Australobarbar (lat. Australobarbarus) found in the Kirov region.

Paleontologists did not find any clear signs that the fangs were used by animals to dig holes. And also the fangs could not serve the Dicinodonts for food, as they were absent in the females. However, these fangs grew during the life of the animal. In the event that the fang broke, it no longer grew again. According to all these signs, scientists concluded that fangs were a manifestation of gender demorphism. Most likely, strong fangs were used by males for ritual battles for the female during the mating season, as well as to protect themselves and their offspring from predators.

Watch the video: Lecture 33a A Closer Look at Dicynodonts (February 2020).

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