Andrew, what is a beast?

Angel beast, an extinct mammal, lived in the Cenozoic era about 30 million to 8 million years ago. It is a carnivore, but it doesn't belong to the canine family. It has long hoofs and patterns on its body, and is a distant relative of modern horses and donkeys.

It is one of the largest land carnivorous mammals in the history of the earth. It is about 2 meters high and its mouth is about 1 meter long. It can easily crush animal bones.

Although the horned beast is a carnivore, it has no territorial consciousness and just preys everywhere at the top of the food chain.

Although the Andes beast is huge and has almost no natural enemies, it was eventually eliminated by nature due to the rapid change of the earth's climate and the massive migration and death of herbivores.

Andrews ungulates in Mongolia belong to Zombidae in Ankle Class. It lived in Mongolia in the late Eocene 50-32 million years ago, and its name was named after its discoverer roy chapman andrews. Probably the largest land predator ever.

1923 The third field trip to Central Asia sponsored by the American Museum of Natural History has entered its third year. Andrews, the leader at that time, discovered and first described this animal in the late Eocene rocks near Harman, Mongolia. Three years ago, this expedition was fruitful under his leadership. World-famous dinosaur fossils, such as the egg-stealing dragon, were found in Mongolian Gobi, and protoceratops's eggs were also found for the first time. In fact, George Olson was the first expedition member to see fossils. He immediately called Andrews to check it out, and the expedition team immediately plunged into excavation, and slowly a spectacular skull fossil appeared in front of everyone. The specimens found are mainly a huge skull and some fragments, and the leader Andrews identified them as an unknown prehistoric large carnivore.

Later, the fossils were compared and identified in detail. Andrews sent the outline of the fossil to the American Museum. Fossils make most researchers first think of the Oligocene giant pig (Entelodon) omnivore. Dr. W. D. Matthew observed and compared the mammal species in China (which belonged to ancient carnivores at that time, but today it is changed to ankle program). It is found that this new specimen is closely related to them. After a series of detailed comparative anatomical studies, the fossil was classified as the ungulates in Andrews, Mongolia, or the ungulates in Andes for short. Its eating habits are generally characterized as omnivorous, not the judgment that Mr. Andrews is a carnivore.

This medium-sized mammal is much larger than the carnivores found in other parts of the world. The total length of the skull is 834mm, which is much longer than that of Ursus gyas. It is estimated that its adult body length is 3820mm(= 12 feet 6.5 inches, which is three times larger according to the head-to-body ratio of Portulaca obtusifolia, and now it is generally believed that it can grow to 5 meters) and its weight can reach 1500 kg. Its skull is twice the length and width of brown bear, three times that of western dog, three times that of its North American relative blunt-toothed dog and three times that of Wendeng dog in northern Utah in Eocene.

The characteristics of mammals in Angles are: the face is extremely long, the cheekbones are wide and swollen, the skull is 834 mm long and the cheekbones are 560 mm wide; ; It has a relatively complete true animal tooth type, so it is different from a strong animal with m3 deletion. P4 is a triangle and molar with a prominent third point. Its m3 posterior apex is missing, and its heterotopia is mainly composed of anterior apex.

Specimen description, with data from 1924 Henry fairfield Osborne's anatomy paper.

(1) skull features

Around these skull specimens, scientists made a detailed description and analysis, and compared with the huge Habagolestes species (Harpagolestes uintensis):

Mongolian subspecies

The total length of the skull is 429 834.

(Face length+skull area)

Zygomatic arch width 270 560

Face length 206 500

(Span from lower 1 incisor i 1 to lower third molar m3)

Cranial region 223 334 (unit: mm)

(m3 returns to articular condyle)

These data show that the middle animal of Angle is almost twice that of H.uintensis, and from the perspective of the proportion of facial area to the whole skull, its snout accounts for a large proportion, while the proportion of cranial area is not large, so it may not be too smart.

(2) The tooth characteristics of Anger's intermediate animals are described as follows:

I2 is extremely increased and i3 is very small; The upper canine teeth have not been preserved, but from the trace of landing position, the size should be very large; Pl is very small, with only one root and tip; P2 has two tooth roots and only one tooth tip; P3 has immature third tooth root, double tooth tip and protruding original cone, but no second tooth tip secondary cone; ; P4 is large and molar, with prominent third and third roots; M 1 is slightly smaller and has three tooth roots; M2 is the width of a triangle, with a big middle tip, a prominent original cone and a third triple cone, and the second one is worn by deuterocone. The original end and the third apex of M3 are prominent, with an immature second apex.

The improvement of the tooth shape of mammals in China shows that they have adapted to the carnivorous habits, but they have not yet possessed the symbol of authentic carnivorous mammals-cracked teeth. The first one with original cracked teeth was the carnivorous tooth that later shared a Mongolian blue sky with mammals in China.

Mammals in China vary greatly in size, ranging from a jackal to several meters. Ankylosaurus belongs to the latest arthropod, and people still know little about this mysterious behemoth because of the lack of fossil evidence. No new stones were found except this skull discovered by 1923. The determination of its species and genus is also based entirely on the fossil morphological characteristics of the skull. Its body length is calculated by referring to the ratio of the skull of a strong animal to the rest of the body. On this basis, the weight and total recovery figure are also obtained. The reason why the skull of the horned beast is compared with the whole body proportion of the strong beast is because they both belong to the broken bone beast and their body structures are more similar.

As far as comprehensive physical fitness is concerned, mesoderm is undoubtedly the most powerful terrestrial mammal carnivore that has ever appeared, and it is well-deserved to be called "the top four of the third year" with carnivores, mighty beasts of Chiroptera and the giant beasts of Chiroptera that have emerged in Mongolia. Only a meat cleaver can compare with it in terms of size.

Angkor's ankle project also has a prominent position, but later ungulates and many other animals have great origins in phylogeny. Ankle arthropods in the northern hemisphere and exotic ungulates in the south are the most important ancient ungulates, which have far-reaching influence compared with the orders of Blupoda and Phopoda. It is believed that cetaceans are closely related to mammals in China, but there is no clear answer as to whether mammals in China evolved into cetaceans or whether they have the same ancestor. It is worth mentioning that the ancestors of flippers, such as walruses, also came from Arctccyonidae of the ankle program.

Angel mesoderm is far more famous in popular science works than all its relatives. It can be said that it is an unavoidable topic in most books on animal evolution and paleontology, which may be due to its mysterious life experience, huge size and its important historical position in its category. In any case, the mesothelidae, represented by the Keratophyllaceae, successfully completed the handover with the top position of the food chain of Carnivora while falling down. After that, carnivores became more specialized, carnivores with cracked teeth became more adaptable to their carnivorous habits, and mammals in the middle also completed their evolutionary mission entrusted by nature.