Bronoterium [1] ( lat. Brontotherium , from other Greek. Βροντο- + θηρίον - thunder beast) is a genus of extinct equine mammals that lived in the late Eocene in North America . Four species of fossil mammals belonging to this genus are known. They died out about 30 million years ago, having failed to adapt to new food, when forests began to be replaced by meadows.
| † Brontoterias |
Skeleton Brontotherium hatcheri
at the National Museum
Natural History (Washington) |
| Scientific classification |
|---|
| No rank : | Bilateral symmetrical |
|
| International scientific name |
|---|
Brontotherium |
| Kinds |
|---|
- Brontotherium gigas typus
- Brontotherium leidyi
- Brontotherium hatcheri
- Brontotherium platyceras
|
Geochronologyextinct 30 million years | million years | Era | F-d | Era |
|---|
| | Th | TO
but
th
n
about
s
about
th | | 2,588 | | | 5.33 | Pliocene | N
e
about
g
e
n | | 23.03 | Miocene | | 33.9 | Oligocene | P
but
l
e
about
g
e
n | | 55.8 | Eocene | | 65.5 | Paleocene | | 251 | Mesozoic |
◄ Nowadays◄ Cretaceous-Paleogene extinction |
|---|
|
Reconstruction of
Megacerops coloradensisThe brontoteria reached a height of 2.5 m in the shoulders. The dental system of the brototeria was brachiodontic (their molars had low crowns and closed roots), which indicates the nutrition of relatively soft vegetation (leaves, possibly fruits). The skull of the brototeria was rather massive, but the brain was small. Their head, characterized by forward-shifted eyes, was "decorated" with grandiose horns formed by overgrown nasal bones; outside, these horns were covered with skin. In some species, wide and long horns forked at the very base, in others they represented a single outgrowth forked at the very end.
Many of the remains of the Bronoteria were found in the states of South Dakota and Nebraska . It is believed that the places where the brontoterium lived were moist. Lakes bordered by reed beds and water-loving shrubs. Abundant grass, broad-leaved trees grew on land.
The Australian scientist O. Abel suggested such an unexpected solution: brontoteria became extinct from a deadly disease for some animals - Nagan. Its causative agent is the flagellate trypanosome. A carrier is the well-known tsetse fly . However, many paleontologists do not accept such an original explanation of the disappearance of the brototeria. There is another point of view on the problem of the extinction of these mysterious animals. Scientists believe that climate and vegetation change is the main cause of the extinction of hippomorphic "thunder animals."
In the past, their skeletons, which appeared on the surface due to rains, were found by Indian tribes. The Indians believed that these animals create lightning when they run through the clouds, and called them "Thunder beasts." Most of the skeletons found by the Indians belonged to animals that died during volcanic eruptions. The spine of the brototherium had long bone outgrowths necessary for fastening powerful neck muscles .
The closest relative of the North American brototherium in the Old World was the embolotery , which lived in the late Eocene and the Oligocene in Central Asia, the remains of which were examined and described in 1929 by the American paleontologist Henry Osborne .
