Protembolotherium
| Protembolotherium | |
|---|---|
| Skulls of P. efremovi, Moscow Paleontological Museum | |
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Mammalia |
| Infraclass: | Placentalia |
| Order: | Perissodactyla |
| Family: | †Brontotheriidae |
| Subfamily: | †Brontotheriinae |
| Tribe: | †Brontotheriini |
| Subtribe: | †Brontotheriina |
| Infratribe: | †Embolotheriita |
| Genus: | †Protembolotherium Yanovskaya, 1954 |
| Species: | †P. efremovi
|
| Binomial name | |
| †Protembolotherium efremovi Yanovskaya, 1954
| |
Protembolotherium (lit. 'first battering ram beast') is an extinct genus of horned brontothere that lived in East Asia during the Late Eocene, in the Ergilian land mammal age.[a] A single species is recognized, P. efremovi, known from the Ergilin Dzo Formation in Mongolia.
Research history
Protembolotherium efremovi was described by N. M. Yanovskaya in 1954, based on two skulls and several other fossils found in the lower part of the Ergilin Dzo Formation in Dornogobi, Mongolia. The type specimen is PIN 473-311, a partial skull that lacks most of the nasal bones.[1] The other skull referred to the genus in 1954 is PIN 473-310, which also preserves the ram-like protuberance at the front of the skull. In 1980, Yanovskaya referred an additional skull from the Ergilin Dzo Formation, PIN 3109-40, to P. efremovi.[1] Yanovskaya also referred several more fragmentary specimens to P. efremovi, including jaws, but the location of these specimens is unclear and they have been argued to be non-diagnostic.[1]
Description
Protembolotherium was a large brontothere.[1]
Protembolotherium is the only horned brontothere other than Embolotherium in which the horns are fused into an elongated ram-like structure.[1] Since the ram of Protembolotherium is shorter and less elaborate, it has been interpreted as a transitional form between more primitive horned brontotheres and Embolotherium.[3] Protembolotherium is distinguished from Embolotherium in that it in addition to the ram also had an additional pair of short horns above the orbits (eye sockets).[1]
Several additional features closely link Protembolotherium to Embolotherium, including the saddle-shaped skull, the wide upper surface of the skull and expanded zygomatic arches, and several characteristics of the teeth.[1] Several features also distinguish the two, such as the skull of Embolotherium being even more deeply saddle-shaped, the occiput (the furthest back portion of the skull) is shorter and more upright, the shorter ram, the additional horns, and the steep upwards slope at the dorsal (upward-facing) part of the rostrum.[1]
Notes
References
- ^ a b c d e f g h i Mihlbachler, Matthew C. (2008). "Species Taxonomy, Phylogeny, and Biogeography of the Brontotheriidae (Mammalia: Perissodactyla)". Bulletin of the American Museum of Natural History. 501: 186–189, 393, 412–414. doi:10.1206/0003-0090(2008)501[1:STPABO]2.0.CO;2.
- ^ Bai, Bin; Meng, Jin; Janis, Christine M.; Zhang, Zhao‐Qun; Wang, Yuan‐Qing (2020). "Perissodactyl diversities and responses to climate changes as reflected by dental homogeneity during the Cenozoic in Asia". Ecology and Evolution. 10 (13): 6333–6355. doi:10.1002/ece3.6363. ISSN 2045-7758. PMC 7381588. PMID 32724516.
- ^ Mihlbachler, Matthew C.; Lucas, Spencer G.; Emry, Robert J.; Bayshashov, Bolat (2004). "A New Brontothere (Brontotheriidae, Perissodactyla, Mammalia) from the Eocene of the Ily Basin of Kazakstan and a Phylogeny of Asian "Horned" Brontotheres". American Museum Novitates. 3439 (1): 1. doi:10.1206/0003-0082(2004)439<0001:ANBBPM>2.0.CO;2. ISSN 0003-0082.