Brachypotherium

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Brachypotherium
Lower jaw of Brachypotherium

Lower jaw of Brachypotherium

Temporal occurrence
Middle Miocene to Lower Pliocene ( Langhium to Zancleum )
17 to 4.2 million years
Locations
  • Asia
  • Europe
  • Africa
Systematics
Higher mammals (Eutheria)
Laurasiatheria
Unpaired ungulate (Perissodactyla)
Rhinocerotoidea
Rhinoceros (Rhinocerotidae)
Brachypotherium
Scientific name
Brachypotherium
Roger , 1904

Brachypotherium is a genus of extinct rhinos whose representatives were distributedover large parts of Europe, Asia and Africain the Middle and Upper Miocene 17 to 4 million years ago. The animals were characteristically short-legged and had no horn formation. With an estimated live weight of 5 tons, they were among the largest known rhinos. They lived in open forest landscapes and ate a soft vegetable diet.

features

The representatives of Brachypotherium were large to very large rhinos with a plump body, a short skull and relatively short limbs , which each end in three toes. With an estimated body weight of more than 5 t in some cases, they were the largest representatives of the rhinoceros of their time and, along with the species of the genus Elasmotherium, the largest known rhinoceros from the tribal history of this group of mammals.

The skull of the Brachypotherium species was relatively short and had a wedge-like outline. Furthermore, it was quite flat in shape when viewed from the side. The length was up to 71 cm. The occiput showed a rather short and rectangular shape and was partly rounded in the rear area. The nasal bone was also relatively short and reached up to 12 cm in length. It had no roughening on the surface that one can assume that the Brachypotherium species had no horn. Furthermore, the nasal bone was not connected to the intermaxillary bone , but ended around 15 cm from its front edge. The eye sockets , which were located quite far forward and above the second molar, were also striking .

The lower jaw was at least 45 cm long and was very massive with a bone body up to 9 cm high and wide joint ends. The dentition was significantly reduced, especially in the front area. The dental formula for adult animals is: . The conical lower incisors , which were very elongated up to 11 cm, had a distinctive shape and were slightly curved so that the tips pointed upwards and thus resembled small tusks . However, the roots of the incisors were relatively short. The upper incisors, on the other hand, were flat. The posterior teeth had rather low tooth crowns ( brachyodont ), but sometimes reached a moderate height of the teeth. These were built quite primitively, but had individual anatomical features. In addition, the premolars resembled the molars, meaning that they were clearly molarized. The premolars and molars had very wide chewing surfaces. The largest were the last two molars, which were up to 6 cm long.

The most characteristic feature of the body skeleton were the shortened limbs. The humerus was very solid and about 49 cm long, the radius up to 36 cm. The thigh bone reached 47 cm in length, the shin, however, up to 35 cm. Both the front and rear limbs ended - as in today's modern rhinos - in three toes, whereby the central ray ( Metapodium III) was most strongly developed and at the hand 18 cm ( metacarpus ), at the foot 16 cm ( metatarsus ) got long. In contrast to other three-toed rhinos, the second ray (Metapodium II) was hardly reduced in size.

Locations

Fossil remains of Brachypotherium are known mainly from Central , Western and Southern Europe , Western and Central Asia and Africa , where they generally achieved a fairly wide distribution. In Germany finds are mainly in the southern parts of the country. They were discovered in the Dinotherien sands near Eppelsheim , but fossils also came to light in the Upper Freshwater Molasse, for example in Steinheim am Albuch . However, there are mostly only single finds. From Austria fossils from Atzelsdorf northeast of Vienna have been described. A lot of postcranial skeletal material came to light in Dúbravska-Pole in Slovakia . Outstanding are the remains of Simorre in France , which in addition to skull finds also include extensive remains of the body skeleton. Finds of tooth and bone remains from Spain , but also from Southeast Europe, are also common.

Numerous and outstanding finds from Anatolia come from Asia , for example from the hominoid sites Pasalar and Çandir, as well as from the Sinap Formation, and include both skull fragments and postcranial skeletal elements. All of these finds belong largely to the Middle Miocene . Numerous, but often fragmented, fossils are known from the Siwaliks in Pakistan , where they are assigned to the Kamlial and Chinji Formations . Also worth mentioning are jaw fragments from Late Middle to Upper Miocene deposits of the Irrawaddy in Burma . Finds from Japan, where various teeth, but also a lower jaw from various Middle and Upper Miocene rock deposits in the east of the island of Honshū , are clearly isolated . In addition to fossils from North Africa, one of the most important finds on this continent is an almost complete skull from Lothagam un Buluk , both in Kenya , while a lower jaw fragment from Namibia is one of the southernmost finds of this rhino genus.

Paleobiology

The partially low-crowned molars indicate Brachypotherium as a genus of herbivores specializing in soft vegetable foods such as leaves , twigs or buds . The typical grinding patterns on the teeth also suggest a certain amount of hard grass . The habitat of these rhinos should have been forests with a certain amount of open land. The structure of the limbs, but above all the hand and foot bones, still speaks for locomotion in more open terrain, so swampy areas were probably rarely visited. A frequently postulated semi-aquatic way of life, as its hippopotamus habitus might suggest, has not yet been proven. The frequent association of Brachypotherium with the proboscis representatives of the genus Deinotherium , which preferred a similar landscape, confirms these views.

Systematics

Brachypotherium is a genus from the subfamily Aceratheriinae, a rhinoceros group of often hornless animals. Within these she belongs to the tribe of the Teleoceratini , whose members are distinguished by shortened legs. However, Brachypotherium represents a rather conservative branch of the tribe, as the genus did not undergo any significant specialization in hard plant food despite the spread of open landscapes and thus largely retained its mostly low-crowned molars. The limb cuts were also significantly less than in the closely related and simultaneous Teleoceras that live in North America .

Several species have been described by Brachypotherium , the following of which are valid today:

Species originally described from the Lower Miocene, such as B. aurelianense, are now largely assigned to Prosantorhinus , others to Diaceratherium . B. americanum , which was once regarded as the American representative, has now been assigned to the genus Teleoceras , which only occurs there . The problem is the species B. fatehjangensis , which was originally created in 1910 by Guy Ellcock Pilgrim based on an upper jaw fragment from Fatehjang in what is now Punjab . Pilgrim put her in connection with Teleoceras . In 1972, however, Kurt Heissig referred her to the form aprotodon , which is closely related to Brachypotherium , citing the finds of teeth and limbs from the Siwaliks , which some scientists advocate. Yet other researchers see them as representatives of Brachypotherium .

The first description of Brachypotherium was in 1904 by O. Roger, which he made on the basis of finds from the Dinotheria sands. However, Roger had previously used the name in an unpublished manuscript. The Brachypotherium species, some of which were described quite early, were often initially assigned to other rhino genera such as Rhinoceros , Teleoceras or Aceratherium . The name Brachypotherium is derived from the Greek words βραχύς ( brachýs "short"), πούς ( pous "foot") and θηρίον ( thērion "animal") and refers to the briefly developed limbs of animals.

Tribal history

The first appearance of Brachypotherium was at the beginning of the Middle Miocene . Possibly the genus emerged from the predecessor form Prosantorhinus from the Lower Miocene. Early finds come from the Siwaliks in Central Asia and Western Europe. It was most widespread in the Upper Miocene, where representatives of the genus were found in Asia, Europe and Africa. The last appearance of this rhinoceros genus in Europe is guaranteed around 8 million years ago, where it is still known from sites in Bulgaria. The most recent finds were made in eastern Africa and are dated to the early Pliocene around 4.2 million years ago.

Individual evidence

  1. ↑ Esperanza Cerdeño: Diversity and evolutionary trends of the the family Rhinocerotidae (Perissodactyla). Palaeo 141, 1998, pp. 13-34
  2. ^ A b c Dirk A. Hooijer and B. Patterson: Rhinoceroses from the pliocene of Northwestern Kenya. Bulletin of the Museum of Comparative Zoology, Harvard University 144 (1), 1972, pp. 1-26
  3. ↑ a b Denis Geraads: Rhinocerotidae. In: L. Werdelin and DJ Sanders (eds.): Cenozoic Mammals of Africa. Berkeley, 2010, pp. 669-683
  4. ↑ a b c A. M. Khan, A. Habib, MA Khan, M. Ali and M. Akhtar: New remains of Brachypotherium fatehjangense from Lower Siwalik Hills, Punjab, Pakistan. The Journal of Animal & Plant Sciences, 20 (2), 2010, pp. 79-82
  5. ↑ a b c Donald R. Prothero: Rhinocerotidae. In: Christine M Janus, Kathleen M Scott and Louis L Jacobs (Eds.): Evolution of the tertiary mammals of North America. Volume 1: Terrestrial carnivores, ungulates and ungulatelike mammals. Cambridge University Press 1998, pp. 595-605
  6. ↑ a b c Esperanza Cerdeño: Etude sur Diaceratherium aurelianense et Brachypotherium brachypus du Miocene Moyen de France. Bulletin du Museum National d'Histoire Naturelle de Paris Series 4 (15) C (1-4), 1993, pp. 25-77
  7. ↑ a b Denis Geraads and Gercek Saraç: Rhinocerotidae from the Middle Miocene Hominoid Locality of Çandir (Turkey). Courier des Forschungsinstitut Senckenberg 240, 2003, pp. 217–231
  8. ↑ a b c d Kurt Heissig: Family Rhinocerotidae. In: Gertrud E. Rössner and Kurt Heissig: The Miocene land mammals of Europe. Munich, 1999, pp. 175-188
  9. ↑ a b Volker Jürgen Sach: Litho- and biostratigraphic investigations in the upper fresh water molasse of the district of Biberach ad Riss (Upper Swabia). Stuttgart Contributions to Natural History Series B 276, 1999, pp. 1–167
  10. ↑ Kurt Heissig: The early Vallesian vertebrates of Atzelsdorf (Late Miocene, Austria) 11. Rhinocerotidae and Chalicotheriidae (Perissodactyla). Annals of the Natural History Museum in Vienna 111 A, 2009, pp. 619–634
  11. ↑ Júlia Zervanová, Martin Sabol *, Natália Hudáčková-Hlavatá and Peter Holec: Brachypotherium cf. brachypus and Lartetotherium sp. (Rhinocerotidae, Perissodactyla, Mammalia) from the Middle Miocene Dúbravka-Pole site (western Slovakia). Acta Geologica Slovaca 5 (1), 2013, 55-68
  12. ↑ Pierre-Olivier Antoine, Christian Bulot, Léonard Ginsburg: Les rhinocérotidés (Mammalia, Perissodactyla) de l'Orléanien des bassins de la Garonne et de la Loire (France): intérêt biostratigraphique. Earth and Planetary Sciences 330, 2000, pp. 571-576
  13. ↑ Esperanza Cerdeño: Spanish Neogene rhinoceroses. Palaeontology 35 (2), 1992, pp. 297-308
  14. ↑ a b c Denis Geraads and Nikolai Spassov: Rhinocerotidae (Mammalia) from the Late Miocene of Bulgaria. Palaeontographica A, 287, 2009, pp. 99-122
  15. ↑ a b Mikael Fortelius: Rhinocerotidae from Pasalar, middle miocene of Anatolia (Turkey). Journal of Human Evolution 19, 1990, pp. 489-508
  16. ↑ Mikael Fortelius, Kurt Heissig, Gercek Saraç and S. Sen: Rhinocerotidae (Perissodactyla). in Mikael Fortelius, JW Kappelman, S. Sen, and RL Bernor (Eds.): Geology and paleontology of the Miocene Sinap Formation, Turkey. Columbia University Press 2003, pp. 282-307
  17. ↑ AM Khan, M. Akhtar, MA Khan and A. Shaheen: New fossil remains of Brachypotherium perimense from the Chinji and Nagri formations of Pakistan. The Journal of Animal & Plant Sciences 22 (2), 2012, pp. 347-351
  18. ↑ Zin-Maung-Maung-Thein, Masanaru Takai, Takehisa Tsubamoto, Naoko Egi, Thaung-Htike, Takeshi Nishimura, Maung-Maung and Zaw-Win: A review of fossil rhinoceroses from the Neogene of Myanmar with description of new specimens from the Irrawaddy sediments. Journal of Asian Earth Sciences 37, 2010, pp. 154-165
  19. ↑ Zin-Maung-Maung-Thein, Hajime Taru, Masanaru Takai and Akira Fukuchi: A Rhinocerotid (Mammalia, Perissodactyla) from the Late Miocene Oiso Formation, Kanagawa Prefecture, Japan. Paleontological Research, 13 (2), 2009, pp. 207-210.
  20. ↑ Akira Fukuchi and Kouji Kawai: Revision of Fossil Rhinoceroses from the Miocene Mizunami Group, Japan. Paleontological Research, 15 (4), 2011, pp. 247-257
  21. ↑ Denis Geraads and Ellen Miller: Brachypotherium minor n. Sp., And other Rhinocerotidae from the Early Miocene of Buluk, Northern Kenya. Geodiversitas 35 (2), 2013, pp. 359-375
  22. ↑ Kurt Heissig: Brachypotherium from the Miocene of South West Africa. Communications from the Bavarian State Collection for Paleontology and Historical Geology 11, 1971, pp. 125–128
  23. ↑ Guy E. Pilgrim: The vertebrate fauna of the Gaj Series in the Bugti Hills and the Punjab. Memoirs of the Geological Survey of India (Palaeontologia Indica) New Series 4 (2), 1912, pp. 1-83
  24. ↑ Kurt Heissig: Paleontological and geological investigations in the tertiary of Pakistan. 5. Rhinocerotidae (Mamm.) From the lower and middle Siwalik layers. Bavarian Academy of Sciences, mathematical and natural science class, Abhandlungen 152, 1972, pp. 7–112
  25. ↑ Qiu Zhanxiang and Xie Junyi: A new species of Aprotodon (Perissodactyla, Rhinocerotidae) from Lanzhou Basin, Gansu, China. Vertebrata Palasiatica 35 (4), 1997, pp. 250-267
  26. ↑ Deng Tao: Incisor fossils of Aprotodon (Perissodactyla, Rhinocerotidae) from the Early Miocene Shangzhuang Formation of the Linxia Basin in Gansu, China. Vertebrata Palasiatica, Beijing 51 (2), 2013, pp. 131-140
  27. ↑ Oliver Chavasseau, Yaowalak Chaimanee, Soe Thura Tun, Aung Naing Soe, John C. Barry, Bernard Marandat, Jean Sudre, Laurent Marivaux, Stéphane Ducrocq and Jean-Jaques Jaeger: Chaungtha, a new Middle Miocene mammal locality from the Irrawaddy Formation, Myanmar. Journal of Asian Earth Sciences 28, 2006, pp. 354-362
  28. ↑ Otto Roger: About Rhinoceros goldfussi Kaup and the other simultaneous Rhinoceros species. In: Wirth animal remains from the Dinotheriensande of the Bavarian-Swabian plateau. Report of the Natural Science Association for Schwaben and Neuberg, 1904, pp. 12-14
  29. ↑ Esperanza Cerdeño: Prosantorhinus, the small teleoceratine rhinocerotid from the Miocene of Western Europe. Geobios 29 (1), 1996, pp. 111-124