Deinotheriidae

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Deinotheriidae
Skeletal reconstruction of Deinotherium

Skeletal reconstruction of Deinotherium

Temporal occurrence
Middle Oligocene to early Pleistocene
29 to 1 million years
Locations
Systematics
Higher mammals (Eutheria)
Afrotheria
Paenungulata
Tethytheria
Russell animals (Proboscidea)
Deinotheriidae
Scientific name
Deinotheriidae
Bonaparte , 1845

The deinotheriidae (Deinotherien even Dinotherien or "Hauer elephant") were a very early, successful branch of fossil mammoths (Proboscidea), including the extant elephant count. They lived in much of the Old World from the Oligocene to the early Pleistocene . The name is composed of the Greek words δεινός ( deinos , horror) and θηρίον ( thērion , animal), while dino represents the Latinized version of deinos . Two genera are assigned to the Deinotherium , Chilgatherium and Deinotherium , a possible third, but sometimes controversial, genus is Prodeinotherium .

features

The Deinotherien had a massive physique comparable to today's elephants with columnar legs and a skull, some of which already had air-filled bones to reduce body mass. With a shoulder height of less than 2 m, the earliest representatives were significantly smaller than the later ones , some of which could measure over 4 m and, according to calculations, weighed up to 14 t. Compared to today's elephants, the skull was still clearly flat. The most striking difference to most other proboscis was the development of the tusks only in the lower jaw, which had a downward position there, so that the pointed ends sometimes pointed backwards. The tusks were formed from the first incisors of the lower jaw. Due to the shape of the tusks, the lower jaw also had a distinctive, downward-pointing symphysis . The structure of the rear dentition was also characteristic, whereby all teeth were functional at the same time, which in turn was a clear difference to modern proboscis with only one functional tooth per half of the jaw. The molars had high ridges of enamel on the chewing surfaces, the maximum number of these was three ( trilophodont ).

Fossil finds

Fossil remains from Deinotheria are relatively common. The most original representative, Chilgatherium , has so far only been proven from the Chilga site in Ethiopia , the fossil material only includes a few teeth. The finds are to be assigned to the Oligocene and date to an age of 29 to 27 million years. Deinotherium, on the other hand, is known from numerous sites in the Old World . Reference should only be made to the two particularly complete skeletons from Eserowo near Plovdiv ( Bulgaria ) and Mânzați ( Romania ). The finds belong largely to the Miocene , the most recent are from the early Pleistocene and are of African origin. In contrast to numerous other and simultaneously occurring groups of proboscis, representatives of the Deinotheria never reached the American double continent.

Systematics

Abbreviated internal systematics of the early proboscis according to Tabuce et al. 2019
  Proboscidea  

 Eritherium


   

 Phosphatherium


   

 Daouitherium


   

 Numidotherium


   


 Barytherium


   

 Omanitherium



   

 Arcanotherium


   

 Saloumia


   

 Moeritherium


   

 younger Proboscidea (Elephantiformes)


   

 Deinotheriidae



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The deinotheriidae provide a family within the order of the mammoths is (Proboscidea). The origin of Deinotherien is in Africa, where they differentiated to a time when the continent was not connected by land bridges to other continents. The peculiarities of the tooth and dentition structures in this group of proboscis sometimes led to the assumption that they were more closely related to the manatees than to the proboscis. However, this view is mostly rejected with reference to convergent evolution in animals that are not directly related.

The early splitting off in the proboscis family tree as early as the Oligocene around 30 million years ago shows above all the vertical tooth change, a feature that places the Deinotheriidae in the earliest radiation phase of the proboscis. Within these early proboscis, it is unclear whether the Deinotheria belong to the Plesielephantiformes as the most primitive group of proboscis with only two enamel ridges on the two front molars ( bilophodont ) or to the more modern elephantiformes with three or four enamel folds ( tri- or tetralophodont ). Chilgatherium had three enamel strips on all three molars, while the more modern Deinotherium (and Prodeinotherium ) only had these on the foremost and the second was bilophodont. Due to this complex tooth structure, it is not yet known from which predecessor form the deinotherms emerged. The phylogenetically older Moeritherium and barytherium from North Africa had a much richer set of teeth with anterior molars, formed by two enamel strips. Palaeomastodon , which also formed in North Africa about 34 million years ago, had three, but incompletely formed, ridges on the first two molars. It is possible that both the Deinotheria and Palaeomastodon descend from an even older ancestor with trilophodontic molars and the Deinotheria reduced their third groin on the two rear teeth over time.

The family name Deinotheriidae was coined by Charles Lucien Jules Laurent Bonaparte (1803-1857) for the first time in 1845. Within the Deinotheriidae, a distinction is made between two genera , each assigned to its own subfamily. The distinction between the subfamilies goes back to William Sanders , John Kappelmann and D. Tab Rasmussen and is based on the different structure of the molars:

Whether the Prodeinotherium (referred to as Prodinotherium by Éhik ), introduced by J. Éhik in 1930 on the basis of Hungarian fossils, forms an independent genus within the Deinotheriinae is disputed; the few distinguishing features, along with clear differences in body size, are in the form of the third premolar the roof of the skull and the structure of the occiput . For some researchers, however, this is not enough to justify two separate genres. The tribal history of the Deinotherien is generally characterized by a constant increase in body size, which lasted until the very end and so often led to different taxonomic names.

Individual evidence

  1. a b Jehezekel Shoshani, Robert M. West, Nicholas Court, Robert JG Savage and John M. Harris: The earliest proboscideans: general plan, taxonomy, and Palaeoecology. In: Jeheskel Shoshani and Pascal Tassy (eds.): The Proboscidea. Evolution and palaeoecology of the Elephants and their relatives. Oxford, New York, Tokyo, 1996, pp. 57-75
  2. Ursula B. Göhlich: Tertiary Urelefanten from Germany. In: Harald Meller (Hrsg.): Elefantenreich - Eine Fossilwelt in Europa. Halle / Saale, 2010, pp. 340–362–372
  3. ^ Per Christiansen: Body size in proboscideans, with notes on elephant metabolism. Zoological Journal of the Linnean Society 140, 2004, pp. 523-549
  4. ^ Cyrille Delmer: Reassessment of the generic attribution of Numidotherium savagei and the homologies of lower incisors in proboscideans. Acta Palaeontologica Polonica 54 (4), 2009, pp. 561-580
  5. ^ A b Jan van der Made: The evolution of the elephants and their relatives in the context of a changing climate and geography. In: Harald Meller (Hrsg.): Elefantenreich - Eine Fossilwelt in Europa. Halle / Saale, 2010, pp. 340-360
  6. John Kappelman, D. Tab Rasmussen, William J. Sanders, Mulugeta Feseha, Thomas Bown, Peter Copeland, Jeff Crabaugh, John G. Fleagle , Michelle Glantz, Adam Gordon, Bonnie Jacobs, Murat Maga, Kathleen Muldoon, Aaron Pan, Lydia Pyne, Brian Richmond, Timothy Ryan, Erik R. Seiffert, Sevket Sen, Lawrence Todd, Michael C. Wiemann and Alisa Winkler: Oligocene mammals from Ethiopia and faunal exchange between Afro-Arabia and Eurasia. Nature 426, 2003, pp. 549-552
  7. ^ A b William Sanders, John Kappelmann and D. Tab Rassmussen: New large-bodied mammals from the late Oligocene site of Chilga, Ethiopia. Acta Palaeontologica Polonica 49 (3), 2004, pp. 365-392, 2004
  8. Dimitar Kovachev and Ivan Nikolov: Deinotherium thraceiensis sp. nov. from the Miocene near Ezerovo, Plovdiv District. Geologica Balcanica 35 (3-4). 2006, pp. 5-40
  9. Grigoriu Stefanescu: Deinotherium gigantissimum . Annuarulu Museului de Geologia si de Paleontologia. 1894, pp. 126-199
  10. Karol Schauer: Notes and sources on the evolution table of the Proboscidea in Africa and Asia. In: Harald Meller (Hrsg.): Elefantenreich - Eine Fossilwelt in Europa. Halle / Saale, 2010, pp. 630–650
  11. Rodolphe Tabuce, Raphaël Sarr, Sylvain Adnet, Renaud Lebrun, Fabrice Lihoreau, Jeremy E. Martin, Bernard Sambou, Mustapha Thiam and Lionel Hautier: Filling a gap in the proboscidean fossil record: a new genus from the Lutetian of Senegal. Journal of Paleontology, 2019, doi: 10.1017 / jpa.2019.98
  12. ^ HJ Gregor, R. Kuhn and DH Storch: Deinotherium? a proboscidian? Documenta Naturae 130, 2000, pp. 1-141
  13. Kati Huttunen and Ursula Bettina Göhlich: A partial skeleton of Prodeinotherium bavaricum (Proboscidea, Mammalia) from the Middle Miocene of Unterzolling (Upper Freshwater Molasse, Germany). Geobios 35, 2002, pp. 489-514
  14. Jehezekel Shoshani: Understanding proboscidean evolution: a formidable task. Tree 13, 1998, pp. 480-487
  15. a b Athanassios Athanassiou: On a Deinotherium (Proboscidea) finding in the Neogene of Crete. Notebooks on Geology - Letter 2004/05, pp. 1-7
  16. Kati Huttunen: Systematics and Taxonomy of the European Deinotheriidae (Proboscidea, Mammalia). Annalen des. Naturhistorisches Museum zu Wien 103 A, 2002, pp. 237–250

Web links

Commons : Deinotheriidae  - collection of images, videos and audio files