Deinotherium

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Deinotherium
Deinotherium (Prodeinotherium) bavaricum from the freshwater molasse near Langenau. Skeleton reconstruction in the Stuttgart Museum at the Löwentor.

Deinotherium ( Prodeinotherium ) bavaricum from the freshwater molasse near Langenau . Skeleton reconstruction in the Stuttgart Museum at the Löwentor .

Temporal occurrence
Miocene to early Pleistocene
22 to 1 million years
Locations
Systematics
Afrotheria
Paenungulata
Tethytheria
Russell animals (Proboscidea)
Deinotheriidae
Deinotherium
Scientific name
Deinotherium
Kaup , 1829

Deinotherium even Dinotherium or "Hauer Elephant" is an extinct genus of mammoths (Proboscidea), including the extant elephant count. It livedin much of the Old World from the beginning of the Miocene to the early Pleistocene 22 to 1 million years agoand was a very successful early representative of the proboscis. Later forms in particular were among the largest land-living mammals of their time. Characteristic of Deinotherium were the downward-pointing tusks of the lower jaw and a structure of the rear dentition, which clearly separates it from later proboscis forms and refers the genus to the primeval proboscis forms. Due to the structure of the molars, a predominant diet of soft plants is assumed. According to anatomical findings, Deinotherium also had a trunk, the length and appearance of which are still the subject of discussion today. The systematic allocation of small representatives, some of which are referred to as Prodeinotherium, is also unclear .

features

Skull of Deinotherium
Deinotherium (artist's impression)

Deinotherium represented a medium-sized to very large proboscis. While early forms, some of which are assigned to the not generally recognized genus Prodeinotherium , still had a relatively small growth and reached shoulder heights between 2 and 2.5 m, late representatives of the genus Deinotherium with 3 , 6 to sometimes over 4 m shoulder height among the largest land mammals of their time. This can also be seen in the weight, which was a good 14 t for the largest representatives. Overall, this proboscis was characterized by an elephant-like skeleton structure with columnar but rather slender limbs, the front legs being longer than the rear legs. Both the hand and foot bones were short and broad in shape, like an elephant. Furthermore, the length of the cervical vertebrae had not yet been reduced so much, so that Deinotherium had a longer neck than today's elephants.

The skull was very elongated and reached a length of 80 to 90 cm in the smaller species and 120 to 130 cm in the larger representatives. The flat forehead, which was still very reminiscent of the older proboscid forms and was significantly higher in later Proboscidians, was very original. For this, the skull bones had the air-filled spaces typical for proboscis to reduce the weight of the head, which is one of the earliest evidence within this order. The protruding intermaxillary bone is also remarkable . The lower jaw was very massive and elongated. It had a typical downward-drawn symphysis , on which the alveoli for the tusks were also located.

Another characteristic feature was the dentition structure , which was generally characterized by a reduction in the number of teeth, especially the incisors , the canines and the premolars per jaw branch. The tooth formula for permanent dentition is therefore; . The individual molars were clearly low-crowned ( brachyodont ) and consisted of several sharp-edged ridges or yokes (lophodont). When chewing, these pointed yokes reached into the “cross valley” of the opposite tooth and thus crushed the food. The first molar had three ridges ( trilophodont ), while the remaining teeth only had two ( bilophodont ). The enamel was particularly thick, sometimes over 5 mm. All teeth of the permanent dentition were in function at the same time, that is, Deinotherium still had the vertical tooth change typical of the other mammals . This clearly distinguishes it from the later proboscis and today's elephants, which have a horizontal tooth change, in which a new tooth only pushes out of the rear part of the jaw when the front is largely worn out.

One of the most distinctive features of this proboscis representative were the tusks located in the lower jaw, which had a downwardly curved shape, with the tips of these teeth partially running almost vertically. In the larger types of Deinotherium , the curvature was also more pronounced and the tips pointed backwards. The German term "tusk elephant" is derived from this shape of the tusks. The tusks were formed from the first incisor. They reached a length of 1.4 m, some of which was still stuck in the alveoli, and were slightly compressed laterally so that they had an oval cross-section. The size of the cross-section varied and was 13 to 17 cm in large animals. The upper tusks, which were and are particularly pronounced in modern elephants as well as in numerous fossil trunk forms ( mammoths , gomphotheria ), were missing.

Fossil record

Deinotherium giganteum in the Antipa Natural History Museum Bucharest ( Romania )
Skeleton reconstruction of Deinotherium in the Natural History Museum Vienna

Deinotherium fossil finds have come down to us from large parts of the ancient world. They are very common in south-eastern Europe, where at least 80 sites with remains of Deinotherium are known, 40 of them in Bulgaria alone . Three quarters of all these fossil deposits contained the remains of large representatives. Of outstanding importance is the almost complete skeleton of a very large Deinotherium , which was found in Eserowo near Plovdiv and is now exhibited in the Natural Science Museum in Sofia . A relatively late find here comes from Aksakovo near Varna . Another, largely completely preserved skeleton of Deinotherium was discovered in Romania in 1894 by the paleontologist Grigoriu Ștefănescu near the town of Mânzați in the Vaslui district and described by him as Deinotherium gigantissimum , a species name that is now invalid. This skeleton is now with a reconstructed size of 4.5 m in the natural history museum Grigore Antipa in Bucharest . In Greece these proboscis are still documented at almost a dozen sites, whereby those with Deinotherium predominate here too . An almost complete skeleton excavated near Siteia on Crete was one of the largest representatives of the Deinotherium genus with a shoulder height of 4.3 m and is now part of the exhibition in the Natural History Museum of Crete in Heraklion . In the northern Black Sea region , a largely complete skeleton of an equally large Deinotherium was discovered in the early 1980s in Obuhovka near Rostov-on-Don ( Russia ). Other significant finds come from Hungary , Portugal , Spain , France and Georgia . In addition, Deinotherium is also known from Turkey , the Arabian Peninsula and the Indian subcontinent, while the most easterly sites are in East Asia . In Africa , the finds are largely concentrated in the eastern ( Kenya , Tanzania , Uganda , Ethiopia ) and northern ( Tunisia , Libya ) continental areas. The finds usually include teeth, but skulls are rare and come from Djebel tents in Libya for smaller forms and from Koobi Fora for larger ones . The most recent finds of Deinotherium in Africa were also discovered. They came to light in Kenya and date to the Old Pleistocene .

There are also numerous finds of Deinotherium in Central Europe . In Germany , remnants are mainly known from the southern parts of the country and come either from the Dinotherien sands of the Mainz basin in Rheinhessen or from the upper freshwater molasses of the Alpine foothills . So far they have been documented at more than 30 sites. The Mainz Basin in particular contained a large number of finds. More than 750 tooth finds have been recovered here alone, which is around 16% of the previously known finds worldwide. The finds spread over a period between 17 and 6 million years, which takes up the majority of the Miocene . One of the most important sites here is the Eppelsheim sand pit ( Rhineland-Palatinate ), where both large and small representatives have been identified. The complete Deinotherium skull discovered here in 1835 had a decisive influence on the understanding of these proboscis. Another important place is Sprendlingen , also in Rhineland-Palatinate, from where 109 almost unweathered teeth come from. In turn, skeletal elements and skeletons that belong together have been discovered from the Molasse Basin. A very extensive skeleton, which belongs to a small form, comes from Langenau near Ulm ( Baden-Württemberg ) and is now exhibited in the State Museum of Natural History in Stuttgart . The skeleton from Unterzolling ( Bavaria ) also represents a small species . Also in Austria is Deinotherium quite often occupied. A partial skeleton of a medium-sized form is known from Gratkorn ( Styria ). The not fully grown, but sexually mature animal weighed about 6 tons during its lifetime. Skeletal remains with a well-preserved lower jaw still come from Kettlasbrunn near Wilfersdorf ( Lower Austria ). In addition, a well-preserved skeleton of a smaller form has come down to us from the Czech Františkovy Lázně .

Paleobiology

In the absence of organic fossil conservation , it is difficult to make further statements about the appearance of Deinotherium . Problems are the length and appearance of the trunk . The shape and size of the nostril as well as the size of the paired infraorbital foramen and the protruding nostril ( naris ) as attachment points suggest the presence of a proboscis. The partially almost horizontal position of the intermaxillary bone on the upper side of the skull disproves the morphological construction, however, that this trunk, which only exists as a muscle tube, reached the length of today's elephants. That is why such an elephant-like trunk was questioned relatively early on. For this reason, some researchers have reconstructed a short, tapir-like proboscis. However, since the later representatives of Deinotherium in particular were very large and had a neck, albeit a longer but comparatively short neck than today's elephants, the trunk must have been at least long enough for the animals to reach the urgently needed drinking water when their heads were lowered . Furthermore, due to the structure of the symphysis of the lower jaw, it is assumed that Deinotherium had a particularly pronounced lower lip .

Both the physique, especially the long, slender legs and the head, which is more mobile due to the slightly longer neck, as well as the structure of the teeth characterize Deinotherium as a inhabitant of forests and alluvial forests . The low crown height of the teeth and their structure of pointed, burr-like transverse ridges with clearly recessed valleys in between are typical for animals that prefer soft plant food, which they simply crush in the teeth. Leaves, twigs and bark were available to them as food resources ( browsing ). Isotope studies on tooth enamel confirmed this assumption. The late species of Deinotherium possibly lived in more open areas or in parklands due to climatic cooling, which would also explain their enormous increase in size.

The function of the downward curved tusks was discussed for a long time. Originally a semi-aquatic way of life was assumed. The tusks were supposed to serve as digging tools in swampy forests. Given the size of the animals and their relatively short neck, a kneeling position would have to be assumed. The tusks probably had a function in feeding. As leaf eaters, they preferred bushes and treetops as sources of food. Presumably twigs and branches were pulled up or held in place with the tusks and then broken off with the trunk and eaten. Furthermore, some tusks show signs of wear or even damage. This wear and tear can be traced back to the peeling of tree bark, while the damage is believed to be related to the splitting or uprooting of trees, similar to what happens with today's elephants. A use of the tusks in sexual or dominance struggles can be excluded due to the shape.

Systematics

Deinotherium provides a genus within the order of Rüsseltiere (Proboscidea), within these, there is the family of deinotheriidae provided. This family includes a very early branch in the trunk of the proboscis, which originated in the Oligocene around 30 million years ago. This is shown above all by the vertical change of teeth, a feature that places them in the earliest radiation phase of the proboscis. It is unclear whether Deinotherium belongs to the most original group, the Plesielephantiformes with two enamel ridges on the first two molars ( bilophodont ), or to the more developed elephantiformes with three or four ridges ( tri- or tetralophodont ). Deinotherium had a trilophodontic first molar, while the two posterior molars were bilophodontic. The more primitive Chilgatherium , which is also one of the Deinotheria, had three ridges on each of the three rear molars. Possibly the bilophodontic second molar of Deinotherium is not an original, but a derived feature, which would support a position within the Elephantiformes.

So far, about 30 species have been described, but most of them are not valid because they are synonyms for previously named representatives. The validity of the existing species is often discussed, the following are often considered valid in the literature (broken down by region):

  • European species:
  • D. giganteum Kaup , 1829
  • D. levius Jourdan , 1861
  • D. proavum Eichwald , 1835
  • D. ( Prodeinotherium ) bavaricum by Meyer , 1831
  • D. ( Prodeinotherium ) cuvieri Kaup , 1832
  • African species:
  • Asian species:
  • D. indicum Falconer , 1868
  • D. ( Prodeinotherium ) pentapotamiae Falconer , 1868
  • D. ( Prodeinotherium ) sinense ( Qiu , Wang , Li , Deng & Sun , 2007)

In Europe in particular, numerous types of synonym have been established in the course of research history, some of which were due to the strong variation in the body size of Deinotherium . Among other things, D. gigantissimum and D. thraceiensis denote larger individuals than D. giganteum , which, however, according to some researchers, had too few deviating characteristics to represent independent species. The same applies to smaller forms such as D. intermedium or D. levius . Investigations on teeth from the entire find area of ​​the genus, which were carried out at the beginning of the 21st century, revealed at least five species for Europe, which more or less followed one another in time and continuously increased in size. Thus, D. Levius a medium-sized shape of the Middle Miocene, whereas D. giganteum heard as large type in the outgoing Miocene. D. proavum in turn represents the largest and latest representatives, the listed taxa D. gigantissimum and D. thraceiensis are to be regarded as synonymous with this. However, there is no agreement as to whether D. proavum or D. gigantissimum should be preferred, but since the name of D. proavum predates in time, even if Eichwald described a supposed tapir, this name is to be regarded as the valid one. The investigation further revealed that the gigantic D. indicum to settlements with finds from Central Asia only a few different dental characteristics to D. proavum owns and therefore conspecific would. The same would apply to the African representative D. bozasi . With this approach it is currently unclear whether two types of Deinotherium lived at the same time, for which further analyzes have to be carried out. A species discovered in China in 2007 shows an intermediate position between the small and large species of Deinotherium in terms of size , but was not taken into account in the studies mentioned.

Compared to Deinotherium , the taxonomic independence of Prodeinotherium is a frequent discussion among experts. The main difference between the two forms is the size of the animals, the development of the third premolar, the shape of the roof of the skull and the structure of the occiput . Some researchers consider these differences to be too small for the formation of two independent genera, which is why I. Gräf in 1957 equated Prodeinotherium with Deinotherium for reasons of priority . Although the assignment Prodeinotherium was reintroduced in 1973 , there has so far been no agreement on the systematic position of this genus. The clarification of the so far unknown origin of the large forms of Deinotherium , whether originated separately again in Africa or emerged continuously from the smaller forms, can contribute to the solution of the question of the independence of both genera.

Tribal history

The tribal history of Deinotherium is characterized by a constant increase in body size, which lasted until the end. The first smaller representatives, sometimes referred to as Prodeinotherium , appeared in the early Miocene almost 22 million years ago. The earliest evidence comes from Kenya (East Africa). More than 18 million years ago, Deinotherium emigrated from Africa to Eurasia due to the formation of the land bridges ( Proboscidean datum event : first emigration of proboscis from Africa) and also reached the Indian subcontinent . Early finds of large representatives of Deinotherium come from France in the middle Miocene 15 million years ago , in Africa the oldest finds of large animals are around 12 million years old and have also been reported from Kenya. Deinotherium was distributed over all three continents of the Old World , unlike other proboscis of the time, it never reached America .

While the small Deinotherium species had already disappeared ten million years ago, the large representatives in Asia survived until the late Miocene seven million years ago, whereas in Europe it only died out in the late Pliocene . The extinction of Deinotherium has been linked to the deterioration in climate at the transition from the Pliocene to the Pleistocene . Due to the increased seasonality of the climate and the spread of steppes , these proboscis may have been deprived of their food source. In Africa it lived until the early Pleistocene a million years ago.

Research history

Johann Jakob Kaup (1803–1873)

The first finds of Deinotherium were probably made near Lyon (France) at the beginning of the 17th century and were later brought to the Muséum national d'histoire naturelle in Paris . There it was assessed in 1715 by the French naturalist René-Antoine Ferchault de Réaumur (1683–1757), but he could not assign it to any animal species he knew. The French vertebrate paleontologist Georges Cuvier initially believed he was looking at the remains of a giant tapir when he was presented with the remains of giant molars in the early 19th century. The name Tapirus gigantesque, which he introduced in 1822, was based on this conception . Johann Jakob Kaup from the Grand Ducal Museum in Darmstadt was the first to reconstruct a lower jaw with tusks in 1829 and gave the new genus the name Deinotherium . That the tusks of the living animal were not bent upwards, but downwards like tusks, Kaup only realized after finding the skull of Eppelsheim. The name Deinotherium is composed of the Greek words δεινός ( deinos , horror) and θηρίον ( thērion , animal), while dino represents the Latinized version of deinos .

For the smaller and historically partly older form, the taxon Prodinotherium was originally established by J. Éhik in 1930 on the basis of finds from Kotyháza and Királd (both Hungarians ), but the original finds have been destroyed. The name Prodeinotherium was first used in 1973 by JM Harris.

Individual evidence

  1. ^ A b c d e Jeheskel 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. ↑ a b c d e f g Ursula B. Göhlich: Tertiary primeval elephants 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. ↑ a b c d e f g h i j k Kati Huttunen: Systematics and Taxonomy of the European Deinotheriidae (Proboscidea, Mammalia). Annalen des. Naturhistorisches Museum zu Wien 103 A, 2002, pp. 237–250.
  5. ↑ a b c d e 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.
  6. ↑ a b c d e Friedrich Bachmayer and Helmuth Zapfe: An important find of Dinotherium from the Pannon of Lower Austria. In: Annalen des Naturhistorisches Museum zu Wien 80, 1976, pp. 145–162.
  7. ↑ a b c d e 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.
  8. ^ 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.
  9. ↑ a b Nikos Poulakakis, Petros Lymberakis and Charalampos Fassoulas: Deinotherium giganteum (Proboscidea, Deinotheriidae) from the Late Miocene of Crete. Journal of Vertebrate Paleontology 25 (3), 2005, pp. 732-736.
  10. ↑ a b I. Vörös: Prodeinotherium petenyii sp. n. from the Lower Miocene at Putnok (North Hungary). Fragmenta Mineralogica et Palaeontologica 14, 1989, pp 101-110.
  11. ^ Georgi N. Markov: The fossil proboscideans of Bulgaria and the importance of some Bulgarian finds - a brief review. Historia naturalis bulgarica 16, 2004, pp. 139-150.
  12. ↑ a b Stoyan Vergiev and Georg N. Markov: A mandible of Deinotherium (Mammalia: Proboscidea) from Aksakovo near Varna, Northeast Bulgaria. Palaeodiversity 3, 2010, pp. 241-247.
  13. ↑ Grigoriu Stefanescu: Deinotherium gigantissimum . Annuarulu Museului de Geologia si de Paleontologia. 1894, pp. 126-199.
  14. ↑ a b c d e Athanassios Athanassiou: On a Deinotherium (Proboscidea) finding in the Neogene of Crete. Notebooks on Geology - Letter 2004/05, pp. 1-7.
  15. ↑ S. Vera Bajgusheva and V. Vadim Titov: About teeth of Deinotherium giganteum Kaup from eastern Paratethys. Hellenic Journal of Geosciences 41, 2006, pp. 177-182.
  16. ↑ a b c d e Miguel Telles Antunes and L. Ginsburg: The Deinotherium (Proboscidea, Mammalia): an abnormal tusk from Lisbon, the Miocene record in Portugal and the first appearance datum. Evidence from Lisbon, Portugal. Ciencias da Terra 15, 2003, pp. 173-190.
  17. ↑ a b B. N. Tiwari, BC Verma and Ansuya Bhandari: Record of Prodeinotherium (Proboscidea: Mammalia) from the Mid-Tertiary Dharmsala-group of the Kangra valley, NW Himalaya, India: Biochronologic and palaeobiogeographic implications. Journal of the Palaeontological Society of India 51 (1), 2006, pp. 93-100.
  18. ↑ a b c Qiu Zhan-Xiang, Wang Ban-Yue, Li Hong, Deng Tao and Sun Yan: First discovery of deinothere in China. Vertebrata Palasiatica 45 (4), 2007, pp. 261-277.
  19. ↑ a b Karol Schauer: Notes and references to 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.
  20. ^ William J. Sanders, Emmanuel Gheerbrant, John M. Harris, Haruo Saegusa and Cyrille Delmer: Proboscidea. In: Lars Werdelin and William Joseph Sanders (eds.): Cenozoic Mammals of Africa. University of California Press, Berkeley, London, New York, 2010, pp. 161-251.
  21. ↑ a b c d e Martin Pickford and Zeinolabedin Pourabrishami: Deciphering Dinotheriensande deinotheriid diversity. Palaeobiodiversity and Palaeoenvironments 93, 2013, pp. 121–150.
  22. ↑ 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.
  23. ↑ a b Manuela Aiglstorfer, Ursula B. Göhlich, Madelaine Böhme and Martin Gross: A partial skeleton of Deinotherium (Proboscidea, Mammalia) from the late Middle Miocene Gratkorn locality (Austria). Palaeobiodiversity and Palaeoenvironments 94, 2014, pp. 49-70.
  24. ↑ Kati Huttunen: On a Prodeinotherium bavaricum (Proboscidea, Mammalia) skeleton from Franzensbad, Czech Republic. Annals of the Natural History Museum in Vienna 105A, 2004, pp. 333–361.
  25. ↑ a b c G. N. Markov, N. Spassov and V. Simeonovski: A reconstruction of the facial morphology and feeding behavior of the deinotheres. In: G. Cavarretta et al. (Eds.): The World of Elephants - International Congress. Consiglio Nazionale delle Ricerche. Rome, 2001, pp. 652-655.
  26. ↑ Thure E. Cerling, John M. Harris and Meave G. Leakey: Browsing and grazing in elephants: the isotope record of modern and fossil proboscideans. Oecologia 120, 1999, pp. 364-374.
  27. ↑ Jehezekel Shoshani: Understanding proboscidean evolution: a formidable task. Tree 13, 1998, pp. 480-487.
  28. ^ 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.
  29. ↑ Jehezekel Shoshani, WJ Sanders and Pascal Tassy: Elephants and other Proboscideans: a summary of recent findings and new taxonomic suggestions. In: G. Cavarretta et al. (Eds.): The World of Elephants - International Congress. Consiglio Nazionale delle Ricerche. Rome, 2001, pp. 676-679.
  30. ↑ a b c Madelaine Böhme, Manuela Aiglstorfer, Dieter Uhl and Ottmar Kullmer: The Antiquity of the Rhine River: Stratigraphic Coverage of theDinotheriensande (Eppelsheim Formation) of the Mainz Basin (Germany). PlosOne 7 (5), 2012, p. E36817.
  31. ↑ George D. Koufos, Nikolaos Zouros and Olga Mourouzidou: Prodeinotherium bavaricum (Proboscidea, Mammalia) from Lesvos island, Greece; the appearance of deinotheres in the Eastern Mediterranean. Geobios 36, 2003, pp. 305-315.
  32. ↑ Denis Geraads, Tanju Kaya and Serdar Mayda: Late Miocene large mammals from Yulafli, Thrace region, Turkey, and their biogeographic implications. Acta Palaeontologica Polonica 50 (3), 2005, pp. 523-544.

Web links

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