Mammoths

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Mammoths
Skeletal reconstruction of a mammoth

Skeleton reconstruction of a mammoth

Temporal occurrence
Upper Oligocene to Upper Pleistocene
27 million years to 10,000 years
Locations
Systematics
Afrotheria
Paenungulata
Tethytheria
Russell animals (Proboscidea)
Elephantimorpha
Mammoths
Scientific name
Mammutidae
Hay , 1922

The Mammutiden (Mammutidae), originally True mastodons called, are an extinct family of mammoths (Proboscidea) from Neogene and Quaternary . Within this, they represent a very primitive form. They were spread over the entire Old World as far as America and only died out there at the end of the Pleistocene around 10,000 years ago.

description

The mammoth body was similar to that of the elephant , but was longer and lower. The receding forehead was characteristic. In contrast to the gomphotheria with their humped tooth pattern, the mammutids had clearly zygodontic molars , that is, the teeth had strong ridges on their chewing surfaces between the paired enamel cusps arranged transversely to the longitudinal axis of the teeth . The deciduous molars and the first two permanent molars each had three ridges ( trilophodont ), while the last molar had four. The tooth morphology suggests a deciduous diet. Early representatives of the mammoths still had four tusks , one pair each in the upper and lower jaws, which, like all proboscis, were formed from the second upper incisor and the first incisor of the lower jaw. Late forms had only upper tusks, while the lower ones were reduced by the shortening of the lower jaw and later no longer developed.

Evolution and species

Artist's impression of a mammoth by Heinrich Harder , probably from 1920 (then known as a mastodon)

The first mammoths developed in Africa from the palaeomastodon . According to molecular genetic studies, they split off from the evolutionary line of today's real elephants in the Upper Oligocene 26 million years ago . The first fossil record comes from this phase with Losodokodon , the form was scientifically introduced in 2009 by D. Tab Rasmussen and Mercedes Gutiérrez on the basis of individual teeth from northwestern Kenya. In the Lower Miocene , around 22 million years ago, the eozygodon appeared, from which the zygolophodon later developed. This genus of proboscis reached Eurasia and finally America around 20 million years ago with the gradual closure of the Tethys Ocean and the formation of a land bridge between Africa and the northern continental masses . It had four tusks, the upper ones curved downwards, while the much smaller lower ones were straight. In the course of development, however, the lower tusks were reduced, while the molars assumed a more zygodontic shape. In Central Europe, finds of the species Zygolophodon turicensis from Elgg ( Canton Zurich ) and Esselborn ( Rhineland-Palatinate ) are known.

The mammoths from the late Miocene, beginning around 10 million years ago, belong to the genus Mammoth . These only had two upper tusks. The generic name Mammut can lead to confusion with Mammuthus , the generic name of the mammoth , an extinct group of elephants (Elephantidae). One of the largest forms was the Eurasian species Mammut borsoni from the Miocene and Pliocene . She reached a shoulder height of 3.5 to just under 4 m. The extremely long, barely curved tusks of this species are remarkable. A recently discovered skeleton from Macedonia ( Greece ) had tusks with a length of 4.5 m. Finds from Kaltensundheim ( Thuringia ) come from Germany , where a partial skeleton was recovered in 1958 and an almost complete skeleton between 1976 and 1978. With Mammut borsoni , the last representative of the mammoths died out in Eurasia in the early Pleistocene around 2.5 to 2 million years ago. The extinction of the proboscis is explained by the increasing cooling of the climate and the spread of steppes in Eurasia during this period , which deprived the specialized leaf-eaters of their food sources.

In America, however, the mammoths existed much longer. The American mastodon ( Mammut americanum ) lived in North America until about 10,000 years ago and was one of the last members of a whole group of primeval proboscis. It reached a shoulder height of about 2.5 m and had a fur to adapt to the cool to cold climate. The tusks were clearly curved upwards. It has been proven by numerous sites in Canada and the USA , but also by some sites in Central America , as is shown by finds from Mexico and Honduras . Around the same time, Mammut pacificus appeared in western North America . This differs from its relative in that the last molars are narrower, the lower tusks are completely absent and there are a few other special features in the skeleton.

Systematics

Originally, the mammoths (sometimes called "real mastodons") were combined with the gomphotheria to form the superfamily of mastodons (Mastodontoidea), which largely goes back to Henry Fairfield Osborn's work at the beginning of the 20th century. This classification is no longer valid today. They now belong within the group of the Elephantiformes to the superfamily Mammutoidea, which is the more primitive sister group of the superfamily Gomphotherioidea (with the Gomphotheria). From the latter, the real elephants (Elephantidae) with the genera still existing today developed over the stegodonts (Stegodontidae). These two groups of proboscis belong to the superfamily Elephantoidea. The family name Mammutidae recognized today goes back to Oliver Perry Hay from 1922, who criticized Osborn in an essay for his choice of names for various groups of proboscis. Hay emphasized that the name Mastodontidae chosen by Osborn for the mammoths was not based on a valid generic name. Hay himself led the group called Mammutinae at the level of a subfamily.

The following genera belong to the mammoth family:

Naming

Molar of Gomphotherium angustidens

The name mastodon is derived from the Greek μαστός ( mastos , "teat" or "breast") and οδον ( odon , "tooth") and refers to the special tooth structure. It was officially introduced in 1817 by the French paleontologist Georges Cuvier . He used it, however, for an animal that is now known as the Gomphotherium angustidens and belongs to the more modern trunk animals from the group of the Gomphotheria . Because of this, this term is rarely used in the specialist literature today and mostly refers to the American mastodon, as a group of trunk animals, the "real mastodons" are called mammoths by experts. The name mammoth (not to be confused with Mammuthus , the genus of mammoths), from which the technical term is derived, goes back to Johann Friedrich Blumenbach , who first mentioned the American mastodon as Mammut ohioticum in his Handbook of Natural History from 1799 .

literature

  • 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.
  • 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.

Individual evidence

  1. ↑ 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.
  2. ↑ Jehezekel Shoshani, Robert C. Walter, Michael Abraha, soap Berhe, Pascal Tassy, William J. Sander, Gary H. Marchant, Yosief Libsekal, Tesfalidet Ghirmai and Dietmar Zinner: A proboscidean from the late Oligocene of Eritrea, a '' missing link '' between early Elephantiformes and Elephantimorpha, and biogeographic implications. PNAS 103 (46), 2006, pp. 17296-17301.
  3. ↑ Nadin Rohland, Anna-Sapfo Malaspinas, Joshua L. Pollack, Montgomery Slatkin, Paul Matheus and Michael Hofreiter: Proboscidean mitogenomics: Chronology and mode of elephant evolution using mastodon as outgroup. PLOSBiology 5 (Aug), 2007, pp. 1663-1671.
  4. ^ A b D. Tab Rasmussen and Mercedes Gutiérrez: A Mammalian fauna from the Late Oligocene of Northwestern Kenya. Palaeontographica Department A 288 (1-3), 2009, pp. 1-52
  5. ↑ a b Ursula B. Göhlich: Tertiary primeval elephants from Germany. In: Harald Meller (Hrsg.): Elefantenreich - Eine Fossilwelt in Europa. Halle / Saale, 2010, pp. 362–372.
  6. ↑ 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.
  7. ↑ Ralf-Dietrich Kahlke: The sequence of plio / Pleistocene mammalian faunas in Thuringia (Central Germany). Cranium 12 (1), 1995, pp. 5-18.
  8. ^ Adrian Lister and Paul Bahn: Mammuts - The Giants of the Ice Age. Sigmaringen, 1997.
  9. ^ G. Haynes and J. Klimowicz: Mammoth (Mammuthus spp.) And American mastodont (Mammut americanum) bonesites: what do the differences mean ?. Deinsea 9, 2003, pp. 185-204
  10. ^ OJ Polaco, J. Arroyo-Cabrales, E. Corona-M. and JG López-Oliva: The American Mastodon Mammut americanum in Mexico. In: G. Cavarretta et al. (Eds.): The World of Elephants - International Congress. Consiglio Nazionale delle Ricerche. Rome, 2001, pp. 237-242.
  11. ↑ Spencer G. Lucas and Guillermo E. Alvarado: Fossil Proboscidea from the Upper Eozoic of Central America: Taxonomy, evolutionary and paleobiogeographic significance. Revista Geológica de América Central, 42, 2010, pp. 9-42.
  12. ↑ Alton C. Dooley Jr, Eric Scott, Jeremy Green, Kathleen B. Springer, Brett S. Dooley, and Gregory James Smith: Mammut pacificus sp. nov., a newly recognized species of mastodon from the Pleistocene of western North America. PeerJ 7, 2019, p. E6614, doi: 10.7717 / peerj.6614 .
  13. ^ Henry Fairfield Osborn: Adaptive radiation and classification of the Proboscidea. PNAS 7, 1921, pp. 231-234.
  14. ↑ a b Jeheskel Shoshani and Pascal Tassy: Advances in proboscidean taxonomy & classification, anatomy & physiology, and ecology & behavior. Quaternary International 126-128, 2005, pp. 5-20.
  15. ↑ Oliver Perry Hay: Further observations on some extinct elephants. Proceedings of The Biological Society of Washington 35, 1922, pp. 97-101 ( [1] )
  16. ^ 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.
  17. ↑ Dimilla Mothé, Leonardo S. Avilla, Desi Zhao, Guangpu Xie and Boyang Sun: A new Mammutidae (Proboscidea, Mammalia) from the Late Miocene of Gansu Province, China. Anais da Academia Brasileira de Ciências 88 (1), 2016, pp. 65-74.
  18. ↑ Shi-Qi Wang, Xiao-Xiao Zhang and Chun-Xiao Li: Reappraisal of Serridentinus gobiensis Osborn & Granger and Miomastodon tongxinensis Chen: the validity of Miomastodon. Vertebrata PalAsiatica 58 (2), 2020, pp. 134–158, doi: 10.19615 / j.cnki.1000-3118.200310 .
  19. ^ Pascal Tassy: Who is who among the Proboscidea? In: Jeheskel Shoshani and Pascal Tassy (eds.): The Proboscidea. Evolution and palaeoecology of the Elephants and their relatives. Oxford, New York, Tokyo, 1996, pp. 40-48.
  20. ↑ Ursula Bettina Göhlich: Elephantoidea (Proboscidea, Mammalia) from the Middle and Upper Miocene of the Upper Freshwater Molasse of Southern Germany: Odontology and Osteology. Munich Geoscientific Treatises Series A 36, Munich, 1998.
  21. ^ Johann Friedrich Blumenbach: Handbook of natural history. Göttingen, 1799 (pp. 697-698).

Web links

Commons : Mammutids (Mammutidae)  - Collection of pictures, videos and audio files