Anancus

Anancus
Skeleton reconstruction in the Paleontological Museum of Florence (Museo Paleontologico di Firenze).
Temporal occurrence
Late Miocene to Lower Pleistocene
7 to 1.8 million years
Locations
Africa Europe Asia
Systematics
Paenungulata Tethytheria Russell animals (Proboscidea) Elephantimorpha Elephantida Anancus
Scientific name
Anancus
Aymard , 1855

Anancus (from Greek :. Toggle = unalloyed and lat . Ancus = curved) is an extinct species of Rüsseltiere and went out of the gomphotheres forth. About ten types are distinguished. With a shoulder height of more than 3.5 meters in some places, anancus is one of the largest genera of the proboscis and lived about 7 to 2 million years ago.

features

Anancus was a large trunk animal and, compared to the gomphotheria, had clearly more developed characteristics in the direction of the real elephants (Elephantidae). He had a short skull with a convex and significantly higher skull roof than that of his ancestral older relatives. The alveoli of the upper tusks were at a clear angle to each other, the tusks themselves reached up to 3 m in length. The lower jaw was significantly shortened, which meant that the lower jaw tusks typical of the gomphotheria were severely atrophied or completely missing.

The dentition was characterized by three bunodontal molars in each branch of the jaw. The two front molars each had four ridges with high enamel cusps at the ends, while the last molar had five or six ridges. What was striking about the teeth of Anancus was that these ridges did not run continuously, but were divided (half yokes) and alternately offset from one another. In primary teeth were still - trained premolars - the last two.

The tusks were almost completely straight, which gave the species of proboscis its name, and up to 3 m long in the larger representatives. Their largely round cross-section distinguished them from the tusks of the gomphotheria, which often had horizontal or vertical compression. A specimen found in the Siwaliks ( Pakistan ) in 2004 had a length of 2.72 m with a maximum diameter of 17.2 cm. Noteworthy are the Schreger lines appearing in cross-section , rosette-like shaped, alternating light and dark colored structures, which go back to a regular change in the collagen content in the dentin . These structures are also found in other trunk animals with large tusks, such as today's elephants , the mammoth, but also in some mastodons. The angles at which the lines regularly meet are very acute in Anancus and thus differ characteristically from those of other species of proboscis.

Distribution and types

The range of Anancus covered large areas of the Old World . The proboscis was widespread throughout Eurasia and penetrated as far as England in the north, and on the Japanese islands in the east . It also occurred relatively frequently in Central Asia. Furthermore anancus in North and Central Africa demonstrated, but for the last region he disappeared relatively early again. Finds of anancus are relatively rare in Central Europe . They are proven in sediments from the Upper Miocene and the Pliocene of Rheinhessen and Hessen . Significant areas of discovery here are above all the Dorn-Dürkheim Formation and the so-called Arvernensis gravel of the Mainz Basin .

Ten types of anancus have been described so far . Their taxonomic independence is not guaranteed in every case, since according to some paleontologists they are partly synonyms . Thus anancus osiris as a synonym of kenyensis anancus or anancus alexeevae as such by anancus arvernensis viewed.

• Anancus alexeevae Baigusheva , 1971, Upper Pliocene, Europe;
• Anancus arvernensis ( Croizet & Jobert , 1828), type species , Pliocene to Lower Pleistocene , Europe;
• Anancus capensis ( Sanders , 2007);
• Anancus kazachstanensis ( Auberkova , 1974), Upper Pliocene, Central Asia;
• Anancus kenyensis ( MacInnes , 1942), late Miocene of Central and East Africa, Pliocene of North Africa;
• Anancus osiris ( Arambourg , 1945), Pliocene, North Africa;
• Anancus perimensis ( Falconer & Cautley , 1847), South Asia (Siwaliks, India);
• Anancus petrocchii ( Coppens , 1965), Upper Miocene, North Africa;
• Anancus sinensis ( Hopwood , 1935), Pliocene, East Asia;
• Anancus sivalensis ( Cautley , 1837), Pliocene South Asia (Siwaliks, Pakistan).

Tribal history

Anancus first appeared at the end of the Miocene about 7 million years ago, replacing the Tetralophodon , from which it is believed to have descended. Both genera are closely related to the gomphotheria. Due to the distinctive structure of the anterior molars with four horizontal ridges, they are also known as "tetralophodont" gomphotheria, while researchers assign the genetically older genuine gomphotheria to the "trilophodont". The bunodonte tooth structure suggests a specialized leaf eater (browser). Some of the later representatives, such as Anancus alexeevae , also showed adaptations to open landscapes. Anancus disappeared again in the lower Pleistocene around 1.8 million years ago . The extinction of this genus of proboscis is probably causally related to the climatic changes at the transition from the Pliocene to the Pleistocene, which favored the spread of open landscapes with the formation of steppes in large parts of Eurasia.

Taxonomy

In the first half of the 19th century, Auguste Aymard, curator at the Musée Crozatier in Le Puy-en-Velay in France, repeatedly found teeth and bones of mastodons, including a species that he later called Anancus macroplus called. A bone of the metacarpus and two molars were described in the Bulletin de la Société Géologique de France in 1847 , but without mentioning the name Anancus . The paleontology was then still in its initial phase, however, it came true for compiling a list of the discovered by Auguste Aymard species at a meeting of the Societe Academique in January 1855 and a mention in the writings of the Congrès Scientifique de France 1855, no valid First description of the genus Anancus or the species Anancus macroplus . The fossils of the mastodons were kept in the Musée Croizet along with other early Pleistocene mammal remains from the Auvergne . In 1859 Edouard Lartet compared the teeth labeled Anancus macroplus with those of Mastodon arvernensis , which had been described by Jean-Baptiste Croizet and Antoine Claude Gabriel Jobert in 1828 . Although Croizet and Jobert had only found milk teeth, Lartet found that they had the same structure as that of Anancus macroplus . The previously discovered Mastodon arvernensis was therefore newly combined the type species of the genus Anancus and the name to Anancus arvernensis . The year of the first description of Anancus is usually given as 1855, but many palaeontologists are of the opinion that this genus was only validly described by Lartet's work in 1859.

Originally, anancus was seen as a genus within the gomphotheria of the superfamily Gomphotherioidea. Due to recent investigations, including by Jeheskel Shoshani and Pascal Tassy, ​​it was separated from this group again and, because of its more modern skull structure, placed on the basis of the elephantoidea superfamily, which was further developed compared to the gomphotheria, to which the stegodonts and today's elephants also belong. An assignment to a specific family has not yet been made ( family incertae sedis ). However, some paleontologists stick to the traditional structure and leave anancus with the gomphotheries.

Individual evidence

1. ↑ MP Ferretti and RV Croitor: Functional morphology and ecology of Villafranchian Proboscideans from Central Italy. In: G. Cavarretta et al. (Ed.): The World of Elephants - International Congress. Consiglio Nazionale delle Ricerche (Rome), 103-108
2. ↑ ^{a b c} Ursula B. Göhlich: Tertiary primeval elephants from Germany. In: Harald Meller (Hrsg.): Elefantenreich - Eine Fossilwelt in Europa. Halle / Saale, 2010, pp. 362–372
3. ↑ В. В. Титов: Крупные млекопитающие позднего плиоцена Зеверо-Восточного Приазовья. (Rostov on Don) 2008
4. ↑ ^{a b c d e f g} Muhammad Akbar Khan, George Iliopoulos, Muhammad Akhtar, Abdul Ghaffar and Zubaid-ul-Haq: The longest tusk of cf. Anancus sivalensis (Proboscidea, Mammalia) from the Tatrot Formation of the Siwaliks, Pakistan. Current science 100 (2), 2011, pp. 249-255
5. ↑ Maria Rita Palombo: Elephantinae identification by means of Schreger patterns. http://www.incentivs.uni-mainz.de/downloads/AnnualMeeting2006/AM2006_palombo.pdf
6. ↑ IA Vislobokova and MV Sotnikova: Pliocene faunas with Proboscideans of the Former Soviet Union. In: G. Cavarretta et al. (Ed.): The World of Elephants - International Congress. Consiglio Nazionale delle Ricerche (Rome), 157–160
7. ↑ ^{a b c d} 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. ^ E. Schweizerbart: New Yearbook for Geology and Palaeontology : Monthly Issues: Volume 1996, Issue 1. P. 710–711
9. ↑ 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
10. ^ Société Géologique de France: Séance du January 11, 1847. Bulletin de la Société Géologique de France, 2e sér., IV, 1, pp. 405-421, 1847, pp. 414-415
11. ↑ J. Dorlhac: Cratère you Coupet . Annales de la Société d'agriculture, sciences, arts et commerce du Puy, XIX, pp. 497-517, (1854), 1855, p. 507
12. ^ Congrés Scientifique de France 1855. I, 1856, p. 241 and p. 271
13. ↑ Edouard Lartet: Sur la dentition des proboscidiens fossiles (″ Dinotherium ″, mastodontes et éléphants), et sur la distribution de leurs débris en Europe . Bulletin de la Société géologique de France, séance du 21 mars 1859. 2nd série. T. XVI, pp. 469-516, 1859, p. 493
14. ^ Henry Fairfield Osborn: Proboscidea: a monograph of the discovery, evolution, migration and extinction of the mastodonts and elephants of the world. 1936, p. 631
15. ↑ Jehezekel Shoshani and Pascal Tassy: Advances in proboscidean taxonomy and classification, anatomy & physiology, and ecology and behavior. Quaternary International 126-128, 2005, pp. 5-20

literature

• Alan Turner, Mauricio Antón: Evolving Eden. An Illustrated Guide to the Evolution of the African Large Mammal Fauna. Columbia University Press, New York NY 2004, ISBN 0-231-11944-5 .
• Jordi Augusti, Mauricio Antón: Mammoths, Sabertooths, and Hominids. 65 Million Years of Mammalian Evolution in Europe. Columbia University Press, New York NY et al. 2002, ISBN 0-231-11640-3 .

Web links

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

• The Paleobiology Database: Anancus