African elephants

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African elephants
African elephant family group (Loxodonta africana) in the Serengeti

Family group of African elephants ( Loxodonta africana ) in the Serengeti

Systematics
Superordinate : Afrotheria
without rank: Paenungulata
without rank: Tethytheria
Order : Russell animals (Proboscidea)
Family : Elephants (Elephantidae)
Genre : African elephants
Scientific name
Loxodonta
Anonymous, 1827

The African elephants ( Loxodonta ) are a genus of elephants (Elephantidae). With the African elephant ( L. africana ) and the forest elephant ( L. cyclotis ) it contains two of the three recent elephant species. The third represents the Asian elephant ( Elephas maximus ), which differs from the elephants of Africa in several anatomical details. Both species occur on the African continent . The former inhabits a variety of different landscapes, the latter is at home in wooded habitats . The animals live in social groups with complex relationships and varied communication. They migrate in an annual rhythm that is largely determined by the food supply. Hard and soft parts of the plant form the basis of nutrition, the composition of the food varies regionally and seasonally. Reproduction takes place all year round, with one calf being born per mother. The rutting of the cows starts at intervals of several years, bulls come to the Musth once a year . The tribal history of the African elephants goes back several million years. They differentiated themselves as a genus in the transition from the Miocene to the Pliocene . Several extinct species have been documented, all of which had an African distribution area. The generic name that is valid today was established in 1827, but is based on an older name suggestion. The entire population of African elephants is considered to be endangered.

features

Habitus

Comparison of the head and front part of the body of Asian (1) and African (2) elephants

The two current species of the genus Loxodonta are characterized by the typical physique of the elephant, which consists of a compact body with columnar legs, short neck and massive head with tusks in the upper row of teeth and typical trunk formation . The African elephant ( Loxodonta africana ) is the larger of the two representatives and represents the largest land-living mammal of today, the forest elephant ( Loxodonta cyclotis ) is smaller and can be regarded as a typical form of forest. The African elephants differ from the Asian elephant ( Elephas maximus ) primarily through individual external characteristics. In terms of body size, the Asian elephant stands between the other two species. The anatomical differences include the higher shoulders. The highest point of the African elephants are the shoulders, the back is concave. In the Asian elephant, however, the highest point is the head, while the back is straight or convex. The ears of the African elephant are, in relation to the head, much larger than those of the Asian elephant. On the tip of the trunk, African elephants have two opposite trunk fingers, while the Asian elephant has only one. In addition, in Loxodonta both sexes usually have pronounced tusks , in the Asian elephant often only the bulls. In all elephants today, the hands and feet each have five rays with a sixth additional ray of cartilage ( prepollex and prehallux ). They are embedded in a round to oval sole without externally separated fingers or toes. On the front outside, however, there are nail-like structures, the number of front and rear feet of which are often used to differentiate between species. However, the number varies greatly. The African elephant often has four on its hands and three on its feet. Within individual populations , however, the value varies between five and four on the front feet and three and four on the rear feet. The corresponding values ​​for the forest elephant are five in front and four in the back, as is the case with the Asian elephant.

Skull and dentition features

In terms of skull anatomy and tooth morphology, the African elephants represent the more conservative forms compared to the Asian elephants. All members of the genus Loxodonta have a rounded skull that does not appear as stretched upwards as the Asian elephant. When viewed from the front, the forehead line bulges or runs largely straight, while the Asian elephant has two humps there with a deep indentation in between. Further features are found in the parietal bones that are not elongated and the alveoli of the upper tusks, which diverge at the end . A noticeable characteristic of all elephant species can be found in the air-filled, honeycomb-shaped chambers that fill the top of the skull. This pneumatization increases the surface area of ​​the skull, which means that more surface area is available for the neck and masticatory muscles, while at the same time reducing the total weight of the skull. Compared to the Asian elephant, the lower jaw has an elongated, horizontal bone body. The ascending branch strives vertically upwards, while the crown process is located in the second half of the lower jaw. In the Asian elephant, the ascending branch is directed inwards and the crown process rises above the middle of the strongly compressed horizontal bone body. The symphysis at the front end of the lower jaw is oriented forward in the representatives of the genus Loxodonta and not downward as in the Asian cousin.

Comparison of the molars of elephants. Above: African elephant. Middle: Asian elephant. Below: woolly mammoth

The dentition shows the typical structure of the elephant. In the front set of teeth it is composed of the upper tusks, which represent the second incisor , and in the rear set of three premolars and three molars per jaw arch. The tooth formula is therefore:, The number of teeth is 26. Due to the shape of the tusk alveoli, the tusks of the African elephants protrude laterally downwards. They are also slightly curved over their entire length and not only in the last third, as in the Asian elephant. In the rear dentition the teeth are changed horizontally , a typical characteristic of many proboscis, which differs from the vertical change of teeth in most other mammals. As a result, there is usually only one or one and a half teeth per jaw branch in the chewing position at the same time, a subsequent tooth is pushed out by chewing the preceding tooth. The horizontal change of teeth means that today's elephants can change the tooth in each jaw arch five times in the course of their life and after the eruption of the first tooth. In general, the back teeth of elephants are characterized by a lamellar structure consisting of several enamel folds lying one behind the other . In the African elephant, the enamel folds are thicker and less tightly set than in the Asian elephant, so that the latter has more on average. The lamella formula of the African elephant is 4 to 5 (number of lamellae per 10 cm tooth length), 10 to 14 enamel folds can occur on the last molar. The most striking difference between the African elephant and the Asian elephant is the diamond-shaped bulge of the enamel folds in the middle . The teeth are also less high-crowned than in the Asian elephant, the height of a tooth only slightly exceeds its width.

distribution

Distribution of the African elephants (genus Loxodonta ) in 2007

The African elephants are today at the Africa south of the Sahara limited. The African elephant inhabits a wide variety of landscapes, ranging from partially closed forests to open grass and savannah landscapes , wet areas such as floodplains or swamps to desert-like areas and can be located in lowlands as well as in higher mountain regions up to over 4000 m. Its distribution area includes the eastern , southern and western parts of the continent . The forest elephant , on the other hand, is adapted to the tropical rainforests of central and western Africa. Both elephant species hybridize in the contact area of ​​their respective habitats. The total area inhabited by the African elephants is given as around 5.2 million square kilometers, but this only accounts for around 20% of the usable habitat.

Way of life

Territorial behavior

The way of life of the African elephants has been extensively researched, especially for the larger savanna form, and to a lesser extent for the smaller forest form. The animals live in social associations, the core unit is the herd or family group consisting of one or more, often related cows and their offspring. The herd is led by a lead cow, the individual ranks are organized linearly. As a result, the oldest daughter usually takes over the group after the lead cow dies. Sometimes larger associations can then split up into individual smaller ones. Several herds, in turn, form higher-level clans that often use similar action areas . The individual family groups that belong together meet at certain intervals and separate again after a while. The way of life is referred to as a fission-fusion social community (“separating and coming together”). The bulls of the African elephant in turn form "bachelor groups", while those of the forest elephant usually live solitary. The action spaces have different dimensions depending on the landscape. They are generally more extensive in open areas, with the largest in dry to desert habitats. In contrast, they are smaller in size in forest habitats. Communication within the herd and between the various herds takes place by means of vocalisation in the low-frequency range. Warning calls are mostly in a wave range that can also be heard by humans. Otherwise there is a wide range of different gestures and postures, which also serve to communicate with one another, as well as chemical signals are perceived via the feces and urine . African elephant activity can be seen both during the day and at night.

nutrition

Forest elephant ( Loxodonta cyclotis ) in Ivindo National Park , Gabon

The African elephants feed on mixed plant-based food ( mixed feeder ), with hard grass food being preferred when fresh in the rainy season. Softer plants such as leaves or fruits dominate in the dry season. The exact composition of the food depends on regional conditions, which means that there is great geographical variability. The availability of different food plants also determines the migration behavior of the family groups. The African elephants spend a large part of their daily time budget eating. They are also important spreaders of seeds that they excrete in the faeces. Mineral leaks and water are also of great importance.

Reproduction

The reproduction takes place all year round, regional but seasonal accumulations can occur. Bulls have an annual musth that sets in individually and the duration of which increases with the age of the animals. The Musth can be recognized, among other things, by secretions from the temporal glands . During the musth, bulls can be very aggressive and fight dominance fights. The mating cycle of the cows, on the other hand, follows an interval of several years. As a result, cows willing to mate are rather rare within a population and the bulls go on the move and visit several herds. There they advertise for cows that are ready to breed. The gestation period lasts about 660 days. As a rule, a calf is born and the birth takes place in the family group. Often the entire herd takes care of the offspring, in some cases older female siblings take over the supervision ("allomaternal care"). However, the dams only nurse their own calves. Female young animals reach sexual maturity at around 14 years of age, while males leave the maternal herd around the same time. Their reproductive activities do not begin until later, as they are not yet fully grown at this point and therefore cannot compete with the old bulls. They go through their first musth when they are around 29 years old. The maximum age for both sexes is assumed to be around 60 to 65 years, but in the wild it is usually below that.

Systematics

Internal systematics of today's elephants according to Meyer et al. 2017
 Elephantidae  
  Loxodonta  

 Loxodonta africana


   

 Loxodonta cyclotis



   

 Elephas



Template: Klade / Maintenance / Style

The African elephant ( Loxodonta ) are a genus within the family of elephants (Elephantidae), in turn, to the order of the mammoths belongs (Proboscidea). They represent the sister taxon of the genus Elephas with the Asian elephant ( Elephas maximus ) as the only member. Together, both genera belong to the subfamily of the Elephantinae . Here the African elephants are referred to the tribe of the Loxodontini , the Asian elephant, however, to the tribe of the Elephantini . The trunk animals themselves form a very old group of originally African animals. Its origins can be traced back around 60 million years. In the course of their tribal history, they proved to be very rich in shape with diverse adaptations to different biotopes and climatic regions. The proboscis spread over large parts of Eurasia and America . In contrast, the elephants are to be seen as a relatively young line of development. Its earliest records date back to the late Miocene around 7 million years ago. According to molecular genetic studies, the African and Asian elephants separated from each other around 7.6 million years ago.

The genus Loxodonta contains two recent species:

The African elephant is the larger of the two representatives and occurs mainly in open savannah landscapes , but can also be found in forests and in desert-like regions. The forest elephant represents the smaller species and is restricted to the rainforests of central and western Africa. The lines of the two species differentiated from a genetic point of view 5.6 to 2.6 million years ago.

In addition to the two recent representatives, some extinct species are recognized:

According to recent genetic data from 2017, the relationships within the genus Loxodonta and to other members of the family seem to be relatively complex. DNA samples from the bones of the European forest elephant ( Palaeoloxodon antiquus ) around 200,000 years old have shown that it is closer to the forest elephant of western Africa than the African elephant. Relationships to the African elephant and in addition to the genus Mammuthus also occur subordinately . This is explained by possible mix-ups between representatives of Palaeoloxodon , Loxodonta and Mammuthus in the early phase of their tribal development.

Frédéric Cuvier

The generic name Loxodonta goes back to Frédéric Cuvier in 1825. He used them in a two-sided portrait of the African elephant within the work Histoire naturelle des mammifères published by him and Étienne Geoffroy Saint-Hilaire between 1824 and 1842 . In it he set the African elephant apart from its Asian relatives due to different tooth features and underpinned this with the new generic name, which he gave as Loxodonte . F. Cuvier decided not to Latinize his proposed name, which is why his authorship is not recognized according to the rules of zoological nomenclature . In 1827 a review of the Histoire naturelle des mammifères appeared without giving an author's name. In this review, the name of the genus is correctly rendered with Loxodonta . Nicholas Aylward Vigors is partly suspected of being the author , as he was the editor of the magazine in which the review was printed at the time. In some specialist articles there is therefore the reference to Loxodonta Vigors , 1827. The name Loxodonta is derived from the Greek words λοξός ( loxos for “oblique”) and ὀδούς ( odoús for “tooth”). It refers to the diamond-shaped expression of the enamel folds on the chewing surface.

Tribal history

The earliest fossil record of the genus Loxodonta dates to the end of the Miocene and the beginning of the Pliocene around 7 to 5 million years ago. These are individual isolated teeth from the Lukeino Formation and the Chemeron Formation in the Tugen Mountains in Kenya and from the Nkondo-Kaiso region in the western rift system in Uganda in eastern Africa. They already show the typical diamond-shaped expansion of the melting folds of the African elephants. Their age is 6.2 to 4.0 million years. It is possible that they are identical to Loxodonta cookei , which is known from finds from south-western Africa, more precisely from the Varswater formation at the Langebaanweg site in South Africa . Here, too, mostly isolated teeth plus individual jaw remains have been handed down. The shape is characterized by primeval molars with low crowns, the height of which was less than their width. They also had thick enamel lamellae, the frequency of the lamellae was low (4), and there were a total of seven to eight lamellae on the last molar. The presence of permanent posterior premolars can also be rated as relatively primitive. After isotope analyzes that have been made on the teeth, is fed Loxodonta cookei significantly more flexible than the simultaneously occurring here anancus and moved next leaf diet also grasses with one. Loxodonta adaurora occurred much more frequently than Loxodonta cookei during the Pliocene . First described on the basis of an almost complete skeleton from the Lower Pliocene of Kanapoi in Kenya, two types are distinguished in shape. In addition to the nominate form L. a. adaurora exists with L. a. kararae a dwarf form from Koobi Fora, again Kenya, and from the find area on the Omo River in Ethiopia . In addition to the relatively low tooth crowns and the wide enamel lamellae, which result in a lamella formula of 2.5 to 4 with a maximum of ten lamellae on the last molar, the teeth of Loxodonta adaurora are characterized by a less pronounced diamond-shaped expansion of the enamel lamellae. This implies that Loxodonta adaurora possibly represents an early split within the genus Loxodonta and therefore does not belong in the direct ancestral line of today's African elephants. In the further structure of the skull, Loxodonta adaurora was similar to today's African elephants, but the facial area was wider, the alveoli for the upper tusks more expansive and the frontal bone more elongated.

Two molars from Loxodonta atlantica , above the second lower molar, below the third upper molar (24 and 32.4 cm long, respectively)

Loxodonta atlantica is documented from the Pliocene and the Pleistocene of northern, eastern and southern Africa . This extremely large member of the genus was larger than today's African elephants. This can be seen from the size of the lower last molar, which is on average 35 cm long in Loxodonta atlantica , but on average 21 cm long in Loxodonta africana . Of all members of Loxodonta , Loxodonta atlantica is probably the most modern form. The teeth were very high crowned with a height twice as large as the width, which is far more striking than that of today's African elephant. In addition, they had 10 to 15 enamel folds on the last molar, which is more than today's African species. The frequency of the lamellae was 3.4 to 5.4. The skull largely corresponded to that of the recent representatives, differences concern the larger occipital joints and the narrower mid-jaw region. Was introduced Loxodonta atlantica of Auguste Pomel In 1879, based on molar teeth and tusk fragments from Terni Fine in northern Algeria . Today, two geographically separated subspecies are distinguished: on the one hand L. a. atlantica from northern Africa, on the other hand L. a. Zulu from the southern. The latter had significantly thinner enamel lamellae. For a third form, L. a. angammenis from the Lower Pleistocene of Angamma-Yayo in Chad , a position within the species Loxodonta atlantica is controversial because its tooth features are noticeably more original. The first person to describe the subspecies, Yves Coppens , therefore later speculated that this could be an early form of the African elephant. Overall, Loxodonta atlantica appears to be too developed to be part of the ancestral line of today's species. Presumably it is a specialized grass-eater that shows individual parallel developments to the genus Elephas . Loxodonta exoptata , which occurred in the Lower and Upper Pliocene in eastern Africa, could be a possible precursor of the African elephant . The species was named by Wilhelm Otto Dietrich in 1942 , based on around 100 tooth finds from the southern Serengeti . Although Dietrich led his new species within the genus Archidiskodon (today mostly equated with Mammuthus ), he recognized the close relationship with Loxodonta . In the course of research history, Loxodonta exoptata was partially equated with Loxodonta adaurora as well as with Palaeoloxodon recki , today it is again considered independent. The skull is so far unknown, the molars were less high crowned than in Loxodonta atlantica , their height was only slightly larger than their width, but significantly higher than in Loxodonta cookei . The lamella frequency was 4.1 to 5.5 with a maximum of eleven to twelve lamellae on the last molar. As a result, the enamel was only moderately thick compared to Loxodonta cookei . The most important finds so far came to light in Laetoli in Tanzania. Since Palaeoloxodon recki is missing here, which was more adapted to dry climates, a more humid living environment was originally reconstructed for Loxodonta exoptata . In the meantime, interpretations of the paleontological findings by Laetoli have given a more diverse picture, ranging from semi-arid bush lands to closed forests. It is possible that Loxodonta exoptata, like today's African elephant and numerous early elephant forms that are now extinct, specialized in a mixed vegetable diet.

Fossil finds of the African elephant date back to the Middle Pleistocene of eastern and northern Africa, some remains from southern Africa are somewhat more recent. The forest elephant has no fossil record.

Threat and protection

The population of both species of African elephant is threatened by poaching , predominantly transported by hunting for ivory . Added to this is the destruction of the environment and the spread of the human population, which results in the fragmentation of habitable habitats. The IUCN does not list the two current representatives separately, but considers the African elephants as the only species. According to the environmental protection organization, the entire population is considered "endangered" ( vulnerable ). Since 1989, the total population has been listed in Appendix I of the Washington Convention on the Protection of Species (CITES), which means that commercial trade in animals is prohibited, even if individual loosening has taken place regionally since then. Both the African elephant and the forest elephant are represented in numerous nature reserves.

literature

  • Larry Laursen, Marc Bekoff: Loxodonta africana. (= Mammalian Species. 92). 1972.
  • William J. Sanders, Emmanuel Gheerbrant, John M. Harris, Haruo Segusa, Cyrille Dellmer: Proboscidea. In: Lars Werdelin, William Joseph Sanders (eds.): Cenozoic Mammals of Africa. University of California Press, Berkeley / Los Angeles / London 2010, pp. 161–251.
  • Pascal Tassy, ​​Jehehskel Shoshani: Genus Loxodonta African Elephants. In: Jonathan Kingdon, David Happold, Michael Hoffmann, Thomas Butynski, Meredith Happold, Jan Kalina (Eds.): Mammals of Africa Volume I. Introductory Chapters and Afrotheria. Bloomsbury, London 2013, pp. 178-180.
  • G. Wittemyer: Family Elephantidae. In: Don E. Wilson, Russell A. Mittermeier (eds.): Handbook of the Mammals of the World. Volume 2: Hooved Mammals. Lynx Edicions, Barcelona 2011, ISBN 978-84-96553-77-4 , pp. 50-79.

Individual evidence

  1. ↑ GE Weissengruber, GF Egger, JR Hutchinson, HB Groenewald, L. Elsässer, D. Famini, G. Forstenpointner: The structure of the cushions in the feet of African elephants (Loxodonta africana). In: Journal of Anatomy. 209, 2006, pp. 781-792.
  2. ↑ John R. Hutchinson, Cyrille Delmer, Charlotte E. Miller, Thomas Hildebrandt, Andrew A. Pitsillides, Alan Boyde: From Flat Foot to Fat Foot: Structure, Ontogeny, Function, and Evolution of Elephant “Sixth Toes”. In: Science. 334, 2011, pp. 1699-1703.
  3. ^ Ian SC Parker, Alistair D. Graham: The African elephants' toe nails. In: Journal of East African Natural History. 106 (1), 2017, pp. 47–51.
  4. ^ A b c Larry Laursen, Marc Bekoff: Loxodonta africana. (= Mammalian Species. 92). 1972.
  5. ↑ a b c d Pascal Tassy, ​​Jehehskel Shoshani: Genus Loxodonta African Elephants. In: Jonathan Kingdon, David Happold, Michael Hoffmann, Thomas Butynski, Meredith Happold, Jan Kalina (Eds.): Mammals of Africa Volume I. Introductory Chapters and Afrotheria. Bloomsbury, London 2013, pp. 178-180.
  6. ^ A b Nancy E. Todd: Qualitative Comparison of the Cranio-Dental Osteology of the Extant Elephants, Elephas Maximus (Asian Elephant) and Loxodonta africana (African Elephant). In: The Anatomical Record. 293, 2010, pp. 62-73.
  7. ↑ a b c d e f William J. Sanders, Emmanuel Gheerbrant, John M. Harris, Haruo Segusa, Cyrille Dellmer: Proboscidea. In: Lars Werdelin, William Joseph Sanders (eds.): Cenozoic Mammals of Africa. University of California Press, Berkeley / Los Angeles / London 2010, pp. 161–251.
  8. ^ Régis Debruyne: A case study of apparent conflict between molecular phylogenies: the interrelationships of African elephants. In: Cladistics. 21, 2005, pp. 31-50.
  9. ↑ Yumie Murata, Takahiro Yonezawa, Ichiro Kihara, Toshihide Kashiwamura, Yuji Sugihara, Masato Nikaidoa, Norihiro Okada, Hideki Endo, Masami Hasegawa: Chronology of the extant African elephant species and case study of the species identification of the small African elephant with the molecular phylogenetic method. In: Genes. 441, 2009, pp. 176-186.
  10. Jump up ↑ Samrat Mondol, Ida Moltke, John Hart, Michael Keigwin, Lisa Brown, Matthew Stephens, Samuel K. Wasser: New evidence for hybrid zones of forest and savanna elephants in Central and West Africa. In: Molecular Ecology. 24, 2015, pp. 6134-6147.
  11. ↑ a b J. Blanc: Loxodonta africana. The IUCN Red List of Threatened Species 2008. e.T6410A21282601 ( [1] ), accessed October 24, 2018
  12. ^ A b c Larry Laursen, Marc Bekoff: Loxodonta africana. (= Mammalian Species. 92). 1978, pp. 1-8.
  13. ↑ a b c Ian Whyte: Loxodonta africana (Blumenbach1797) - African savanna elephant. In: John D. Skinner, Christian T. Chimimba (Eds.): The Mammals of the Southern African Subregion. Cambridge University Press, 2005, pp. 51-59.
  14. ↑ a b c G. Wittemyer: Family Elephantidae. In: Don E. Wilson, Russell A. Mittermeier (eds.): Handbook of the Mammals of the World. Volume 2: Hooved Mammals. Lynx Edicions, Barcelona 2011, ISBN 978-84-96553-77-4 , pp. 50-79 (p. 77).
  15. ↑ a b c Joyce Poole, Paula Kahumbu, Ian Whyte: Loxodonta africana Savanna Elephant (African Bush Elephant). In: Jonathan Kingdon, David Happold, Michael Hoffmann, Thomas Butynski, Meredith Happold, Jan Kalina (Eds.): Mammals of Africa Volume I. Introductory Chapters and Afrotheria. Bloomsbury, London 2013, pp. 181–194.
  16. ↑ a b c Andrea Turkalo, Richard Barnes: Loxodonta cyclotis Forest Elephant. In: Jonathan Kingdon, David Happold, Michael Hoffmann, Thomas Butynski, Meredith Happold, Jan Kalina (Eds.): Mammals of Africa Volume I. Introductory Chapters and Afrotheria. Bloomsbury, London 2013, pp. 195-200.
  17. ↑ a b Matthias Meyer, Eleftheria Palkopoulou, Sina Baleka, Mathias Stiller, Kirsty EH Penkman, Kurt W. Alt, Yasuko Ishida, Dietrich Mania, Swapan Mallick, Tom Meijer, Harald Meller, Sarah Nagel, Birgit Nickel, Sven Ostritz, Nadin Rohland , Karol Schauer, Tim Schüler, Alfred L Roca, David Reich, Beth Shapiro, Michael Hofreiter: Palaeogenomes of Eurasian straight-tusked elephants challenge the current view of elephant evolution. In: eLife. 6, 2017, S. doi: 10.7554 / eLife.25413
  18. ↑ a b Jehezekel Shoshani: Taxonomy, Classification, History, and Evolution of Elephants. In: Murray Fowler, Susan K. Mikota (Eds.): Biology, Medicine, and Surgery of Elephants. Blackwell Publishing, 2006, pp. 3-14.
  19. ^ 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.
  20. ↑ Jehezekel Shoshani, Pascal Tassy: Family Elephantidae Elephants. In: Jonathan Kingdon, David Happold, Michael Hoffmann, Thomas Butynski, Meredith Happold, Jan Kalina (Eds.): Mammals of Africa Volume I. Introductory Chapters and Afrotheria. Bloomsbury, London 2013, pp. 176-178.
  21. ↑ a b Nadin Rohland, Anna-Sapfo Malaspinas, Joshua L. Pollack, Montgomery Slatkin, Paul Matheus, Michael Hofreiter: Proboscidean Mitogenomics: Chronology and Mode of Elephant Evolution Using Mastodon as Outgroup. In: PLoS Biology. 5 (8), 2007, p. E207 doi: 10.1371 / journal.pbio.0050207
  22. ↑ a b Nadin Rohland, David Reich, Swapan Mallick, Matthias Meyer, Richard E. Green, J. Nicholas Georgiadis, Alfred L. Roca, Michael Hofreiter: Genomic DNA Sequences from Mastodon and Woolly Mammoth Reveal Deep Speciation of Forest and Savanna Elephants. In: PLoS Biology. 8 (12), 2010, p. E1000564 doi: 10.1371 / journal.pbio.1000564
  23. ↑ Don E. Wilson, DeeAnn M. Reeder (Ed.): Mammal Species of the World. A taxonomic and geographic reference. Johns Hopkins University Press, Baltimore, Md., 2005, ISBN 0-8018-8221-4 ( departments.bucknell.edu )
  24. ↑ Eleftheria Palkopoulou, Mark Lipson, Swapan Mallick, Svend Nielsen, Nadin Rohland, Sina Baleka, Emil Karpinski, Atma M. Ivancevic, Thu-Hien To, R. Daniel Kortschak, Joy M. Raison, Zhipeng Qu, Tat-Jun Chin, Kurt W. Alt, Stefan Claesson, Love Dalén, Ross DE MacPhee, Harald Meller, Alfred L. Roca, Oliver A. Ryder, David Heiman, Sarah Young, Matthew Breen, Christina Williams, Bronwen L. Aken, Magali Ruffier, Elinor Karlsson , Jeremy Johnson, Federica Di Palma, Jessica Alfoldi, David L. Adelson, Thomas Mailund, Kasper Munch, Kerstin Lindblad-Toh, Michael Hofreiter, Hendrik Poinar, David Reich: A comprehensive genomic history of extinct and living elephants. In: PNAS. 2018 doi: 10.1073 / pnas.1720554115
  25. ^ Fréderic Cuvier: Eléphant d'Afrique. In: Étienne Geoffroy Saint-Hilaire, Fréderic Cuvier (ed.): Histoire naturelle des mammifères: avec des figures originales, coloriées, dessinées d'après des animaux vivans. Tome sixième. Paris 1825. ( biodiversitylibrary.org )
  26. ↑ Anonymous: Histoire naturelle des mammifères: avec des figures originales, coloriées, dessinées d'après des animaux vivans; & c. by MM. Geoffroy Saint-Hilare and F. Cuvier. Livraisons 52de et 53eme. In: The Zoological Journal. 3, 1827, pp. 140-142. ( biodiversitylibrary.org )
  27. ↑ Miklós Kretzoi: Stegeloxodon nov. gen., a loxodonta elefántok esetleges ázsiai öse (Stegoloxodon nov. gen., a possible Asiatic ancestor of true loxodonts). In: Földtani Közlöny. 80, 1950, pp. 405-408.
  28. ↑ Jehezekel Shoshani, Pascal Tassy (ed.): The Proboscidea. Evolution and palaeoecology of the Elephants and their relatives. Oxford / New York / Tokyo 1996, p. 361 (Appendix C)
  29. ^ William J. Sanders: Taxonomic review of fossil Proboscidea (Mammalia) from Langebaanweg, South Africa. In: Transactions of the Royal Society of South Africa. 62 (1), 2007, pp. 1-16.
  30. ^ William J. Sanders: Horizontal tooth displacement and premolar occurrence in elephants and other elephantiform proboscideans. Historical Biology 30 (1–2), 2018, pp. 137–156, doi: 10.1080 / 08912963.2017.1297436
  31. ↑ Patricia A. Groenewald, Judith Sealy, Deano Stynder and Kathlyn M. Smith: Dietary resource partitioning among three coeval proboscidean taxa (Anancus capensis, Mammuthus subplanifrons, Loxodonta cookei) from the South African Early Pliocene locality of Langebaanweg E Quarry. Palaeogeography, Palaeoclimatology, Palaeoecology 543, 2020, p. 109606, doi: 10.1016 / j.palaeo.2020.109606
  32. ↑ Vincent J. Maglio: Four new species of Elephantidae from the Plio-Pleistocene of north-west Kenya. In: Breviora. 341, 1970, pp. 1-43.
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  34. ↑ Auguste Pomel: Ossements d'Élephants et d'Hippopotames découverte dans une stationpréhistorique de la plaine d'Eghis (province d'Oran). In: Bulletin de la Sociètè geologique de France. 3 (7), 1879, pp. 44–51 ( biodiversitylibrary.org )
  35. ^ A b Yves Coppens, Vincent J. Maglio, Cary T. Madden, Michel Beden: Proboscidea. In: Vincent J. Maglio, HBS Cooke (Ed.): Evolution of African Mammals. Harvard University Press, 1978, pp. 336-367.
  36. ↑ Wilhelm Otto Dietrich: Ältestquartäre mammals from the southern Serengeti, German East Africa. In: Palaeontographica. 94A, 1942, pp. 43-133.
  37. ^ CITES: African elephant . accessed on September 7, 2018

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