Embrithopoda

from Wikipedia, the free encyclopedia
Embrithopoda
Skeletal reconstruction of Arsinoitherium

Skeletal reconstruction of Arsinoitherium

Temporal occurrence
Upper Paleocene to Upper Oligocene
60 to 24 million years
Locations
Systematics
Mammals (mammalia)
Higher mammals (Eutheria)
Afrotheria
Paenungulata
Tethytheria
Embrithopoda
Scientific name
Embrithopoda
Andrews , 1906

The Embrithopoda are an extinct and so far little studied group of mammals that lived from the late Paleocene to the late Oligocene around 60 to 24 million years ago. They belong to the Afrotheria and are more closely related to the trunk animals and manatees . The main distribution area was Africa together with the then connected Arabian Peninsula and western Eurasia , although so far only finds from Turkey and Romaniaare known. The most important and best-documented representative is Arsinoitherium , which was first discovered in the Fayyum at the beginning of the 20th century . Until the 1970s, Arsinoitherium was also the only member of the Embrithopoda, only then were other genera and species gradually discovered. According to reconstructions, the representatives of the Embrithopoda lived on the edges of lakes and swamps.

features

Arsinoitherium skull

The Embrithopoda were a group with few shapes and sizes , whose representatives, apart from the terminal form Arsinoitherium, are largely only known on the basis of material found in teeth and skulls. Special features are here in a dentition with an unreduced number of teeth, so that the complete dentition of the early higher mammals existed with 44 teeth. The row of teeth was closed and not interrupted by a diastema . In addition, with the exception of the earliest representatives, they had very high ( hypsodontic ) tooth crowns. Furthermore, the molars had two transverse enamel strips on the chewing surface, so they were typically bilophodontic for ungulates . Lophodontia in the Embrithopoda was not achieved by ridges between the four main cusps of a molar (para- and metaconus on the cheek side and proto- and hypoconus (pseudohypoconus in the Tethytheria) on the tongue side; each related to the upper molars). Rather, in the Embrithopoda, the para- and metaconus shifted from the cheek to the tongue side, while the cusps there were reduced. On the cheek side, two minor humps (para- and mesostyle) resulted in two larger humps, which then connected to the para- and metaconus via ridges. The ridges between the cheek-side and tongue-side cusp structures are therefore also referred to as prepara- and premetacrista in the Embrithopoda and viewed as pseudolophene (“pseudo-ridges”). This also distinguishes the Embrithopoda from the ungulates and the other Tethytheria, in which the ridges connecting the cusps are formed by the proto- and paraloph. Due to the somewhat different structure, one assumes a “pseudolophodontia” among the Embrithopoda.

In the rest of the skeleton structure, arsinoitherium in particular shows an outwardly rhinoceros-like design with a long and strong body, columnar, short legs and five-pointed front and rear feet. The skull had two characteristic pairs of bony horns, the front one of which was very large and was formed entirely from the nasal bone . The back little one sat on the frontal bone . The formation of blood tubules on the horns indicates that they were originally covered by skin. Individual skull remains from early forms such as Stylolophus and Palaeoamasia indicate that this one had no horns. Early tribal representatives like Stylolophus probably had a body weight of 20 to 128 kg, the less modern Palaeoamasia weighed around 275 kg. Arsinoitherium as the youngest member reached enormous proportions with a live weight of probably 1.5 to 2.4 t.

Paleohabitat and Paleobiology

Live reconstruction of Arsinoitherium , drawing by Heinrich Harder

The Embrithopoda inhabited the regions north and south of the former Tethys Ocean . They are known from finds from Turkey , Romania and large parts of Africa . The most important and so far most extensive remains come from the Fayyum in Egypt . The animals show a typical adaptation to a heavy physique with very long upper leg sections (upper arm and thigh bones ) and short lower ones , whereby the knee joint on the hind legs was very low and implies a short stride length. The feet were extremely plantigrad , even stronger than today's elephants . The non-fused lumbar vertebrae indicate a poorly developed pelvic girdle, while the structure of the cervical vertebrae indicates that the skull was mostly held high. As a result, the Embrithopoda and especially Arsinoitherium were probably adapted to a semi-aquatic life. The animals lived in swamplands, where they occasionally went for food on land. Since fossils of, among other things, Palaeoamasia were found in coal layers , which were formed in a swampy environment, such a way of life can also be assumed for earlier forms.

Systematics

External and internal systematics

Systematic position of the Embrithopoda according to Gheerbrant et al. 2018
 Paenungulatomorpha  

 Ocepeia (†)


   

 Abdounodus (†)


  Paenungulata  

 Hyracoidea (hyrax)


  Tethytheria  

 Embrithopoda (†)


   

 Proboscidea ( proboscidea )


   

 Sirenia (manatees)







Template: Klade / Maintenance / Style

The Embrithopoda are classified in the mammalian group of the Paenungulata and, within this group, more precisely in the taxon of Tethytheria . The Tethytheria include the elephants and manatees living today , which are the closest recent relatives of the Embrithopoda. As a result, the Embrithopoda are to be assigned to the superordinate order of Afrotheria , one of the four main lines of the higher mammals, which, however, represent a taxon defined by molecular genetics . While Charles W. Andrews initially placed the Embrithopoda in the systematic vicinity of the hyrax in 1906, later investigations showed a relationship with the elephants and manatees. The position within the Tethytheria is indicated, among other things, by a number of features of the skull, such as the rearwardly elongated middle jawbone which contacts the frontal bone . This characteristic also unites the manatees and the proboscis and is considered a characteristic of the Tethytheria. Something similar can be said about the rear teeth, which in the Tethytheria no longer have a selenodontic effect due to the reduction of the ectoloph, an enamel bar on the outside of the tooth, as is the case with the sleepers and some other paenungulata. The exact position within the Tethytheria is under discussion. Some researchers see the Embrithopoda as a sister group of the sirens or the proboscis or as the parent group of the Tethytheria. Others place them near the Phenacolophidae . In some cases, the Phenacolophidae, which include Phenacolophus and Minchenella from the Paleocene of eastern Asia , are classified as the most primitive members of the Embrithopoda. In the past, this has often been questioned with indications that this view was not supported. Investigations into the microstructure of the tooth enamel show that the Phenacolophidae do not belong to the Embrithopoda. Sometimes the Phenacolophidae are considered to be a more basic group within the Tethytheria, the structure of the molars could also suggest a closer relationship to the Laurasiatheria , especially the odd-toed ungulates .

Internal structure of the Embrithopoda according to Gheerbrant et al. 2020
 Embrithopoda  

 Stylolophus


   

 Palaeoamasia


   

 Hypsamasia


   

 Crivadiatherium


   

 Namatherium


   

 Arsinoitherium


Template: Klade / Maintenance / 3Template: Klade / Maintenance / 4



Template: Klade / Maintenance / Style
Internal structure of the Embrithopoda according to Erdal et al. 2016
 Embrithopoda  

 Namatherium


  Arsinoitheriidae  
  Arsinoitheriinae  

 Arsinoitherium


  Palaeoamasinae  

 Palaeoamasia


   

 Hypsamasia


   

 Crivadiatherium






Template: Klade / Maintenance / Style

Within the Embrithopoda six genera with eight or nine species are distinguished. The internal structure has caused difficulties so far. The reason for this is the sparsely transmitted material. Accordingly, there are remains of the upper and lower dentition of three genera ( Stylolophus , Palaeoamasia and Arsinoitherium ), another two genera ( Namatherium and Hypsamasia ) are only known about upper dentition remains , another genus ( Crivadiatherium ) only about lower ones . As a result, the possibilities for comparison are limited and the relationships to one another can only be partially reconstructed. The very primeval Stylolophus is seen at the base of the development of the embryopod , which is supported by the low crown height of the teeth and individual special tooth features. The genus is placed in the monotypical family of Stylolophodae. The structure of the other genera is not clear. Some researchers prefer a split into two families, the Palaeoamasidae and the Arsinoitheriidae , which two studies from 2018 and 2020 also confirm. The Palaeoamasidae are restricted to Eurasia and are early tribal members of the group, while the Arsinoitheriidae were widespread in Africa and the Arabian Peninsula, which at that time formed a unit with the continent, and include the younger forms in tribal history. Both groups differ in the size of the animals in general, the degree of hypsodontia of the posterior molars and the intensity of the formation of a third lophe on the last molar. A phylogenetic study from 2016, however, supports the allocation to a family, the Arsinoitheriidae, which then combines two subfamilies with the Palaeoasaminae and the Arsinoitheriinae. The problem is the position of Namatherium , which in its first description including numerous skull features was considered to be closely related to Arsinoitherium . However, the phylogenetic studies from 2016 see it as a sister taxon to the other representatives of the Embrithopoda (with the exception of Stylolophus , which was not known at the time) due to its dental morphological characteristics . In contrast, the studies from 2018 and 2020 again plead for a close relationship with arsinoitherium .

Overview of the families and genera of the Embrithopoda

A total of six genus with eight to nine species are distinguished, some other species have not yet been described. The structure presented here follows Gheerbrant et al. 2020:

  • Order: Embrithopoda Andrews , 1906

Tribal history

The Embrithopoda have a relatively long phylogenetic past that began in the late Paleocene around 60 million years ago. Their origin and evolutionary history are largely unclear. The distribution of the fossil material with the palaeoamasinen forms on the northern and the arsinoitheriinen forms on the southern edge of the Tethys Ocean initially led to the discussion of a both Eurasian and Afro-Arabian origin with respective subsequent emigration events. The fact that the youngest representatives of the Palaeoamasidae and the oldest of the Arsinoitheriidae overlap in time makes a direct origin of the latter from the former appear doubtful. Accordingly, the splitting of the Embrithopoda must lie much further in the past, which in turn is also supported by the paleobiogeographical distribution of the two kin groups. General development trends within the Embrithopoda can be found in the general massive increase in body size and the reshaping of the molars from low to high crowns.

The most original form to date in terms of genealogy is Stylolophus from the Ouled-Abdoun Basin in Morocco and dates to the Lower Eocene . The relatively small animal with a row of molars 4 cm long already had the typical molar teeth with two ridges, but the tooth crowns were still relatively low. The skull is documented over a fragmented piece. No horns can yet be recognized on this, but enlarged frontal sinuses appear, which can possibly be viewed as preliminary stages of horn formation. Both the old age and the primeval characteristics of Stylolophus can be interpreted as an indication that the Embrithopoda originated in Africa and only later spread to the north via the Tethys. The former ocean then separated the Eurasian from the African continental mass.

From the northern edge of the Tethys, however, the oldest fossil evidence of the Embrithopoda was found. It is Hypsamasia from the Uzunçarsidere Formation in the Haymana Polatlı Basin near Ankara in central Anatolia . The stratigraphic position of this fossil-rich rock formation is assumed on the basis of accompanying finds such as the ungulate Hilalia from the group of Pleuraspidotheriidae with the end of the Paleocene , but the exact classification is under discussion. Hypsamasia is only known from a few maxillary molars that are clearly high crowned ( hypsodont ). Compared to Hypsamasia , Palaeoamasia with its rather low-crowned ( brachyodont ) molars was designed even more primeval. In addition, it did not reach the dimensions of its relative, the second molar was an average of 2.9, the third 4 cm wide. The type discovery site includes the Eski-Çeltek formation near Amasya in northern, central Turkey . This belongs to the ypresian the Lower Eocene on what basis of a thin foraminiferenhaltigen tape is displayed close to the actual Fund layer, further by the presence of the with Hilalia related Parabunodon . So far, Palaeoamasia is known from around half a dozen sites in Turkey, including Bultu-Zile and Çiçekdag, also both Turkey. Dental finds from Boyabat on the Turkish Black Sea coast belong to the transition from the Eocene to the Oligocene and represent the most recent finds of the Embrithopoda in Eurasia. The entire find material from Palaeoamasia includes only around a dozen remains of mandibular and maxillary fragments to parts of the skull. The preservation of the cranial roof of the two known skulls suggests that no bony horns were formed in Palaeoamasia . Crivadiatherium, on the other hand, showed significantly more modern features compared to Palaeoamasia and Hypsamasia , which are reflected, among other things, in more strongly molarized premolars. It was also larger overall, with a second molar about 4.8 cm and a third about 5.5 cm long. The genus, to which at least two species can be assigned, was discovered in the Hateg depression in the western part of Romania . The age of the site is not fully understood, but lies between the Lower Oligocene and the Middle Eocene.

In Africa, the embryopods can only be covered with Namatherium again in the Middle Eocene around 49 million years ago . This has so far only been handed down on the basis of a partial skull from near Black Crow in the restricted area of Namibia . It is characterized by a simpler tooth structure with little molarized front molars, the rear teeth were more high-crowned than in the Eurasian embryo. However, Namatherium did not reach the dimensions of the later embryopods of Africa, which is shown by the length of the molar series of about 11.6 cm. Whether the genus already had horns cannot be answered due to the preservation of the skull, but some anatomical features in the area of ​​the nose indicate this. The best-known and most widely handed down representatives were the Embrithopoda with Arsinoitherium , which was spread over large parts of today's Africa from the Upper Eocene to the end of the Oligocene . In total, more than 47 individuals have come down to us. The skeleton has been studied almost extensively, but there is no fully articulated skeleton. It is also the largest member of the Embrithopoda, the two rear molars of which were 7.7 and 7.4 cm in length and the entire row of molars was up to 23 cm long. In addition, the molars were extremely hypsodontic and reached a crown height of up to 13 cm. Outstanding are the finds of the Fayyum in Egypt whose deposits date from the Upper Eocene and Lower Oligocene 40 to 30 million years ago. The remains of the equally important Dor el Talha site in Libya have a similar stratigraphic range . Other Upper Ocene finds come from Tunisia and Oman on the Arabian Peninsula , which at that time formed a land mass with Africa. Finds from Malembe in Angola and from the Chilga site in Ethiopia continue to be found from the Lower Oligocene . At the latter site, the larger of the two described species of Arsinoitherium could also be recognized as a unique specimen . The most recent record of Arsinoitherium and thus also of the Embrithopoda comes from Lothidok in northwestern Kenya . It dates back to the Upper Oligocene between 27 and 24 million years ago, but so far has only included one isolated molar. According to current knowledge, the Embrithopoda died out before the beginning of the subsequent Miocene , no finds from this period are known. Its end could go hand in hand with the serious changes in the transition from the Oligocene to the Miocene, when the closure of the Tethys created a land bridge to Eurasia and so began a large fauna exchange between these two continental masses. In contrast to the more conservative Embrithopoda, other originally endemic African animal groups, such as the proboscis, experienced extensive diversification and successfully colonized Eurasia.

Research history

Originally, the Embrithopoda were only known from the Fayyum in Egypt , with all finds belonging to the genus Arsinoitherium , which is also the most common and best-studied member of the entire order. These were first discovered in the transition from the 19th to the 20th century when the British geologist Hugh John Llewellyn Beadnell first examined the deposits of the Fayyum Basin and found fossils there. After Charles William Andrews had joined him, further finds could be recovered from 1901, including giant snakes such as Gigantophis or proboscis such as Barytherium and Moeritherium . The finds also included the remains of a mammal up to 3.4 m long with two pairs of bony horns on its skull, which in 1902 was given the scientific name Arsinoitherium by Beadnell . Further on-site work was carried out around the same time by the German and Austrian researchers Eberhard Fraas and Richard Markgraf , who also found arsinoitherium . In 1907, the American Museum of Natural History led by Henry Fairfield Osborn carried out a large expedition to the Fayyum region and discovered at least six complete skulls of Arsinoitherium . Until well after the middle of the 20th century, both the genus Arsinoitherium and the entire order of the Embrithopoda were only known from the Fayyum. It was not until the 1980s that additional finds were discovered in other areas of the African continent, for example in the northern part, such as Libya and Tunisia, in Angola in southwestern Africa and in East Africa, such as Ethiopia and Kenya. At the turn of the millennium, this almost pan-African distribution was expanded to include fossils from the Arabian Peninsula .

As early as 1966, tooth remnants from the Eski-Çeltek coal mine in northern Turkey were assigned to the new genus Palaeoamasia , which, due to the design of the upper jaw molars, was regarded as a member of the Chalicotheriidae and thus standing within the odd ungulate . Further and more informative finds led to classification in the Embrithopoda in 1979. There they formed their own subfamily, the Palaeoamasinae, which faced the Arsinoitheriinae, but was not regarded as their direct phylogenetic ancestor. Just a few years earlier, another member of the Embrithopoda from Romania, Crivadiatherium, was described, which is systematically close to Palaeoamasia . These finds were followed by others of the same genus in the 1980s. This showed that the Embrithopoda were originally much more widespread and occurred from Africa to western Eurasia. Hypsamasia was discovered in central Turkey in the late 1990s . Since a greater variety of forms within the Embrithopoda emerged, the subfamily of the Palaeoamasinae was raised to the family level at the same time, as these representatives, which were previously only found in Eurasia, differed significantly from the African Embrithopods. But this is not generally accepted. In 2008, the Namatherium found in south-western Africa was scientifically introduced as a close relative of Arsinoitherium and as a phylogenetically older representative of the Afro-Arab Embrithopoda. The most primitive form to date received its scientific recognition in 2018 with the genus Stylolophus . Finds have come down to us from Morocco .

Only a few years after the first description of Arsinoitherium , in 1904, Andrews first referred the genus to the Amblypoda group, which at that time also included the Dinocerata and Pantodonta . In the same year he discarded this relationship and created the taxon Barypoda, the name of which is a reference to the strong limbs of Arsinoitherium . (At the same time Andrews introduced the Barytheria, in which he referred to Barytherium , an early representative of the proboscis , and grouped them with the Amblypoda). Barypoda subsequently proved to be preoccupied, as Ernst Haeckel had already used this term for some marsupials in 1866 . For this reason, Andrews renamed his Barypoda Embrithopoda in 1906. The name is made up of the Greek words ἐμβριθής ( embrithēs "heavy" or "weighty") and πους ( pous , "foot") and therefore has the same meaning as Barypoda. The name change was published in the journal Nature , in his comprehensive work A descriptive catalog of the Tertiary Vertebrata of the Fayum, Egypt , which appeared in the same year , Andrews could only mention the name Embrithopoda in a footnote.

literature

  • Ozan Erdal, Pierre-Olivier Antoine and Sevket Sen: New material of Palaeoamasia kansui (Embrithopoda, Mammalia) from the Eocene of Turkey and a phylogenetic analysis of Embrithopoda at the species level. Palaeontology, 2016 doi: 10.1111 / pala.12247
  • Kenneth D. Rose: The beginning of the age of mammals. Johns Hopkins University Press, Baltimore, 2006, pp. 1-431 (pp. 265-267)
  • Sevket Sen: Dispersal of African mammals in Eurasia during the Cenozoic: Ways and whys. Geobios 46, 2013, pp. 159-172

Individual evidence

  1. ↑ Nicholas Court: A unique form of dental bilophodonty and a functional interpretation of peculiarities in the masticatory system of Arsinoitherium (Mammalia, Embrithopoda). Historical Biology: An International Journal of Paleobiology 6 (2), 1992, pp. 91-111.
  2. ↑ a b c d e f g h i j k Emmanuel Gheerbrant, Arnaud Schmitt and László Kocsis: Early African Fossils Elucidate the Origin of Embrithopod Mammals. Current Biology 28 (13), 2018, pp. 2167–2173, doi: 10.1016 / j.cub.2018.05.032
  3. ↑ a b c d Kenneth D. Rose: The beginning of the age of mammals. Johns Hopkins University Press, Baltimore, 2006, pp. 1-431 (pp. 265-267)
  4. ↑ a b c d e f William Sanders, D. Tab Rasmussen and John Kappelman: Embrithopoda. In: Lars Werdelin and William Joseph Sanders (eds.): Cenozoic Mammals of Africa. University of California Press, Berkeley, Los Angeles, London, 2010, pp. 115-122
  5. ↑ a b c d e Emmanuel Gheerbrant, Fatima Khaldoune, Arnaud Schmitt and Rodolphe Tabuce: Earliest embrithopod mammals (Afrotheria, Tethytheria) from the early Eocene of Morocco: anatomy, systematics and phylogenetic significance. Journal of Mammalian Evolution, 2020, doi: 10.1007 / s10914-020-09509-6
  6. ↑ a b c d e Sevket Sen: Dispersal of African mammals in Eurasia during the Cenozoic: Ways and whys. Geobios 46, 2013, pp. 159-172
  7. ↑ a b c Emmanuel Gheerbrant, Mbarek Amaghzaz, Baadi Bouya, Florent Goussard and Charlène Letenneur: Ocepeia (Middle Paleocene of Morocco): The Oldest Skull of an Afrotherian Mammal. PLOSone 9 (1), 2014, p. E89739, doi: 10.1371 / journal.pone.0089739
  8. ↑ Michael J. Stanhope, Victor G. Waddell, Ole Madsen, Wilfried W. de Jong and S. Blair Hedges: Gregory C. Cleven, Diana Kao and Mark S. Springer. 1998. Molecular evidence for multiple origins of Insectivora and for a new order of endemic African insectivore mammals. PNAS 95, 1998, pp. 9967-9972
  9. ^ A b c Charles W. Andrews: A descriptive catalog of the Tertiary Vertebrata of the Fayum, Egypt. London, 1906, pp. 1-324 (pp. Xiv)
  10. ^ Nicholas Court: The skull of Arsinoitherium (Mammalia, Embrithopoda) and the higher order interrelationships of Ungulates. Palaeovertebrata 22 (1), 1992, pp. 1-43
  11. ↑ Erik R Seiffert: A new estimate of afrotherian phylogeny based on simultaneous analysis of genomic, morphological, and fossil evidence. BMC Evolutionary Biology 7, 2007, p. 224
  12. ↑ Julien Benoit, Samuel Merigeaud and Rodolphe Tabuce: Homoplasy in the ear region of Tethytheria and the systematic position of Embrithopoda (Mammalia, Afrotheria). Geobios 46, 2013, pp. 357-370
  13. ↑ Rodolphe Tabuce, Laurent Marivaux, Mohammed Adaci, Mustapha Bensalah, Jean-Louis Hartenberger, Mohammed Mahboubi, Fateh Mebrouk, Paul Tafforeau and Jean-Jacques Jaeger: Early Tertiary mammals from North Africa reinforce the molecular Afrotheria clade. Proceedings of the Royal Society Series B 274, 2007, pp. 1159-1166.
  14. ↑ Malcolm C. McKenna and Earl Manning: Affinities and paleobiogeographic significance of the Mongolian Paleogene genus Phenacolophus. In: JL Hartenberger (Ed.): Faunes de Mammifères du Paléogène d'Eurasie. Geobios, MS 1, 1977, pp. 61-85
  15. ↑ Malcolm C. McKenna and Susan K. Bell: Classification of mammals above the species level. Columbia University Press, New York, 1997, pp. 1-631 (pp. 87-91)
  16. ↑ a b Constantin Radulesco, Gheorghe Iliesco and Maria Iliesco: Un Embrithopode nouveau (Mammalia) dans la Paléogene de la dépression de Hateg (Roumanie) et la géologie de la région. New Yearbook for Geology and Paleontology, Mitteilungshefte 11, 1976, pp. 690–698
  17. ↑ a b c d e M. C. Maas, JGM Thewissen and J. Kappelmann: Hypsamasia seni (Mammalia: Embrithopoda) and other mammals from the Eocene Kartal Formation of Turkey. Bulletin of Carnegie Museum of Natural History 34, 1998, pp. 286-297
  18. ^ Wighart von Koenigswald: Unique differentiation of radial enamel in Arsinoitherium (Embrithopoda, Tethytheria). Historical Biology 25 (2), 2013, pp. 183-192
  19. ↑ Emmanuel Gheerbrant, Andrea Filippo and Arnaud Schmitt: Convergence of Afrotherian and Laurasiatherian Ungulate-Like Mammals: First Morphological Evidence from the Paleocene of Morocco. PLoS ONE 11 (7), 2016, p. E0157556, doi: 10.1371 / journal.pone.0157556
  20. ↑ a b c d e f g Ozan Erdal, Pierre-Olivier Antoine and Sevket Sen: New material of Palaeoamasia kansui (Embrithopoda, Mammalia) from the Eocene of Turkey and a phylogenetic analysis of Embrithopoda at the species level. Palaeontology 59 (5), 2016, pp. 631-655, doi: 10.1111 / pala.12247
  21. ^ A b c William J. Sanders, Wojciech Nemec, Mauro Aldinucci, Nils E. Janbu and Massimiliano Ghinassi: Latest Evidence of Palaeoamasia (Mammalia, Embrithopoda) in Turkish Anatolia. Journal of Vertebrate Paleontology 34 (5), 2014, pp. 1155-1164
  22. ↑ a b c Martin Pickford, Brigitte Senut, Jorge Morales, Pierre Mein and Israel M. Sánchez: Mammalia from the Lutetian of Namibia. Memoir of the Geological Survey of Namibia 20, 2008, pp. 465-514
  23. ↑ Grégoire Métais, Emmanuel Gheerbrant and Sevket Sen: Re-interpretation of the genus Parabunodon (Ypresian, Turkey): implications for the evolution and distribution of pleuraspidotheriid mammals. Palaeobiodiversity and Palaeoenvironments 92, 2012, pp. 477-486
  24. ↑ a b Sevket Sen and Emile Heintz: Palaeoamasia kansui Ozansoy 1966, embrithopode (Mammalia) de l'Éocene d'Anatolie. Annales de Paléontologie (Vertébres) 65 (1), 1979, pp. 73-91
  25. ↑ a b Constin Radulesco and Jean Sudre: Crivadiatherium iliescui n. Sp., Nouvel Embrithopde (Mammalia) de la Paléogene ancien de la depression de Hateg (Roumanie). Palaeovertebrata 15 (3), 1985, pp. 139-157
  26. ↑ Donald R. Prothero and Robert M. Schoch: Horns, tusks, and flippers. The evolution of hoofed mammals. Johns Hopkins University Press, Baltimore, 2003, ISBN 0-8018-7135-2 (pp. 141-143)
  27. ↑ a b Nicolas Vialle, Gilles Merzeraud, Cyrille Delmer, Monique Feist, Suzanne Jiquel, Laurent Marivaux, Anusha Ramdarshan, Monique Vianey-Liaud, El Mabrouk Essid, Wissem Marzougui, Hayet Khayati Ammar and Rodolphe Tabuce: Discovery of an embrithopodino mammal (Arithopodino mammal ?) in the late Eocene of Tunisia. Journal of African Earth Sciences 87, 2013, pp. 86-92
  28. ^ A b Abdul Razak Al-Sayigh, Sobhi Nasir, Anne S. Schulp and Nancy J. Stevens: The first described Arsinoitherium from the upper Eocene Aydim Formation of Oman: Biogeographic implications. Palaeoworld 17, 2008, pp. 41-46
  29. ^ A b c William J. Sanders, John Kappelman and D. Tab Rasmussen: New large-bodied mammals from the late Oligocene site of Chilga, Ethiopia. Acta Palaeontologica Polonica 49 (3), 2004, pp. 365-392
  30. ↑ Martin Pickford: Première découverte d'une faune mammalienne terrestre paléogène d'Afrique sub-saharienne. Comptes Rendus de l'Académie des Sciences de Paris 302, 1986, pp. 1205-1210 ( online )
  31. ^ 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
  32. ↑ 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
  33. ^ Vincent L. Morgan and Spencer G. Lucas: Notes From Diary-Fayum Trip, 1907 (based on the expedition diary and photographs of Walter Granger). Bulletin of the New Mexico Museum of Natural History and Science 22, 2002, pp. 1–148 (online)
  34. ^ Charles W. Andrews: Further notes on the mammals of the Eocene of Egypt. Geological Magazine 5, 1904, pp. 157-162 ( online )
  35. ^ Charles W. Andrews: Note on the Barypoda, an new order of ungulate mammals. Geological Magazine 5, 1904, pp. 481-482 ( online )
  36. ^ Charles W. Andrews: A suggested change in nomenclature. Nature 73, 1906, p. 224
  37. ^ George Gaylord Simpson: The Principles of Classification and a Classification of Mammals. Bulletin of the American Museum of Natural History 85, 1945, pp. 1–350 (pp. 134 and 249)

Web links

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