Evolution Icon Evolution
Intelligent Design Icon Intelligent Design
Paleontology Icon Paleontology

Fossil Friday: Elephants and the Abrupt Origin of Proboscidea

Günter Bechly
Photo: Deinotherium, composite from Wikimedia, Concavenator CC BY-SA 4.0, HeMei CC BY-SA 3.0.

This Fossil Friday features the iconic Deinotherium (16.9-0.78 mya) since today we look into the last order of afrotherian mammals, the Proboscidea and their putative fossil relatives. Proboscideans include the living and fossil elephants such as mammoths, mastodons, gomphotheres, stegodonts, and deinotheres. The fossil record of proboscideans is very extensive with about 50 genera with 185 species. It includes isolated teeth as well as complete skeletons with numerous early representatives from the Paleogene (Tassy 1990, McKenna & Bell 1997, Shoshani & Tassy 2005, Sanders et al. 2010). These fossils certainly provide significant information about the history and development of proboscideans (Tassy & Shoshani 1988, Tassy 1990, Shoshani & Tassy 1996, 2005, Shoshani 19982001Gheerbrant 2009Gheerbrant & Tassy 2009Begum 2021Cantalapiedra et al. 2021). For our purpose we will ignore all of the later radiations of elephant-like mammals and will focus on the earliest representatives of the first radiation. So, when do proboscideans first appearance in the fossil record?

Oldest and Most Primitive

The oldest and most primitive assumed proboscidean is Eritherium azzouzorum from Sidi Chennane in the Ouled Abdoun Basin of Morocco (Gheerbrant 2009Gheerbrant et al. 2012Schmitt & Gheerbrant 2016). This outcrop is of Middle Paleocene (Selandian, 61.7-58.7 mya) age of almost 60 million years, which makes it the oldest known placental mammal locality in Africa. Eritherium was a relatively small animal, only about the size of a fox, and without a trunk or tusks. It did not really look like an elephant at all, and indeed there is a problem with its alleged proboscidean affinity: in some more recent phylogenetic studies, Eritherium is resolved outside of Proboscidea as a more basal paenungulate (Cooper et al. 2014Rose et al. 2019), but it was confirmed as basal proboscidean by Gheerbrant et al. (20142016) and Schmitt & Gheerbrant (2016).

Pretty much undisputed is Phosphatotherium escuilliei from the Early Eocene (earliest Ypresian, 55.8-48.6 mya) of the Ouled Abdoun Basin in Morocco (Gheerbrant et al. 19962005aShoshany & Tassy 2005Sanders et al. 2010), which represents the next oldest and second most primitive proboscidean (Gheerbrant et al. 2005aSchmitt & Gheerbrant 2016). There was one little problem, though, which is the fact that the precise location of its discovery is unknown, because the holotype fossil was acquired from a commercial fossil dealer. The original description by Gheerbrant et al. (1996) admits this but says that an “unambiguous Thanetian age” is documented by the attached phosphatic matrix and the associated shark teeth, which are index fossils for an Upper Paleocene (Thanetian) layer that lacks Ypresian taxa. This “unambiguous” evidence apparently was not so unambiguous after all, because these very phosphatite layers were later recognized as earliest Ypresian by Gheerbrant et al. (20012003), and the Ypresian age was also confirmed by later discovered new material of Phosphatotherium (Gheerbrant et al. 2005a).

Daouitherium rebouli is another primitive proboscidean from the Early Eocene (earliest Ypresian, 55.8-48.6 mya) of the Ouled Abdoun Basin in Morocco (Gheerbrant et al. 2002Shoshany & Tassy 2005Sanders et al. 2010). The original describers mentioned that the discovery of Daouitherium documents “an unexpected early diversity of proboscideans and of the old origin of the order” (Gheerbrant et al. 2002).

Numidotherium koholense was described from the Early Eocene (Ypresian) from El Kohol in Algeria (Mahboubi et al. 1984Court 1995, Shoshani & Tassy 1996, Sanders eat al. 2010). A second species N. savagei was described by Court (1995) from the Upper Eocene (Bartonian, 40.4-33.9 mya) of southern Libya.

Last but not least, there is Khamsaconus bulbous, which was described from a single molar tooth from the Ypresian (55.8-48.6 Mya) of south Morocco. It was initially attributed to the louisinine “condylarths” thus in the possible relationship of the elephant shrew order Macroscelidea (Sudre et al. 1993; also see Bechly 2022c). Most later works rather considered this taxon as a very primitive and small early proboscidean (Gheerbrant et al. 199820022005a2012Gheerbrant 2009Sanders et al. 2010), but sometimes only with a question mark because the taxon is very poorly known.

One of the best-known early proboscideans is the somewhat younger genus Moeritherium, of which six species have been described. The earliest species is M. chehbeurameuri from the Bartonian of Algeria, which is 40.4-33.9 million years old (Delmer et al. 2006). Moeritheriumis quite remarkable for its very elongate body shape, which is certainly a derived trait that excludes Moeritherium from the direct ancestry of later proboscideans. The similarities between Moeritherium and the “walking sea cow” Protosiren led Andrews (1906) to first suggest a close relationship of elephants and sea cows, which later became generally recognized as the Tethytheria clade (McKenna 1975Asher et al. 2003Nishihara et al. 2005Seiffert 2007Tabuce et al. 20072008Asher & Seiffert 2010O’Leary et al. 2013). Similar adaptations were considered by some experts as indicating a common semi-aquatic ancestor for these two mammal orders (Gaeth et al. 1999Thewissen et al. 2000, Shoshani & Tassy 2005, Asher & Seiffert 2010).

Barytherium grave is the youngest of the primitive proboscideans and was discovered at the Eocene/Oligocene Fayum Depression in Egypt (33.9-28.4 mya) (Andrews 1906, Shoshani & Tassy 1996, Sanders et al. 2010), which also yielded other early proboscideans like MoeritheriumPhiomia, and Palaeomastodon.

None of these early proboscideans shows the strange phenomenon of horizontal tooth displacement that is found in more modern elephants and independently originated three times within Tethytheria (Shoshani 2001; also see Bechly 2022a). It is also worth noting that the phylogenetic relationships and classification within Proboscidea proved to be a quite controversial issue (Tassy 1988, Tassy & Shoshani 1988, Court 1995), which is hardly a big surprise as it seems to apply to most issues of higher phylogeny in all groups of organisms.


Embrithopoda is an enigmatic extinct group of large mammals from the Paleogene of the Old World, of which the best-known member is the iconic Arsinoitherium from the Late Eocene and Early Oligocene of Northern Africa. Even though Arsinoitherium resembled a rhino, most experts considered Embrithopoda as tethytherians within Afrotheria (see Erdal et al. 2016: tab. 2), and maybe even close relatives of proboscideans (Benoit et al. 2013Avilla & Mothé 2021). However, the most recent studies rather suggest that embrithopods occupy a more basal position as sister group to all other Tethytheria (Erdal et al. 2016Gheerbrant et al. 20182021), so that the derived similarities with proboscideans have to be considered as convergences (also see Gheerbrant et al. 2005a and Benoit et al. 2013). The allegedly oldest fossil record for this group is Stylophus minor from the Early Eocene (Ypresian, 55.8-48.6 mya) Grand Daoui area in Morocco (Gheerbrant et al. 2018).


The Anthracobunia is a group of primitive perissodactyl-like mammals and includes the extinct families Cambaytheriidae and Anthracobunidae from the Early Eocene (55.8-48.6 Mya) of India and Pakistan (Wells & Gingerich 1983, Rose et al. 200620142019; also see Dunn 2020), and according to some workers may\ even include the extinct Desmostylia we discussed last week (Cooper et al. 2014Rose et al. 2019Gheerbrant et al. 2021; also see Bechly 2023b). Some scientists considered anthracobunids as tethytherians (Wells & Gingerich 1983Ginsburg et al. 1999Ducrocq et al. 2000Rose et al. 2006Tabuce et al. 2007, and Gheerbrant et al. 2014) and some other authors even considered them as basal proboscideans (Gingerich et al. 1990, Shoshani et al. 1996, Thewissen et al. 2000, Gheerbrant et al. 2005b, Asher & Seiffert 2010Erdal et al. 2016), which would make them contemporaneous with some of the earliest proboscideans in Africa (Asher et al. 2003). Shoshany & Tassy (2005) preferred to exclude anthracobunids from Proboscidea until additional evidence becomes available, and Tabuce et al. (2008) mentioned that “the hypothesis that some extinct taxa (desmostylians, embrithopods and anthracobunids) are included in tethytheres is less supported, because the characters used to include them within tethytheres are homoplastic and/or of ambiguous distribution.” Indeed, more recent studies by Cooper et al. (2014)Gheerbrant et al. (2016), and Rose et al. (20142019) unambiguously placed them outside Afrotheria in the stem group of odd-toed ungulates (Perissodactyla). This also makes much more sense from a paleobiogeographic point of view, as all anthracobunids were found in East Asia.

As I discussed in my article on fossil sea cows (Bechly 2023b), Ishatherium subathuensiswas described by Sahni & Kumar (1980) and Sahni et al. (1980) from the early Eocene (Ypresian, 55.8-48.6 mya) Subhatu Formation in the Himalayas. It was described as the oldest known sirenian but only a few authors concurred with this interpretation (Sereno 1982). Domning et al. (1982) questioned the sirenian affinity as well as the dating. Indeed, most other experts think that it could as well be an anthracobunid perissodactyl or a moeritheriid proboscidean (Wells & Gingerich 1983Domning et al. 1986Zalmout et al. 2003Rose et al. 2019), but Cooper et al. (2014) excluded Ishatherium from Anthracobunidae.

Radinskya and Phenacolophus

Both genera have been considered as putative Paenungulata and Tethytheria related to Embrithopoda (McKenna & Manning 1977, McKenna & Bell 1997). Asher et al. (2003)mentioned that “if the hypothesized relation between Arsinoitherium and phenacolophids in the Embrithopoda is correct (McKenna and Manning, 1977), then crown afrotheres are also represented by Paleocene taxa from Central Asia,” which of course would be problematic. The cladistic studies by Gheerbrant et al. (2005a2014) confirmed Phenacolophus as a sister group to Embrithopoda in Paenungulata, but resolved Radinskya as sister group to Perissodactyla. More recent studies (Gheerbrant et al. 20162021) even excluded both genera from Afrotheria and instead placed them in the stem group of odd-toed ungulates (Perissodactyla), just like anthracobunids and possibly desmostylians, which makes much more sense biogeographically. But here is the more general question: Isn’t it strange that two totally unrelated groups like elephants and odd-toed ungulates, which belong to different supergroups like Afrotheria and Laurasiatheria, seem to have so many similarities, that it is difficult to place some extinct groups and even some recent groups like hyraxes (Bechly 2023a) closer to one or the other? Is that what Darwinism would predict? Of course not! Is it instead what intelligent design theory would predict? Indeed it is. Just add two and two together yourself.

Ocepeia and Abdounodus

There are two more taxa that are often discussed in the context of proboscidean phylogeny and evolution, which are the two species Abdounodus hamdii and Ocepeia daouinensisdescribed by Gheerbrant et al. (2001) from the Middle Paleocene (Selandian, 61.7-58.7 mya) phosphatic beds of Ouled Abdoun in Morocco, a fossil locality that also produced some of the earliest fossil proboscideans (see above). They were considered to be the first condylarth-like mammals from Africa and related to Perissodactyla and Paenungulata, which now are attributed to different supergroups of placental mammals. Later studies by the same authors suggested a possibly affinity with aardvarks or basal paenungulates (Gheerbrant et al. 20142016). Abdounodus and Ocepeia have meanwhile been confirmed as basal Paenungulata by several phylogenetic studies (Gheerbrant et al. 2018Avilla & Mothé 2021).

We can conclude that, apart from the usual mess of incongruent phylogenies, it is an undeniable fact that Proboscidea appeared abruptly in the Late Paleocene / Early Eocene with a surprising early diversity (Gheerbrant et al. 2002). Moreover, there are anatomical discontinuities between the distinct radiations of early lophodont proboscideans and later elephant-like forms (Tassy 1988, 1990, Begum 2021Cantalapiedra et al. 2021). Herewith we have completed our review of the afrotherian mammal orders and can move on to the next mammalian supergroup, called Euarchontoglires, which includes primates, tree shrews, colugos, hares, rabbits, and pikas. Since we have already dealt with the origins of primates (Bechly 2022b), we will look into the fossil history of tree shrews next Fossil Friday.

P.S.: If you are interested in this subject you will certainly enjoy a very well-researched article, here, on elephant evolution by ID theorist Wolf-Ekkehard Lönnig.


  • Andrews CW 1906. A Descriptive Catalogue of the Tertiary Vertebrata of Fayûm, Egypt. British Museum (Natural History), London (UK), 324 pp. DOI: https://doi.org/10.5962/bhl.title.55134
  • Asher RJ & Seiffert ER 2010. Systematics of Endemic African Mammals. Chapter 46, pp. 911–928 in: Werdelin L & Sanders WJ (eds). Cenozoic Mammals of Africa. University of California Press, Berkeley (CA), 1008 pp. https://doi.org/10.1525/california/9780520257214.003.0046
  • Asher RJ, Novacek MJ & Geisher JH 2003. Relationships of Endemic African Mammals and Their Fossil Relatives Based on Morphological and Molecular Evidence. Journal of Mammalian Evolution 10(1/2), 131–194. DOI: https://doi.org/10.1023/A:1025504124129
  • Avilla LS & Mothé D 2021. Out of Africa: A New Afrotheria Lineage Rises From Extinct South American Mammals. Frontiers in Ecology and Evolution 9:654302, 1–14. https://doi.org/10.3389/fevo.2021.654302
  • Bechly G 2022a. Fossil Friday: Desmostylia, and the Problem of Horizontal Tooth Displacement. Evolution News November 4, 2022. https://evolutionnews.org/2022/11/fossil-friday-desmostylia-and-the-problem-of-horizontal-tooth-displacement/
  • Bechly G 2022b. Fossil Friday: Purgatorius and the Abrupt Origin of Primates. Evolution News December 9, 2022. https://evolutionnews.org/2022/12/fossil-friday-purgatorius-and-the-abrupt-origin-of-primates/
  • Bechly G 2022c. Fossil Friday: Fossil Elephant Shrews and the Abrupt Origin of Macroscelidea. Evolution News December 30, 2022. https://evolutionnews.org/2022/12/fossil-friday-fossil-elephant-shrews-and-the-abrupt-origin-of-macroscelidea/
  • Bechly G 2023a. Fossil Friday: Fossil Hyraxes and the Abrupt Origin of Hyracoidea. Evolution News January 13, 2023. https://evolutionnews.org/2023/01/fossil-friday-fossil-hyraxes-and-the-abrupt-origin-of-hyracoidea/
  • Bechly G 2023b. Fossil Friday: Fossil Sea Cows and the Abrupt Origin of Sirenia and Desmostylia. Evolution News January 20, 2022. https://evolutionnews.org/2023/01/fossil-friday-fossil-sea-cows-and-the-abrupt-origin-of-sirenia-and-desmostylia/
  • Begum T 2021. The rise and fall of elephant ancestors. Natural History Museum Science News July 28, 2021. https://www.nhm.ac.uk/discover/news/2021/july/the-rise-and-fall-of-elephant-ancestors.html
  • Benoit J, Merigeaud S & Tabuce R 2013. Homoplasy in the ear region of Tethytheria and the systematic position of Embrithopoda (Mammalia, Afrotheria). Geobios 46(5), 357–370. DOI: https://doi.org/10.1016/j.geobios.2013.07.002
  • Cantalapiedra JL, Sanisidro Ó, Zhang H, Alberdi MT, Prado JL, Blanco F & Saarinen J 2021. The rise and fall of proboscidean ecological diversity. Nature Ecology Evolution 5, 1266–1272. DOI: https://doi.org/10.1038/s41559-021-01498-w
  • Cooper LN, Seiffert ER, Clementz M, Madar SI, Bajpai S, Hussain ST & Thewissen JGM 2014. Anthracobunids from the Middle Eocene of India and Pakistan are stem perissodactyls. PLoS ONE 9(10):e109232, 1–15. DOI: https://doi.org/10.1371/journal.pone.0109232
  • Court N 1995. A new species of Numidotherium (Mammalia, Proboscidea) from the Eocene of Libya and the early phylogeny of the Proboscidea. Journal of Vertebrate Paleontology15(3), 650–671. DOI: https://doi.org/10.1080/02724634.1995.10011254
  • Delmer C, Mahboubi M, Tabuce R & Tassy P 2006. A new species of Moeritherium(Proboscidea, Mammalia) from the Eocene of Algeria: New perspectives on the ancestral morphotype of the genus. Palaeontology 49(2), 421–434. DOI: https://doi.org/10.1111/j.1475-4983.2006.00548.x
  • Domning DP, Morgan GS & Ray CE 1982. North American Eocene Sea Cows (Mammalia: Sirenia). Smithsonian Contributions to Paleobiology 52, 1–69. DOI: https://doi.org/10.5479/si.00810266.52.1
  • Domning DP, Ray CE & McKenna MC. 1986. Two New Oligocene Desmostylians and a Discussion of Tethytherian Systematics. Smithsonian Contributions to Paleobiology 59, 1–56. DOI: https://doi.org/10.5479/si.00810266.59.1
  • Ducrocq S, Naing Soe A, Bo B, Benammi M, Chaimanee Y, Tun T, Thein T & Jaeger J-J 2000. First record of an Anthracobunidae (Mammalia, ?Tethytheria) from the Eocene of the Pondaung Formation, Myanmar. Comptes Rendus de l’Académie des Sciences – Series IIA – Earth and Planetary Science 330(10), 725–730. DOI: https://doi.org/10.1016/S1251-8050(00)00187-7
  • Dunn R 2020. Anatomy, Relationships, and Paleobiology of Cambaytherium (Mammalia, Perissodactylamorpha, Anthracobunia) from the lower Eocene of western India. Morphosource project ID: 00000C750. https://www.morphosource.org/projects/00000C750/about?locale=en
  • Erdal O, Antoine P-O & Sen S 2016. 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), 631–655. DOI: https://doi.org/10.1111/pala.12247
  • Fischer MS & Tassy P 1993. The interrelation between Proboscidea, Sirenia, Hyracoidea, and Mesaxonia: the morphological evidence. pp. 217–234 in: Szalay FS, Novacek MJ & McKenna MC (eds). Mammal Phylogeny, Vol. 2: Placentals. Springer, New York (NY), 332 pp.
  • Gaeth AP, Short RV & Renfree MB 1999. The developing renal, reproductive, and respiratory systems of the African elephant suggest an aquatic ancestry. PNAS 96(10), 5555–5558. DOI: https://doi.org/10.1073/pnas.96.10.5555
  • Gheerbrant E 2009. Paleocene emergence of elephant relatives and the rapid radiation of African ungulates. PNAS 106(26), 10717–10721. DOI: https://doi.org/10.1073/pnas.0900251106
  • Gheerbrant E & Tassy P 2009. L’origine et l’évolution des éléphants. Comptes Rendus Palevol 8(2-3), 281–294. DOI: https://doi.org/10.1016/j.crpv.2008.08.003
  • Gheerbrant E, Sudre J & Cappetta H 1996. A Palaeocene proboscidean from Morocco. Nature 383(6595), 68–70. DOI: https://doi.org/10.1038/383068a0
  • Gheerbrant E, Sudre J, Sen S, Abrial C, Marandat B, Sigé B & Vianey-Liaud M 1998. Nouvelles données sur les mammifères du Thanétien et de l’Yprésien du bassin d’Ouarzazate (Maroc) et leur contexte stratigraphique. Palaeovertebrata 27(3-4), 155–202. https://palaeovertebrata.com/Articles/sendFile/230/published_article
  • Gheerbrant E, Sudre J, Iarochene M & Moumni A 2001. First ascertained African “Condylarth” mammals (primitive ungulates: cf. Bulbulodentata and cf. Phenacodonta) from the earliest Ypresian of the Ouled Abdoun Basin, Morocco. Journal of Vertebrate Paleontology, 21(1), 107–118. DOI: https://doi.org/10.1671/0272-4634(2001)021[0107:faacmp]2.0.co;2
  • Gheerbrant E, Sudre J, Cappetta H, Iarochène M, Amaghzaz M & Bouya B 2002. A new large mammal from the Ypresian of Morocco: Evidence of surprising diversity of early proboscideans. Acta Palaeontologica Polonica 47(3), 493–506. https://www.app.pan.pl/article/item/app47-493.html
  • Gheerbrant E, Sudre J, Cappetta H, Mourer-Chauviré C, Bourdon E, Iarochene M, Amaghzaz M & Bouya B 2003. Les localités à mammifères des carrières de Grand Daoui, bassin des Ouled Abdoun, Maroc, Yprésien: premier état des lieux. Bulletin de la Societe Geologique de France 174(3), 279–293. https://www.researchgate.net/publication/27598819
  • Gheerbrant E, Sudre J, Tassy P, Amaghzaz M, Bouya B & Iarocheène M 2005a. New data on Phosphatherium escuilliei (Mammalia, Proboscidea) from the early Eocene of Morocco, and its impact on the phylogeny of Proboscidea and lophodont ungulates. Geodiversitas27(2), 239–333. https://sciencepress.mnhn.fr/en/periodiques/geodiversitas/27/2/nouvelles-donnees-sur-phosphatherium-escuilliei-mammalia-proboscidea-de-l-eocene-inferieur-du-maroc-apports-la-phylogenie-des-proboscidea-et-des-ongules-lophodontes
  • Gheerbrant E, Domning DP & Tassy P 2005b. Paenungulata (Sirenia, Proboscidea, Hyracoidea, and relatives). Chapter 7, pp. 84–105 in: Rose KD & Archibald JD (eds). The Rise of Placental Mammals: Origins and Relationships of the Major Extant Clades. John Hopkins University Press, Baltimore (MD), 280 pp.
  • Gheerbrant E, Bouya B & Amaghzat M 2012. Dental and cranial anatomy of Eritherium azzouzorum from the Paleocene of Morocco, earliest known proboscidean mammal. Palaeontographica Abt. A 297(5-6), 151–183. DOI: https://doi.org/10.1127/pala/297/2012/151
  • Gheerbrant E, Amaghzaz M, Bouya B, Goussard F & Letenneur C 2014. Ocepeia (Middle Paleocene of Morocco): The Oldest Skull of an Afrotherian Mammal. PLoS ONE9(2):e89739, 1–30. DOI: https://doi.org/10.1371/journal.pone.0089739
  • Gheerbrant E, Filippo A & Schmitt A 2016. Convergence of Afrotherian and Laurasiatherian Ungulate-Like Mammals: First Morphological Evidence from the Paleocene of Morocco. PLoS ONE 11(7):e0157556, 1–35. DOI: https://doi.org/10.1371/journal.pone.0157556
  • Gheerbrant E, Schmitt A & Kocsis L 2018. Early African Fossils Elucidate the Origin of Embrithopod Mammals. Current Biology 28(13), 2167–2173.e2. DOI: https://doi.org/10.1016/j.cub.2018.05.032
  • Gheerbrant E, Khaldoune F, Schmitt A & Tabuce R 2021. Earliest Embrithopod Mammals (Afrotheria, Tethytheria) from the Early Eocene of Morocco: Anatomy, Systematics and Phylogenetic Significance. Journal of Mammalian Evolution 28(2), 245–283. DOI: https://doi.org/10.1007/s10914-020-09509-6
  • Gingerich PD, Russell DE & Wells NA 1990. Astragalus of Anthracobune (Mammalia, Proboscidea) from the Early-Middle Eocene of Kashmir. Contributions from the Museum of Paleontology, The University of Michigan 28(3), 71–77. https://hdl.handle.net/2027.42/48539
  • Ginsburg L, Durrani KH, Kassi AM & Welcomme J-L 1999. Discovery of a new Anthracobunidae (Tethytheria, Mammaiia) from the lower Eocene lignite of the Kach-Harnai Area in Baluchistan (Pakistan). Comptes Rendus de l’Académie des Sciences – Series IIA – Earth and Planetary Science 328(3), 209–213. DOI: https://doi.org/10.1016/S1251-8050(99)80098-6
  • Mahboubi M, Ameur R Crochett, J & Jaeger JJ 1984. Earliest known proboscidean from early Eocene of north-west Africa. Nature 308(5959), 543–544. DOI: https://doi.org/10.1038/308543a0
  • McKenna MC 1975. Toward a Phylogenetic Classification of the Mammalia. pp. 21–46 in: Luckett WP & Szalay FS (eds.). Phylogeny of the primates: a multidisciplinary approach. Proceedings of WennerGren Symposium no. 61, Burg Wartenstein, Austria, July 6–14, 1974. Plenum Press, New York (NY). DOI: https://doi.org/10.1007/978-1-4684-2166-8_2
  • McKenna MC & Bell SK 1997. Classification of Mammals Above the Species Level. Colombia University Press, New York (NY), xii+631 pp.
  • McKenna MC & Manning R 1977. Affinities and palaeobiogeographic significance of the Mongolian Paleogene genus PhenacolophusGeobios 10(S1), 61–85. DOI: https://doi.org/10.1016/S0016-6995(77)80008-9
  • Nishihara H, Satta Y, Nikaido M, Thewissen JG, Stanhope MJ & Okada N 2005. A retroposon analysis of Afrotherian phylogeny. Molecular Biology and Evolution 22(9), 1823–1833. DOI: https://doi.org/10.1093/molbev/msi179
  • O’Leary MA, Bloch JI, Flynn JJ et al. 2013. The Placental Mammal Ancestor and the Post–K-Pg Radiation of Placentals. Science 339 (6120), 662–667. DOI: https://doi.org/10.1126/science.1229237
  • Rose KD, Smith T, Rana RS, Sahni A, Singh H, Missiaen P & Folie A 2006. Early Eocene (Ypresian) continental vertebrate assemblage from India, with description of a new anthracobunid (Mammalia, Tethytheria). Journal of Vertebrate Paleontology 26(1), 219–225. DOI: https://doi.org/10.1671/0272-4634(2006)26[219:eeycva]2.0.co;2
  • Rose KD, Holbrook L., Rana RS, Kumar K, Jones KE, Ahrens HE, Missiaen P, Sahni A Smith T 2014. Early Eocene fossils suggest that the mammalian order Perissodactyla originated in India. Nature Communications 5(1):5570, 1–9. DOI: https://doi.org/10.1038/ncomms6570
  • Rose KD, Holbrook LT, Kumar K, Rana RS, Ahrens HE, Dunn RH, Folie A, Jones KE & Smith T 2019. Anatomy, Relationships, and Paleobiology of Cambaytherium (Mammalia, Perissodactylamorpha, Anthracobunia) from the lower Eocene of western India. Journal of Vertebrate Paleontology 39(Sup.1), 1–147. DOI: http://doi.org/10.1080/02724634.2020.1761370
  • Sahni A & Kumar K 1980. Lower Eocene Sirenia, Ishatherium subathuensis, gen. et. sp. nov. from the type area, Subathu Formation, Subathu, Simla Himalayas, H. P. Journal of the Palaeontological Society of India 23-24, 132–135. https://www.researchgate.net/publication/256092090
  • Sahni A, Kumar K & Tiwari BN 1980. Lower Eocene marine mammal (Sirenia) from Dharampur, Simla Himalayas, H. P. Current Science 49, 270–271.
  • Sanders WJ, Gheerbrant E, Harris JM, Saegusa H & Delmer C 2010. Proboscidea. Chapter 15, pp. 161–251 in: Werdelin L & Sanders WJ (eds). Cenozoic Mammals of Africa. University of California Press, Berkeley (CA), 1008 pp. https://doi.org/10.1525/california/9780520257214.003.0046
  • Schmitt A & Gheerbrant E 2015. The ear region of earliest known elephant relatives: new light on the ancestral morphotype of proboscideans and afrotherians. Journal of Anatomy228(1), 137–152. DOI: https://doi.org/10.1111/joa.12396
  • Seiffert ER 2007. A new estimate of afrotherian phylogeny based on simultaneous analysis of genomic, morphological, and fossil evidence. BMC Evolutionary Biology 7(1):224, 1–13. DOI: https://doi.org/10.1186/1471-2148-7-224
  • Shoshani J 1998. Understanding proboscidean evolution: a formidable task. Trends in Ecology & Evolution 13(12), 480–487. DOI: https://doi.org/10.1016/S0169-5347(98)01491-8
  • Shoshani J 2001. Proboscidea (Elephants). Encyclopedia of Life Sciences (eLS), 1–16. DOI: https://doi.org/10.1038/npg.els.0001575
  • Shoshani J & Tassy P 1996. The Proboscidea: Evolution and Palaeoecology of Elephants and Their Relatives. Oxford University Press, Oxford (UK), 502 pp.
  • Shoshani J & Tassy P 2005. Advances in proboscidean taxonomy & classification, anatomy & physiology, and ecology & behavior. Quaternary International 126-128, 5–20. DOI: https://doi.org/10.1016/j.quaint.2004.04.011
  • Shoshani J, West RM, Court N, Savage RJG & Harris JM 1996. The earliest proboscideans: General plan, taxonomy, and palaeoecology. pp. 57–75 In: Shoshani J & Tassy P (eds). The Proboscidea: Evolution and Palaeoecology of Elephants and Their Relatives. Oxford University Press, Oxford (UK), 502 pp.
  • Sudre J, Jaeger J-J, Sige B & Vianey-Liaud M 1993. Nouvelles donnes sur les Condylarthres du Thanetien et de l’Ypresien du bassin d’Ouarzazate (Maroc) [New data about the Thanetian and Ypresian Condylarthres of Ouarzazate basin (Morocco)]. Geobios26(5), 609–615. DOI: https://doi.org/10.1016/0016-6995(93)80040-X
  • Tabuce R, Marivaux L, Adaci M, Bensalah M, Hartenberger JL, Mahboubi M, Mebrouk F, Tafforeau P & Jaeger J-J 2007. Early Tertiary mammals from north Africa reinforce the molecular Afrotheria clade. Proceedings of the Royal Society of London B 274(1614), 1159–1166. DOI: https://doi.org/10.1098/rspb.2006.0229
  • Tabuce R, Asher RJ & Lehmann T 2008. Afrotherian mammals: a review of current data. Mammalia 72(1), 2–14. DOI: https://doi.org/10.1515/MAMM.2008.004
  • Tassy P 1988. The classification of Proboscidea: How many cladistic classifications? Cladistics 4(1), 43–57. DOI: https://doi.org/10.1111/j.1096-0031.1988.tb00467.x
  • Tassy P 1989. The “Proboscidean Datum Event”: How many proboscideans and how many events? pp. 237–252 in: Lindsay EH, Fahlbusch V & Mein P (eds). European Neogene Mammal Chronology. Springer, New York (NY), x+658 pp. DOI: https://doi.org/10.1007/978-1-4899-2513-8_16
  • Tassy P 1990. Phylogénie et classification des Proboscidea (Mammalia): historique et actualité. Annales de Paléontologie 76(3), 159–224.
  • Tassy P & Shoshani J 1988. The Tethytheria; elephants and their relatives. pp. 283–315 in: Benton MJ (ed.). The Phylogeny and Classification of the Tetrapods: Vol. 2. Mammals. The Systematics Association, Special Volume No. 35B. Oxford University Press, Oxford (UK), 344 pp.
  • Thewissen JGM, Williams EM & Hussain ST 2000. Anthracobunidae and the relationships among Desmostylia, Sirenia, and Proboscidea. Journal of Vertebrate Paleontology 20(S3), 73A. DOI: https://doi.org/10.1080/02724634.2000.10010765
  • Wells NA & Gingerich PD 1983. Review of Eocene Anthracobunidae (Mammalia, Proboscidea) with a new genus and species, Jozaria palustris, from the Kuldana Formation of Kohat (Pakistan). Contributions from the Museum of Paleontology (The University of Michigan) 26(7). 117–139. https://hdl.handle.net/2027.42/48515
  • Zalmout IS, Ul-Haq M & Gingerich PD 2003. New Species of Protosiren (Mammalia, Sirenia) from the Early Middle Eocene of Balochistan (Pakistan). Contributions from the Museum of Paleontology (The University of Michigan) 31(3), 79–87. https://hdl.handle.net/2027.42/41257