Brachyodus Depereti, C.G.D. Nees, C.F. Hornschuch & J. Sturm, 1831

Miller, Ellen R., Gunnell, Gregg F., Gawad, Mohammad Abdel, Hamdan, Mohamad, El-Barkooky, Ahmed N., Clementz, Mark T. & Hassan, , 1914, Anthracotheres from Wadi Moghra, early Miocene, Egypt, Journal of Paleontology 88 (5), pp. 967-981: 967-968

publication ID

10.1666/13-122

persistent identifier

http://treatment.plazi.org/id/84581C98-724A-DFAB-6689-A59EB1D73C17

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Donat

scientific name

Brachyodus Depereti
status

 

Type.-CGM 30798, mandible with both dentaries including left i3, m2-3 and right i3, p4-m3 (Fig. 2A) (also figured in Fourtau, 1920; 46, 50), M 29372 is a cast.

Diagnosis.-Revised: very large species of Brachyodus, mlm 3 length about 143 mm, C-Pl diastema about 95 mm, i1-i2 absent, i3 tusk-like, at least in males, pl occasionally absent.

Occurrence.-Early Miocene, Wadi Moghra, Egypt; Gebel Zelten, Libya; Sperrgebiet, Namibia.

Material.-cGm 7210, right M; CGM 30762 right dentary, roots of p3, p4-m3 (Andrews, 1899, pl. XXIII, see below); CGM 30764, left dentary, p3-m2; CGM, 30797, left dentary p2-m2; CGM 30800, right dentary p2-m3; CGM 30801, left maxilla P1, P4; CGM 32984, symphysis; cGm 32985, symphysis; CGM 73660, left dentary p1; CGM unnumbered, right dentary alveolus p1, crown p2 (Andrews, 1899, pl. XXIII); CGM unnumbered, right dentary m2-3; CGM unnumbered, left maxilla P3-M1; CGM unnumbered, right dentary m1-2; CGM unnumbered, right dentary m2-3 (Fourtau, 1920, figs. 32, 33); CGM unnumbered, left dentary, worn m1-3. CUWM 10, right M3; CUWM 14, right maxilla P2-3; CUWM 82, left m3, CUWM 69, right maxilla M2- 3; DPC 2518, left dentary m1, m2 erupting; DPC 4064, right M2; DPC 4065, right maxillary fragment with dP3-M1; DPC 4068, left M3; DPC 4107, left M3 fragment; DPC 4421, left dentary dp4-m2, DPC 4426, right dentary p4-m2; DPC 4438, left M1; DPC 4465, left dentary worn m3; DPC 4586, right dentary p4- m3; DPC 4593; left and right dentaries worn right and left m1-3; DPC 6238, left M2; DPC 6440, left dentary m2-3; DPC 6467, left M2; DPC 6620, right dentary, m1 broken, m2-3 worn; DPC 7373, right upper dP4; DPC 7385, left maxilla fragment; DPC 7501, left dentary m2-3; DPC 7746, left dentary p2-m2; DPC 8930, isolated i3; DPC 8965, right dentary broken m2, m3 erupting; DPC 9028, left dentary m1-3; DPC 9046, isolated i3; DPC 12553, left dentary, p4-m3; DPC 12930, left dentary dp3-4; DPC 14540, molar fragment; DPC 14563, right M1; DPC 14580, left P4, M3; DPC 17679, left maxilla P3-M3; DPC 17681, right dentary m2-3; DPC 17683, right M3; DPC 17684, left maxilla P2-4; DPC 17689, left M3; DPC 17697, left maxilla, P4-M3; M 11067, left P4-M3 (Tables 1, 2).

Remarks.-Brachyodus depereti has been described previously (Dineur, 1982; Fourtau, 1920; Holroyd et al., 2010; Pickford, 1991). Premolars and molars are morphologically similar to the type species, B. onoideus  from Europe, but the teeth of B. depereti are larger. Upper molars are five-cusped with pinched rather than loop-like styles. The dental enamel is finely wrinkled and there is a prominent lingual cingulum. No skull preserving the premaxilla of B. depereti is known, but it is likely that the central upper incisors were tusk-like and pointed anterioinferiorly, as both B. onoideus  and B. aequatorialis  show a similar condition (Pickford, 1991). The i1-2 are absent in B. depereti and, at least in males, i3 is a robust, tusk-like tooth. Upper dP4 is molariform. Black (1978) suggested that the canine is possibly absent in females but no material is available from Moghra that would either support or refute this suggestion (after Pickford, 1991).

Two specimens are identified here as B. depereti, CGM 30762, a right dentary with p4-m3, and an unnumbered dentary fragment with the alveolus for p1 and the crown of p2. These specimens were originally described and figured by Andrews (1899, pl. XXIII), and subsequently CGM 30762 was also figured by Pickford (1991, pl. 3; Figs.1, 2). Both of these authors cited the dentary with p4-m3 as CGM 2849, but the specimen now has the number CGM 30762. How two different catalog numbers came to be associated with this specimen is unknown, but we identify the specimen using the number it has now.

In addition, both of these specimens have a complicated past. Cairo Geological Museum 30762 was originally published by Andrews 1899 as the holotype of Brachyodus africanus  . Fourtau (1918, 1920) and Forster-Cooper (1924) subsequently assigned a small number of specimens from Moghra to this taxon. Pickford (1991) felt that the holotype jaw of B. africanus  did not belong in Brachyodus, although the rest of the hypodigm did. To remedy this, Pickford reassigned CGM 30762 to the genus Afromeryx  , designated it as the type of a new species, A. africanus  , and identified one additional sub-adult mandibular specimen (M 15021) as a member of the A. africanus hypodigm  (see below). Pickford then created a new species, Brachyodus mogharensis (see below), to house the ‘‘genuine’’ Brachyodus material formerly recognized as B. africanus  . Based on size and overall morphology, we believe that CGM 30762 can comfortably be included as a specimen of Brachyodus depereti (see discussion below under Afromeryx  for more details) and support that assignment here.

Brachyodus depereti is well represented at Moghra but is a much rarer element among the Gebel Zelten (Libya) and Sperrgebiet (Namibia) faunas. In Libya, the taxon is documented by the presence of a very large talus in the size range for B. depereti (Pickford, 2003), and in Namibia the presence of B. depereti has been identified on the basis of a distal lateral metacarpal (AM 1' 97), a femur lacking the head and neck (AM 02), and possibly a large talus (unnumbered) (Pickford, 2003). An occurrence of B. depereti has also been reported from Siwa Oasis, Egypt (M 11967) although this is likely an error. Hamilton (1973) published a description of six early Miocene fossil specimens housed in the Natural History Museum (London). A note in the collection indicates that these fossils were purchased by the Museum in 1920 from Lady Moon, who found them ‘‘ near Siwa Oasis’’. However, there appears to be no continental Miocene deposits in or around Siwa. Instead, Siwa has long been known as a crossroad for caravans traversing northern Africa, and the fact that B. depereti is a common element in the Moghra fauna suggests that Moghra may be the original source of the material and that people may have carried material from Moghra to somewhere ‘‘ near Siwa’’.