Libycochoerus ARAMBOURG , 1961

Pickford, Martin, Abdel Gawad, Mohamed, Hamdan, Mohamed, El-Barkooky, Ahmed N. & Al Riaydh, Mohammed H., 2021, New Suoid Fossils (Mammalia, Artiodactyla) From The Miocene Of Moghara, Egypt, And Gebel Zelten, Libya: Biochronological Implications, Fossil Imprint 77 (1), pp. 111-125 : 114-117

Genus Libycochoerus ARAMBOURG, 1961

T y p e s p e c i e s. Libycochoerus massai ARAMBOURG,

1961.

Libycochoerus massai ARAMBOURG, 1961

H o l o t y p e. Left mandible with p/2–m/3, No. 1961-5-8

MNHN Paris.

D i a g n o s i s. Large kubanochoere, about 10–20 % smaller than Kubanochoerus robustus ; upper molar series about 100 mm long ( Pickford 1986). Libycochoerus massai (M1/–M3/ ca. 100 mm long) is much larger than Kenyasus anchidens (M1/–M3/ ca. 70 mm long) and Libycochoerus jeanneli (M1/–M3/ ca. 73 mm long) ( Pickford and Tsujikawa 2019).

T y p e l o c a l i t y a n d a g e. Gebel Zelten, Libya, terminal early Miocene to basal middle Miocene.

M a t e r i a l f r o m M o g h a r a. CGM 94-138, right mandible fragment containing p/4–m/3 ( Tab. 3); CUWM 132 (field number WM DEC06-09) partial right M3/; DPC 17744 canine and DPC 14565 canine are provisionally referred to this species.

R e m a r k s. A right talus (CGM 30791), previously thought to have been collected at Moghara, is in fact from

b

Wadi Natrun, a late Miocene site, and is thus more likely to belong to Sivachoerus syrticus LEONARDI, 1954 , than to Libycochoerus massai .

D e s c r i p t i o n. The mandible CGM 94-138 is poorly preserved, but retains four teeth ( Text-fig. 11 ). The p/4 is missing a small section at the mesial end, but is otherwise in good condition. The protoconid is tall and is positioned above the gap between the two roots. The metaconid is closely applied to the protoconid but is small, as is usually the case in kubanochoeres, its presence being shown by a shallow sulcus on the mesial aspect of the main cusp. The posterior accessory cusplet is about half the height of the main cusp, and distally it has crests that descend either side to the distal cingulum.

The m/1 has four main cusps arranged in two pairs, plus a weak anterior accessory cusplet and strong median and posterior accessory cusplets. The furchen in the main cusps are shallow. There is a cingular remnant at the buccal end of the median transverse valley. The m/2 is of similar construction to the m/1. It is missing the lingual part of the metaconid. The m/3 has lost the enamel of the mesial lophid, but the second lophid and the talonid are well preserved. The furchen are shallow and the talonid complex is separated from the second lophid by the posterior accessory cusplet. The talonid is comprised of a single, centrally positioned main cusp which has beaded crests leading anteriorly on its lingual and buccal sides which terminate at the distal base of the hypoconid and entoconid respectively.

The upper third molar from Moghara ( Text-fig. 12 ) was described previously by Pickford et al. (2010) so it is not necessary to repeat it. However, stereo images are provided for clarification.

The p/4, m/1, and m/ 2 in the mandible from Moghara are somewhat smaller than any of the specimens from Gebel Zelten, but the m/3 and M3/ plot within the lower part of the range of variation of the Libyan sample ( Text-fig. 13 ). The mandible and the isolated M3/ are therefore interpreted to belong to a small individual of the species Libycochoerus massai rather than to a hitherto unidentified species. In particular the length dimensions of the anterior teeth had to be estimated due to their damaged condition.

Figures

Text-fig. 11. CGM 94-138, right mandible fragment containing p/4–m/3 of Libycochoerus massai from Moghara, Egypt. a: lingual view; b: stereo occlusal view; c: buccal view.

Text-fig. 12. CUWM 132, right M3/ of Libycochoerus massai from Moghara, Egypt. a: stereo occlusal views; b: lingual view.

Text-fig. 13. Bivariate plots of teeth of Libycochoerus massai from Gebel Zelten (circles) and Moghara (+ sign).