Orycteropus undetermined

Lehmann, Thomas, 2009, Phylogeny and systematics of the Orycteropodidae (Mammalia, Tubulidentata), Zoological Journal of the Linnean Society 155 (3), pp. 649-702 : 688

SPECIES ORYCTEROPUS SP. LAETOLI

Material: Fragment of a right hemimandible ( KNM LAET 1418), isolated M 2 ( KNM LAET 4937), left radius ( KNM LAET 1813), proximal fragment of ulna ( KNM LAET 3625), distal fragment of tibia ( KNM LAET 4891), distal fragment of fibula ( KNM LAET 3010), left talus ( KNM LAET 3234), and isolated phalanx of the foot ( KNM LAET 1812; KNM LAET 2711; KNM LAET 2737; KNM LAET 3469), housed at the NMK, Nairobi; as well as a fragment of a right hemimandible ( MB 30867) and isolated right metacarpals V ( MB 30868; MB 30869), housed at the Museum für Naturkunde, Berlin. The MB specimens have been described by Dietrich (1942), and were identified as ‘ Orycteropus sp. cf. aethiopicus ’. Leakey (1987) referred the NMK specimens to Orycteropus sp.

Locality and age: Laetoli ( Tanzania): localities 3, 5, 9, 10w, 11, and 22; as well as Garusi, ‘Grey Tuffs from the Vogelriver’, and north-western bay of the Njarasa lac. Localities 3, 5, 9, 10w, 11, and 22 come from the Upper Laetolil Beds , dated from the Pliocene, more precisely between 3.8 and 3.5 Mya ( Drake & Curtis, 1987) .

Remarks: Leakey (1987: 297) pointed out that the specimens described by Dietrich (1942); Garusi, Grey Tuffs, and Njarasa lac) are of uncertain provenance. Discussion: The specimens discovered by Dietrich (1942) are added to the material found by Leakey (1987) because they also come from the Laetoli area. However, there are no comparable metacarpals in the fossils collected by the latter author.

The molars found in Laetoli show a rectangular outline and a deep lingual groove, as in O. afer and O. crassidens . However, the teeth of O. crassidens and of O. djourabensis are significantly larger. Additionally, the M 2 is more slender than any other upper molars of Orycteropus . The articulation axis of the semilunar notch is perpendicular to the diaphysis of the ulna, unlike in Amphiorycteropus and O. djourabensis . The talus is quadrate, as in Orycteropus , and the condyle for the navicular is round in shape, unlike in O. djourabensis . However, this talus is significantly smaller than those in any other taxa from the genus Orycteropus . Finally, the fossil aardvarks from Laetoli are very close to O. afer in their morphology, and clearly belong to the genus Orycteropus . Nonetheless, they are significantly smaller than any of the known Orycteropus species. Therefore, I propose keeping the uncertainty at the species level until new material is discovered.