Chlamydotis sp.

Mourer-Chauviré, Cécile & Geraads, Denis, 2010, The Upper Pliocene Avifauna of Ahl al Oughlam, Morocco. Systematics and Biogeography, Records of the Australian Museum 62 (1), pp. 157-184 : 173

Chlamydotis sp. cf. C. mesetaria

Sánchez-Marco, 1990

Fig. 5C–E

Material. Right tarsometatarsus, proximal part and shaft, AaO-2664.

Measurements. See Table 8.

This tarsometatarsus shows the morphological characteristics of the genus Chlamydotis as follows. There is a strong difference in level between the lateral and the medial cotylae. The lateral cotyla is offset clearly lower in the distal direction than the medial cotyla. The lateral cotyla has an almost octogonal shape. It has two articular facets on its lateral side, a cranial one and a plantar one. There is a small groove on the cranial side of the medial cotyla, on the medial side of the Eminentia intercotylaris. In the hypotarsus there is a large roofed groove. The Crista medialis hypotarsi does not project plantarly as far as in the genus Otis , but it is extended by a straight ridge on the medioplantar side.

At the present time, the genus Chlamydotis only includes one species, Chlamydotis undulata , the Houbara bustard, but an extinct species, C. mesetaria , has been described from the locality of Layna, Spain (Sánchez-Marco, 1990), dated to be from the end of the mammal reference-level MN 15, or about 3.5 Ma ( Daams et al., 1999). This species is only known by a tibiotarsus. It is characterized by a slightly larger size than in the Recent species C. undulata , and the width of the shaft in the middle, as well as just proximally to the condyles, shows that it was a proportionally more robust form. In the Ahl al Oughlam form, the measurements are very slightly larger than in the Recent species, but the shaft is clearly stronger. For that reason we designate it as Chlamydotis sp. cf. C. mesetaria , the age of which is also comparable.

A bustard, designated as cf. Chlamydotis undulata has been reported from the Middle Miocene of Maboko Island, in Kenya (C. Harrison, 1980).

Figures

Figure 5. Otis sp. size Otis tarda, A–B: (A) right ulna, proximal part, AaO-766, cranial view: (B) right ulna, distal part, AaO-767, ventral view.Chlamydotis sp. cf. C. mesetaria, C–E: (C) right tarsometatarsus, proximal part and shaft,AaO-2644, caudal view; (D) idem, cranial view; (E) idem, proximal view. cf. Lophotis sp., F–G: (F) right coracoid, almost complete,AaO-768, dorsal view; (G) idem, ventral view. (H) Columba sp. cf. C. pisana, right humerus, distal part and shaft,AaO-2672, cranial view. (I) Catharacta sp. cf. C. skua, right humerus, distal part and shaft, AaO-4793, cranial view. … [caption continued on facing page]