Surnia robusta Janossy, 1977

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 : 179-180

Surnia robusta Janossy, 1977

Fig. 5U –AA

Material. Rostrum maxillare, AaO-818; left humerus, distal part, AaO-839; left ulnae, proximal part and shaft, AaO-815, distal part and shaft, AaO-816; left femur, AaO-814; right tarsometatarsus, almost complete, AaO-817 (only the Crista medialis hypotarsi is missing).

Measurements. See Table 11.

This species was described by D. Janossy from material from four Plio-Pleistocene localities of Hungary ( Janossy, 1977; 1983), and it has not been reported from any other locality. It is characterized by its size which is much larger than in the Recent and fossil forms of the species Surnia ulula , the Hawk Owl, the only present-day species of the genus Surnia .

This material shows the morphological characteristics of the genus Surnia , with its particularly short and robust tarsometatarsi. On the rostrum maxillare the ventral face of the os premaxillare is flattened. In the Recent Surnia ulula this surface is variable, it is flattened in half of the individuals, and grooved in the other half. The distal humerus shows the same characteristics as are found in the genus Surnia . It is strongly ventrally elongated. The impression of M. brachialis is very long and extends very far proximad along the shaft. The ectepicondylar prominence is broken on the fossil, but it is possible to see that it was situated just proximally to the dorsal condyle. In the genus Surnia , it is small, but clearly projecting and its top forms a right angle. On the proximal ulna, on the cranial side, distally to the cotylae, the bicipital attachment forms a proximodistally elongated and sharply defined ridge. In the Recent Surnia ulula , this ridge projects less and has a variable shape, but it is rather dorsoventrally oriented. The distal ulna does not differ from the Recent S. ulula except by its size. The femur also shows the morphological characteristics of the genus Surnia . On the femoral head the Fovea lig. capitis is very deep. On the caudal face the lateral condyle extends proximally by a ridge. This ridge closes the Fossa poplitea on its medial side and delimits laterally a deep fossa that is situated proximally compared to the lateral and fibular condyles. On the tarsometatarsus, the Crista medialis hypotarsi is missing. This tarsometatarsus shows the same proportions as in the Recent species, S. ulula , but it is larger. Its dimensions are very close to those of the holotype tarsometatarsus of Surnia robusta , from Villány 3, which is almost of the same age as Ahl al Oughlam (MN 17, ca. 2–2.5 Ma) ( Tyrberg, 1998). The Ahl al Oughlam material has been compared with a sample of 6 to 15 individuals of Recent S. ulula , including males and females, from the collections of the MNHN (Laboratoire d’Anatomie comparée and Institut de Paléontologie humaine), in Paris, the NMNH, in Washington, the UCB, in Lyon, and the Paleontological Institute of the Russian Academy of Sciences, in Moscow. On average the postcranial elements of the Moroccan Surnia robusta are 31% larger than those of the Recent Surnia ulula .

As Janossy has pointed out, the Recent species lives in the taiga zone of Eurasia and North America, and in the mountain regions of Central Asia. “It is a question whether the Lower Pleistocene form had the same ecological significance, in view of the fact that most of the remains originate—as we have seen—from the Submediterranean region of the Villány Mountains” ( Janossy, 1977, p. 14). The occurrence of this species at Ahl al Oughlam is not accidental because it is represented by at least two individuals.

Order Passeriformes

A few elements can be attributed to species of the family Alaudidae . Some other elements cannot be identified more accurately, mainly because of the lack of comparative material.

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]