Leptoptilos patagonicus, Noriega & Cladera, 2008

Noriega, Jorge Ignacio & Cladera, Gerardo, 2008, First record of an extinct marabou stork in the Neogene of South America, Acta Palaeontologica Polonica 53 (4), pp. 593-600 : 595-596

Leptoptilos patagonicus sp. nov.

Figs. 2 , 3 .

Etymology: After its geographic provenance from the Patagonian region of Argentina, South America.

Holotype: MEF 1363. Associated partial skeleton of one individual with wing and leg bones, and a few fragments of the skull, collected by Pablo Puerta in 2000.

Type locality: Punta Buenos Aires, Península Valdés, Chubut Province, Patagonia, Argentina ( Fig. 1A ) .

Type horizon: Puerto Madryn Formation ( Fig. 1B ), informally known as “Entrerriense” unit; late Miocene ( Haller 1978, 1981).

Material.—The specimen includes tip of the mandible, fragments of the ramus mandibulae and of the articular bone, right humerus missing proximal end, right distal ulna, left ulna missing proximal end, right radius with incomplete distal end, left radius with incomplete proximal end, complete left and right carpometacarpi, complete left cuneiform, right ilium, ischium and pubis, complete right tibiotarsus with proximal end lightly damaged, complete carina and incomplete corpus of sternum ( Figs. 2 , 3 ).

Diagnosis.—Larger than the living Leptoptilos javanicus , but overlapping with the largest individuals of L. crumeniferus and L. dubius , and smaller than the extinct L. falconeri . Hindlimbs larger than forelimbs compared with extant species of the genus, similar to the condition observed in L. falconeri . Leptoptilos patagonicus differs from L. crumeniferus , L. dubius , and L. javanicus by having ventral and dorsal lips of sulcus articularis coracoideus of sternum wider; humeral scars for M. pronator profundus and M. flexor carpi ulnaris larger and deeper; processus flexorius more strongly projected; epicondylus ventralis less protrudent medio−distally; internal rim of trochlea carpalis less rounded, merging with os metacarpale minus more distally; proximal surfaces of tibiotarsal condyles more extended up the shaft; ala ischii more expanded ventrally with its lower border more curved.

Figures

Fig. 2. The marabou stork Leptoptilos patagonicus sp. nov., specimen MEF−1363 (holotype) from the Puerto Madryn Formation (late Miocene), Punta Buenos Aires, Península Valdés, Chubut Province, Patagonia, Argentina. A. Right humerus in anconal (A1), palmar (A2), and distal (A3) views. B. Sternum in lateral aspect. C, D. Right (C) and left (D) ulnae in palmar and anconal views. E, F. Left (E) and right (F) radii, in palmar views. G. Left carpometacarpus in internal (G1) and external (G2) views.

Fig. 3. The marabou stork Leptoptilos patagonicus sp. nov., specimen MEF−1363 (holotype) from the Puerto Madryn Formation (late Miocene), Punta Buenos Aires, Península Valdés, Chubut Province, Patagonia, Argentina. A. Right tibiotarsus in posterior (A1) and anterior (A2) views. Details of the distal end of right tibiotarsus in medial (A3), anterior (A4), and lateral (A5) views. B. Tip of mandible in lateral (B1) and dorsal (B2) views. C. Pelvis in lateral view.

Fig. 1. A. Location of the Península Valdés area with the fossiliferous site at Punta Buenos Aires, Chubut Province, Patagonia; Argentina. B. Stratigraphic section of the Puerto Madryn Formation. The bone symbol indicates the fossiliferous level.