On the systematic status of Meganhinga chilensis Alvarenga, 1995 (Aves, Suliformes)

DIEDERLE, J.M.

Diamante

Simposio; 9Th International Meeting of the Society of Avian Paleontology and Evolution; 2016

Centro de Investigaciones Científicas y Transferencia a la Producción

Anhingidae, integrated actually by four species, wasrepresented in the fossil record by a major diversity of species during theNeogene of South America. Particularly, Meganhingachilensis was founded by Alvarenga using an incomplete tarsometarsus fromthe Malla-Malla Member (early late Miocene) in the Cura-Mallín Formation ofMalleco, Chile; coming of the same locality and Formation, were referred pelvicgirdles, cervical vertebra (previously consider as thoracic vertebra), thoracicvertebrae (first, second and third; previously not ordained), coracoids,scapula, humerus, ulna, carpometacarpus, tibiotarsus and several phalanges. Thesystematic validity of this genus is revised, and an emended diagnosis for thespecies is proposed. The morphological characters of the tarsometatarsus(holotype), pelvic girdle and humerus of Me.chilensis are majorly shared withthose of Macranhinga paranensis,except its lesser size, and five characters of the tarsometatarsus (metaphysiswith medial side wider; cristamedialis hypotarsi proyected posteriorly; in proximal view, crista intermediae hypotarsi inclinedover the crista lateralis hypotarsi;crista lateralis hypotarsi wide and low; origin of musculus flexor hallucis brevis is more inclinedforward) and two of the pelvicgirdle (crista spinosa synsacri with lateral edge shallower; vertex craniolateralisilii is more cranial with respect to theantitrochanter). This result allows to argument that Meganhinga is a possible synonym of Macranhinga. If this hypothesis is confirmed, this would be thefirst record of the genus west of the Andes Cordillera in Patagonia and would confirm theirpresence during thelate early Miocene.