Antarcticavis capelambensis gen. nov. et sp. nov. (1 Viewer)

Amanda Cordes-Person, Carolina Acosta Hospitaleche, Judd Case, James Martin, 2019

An enigmatic bird from the lower Maastrichtian of Vega Island, Antarctica

Cretaceous Research, in press
doi: https://doi.org/10.1016/j.cretres.2019.104314
https://www.sciencedirect.com/science/article/pii/S0195667118304944

Abstract: https://www.sciencedirect.com/science/article/pii/S0195667118304944?via=ihub

We describe a partial skeleton from the lowest Maastrichtian levels of the Snow Hill Island Formation (Vega Island, West Antarctica). Because of the anatomical differences with the Antarctic Vegavis iaai and Polarornis gregorii, this fossil is recognized here as a new genus and species. The results of our phylogenetic analysis suggest that A. capelambensis would be placed inside the Ornithuromorpha, and probably nested within the Ornithurae. This provisional assignment could only be confirmed through the finding of most complete and better preserved specimens. Antarcticavis capelambensis is the geologically oldest bird described from Antarctica.

Enjoy,

Fred

Systematic paleontology
Aves Linnaeus, 1758
Ornithotoraces Chiappe and Calvo, 1994
Ornithuromorpha Chiappe 2001

Antarcticavis gen. nov.
Type species Antarcticavis capelambensis
Etymology. Antarctic; referring to the continent where the bird was found + avis (Latin for bird).

ANTARCTICAVIS CAPELAMBENSIS sp. nov.

Holotype. South Dakota School of Mines and Technology (SDSM 78147, plus cast SDSM C-642), two thoracic vertebrae, sternal keel, articulated right coracoid and scapula, sternal portion of left coracoid, complete right humerus, left humerus (proximal and distal halves), proximal right ulna, proximal left ulna and radius (articulated), proximal right carpometacarpus, proximal left carpometacarpus, distal left carpometacarpus, synsacrum, right femur, left femur (without articular ends), proximal right tibiotarsus, right and left distal tibiotarsus articular ends, and proximal right tarsometatarsus.

Derivation of the name. Cape Lamb; referring to both the geographic location (Cape Lamb, Vega Island) and the stratigraphic location (Cape Lamb Member of the Snow Hill Island Formation) from which the holotype came + ensis; latin suffix meaning native or resident in.

Locality and horizon. SDSM Locality V9945, Al’s Bird Site, S 63° 52’ 39.41”; W 57° 36’ 18.76” located on the western side of Cape Lamb, Vega Island, Antarctic Peninsula It is assigned to the Cape Lamb Member (of the Snow Hill Island Formation sensu Crame et al., 2004), lowest Maastrichtian, 20 m above the level of the 71.0 ±.03 Ma based on 87Sr/86Sr ratios (Crame et al., 1999).

Fred


Axial and girdle elements of Antarcticavis capelambensis. (A) two articulated thoracic vertebrae in lateral view, (B) sternal keel in lateral view, (C) synsacrum in left view, (D) right scapula and coracoid in dorso-medial view, (E) right coracoid in ventral view, (F) left coracoid in ventral view, (G) synsacrum and and right femur in right view,
Scale bar represents 10 mm.