Description and ecologic analysis of Hollanda luceria, a Late Cretaceous bird from the Gobi Desert (Mongolia)

Avian fossils from the Upper Cretaceous of Mongolia provide significant scientific insight into the evolution of early birds, primarily due to the scarcity of continental interiors with a well-documented avifauna in the Cretaceous record. This paper describes in detail the anatomy and histology of a new taxon of early ornithuromorph bird, Hollanda luceria, from the Barun Goyot Formation at Khermeen Tsav in the Gobi Desert of Mongolia. The new taxon is represented exclusively by hindlimb elements, and is characterized by having elongated hindlimbs with an extremely reduced metatarsal IV and an unusual tibiotarsal-femoral articulation centered on a highly peaked lateral articular facet of the tibiotarsus. Cladistic and ecospace analyses were also carried out in order to infer evolutionary relationships and ecology of this primitive bird. These analyses indicate that the new taxon is a previously undescribed lineage of basal ornithuromorph and an outgroup of Ornithurae (sensu Chiappe, 2002), which may have had a cursorial lifestyle similar to that of the modern roadrunner, Geococcyx californianus.