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| Consoravis turdirostris Ksepka, Bertelli, Balanoff & Grande, 2025 |
ABSTRACT
Morsoravidae is a small clade of probable stem passerines known from the Eocene of Europe and North America. Here, we report an articulated skeleton of a new species of Morsoravidae from the Green River Formation of Wyoming. In contrast to Morsoravis sedilis and Pumiliornis tessellatus, in which the nares appear to have been schizorhinal, the nares of the Consoravis turdirostris gen. et sp. nov. are ovoid and do not extend caudally beyond the nasofrontal hinge. In addition, the processus retroarticularis is much shorter in Consoravis than in Morsoravis. The humerus is similar to that of extant passerines, with a short shaft, short crista deltopectoralis, well-developed tuberculum supracondylare dorsale, and strongly projected processus flexorius. However, the more distal wing elements differ from those of crown passerines in that the olecranon is blunt and the carpometacarpus has a weakly developed processus extensorius. Although fully zygodactyl stem passerines are now well-documented, Consoravis and Sororavis exhibit a semi-zygodactyl foot, in which the trochlea of the fourth metatarsal bears a wing-like flange but lacks a fully developed trochlea accessoria. The unspecialized beak, modest wing length, and relatively short leg together suggest arboreal habits and a generalized diet of invertebrates and fruit for Consoravis, in contrast to more specialized diets of the nectivorous Pumiliornis and the rhynchokinetic, possibly probe-feeding Morsoravis. Phylogenetic analyses support the monophyly of Morsoravidae and weakly support the placement of this clade as sister to all other passerines. These analyses also support the identification of the Oligocene Jamna szybiaki as a stem passerine and the paraphyly of Zygodactylidae.
Consoravis turdirostris gen. et sp. nov.
Daniel T. Ksepka, Sara Bertelli, Amy M. Balanoff and Lance Grande. 2025. A New Species of Morsoravidae sheds light on Beak and Limb Morphology in stem Passerines. Journal of Vertebrate Paleontology. 45(1); e2514121. DOI: doi.org/10.1080/02724634.2025.2514121 [03 Jul 2025]
