Becassius charadriioides, an early Miocene pratincole-like bird from France: with comments on the early evolutionary history of the Glareolidae (Aves, Charadriiformes)

Abstract

The early Miocene charadriiform bird Becassius charadriioides De Pietri and Mayr, 2012, from the Saint-Gerand-le-Puy area in France, was originally described as a member of uncertain affinities within the shorebird clade Scolopaci (jacanas, seedsnipe, painted-snipe, sandpipers, and allies). Following a re-assessment of the material attributed to this taxon and in the context of a larger comparative sample of extinct and extant charadriiform birds, we conclude that it is a member of the Glareolidae (pratincoles and coursers). We also demonstrate that certain elements, such as the coracoid, which were only tentatively referred to B. charadriioides, are very likely to belong to this taxon. We describe for the first time a tarsometatarsus that we tentatively attribute to this species. Based on the morphology of the humerus and other elements, it is not possible to associate Becassius charadriioides with any extant lineage within Glareolidae; it displays a combination of morphological features that can be presumed to be ancestral to Glareolidae based on outgroup comparisons and on the distinctiveness of B. charadriioides among other glareolids. The referral of Becassius charadriioides to Glareolidae bridges a gap in the evolutionary history of the clade, attesting to the presence of members of this clade in Europe during the earliest Miocene. Additionally, we provide a review of the fossil record of Glareolidae and re-assess some of the oldest fossils to have been attributed to this group.