Ypresicolius, Mayr & Kitchener, 2024

Mayr, Gerald & Kitchener, Andrew C., 2024, A new mousebird (Aves, Coliiformes) from the early Eocene London Clay of Walton-on-the-Naze (Essex, United Kingdom) constitutes a morphological link between sandcoleids and coliids, Geodiversitas 46 (20), pp. 979-993 : 982-983

Genus Ypresicolius n. gen.

urn:lsid:zoobank.org:act:51DC8BAA-0E70-45F4-9A05-E7EE4F33F23D

TYPE SPECIES. — Ypresicolius sandcoleiformis n. sp.

DIFFERENTIAL DIAGNOSIS. — The new taxon is characterised by the asymmetric position of the foramina vascularia proximalia, with the medial foramen being situated much farther distally than the lateral foramen. Furthermore, it differs from:

– Eoglaucidium Fischer, 1987 in: Extremitas sternalis of coracoid forming a pronounced medial bulge; os carpi ulnare with broader crus breve; hypotarsus proximodistally longer and with single canal for the tendon of musculus flexor hallucis longus, and deep, plantarly open sulcus for the tendon of m. flexor digitorum longus;

– Eobucco Feduccia & Martin, 1976 in: Plantar flange formed by accessory trochlea of trochlea metatarsi IV less medially inflected; – Sandcoleus Houde & Olson, 1992 in: Extremitas sternalis of coracoid forming a pronounced medial bulge; sternum with proportionally much longer processus craniolaterales; hypotarsus with single canal for the tendon of musculus flexor hallucis longus, and a deep, plantarly open sulcus for the tendon of m. flexor digitorum longus;

– Anneavis Houde & Olson, 1992 in: Extremitas sternalis of coracoid forming a pronounced medial bulge; hypotarsus with single canal for the tendon of musculus flexor hallucis longus, and a deep, plantarly open sulcus for the tendon of m. flexor digitorum longus; – Uintornis Marsh, 1872 in: Trochlea metatarsi III is proportionally larger and of symmetric shape, and trochleae metatarsorum II and IV reach less far distally;

– Botauroides Shufeldt, 1915 in: Tarsometatarsus has a proportionally wider distal end and the trochlea metatarsi II reaches less far distally.

– Chascacocolius Houde & Olson, 1992 in: Coracoid with foramen nervi supracoracoidei;

– Masillacolius Mayr & Peters, 1998 and Selmes Peters, 1999 in: Coracoid with foramen nervi supracoracoidei; tarsometatarsus stouter;

– Tsidiiyazhi Ksepka, Stidham, and Williamson, 2017 in: Trochlea metatarsi II is mediolaterally narrower; trochleae metatarsorum II and IV reach less far distally.

ETYMOLOGY. — The taxon named is derived from the Ypresian type horizon and Colius , the eponymous taxon of crown group Coliiformes .