NASIDYTES GEN. NOV. Zoobank registration: urn: lsid: zoobank. org:act: 8E15FCCA-DB83-4F86-83AB-2861EE336353 Type species: Nasidytes ypresianus sp. nov. Differential diagnosis: Differs from Colymbiculus Mayr & Zvonok, 2011, Colymboides and Gavia in that the hypotarsus lacks distinct sulci for the tendons of musculus (m.) flexor hallucis longus and m. flexor perforatus digiti 2 (the tarsometatarsus of Petralca Mlikovsky, 1987 is unknown); distinguished from Colymboides, Petralca and Gavia by: scapula with proportionally longer acromion, coracoid with longer processus procoracoideus, and os metacarpale alulare of carpometacarpus proportionally shorter and with welldifferentiated processus extensorius and processus alularis (scapula, coracoid and carpometacarpus of Colymbiculus are unknown); differs from Lonchodytes Brodkorb, 1963 by: plantar surface of trochlea metatarsi III with a triangular, tapering outline; trochlea metatarsi IV reaching farther distally. Etymology: From Latin nasus, nose, in reference to the use of ‘Naze’ (semantically related to ‘nose’) in the name of the type locality, and Greek δύτες (dytes), diver.

Published as part of Mayr, Gerald & Kitchener, Andrew C., 2022, Oldest fossil loon documents a pronounced ecomorphological shift in the evolution of gaviiform birds, pp. 1431-1450 in Zoological Journal of the Linnean Society (Zool. J. Linn. Soc.) (Zool. J. Linn. Soc.) 196 (4) on page 1433, DOI: 10.1093/zoolinnean/zlac045, http://zenodo.org/record/7390620