Gypaetinae, Storr, 1784

Mather, Ellen K., Lee, Michael S. Y. & Worthy, Trevor H., 2022, A new look at an old Australian raptor places “ Taphaetus ” lacertosus de Vis 1905 in the Old World vultures (Accipitridae: Aegypiinae), Zootaxa 5168 (1), pp. 1-23 : 14

Gypaetinae .

The gypaetines share with the fossil the states of the following six tarsometatarsi characters: (1) the eminentia intercotylaris projects proximally as in the fossil in all species except Polyboroides typus , where it is hyper-protruding proximally; (2) a narrow sulcus hypotarsus; (3) the base of the sulcus hypotarsus is set plantar to the sulcus flexorius, though in Gypohierax angolensis it is to a lesser degree than in the fossil; (8) a deep fossa infracotylaris dorsalis; (21) the sulcus for the m. abductor digit IV being broad; (22) and the trochlea metatarsi II is slightly longer than trochlea metatarsi IV in Gypohierax angolensis and P. typus and is longer by at least half its length in Neophron percnopterus and Gypaetus barbatus .

Tarsometatarsi of gypaetines differ from the fossil as follows: (5) the notch for the nervus peroneus forms a shallow yet distinct notch in all species except Gypaetus barbatus , where it is deep; (6) the fossa parahypotarsalis lateralis spans a quarter of the shaft length or less in all species except Neophron percnopterus , where it spans a third of shaft length; (9) the impressio ligamentum collateralis lateralis is indistinct in all species except P. typus ; (10) the plantar facies of the hypotarsus crista lateralis is wider than it is long in all species except P. typus , where it is longer than wide; (13) the medial shaft margin is thin dorsal to the fossa parahypotarsalis medialis in all species except N. percnopterus , where it is thick as in the fossil; (14) the proximal end of the fossa parahypotarsalis medialis takes up at least a third of the shaft width in all species, and is deep in all species except G. barbatus , in which it is shallow; (15) the impressiones retinaculi extensorii are present as small ridges in P. typus and G. angolensis , and practically absent in G. barbatus and N. percnopterus ; (16) the tuberositas m. tibialis cranialis is separated distally from the proximal foramina by a distance equivalent to its length; (17) the tuberositas is oval in G. barbatus and N. percnopterus , and an elongate narrow ridge in P. typus and G. angolensis ; (20) the sulcus flexorius is shallow in all species except P. typus , in which it is deep; (22) the trochlea metatarsi III has greater distal extent than trochlea metatarsi II in all species except Gypohierax angolensis , in which trochlea metatarsi II is longer; (27) the trochlea metatarsi II is relatively broad; (28) and the trochlea metatarsi IV is relatively narrow.