Eopachypteryx, Mayr, Gerald, 2015

Mayr, Gerald, 2015, Towards completion of the early Eocene aviary: A new bird group from the Messel oil shale (Aves, Eopachypterygidae, fam. nov.), Zootaxa 4013 (2), pp. 252-264 : 253

Eopachypteryx , gen. nov.

Type species: Eopachypteryx praeterita , sp. nov.

Differential diagnosis. Eopachypteryx differs from:

- the late Eocene/early Oligocene Eocuculus Chandler, 1999 in: tarsometatarsus proportionally shorter and stouter; feet anisodactyl; toes proportionally shorter; second toe not much narrower than fourth toe.

- the early Eocene Fluvioviridavis Mayr & Daniels, 2001 and Palaeopsittacus Harrison, 1982 in: beak not as flattened, with a shorter symphysis mandibularis and a more pointed tip (unknown for Palaeopsittacus ); coracoid without foramen nervi supracoracoidei; sternum with deeper caudal incisions; wings proportionally shorter (humerus about as long as tibiotarsus, whereas the bone distinctly exceeds the tibiotarsus in length in Fluvioviridavis and Palaeopsittacus ); toes proportionally shorter.

- the early Eocene Parvicuculus Harrison & Walker, 1977 in: tarsometatarsus without crista medianoplantaris; trochlea metatarsi IV reaching farther distally.

- the early Eocene Masillatrogon Mayr, 2009 and other Trogoniformes in: humerus with better developed tuberculum dorsale; tarsometatarsus without crista medianoplantaris; hallux proportionally much shorter.

- all “coraciiform” birds including the early Eocene Primobucconidae in: humerus with wide proximal end; ulna only slightly exceeding humerus in length; tarsometatarsus without crista medianoplantaris.

Etymology. Derived from eos (Gr.), Greek goddess of the dawn, pachys (Gr.), robust, and pteryx (Gr.), wing, in reference to the robust wings of this new Eocene taxon.