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<i>Eozygodactylus</i> n.gen. <b>Type species</b>. <i>Eozygodactylus americanus</i> n.gen. and n.sp. <b>Etymology</b>. <i>Eozygodactylus —Eos</i> Greek for dawn,... more
<i>Eozygodactylus</i> n.gen. <b>Type species</b>. <i>Eozygodactylus americanus</i> n.gen. and n.sp. <b>Etymology</b>. <i>Eozygodactylus —Eos</i> Greek for dawn, <i>Zygodactylus</i> —for the zygodactyl foot. <b>Diagnosis</b>. Within the Zygodactylidae, <i>Eozygodactylus</i> n.gen. is diagnosed as follows: (1) humerus with large processus supracondylaris dorsalis; (2) digitus minoris widens distally; and (3) pelvis with foramen obturatum open. Character (1) is shared with <i>Zygodactylus</i> and a not yet named specimen from the London Clay held in a private collection (see also below); <i>Eozygodactylus</i> might be congeneric with the latter. Character (2) is autapomorphic for <i>Eozygodactylus</i>. Character (3) is plesiomorphic and also occurs in many other bird taxa such as e.g., Numididae, Charadriidae, Burhinidae, Rallidae, Phoenicopteridae, Threskiornithidae and Coraciidae, but not in <i>Primozygodactylus</i> (the pelvis is unknown for <i>Primoscens</i> and <i>Zygodactylus</i>). <b>Differential diagnosis</b>. <i>Eozygodactylus</i> n.gen. differs from: (<i>a</i>) the Eocene <i>Primozygodactylus</i> Mayr, 1998 in: Scapula more strongly curved, humerus with smaller crista bicipitalis, carpometacarpus with larger difference in length between the ossa metacarpalia, sternum relatively longer craniocaudally; (<i>b</i>) the Eocene <i>Primoscens</i> Harrison &amp; Walker, 1977 (the differential diagnosis is not only based on the holotype of <i>Primoscens minutus</i>, which only consists of a carpometacarpus, but also on specimen WN 87558A from the private collection of Michael Daniels that Mayr (1998) referred to the genus <i>Primoscens</i> [for figures, see Mayr, 1998: 78]) in: Humerus with processus supracondylaris (absent in cf. <i>Primoscens</i>), longer carpometacarpus (8.8 mm in <i>Eozygodactylus</i> versus 6.9 mm in <i>Primoscens</i>); and (<i>c</i>) the lower Oligocene–Miocene <i>Zygodactylus</i> Ballmann, 1971 in: Coracoid with medium-sized processus procoracoideus (absent in <i>Zygodactylus</i>), carpometa [...]
Figure 12. "Neanis" kistneri, USNM 336268, scale bar 20 mm.
Figure 11. Zygodactylidae indet., NAMAL 2000-0217-004, scale bar 20 mm.
Figure 7. Messelornis nearctica, BHI 1283, scale bar 20 mm.
Figure 10. Eozygodactylus wyomingensis n.gen. and n.sp., paratype, WDC-CGR-014, scale bar 20 mm. The skull is fabricated.
Figure 5. Messelornis nearctica, USNM 336269, scale bar 20 mm.
Figure 8. Messelornis nearctica, BHI 1294, scale bar 20 mm.
Figure 3. Messelornis nearctica, SMNK-PAL 3810, scale bar 20 mm.
Figure 4. Messelornis nearctica, USNM 776273, scale bar 20 mm.
Figure 2. Messelornis nearctica, FMNH A 716, scale bar 20 mm.
Figure 6. Messelornis nearctica, USNM 336277, A = slab, B = counterslab, scale bar 20 mm.
Figure 1. Gallinuloides wyomingensis, referred specimen WDC-CGR-012, scale bar 20 mm.
We identified a second, perfectly preserved skeleton of the earliest known galliform bird, Gallinuloides wyomingensis Eastman. The new specimen clearly shows that G. wyomingensis does not belong to crown group Galliformes as assumed by... more
We identified a second, perfectly preserved skeleton of the earliest known galliform bird, Gallinuloides wyomingensis Eastman. The new specimen clearly shows that G. wyomingensis does not belong to crown group Galliformes as assumed by earlier authors. In particular, the primitive presence of a deeply excavated, concave facies articularis scapularis at the coracoid precludes the inclusion of G. wyomingensis into crown group Galliformes. Gallinuloides wyomingensis is mor− phologically very similar to Paraortygoides messelensis Mayr, a nearly contemporaneous galliform from Messel, Ger− many. The exclusive presence of stem group galliform birds in pre−Oligocene deposits does not support the Gondwanan origin of Galliformes as evidenced by the Southern Hemisphere distribution of basal crown group members (Mega− podiidae and Cracidae).
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Figure 9. Eozygodactylus wyomingensis n.gen. and n.sp., holotype, USNM 299821, scale bar 20 mm.
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The objective of this study is the avifauna of the North American Green River Formation. Five new Green River bird species as well as several new specimens of already known species are described.* Galliformes: Gallinuloides wyomingensis... more
The objective of this study is the avifauna of the North American Green River Formation. Five new Green River bird species as well as several new specimens of already known species are described.* Galliformes: Gallinuloides wyomingensis EASTMAN 1900 A second ...