A New Bird (Family Cracidae) from the Early Oligocene of South Dakota

Abstract

THE FAMILY CRACIDAE, including the curassows, guans, and chachalacas, ranges in the present day from the lower Rio Grande Valley in Texas south to Argentina. The modern distribution of the family gives no clue to the considerable radiation once enjoyed by the group in what is now temperate North America. Fossil species are known from Tertiary deposits in Florida, Nebraska, and South Dakota. This paper describes a new fossil cracid, older than any previously discovered, from the top of the Chadron formation, lower Oligocene of South Dakota. The fossil is preserved in fine-grained, freshwater limestone. Preparation of the specimen in high relief has exposed all of the major skeletal elements except the skull and most of the vertebral column, which probably became disarticulated before the specimen was finally buried although they may lie buried in the slab. The bones, lying more or less in a single plane, are well preserved, although many of the larger ones are moderately to severely crushed. Judging by the fairly close association on the slab of most of the toe bones and the proximity to each other of the limb bones of right and left sides, it seems that the skeleton was partly articulated when buried and that much of the bird was decomposed. Some shifting of individual bones occurred as sediments accumulated over the fossil.

The complete mitochondrial genome of the Sichuan Hill Partridge (Arborophila rufipectus) and a phylogenetic analysis with related species

“…The second calibration point (C2) marks the divergence between the Coturnix and Gallu around 35 Mya (Crowe et al, 2006;Brodkorb, 1964;Tordoff and Macdonald, 1957). The third calibration point (C3) is between G. gallus and G. sonneratii around 8 Mya (Zhang et al, 2003) (Fig.…”

A new genus and species of a galliform bird from the Oligocene of Poland

“…Sobniogallus gen. nov., differs from: * all genera of the crown group Galliformes (Megapodiidae, Cracidae, Numididae, Odontophoridae, and Phasianidae) in: furcula being extremely robust; humerus with pronounced tuberculum ventrale, tuberculum dorsale separated from the caput humeri by a furrow, crista bicipitalis merging with the shaft at a steeper angle, sulcus ligamentosus transversus much deeper and extending to the tuberculum ventrale, and processus flexorius reaching about as far distally as the condylus ventralis (it is always shorter in extant Galliformes); carpometacarpus narrow with straight os metacarpale minus (bowed in extant Galliformes), processus intermetacarpalis rudimentary (in Odontophoridae and Phasianidae it is well-developed, in Numididae it is missing, and in Cracidae and Megapodiidae it is also rudimentary), and the articular surface of the os metacarpale minus extending less distally than the articular surface of the os metacarpale majus (much farther distally in all extant Galliformes); * Gallinuloides Eastman, 1900 in: scapus claviculae (furcula) becoming wider towards extremitas omalis (of equal width in Gallinuloides); presence of a second fossa pneumotricipitalis (humerus) which does not extend into the caput humeri; presence of a transverse ridge at the beginning of the incisura capitis (humerus); carpometacarpus with the articular surface of the os metacarpale minus extending slightly less distally than the articular surface of the os metacarpale majus; * Paraortygoides Mayr, 2000 in: presence of spina interna (sternum) that fuses with spina externa to form a spina communis; humerus with a second fossa pneumotricipitalis which does not extend into the caput humeri and a transverse ridge at the beginning of the incisura capitis; ulna longer than humerus; carpometacarpus with rudimentary processus intermetacarpalis (absent in Paraortygoides), and the articular surface of the os metacarpale minus extending slightly less distally than the articular surface of the os metacarpale majus; * Paraortyx Gaillard, 1908 in: humerus with shallow second fossa pneumotricipitalis which does not extend into the caput humeri, transverse ridge at the beginning of the incisura capitis, and tuberculum dorsale separated from the caput humeri by a furrow; carpometacarpus with processus extensorius more protruding proximo-cranially, the articular surface of the os metacarpale minus extending slightly less distally than the articular surface of the os metacarpale majus; * Pirortyx Brodkorb, 1964 in: humerus with a transverse ridge at the beginning of the incisura capitis, and tuberculum dorsale separated from the caput humeri by a furrow; * Taoperdix Milne-Edwards, 1871 in: furcula with wider scapus claviculae (~3.0 mm vs. 1.3 mm in Taoperdix pessieti); humerus with pronounced tuberculum dorsale that is separated from the caput humeri by a furrow; ulna longer than humerus (in Taoperdix pessieti slightly shorter); * Procrax Tordoff and Macdonald, 1957 in: humerus more slender, with more pronounced tuberculum dorsale, and more abrupt connection of the crista bicipitalis with the shaft; carpometacarpus with less bowed os metacarpale minus; * Archaealectrornis Crowe and Short, 1992 in: humerus with a transverse ridge at the beginning of the incisura capitis, pronounced tuberculum ventrale, tuberculum dorsale separated from the caput humeri by a furrow, and more abrupt connection of the crista bicipitalis with the shaft; * Quercymegapodius Mourer-Chauviré, 1992 in: humerus with tuberculum dorsale separated from the caput humeri by a furrow; carpometacarpus with processus extens...…”

The Significance of the Distribution of the Megapodiidae

“…However, Cracraft's (1973:507) major assumption, that ' the megapodes and the Cracidae, at present a Neotropical family, were both derived from an ancestral galliform group inhabiting Gondwanaland in the Cretaceous, is almost certainly erroneous. The cracids have a well-documented fossil record in the Tertiary of North America extending at least as far back as the early Oligocène (Tordoff and Macdonald 1957). Because cracids have not been able to reach the West Indies, it is unlikely that they gained access to South America until the land connexion between North and South America was effected in the late Pliocene.…”