The fossil rails (Aves: Rallidae) of Fiji with descriptions of a new genus and species

Abstract

A new genus and species of Gallirallus-like flightless extinct rail is described from deposits in western Viti Levu, Fiji, south-west Pacific. It is distinguished by having a longer, more decurved bill, than all other rails. Fossils of the barred-wing rail Nesoclopeus poicilopterus (Hautlaub, 1866) are reported from eastern parts of Viti Levu and several fossil bones suggest the former presence of a probable gallinule. A total of seven rails in seven genera were, therefore, sympatric on Viti Levu in the immediate prehuman period.

Prehistoric Birds and Bats from the Atiahara Site, Tubuai, Austral Islands, East Polynesia

“…Most of the other petrel taxa are widespread in the Pacific and may have either bred or been visitors to the island, with the exception of a bone of Pachyptila, a genus that breeds in southern oceans at latitudes higher than 45 , so that a breeding colony in the Austral Islands is most unlikely, contra Steadman (2006:401). Instead, the specimen more likely represents a vagrant attracted to the island by large populations of other petrels (Worthy 2007). Various species of Pachyptila regularly range into the tropical Pacific during their nonbreeding seasons (Gill et al 2010), so rare bones from such vagrant individuals might be expected in samples from islands with former significant petrel populations.…”

“…One of these, however, a small, endemic, flightless species of Gallirallus, dominates the fauna in terms of specimens recovered, with 61 bones of 10 individuals, and adds to the diversity of the genus, which has recently been shown to have been rich in endemic species across the Pacific (Steadman 1987, 2006, Steadman et al 2000, Worthy 2004, Kirchman and Steadman 2005, 2006a,b, 2007.…”

“…Gallirallus steadmani is much smaller than the flightless, extremely long-billed Vitirallus (Vitilevu), which otherwise differs in numerous features, including a humerus with a much more reduced crista bicipitalis, crista deltopectoralis rolled over the cranial surface, sulcus extensorius separated from medial margin by wider ridge, and cotylae medialis et lateralis near level with each other, rather than the medial cotyla being appreciably offset proximally from the lateral one (Worthy 2004 This specimen is missing the ventral tubercle and head but preserves the characteristic impressio coracobrachialis and most of the larger crista deltopectoralis. The humerus is smaller than the humerus of Heteroscelus brevipes (am O.58080) or Calidris acuminata (am O.71525) but similar to that of Calidris ferriginea (am O.59867).…”

“…56994, 59296, 64202, 71174, 72331, 72342, and 70869; and comparative data obtained from Steadman (1987), Steadman et al (2000), Worthy (2004), and Kirchman and Steadman (2005, 2006a,b, 2007.…”

“…The fossils listed in this section are referred to Gallirallus, sensu Kirchman and Steadman (2006a) and Steadman (2006), rather than to other genera of rails found in the Pacific Ocean region because they have the following combination of characters (modified from Kirchman and Steadman [2006a] and Worthy [2004]). Humerus: fossa pneumotricipitalis deepened ventroproximally with prominent crus ventrale fossae.…”