Australlus, Worthy, 2011

Worthy, Trevor H., 2011, Australlus, a New Genus for Gallinula disneyi (Aves: Rallidae) and a Description of a New Species from Oligo-Miocene Deposits at Riversleigh, Northwestern Queensland, Australia, Records of the Australian Museum 63 (1), pp. 61-77 : 64

Genus Australlus new genus

Type species. Gallinula disneyi Boles, 2005 .

Etymology. From australis, Latin , southern, and as it relates to Australia; and rallus, Latin, name of rails.

Diagnosis. Differs from other genera of the Rallidae by the following unique combination of characters. Humerus with 1), crus dorsale fossae very robust; 2), tuber. ventrale relatively robust and dorsoventrally wide, with an autapomorphic arrangement of the similar sized insertion scars for the three ligaments arranged in an equilateral triangle, with that for the lig. m. coracobrachialis caudalis largest, ovate and occupying the caudal tip of the tuberculum, the scar for lig. m. subscapularis on the dorsal facies distinctly cranial to that for the lig. m. coracobrachialis caudalis and the scar for the lig. m. subcoracoideus on the ventral facies level with, but slightly cranial to, the scar for lig. m. coracobrachialis caudalis and only slightly smaller; 3), tuber. supracondylare ventrale relatively small and not extending proximally as far as condylus dorsalis; 4) and proc. flexorius projecting greatly ventrally. Coracoid, 5), with a prominent crista procoracoidei extending from the proc. procoracoideus to close to the crista medialis. Tarsometatarsus, 6), elongate, about 1.5 times the femoral length; 7), with crista medialis hypotarsi elongate, extending more than half the length of the hypotarsus; and 8), enclosing two hypotarsal canals, one for the tendon for M. flexor digitorum longus (canal 1) and the more plantar one (canal 2) that carried the two tendons, M. flexor perforatus digiti II and M. flexor perforans et perforatus digiti II.

Stratigraphy and age. All specimens of Australlus disneyi derive from sites of Faunal Zone A and B, except QM F20799 from Ringtail Site, which is attributed to Faunal Zone C ( Travouillon et al., 2006), and therefore is presumed to be of Middle Miocene age. QM F20799 does not differ materially from the other specimens of A. disneyi and is of similar size ( Boles, 2005a), so there is no reason to doubt its identity. However, its preservation is unlike the other two specimens from Ringtail and similar to specimens from White Hunter Site, so perhaps its site of origin is incorrectly recorded.