A Logrunner Orthonyx (Passeriformes, Orthonychidae) From the Miocene of Riversleigh, North-western Queensland

Abstract

The logrunners Orthonyx are a distinctive endemic Australo-Papuan group represented by two living species from eastern Australia and highland New Guinea, and two fossil species known from Quaternary deposits of southern Australia. The peculiar feeding method of logrunners gives their femora a distinctive appearance that is diagnostic for the genus. New material from Riversleigh, north-western Queensland, extends the chronological range into the Miocene and increases the known geographical distribution of the genus. Living species inhabit rainforest and contiguous dense vegetation; structurally similar habitats have been interpreted for the fossil species. The presence of Orthonyx at Riversleigh supports vegetation reconstructions for this area during the Tertiary.