A coraciiform-like bird quadrate from the Early Eocene Tingamarra local fauna of Queensland, Australia

Abstract

A fragmentary quadrate from the earliest Eocene Tingamarra local fauna of Murgon, Queensland, combines characters of the coraciiform birds and their closest relatives, a separate pterygoid facet on the orbital process (a feature unknown in this clade), and similarities to the Upupiformes (Upupidae and Phoeniculidae). The new fossil provides the first Paleogene, and thus the oldest, record of the coraciiform-like birds from the Southern Hemisphere. The Tingamarra bird may well represent one of the named families of Paleogene birds whose quadrates remain largely unknown. A great variation of pneumaticity-related features among the coraciiform birds reveals morphogenetic instability in the development of pneumatic diverticula from the tympanic cavity.