Field work targeting the Late Miocene Baynunah Formation deposits of Abu Dhabi, UAE, has resulted in the recovery of two types of fossil ratite eggshell. These are described here as Diamantornis laini and an unnamed aepyornithid-type eggshell. D. laini is a well-diagnosed ootaxon that has been reported only from eastern and southern African sites. The age of D. laini from the Baynunah may be correlated to that from the Lower Nawata Member at Lothagam, dated at 7.4–6.5 Ma (Harrison and Msuya 2005). Such an age accords with previous biostratigraphic estimates of the Baynunah fossil fauna. The discovery of fossilized eggshells attributable to Diamantornis laini in the Late Miocene Baynunah Formation of the UAE serves to: 1) provide an additional biostratigraphic index fossil for estimating the age of the Baynunah fauna; and 2) further strengthen the paleobiogeographic affinities of the fossil Arabian biota with that of Africa, to the exclusion of Europe and Asia, during this time. Further discovery and study of remains of D. laini from radiometrically dated sites in Africa should refine the temporal range of this ootaxon, allowing for more precise statements of biostratigraphy founded on its occurrence in paleofaunas.

The aepyornithid-type eggshell is known from Africa and Asia and spans at least the entire Neogene, certainly in Africa and most likely in Asia. Its pore morphology is exceedingly similar to that of the Malagasy elephant bird Aepyornis, although these similarities may be a product of characters plesiomorphic for the Ratitae.