Cichlid fish biodiversity in an Oligocene lake

Abstract
The Baid formation (Ad Darb locality, Tihamat Asir. SW Saudi Arabia) is Oligocene in age. The sediments have been deposited in one of a series of several alkaline continental lakes that once flanked the early Red Sea Rift. So far seven specimens of cichlid fish have been discovered there. They represent at least three different species. One species from endo‐and exoskeletal characteristics can be assigned to the basal grade of cichlids, today represented mainly in Madagascar and India. The other two species seem to belong to two different clades within the African assemblage that today comprises more than 1000 species.