Giraffidae

Abstract

792 specimens attributed to the Giraffidae were recovered by the Eyasi Plateau Paleontological Expedition (EPPE) from the three Pliocene stratigraphic units at Laetoli, with Giraffa stillei the most common taxon in all three levels. Giraffids are notably well represented in the Upper Laetolil Beds, with further evidence gathered by EPPE for the three previously recognized species from this unit. In the Lower Laetolil Beds Giraffa stillei is provisionally identified, as is Sivatherium. A third, large giraffid species may also be present. Based on a specimen recovered by Kohl-Larsen’s team during the first extensive exploration of Laetoli, we now provisionally recognize Giraffa pygmaea from the Upper Ndolanya Beds, along with Giraffa stillei and Sivatherium maurusium. Evidence for Giraffa jumae in the Upper Ndolanya Beds is not as convincing, as it is based on a small number of postcranial bones. In the time between the formation of the Upper Laetolil Beds and the Upper Ndolanya Beds, it appears that Giraffa stillei increased in size, which has been documented at other contemporary East African localities. This may relate to competition from the smaller Giraffa pygmaea.