PROBOSCIDEA, Illiger, 1811

Benton, MJ, Donoghue, PCJ, Vinther, J, Asher, RJ, Friedman, M & Near, TJ, 2015, Constraints on the timescale of animal evolutionary history, Palaeontologia Electronica (Florence, Italy) 15 (1), pp. 1-107 : 64

CROWN PROBOSCIDEA (64)

Node Calibrated. Divergence of Elephas from Loxodonta .

Fossil Taxon and Specimen. Loxodonta sp. molars from the Lukeino Formation of the Tugen Hills in Kenya ( Hill 2002), including KNM-LU 916 (Sanders et al., 2010), and Toros-Menalla of Chad (Brunet et al., 2000).

Phylogenetic Justification. Following Sanders et al. (2010), isolated teeth from the African sites mentioned above exhibit loxodont apomorphies, including propeller or lozenge shaped wear patterns.

Minimum Age. 5.33 Ma

Soft Maximum Age. 23.03 Ma

Age Justification. The oldest crown proboscideans are represented by cheek teeth from the upper Miocene, including the Lukeino Formation ( Kenya) and Toros Menalla ( Chad). While Toros Menalla is likely older, both correlate to the Messinian marine stage with a minimum bound of 5.33 Ma (Sanders et al., 2010; Gradstein et al., 2012).

Paleogene strata have yielded abundant proboscidean remains, spanning the upper Paleocene ( Gheerbrant, 2009) through the early Miocene (Sanders et al., 2010). Sediments prior to the Miocene lack any fossils remotely similar to members of Elephantinae. Hence, we define the paleontological soft maximum constraint as the Oligocene-Miocene boundary, equivalent to the base of the Aquitanian marine stage at 23.03 Ma.