Figure 4. Left innominates of middle Eocene archaeocetes and the modern hippopotamus, in lateral view (anterior at left). (1) Rayanistes afer n. gen. n. sp. (CGM 42190); (2) Remingtonocetus domandaensis (GSP-UM 3408); (3) Remingtonocetus domandaensis (GSP-UM 3552); (4) Ambulocetus natans (H-GSP 18507); (5) Hippopotamus amphibius (UMMZ 84041); (6) Qaisracetus arifi (GSP-UM 3410); (7) Georgiacetus vogtlensis (GSM 350); (8) Rodhocetus kasranii (GSP-UM 3012); (9) Maiacetus inuus (GSP-UM 3551); (10) Pakicetus attocki (H-GSP 30395 and 30427). The dorsal margins of Rayanistes afer (1) and Remingtonocetus domandaensis (3) are virtually complete. Note the dorsal expansion of the ischium posterior to the acetabulum in R. afer (1), similar to that of A. natans (4), and the contrasting dorsal expansion of the ilium anterior to the acetabulum in R. domandaensis (3). The innominate of A. natans (4)isa composite constructed from left and right innominates (Madar et al., 2002). The innominate of P. attocki (10) is a composite constructed from partial innominates of P. attocki and Nalacetus ratimitus (Madar, 2007). Specimens are compared at the same total length. Principal features are labeled for H. amphibius (5). Scale bar represents 10cm in each illustration.