Morphology
- Small size: the mean estimated body mass is 482kg approximately a third the size of the larger living Hippopotamus amphibius.
- Robust relatively short broad skull: if the crania of the two Malagasy dwarf hippos are compared Hippopotamus lemerlei in contrast has a long narrow skull.
- Superorbital margin thin: Hippopotamus lemerlei in contrast has a thick or swollen superorbital margin.
H. lemerlei (NHM M82190): superorbital margin thick or swollen above eye socket.