Complex sentence: The red hartebeest is a reddish-brown, with a dark face and several black markings all over its body, that are a sharp contrast to the broad white patches mark its flanks and lower rump.
Split into simpler sentences: The red hartebeest is a reddish-brown, with a dark face and several black markings all over its body. These are in sharp contrast with the broad white patches that mark its flanks and lower rump.