Due to the fact that all zoos are closed because of COVID-19, I've been watching a lot of the virtual "zoo to you" videos online. I came across Denver Zoo's one about Indian Rhino Tensing's new female calf who was born in late February. When they showed the baby up close on the video I noticed that the typical shoulder fold of skin which typically ends right above the prominent skin tubercles actually was nearly fully formed around the top of the back as in the Javan Rhino. I was surprised to see this as I can't remember seeing this on any other young Indian Rhino calf. Several years back I did research on Javan Rhinos for a school project (see this source) and discovered that Javan Rhinos evolved in the late Pliocene and that the species is basal to Indian Rhinos which evolved in the Middle Pleistocene. There is speculation that Javan Rhinos originally evolved as a forest species and then became a mixed forest/open grassland species such as the extinct subspecies Rhinoceros sondaicus inermis which lived in northern India alongside the Indian Rhino. When I saw the calf, I immediately thought of the Indian Rhino's evolution and thought I'd share.
Does anyone know if this specific shoulder fold is a rare occurrence on Indian Rhino calfs?
Tensing's calf.
Credit: 9News
Javan Rhino female and calf in Ujung Kulon (notice the shoulder fold behind the head)
Credit: International Rhino Foundation
Does anyone know if this specific shoulder fold is a rare occurrence on Indian Rhino calfs?
Tensing's calf.
Credit: 9News
Javan Rhino female and calf in Ujung Kulon (notice the shoulder fold behind the head)
Credit: International Rhino Foundation