The entire Yahoo and Google search engines couldn’t generate good matches on this term except the original source. I suspect the writer just made it up:


http://www.welcomeargentina.com/paseos/museo_arqueologico_mu...

If the picture showing the corpses indicates how that position is like, then maybe you can put it metaphorically (as would be the case in the original text).


Definitions of cubitus:
http://www.thefreedictionary.com/cubitus

cubitus - hinge joint between the forearm and upper arm and the corresponding joint in the forelimb of a quadruped

cubitus - the arm from the elbow to the fingertips

“dorsal” just means “back” or “back side” in anatomy… Cheers

1）“dorsal”为解剖学的“背”
2）“cubitus”有两义：其一为，［解］前臂；尺骨。其二为，（昆虫的）肘脉。

故，原义似为：
1）尸体埋葬时肘脉背向　或
2）尸体埋葬时前臂背向

外行，瞎说，聊博一粲。