Rachitomi
The Rachitomi were a group of extinct
vertebrae, having large semi-circular intercentra below the notochord and smaller paired though prominent pleurocentra on each side above and behind, forming anchoring points for the ribs.[1]
This form of complex backbone was found in some
phylogenetic unit, the Rachitomi thus are a paraphyletic unit.[2]
References
- ^ ISBN 0-697-24378-8
- ^ Romer, A.S. & Parsons, T.S. (1985): The Vertebrate Body. (6th ed.) Saunders, Philadelphia.