Thursday, May 19, 2011

Conodont Feeding Model

Synchrotron-aided reconstruction of the conodont feeding apparatus and implications for the mouth of the first vertebrates. 2011. N. Goudemand, et al. PNAS early edition.

A fang-like tooth on double upper lips, spiny teeth on the tongue and a pulley-like mechanism to move the tongue backwards and forwards – this bizarre bite belongs to a conodont and, thanks to a fresh fossil find, has now been analyzed and reconstructed to show how the first vertebrates fed.

Most conodonts had to have two upper lips, upon each of which there was a long, fang-like structure. The conodonts also had a kind of tongue bearing a complex set of spiny or comb-like ‘teeth’. The ‘tongue’ rested on pulley-like cartilage and could be moved backwards and forwards thanks to two opposing muscles. The conodonts used the ‘tongue’ and lips to grab food before two pairs of relatively robust, sometimes molar-like ‘throat teeth’ ground and cut it up.

The conodonts’ unique feeding mechanism is fairly similar to that of the extant lamprey, which is widely regarded as the extinct conodonts’ nearest relative. Due to the comparative feeding mechanism and other similarities, lampreys and conodonts must have a common ancestor which was one of the first vertebrates. This common ancestor must also have had a tongue mounted on pulley-like cartilage and therefore eaten in the same manner as the conodonts. link