What is "rhachiodont"

Rhachiodont \Rha"chi*o*dont\, a. [Gr. "ra`chis, -ios, the spine + ???, ???, a tooth.] (Zo["o]l.) Having gular teeth formed by a peculiar modification of the inferior spines of some of the vertebr[ae], as certain South African snakes ( Dasypeltis) which swallow birds' eggs and use these gular teeth to crush them.