The teeth known as Cladodus (type C. mirabilis, Ag.) have a flattened, transversely elongated, sub-elliptical or reniform base, the anterior margin being straighter than the posterior and often slightly excavated in the middle. Anteriorly the base is thick, and generally shows a groove separating the truly basal from the coronal portion, while the posterior margin is thin owing to the downward and backward slope of the ripper surface. From this upper surface anteriorly spring a number of cones or denticles, of which the median is the longest; it is flanked by lateral denticles, of which an outer one on each side is longer than those intermediate. The larger denticles, at least, are flattened antero-posteriorly and have lateral cutting margins.