Birds – American Toothed-birds

IN point of time the next birds of which we have any knowledge, in the line of evolution between the Lizard-tailed birds and those of the present, are the so-called American Toothed-birds, the remains of which came to light some thirty or more years ago in the Cretaceous rocks of western Kansas. If it is true, as has been stated, that the bird-like elements in Archaeopteryx amount to three fourths, and the reptilian features to no more than one fourth, of its make-up, then the Toothed-birds, although presenting a number of anomalous characters, are perhaps entitled to be called nine tenths ” bird,” for they exhibit a very distinct advance over the Lizard-tailed birds, which brings them in some respects quite close to if not indeed fully abreast of modern birds, and this be it remembered at a time so remote as the Cretaceous period. As the name implies, their most marked characteristic is the possession of distinct teeth, a character which they share in common with the Archaeopteryx, but which sharply distinguishes them from all other known birds, either fossil or living. The manner in which the teeth are implanted in the jaw, as well as modifications of the skeleton which have resulted from very different modes of life, serve as a basis for dividing the Toothed-birds into very distinct groups which are thought to be of sufficient importance to rank as separate orders.