The Geological Evidence of Evolution

me thirty years ago.The Hadrosaurus, as it is called, is the representative of a large group of reptiles, the dinosaurs, or terrible reptiles, many of whose members depart just in that much from other reptiles as is indicated by the above characters supposed to belong to birds. In other words, we have here both small and giant animals, whose progression was either largely, or mainly, effected by the hinder appendages alone; in which the pubic bone of the pelvis was directed backward, more or less in a direction parallel with that of the ischium; in which the tibia was provided with a well-developed cnemial crest; and in which, finally, the ankle-joint of the foot and the disposition of the toes were in accordance with the disposition seen in birds. Many of these animals, furthermore, had the pneumatic character of the bones of birds, ensuring a certain amount of lightness to an otherwise ponderous frame. These singular creatures, one of which, the Iguanodon, is represented in the diagram before you, first appeared in the Triassic age, or in the period immediately Iguanodon Bernismrtensls.?Specimen in the Brussels Museum. preceding the advent of the earliest known bird, Archseopteryx, although they do not acquire any special development until the period following, the Jurassic. It is to them that we owe those remarkable foot-tracks which have made the red- sandstone of the Connecticut Valley famous, and which for full half a century after their disc... --This text refers to an alternate Paperback edition.