. The structure and life of birds . r to being abird that we must, before leaving the subject, brieflyshow why he is after all a reptile. (1) The hand hasat least four fingers, all but the last of these bear-ing claws; (2) there are no feathers ; (3) the ischiumand pubis are at right angles to the ilium, instead ofrunning parallel as in birds ; (4) the pelvis is weak,so that it is extremely unlikely that he could walkupright. In spite of their presumable intelligence andhigh temperature, in spite of their power of flight,pterodactyls were still reptiles. Many species of them,some not larger th
. The structure and life of birds . r to being abird that we must, before leaving the subject, brieflyshow why he is after all a reptile. (1) The hand hasat least four fingers, all but the last of these bear-ing claws; (2) there are no feathers ; (3) the ischiumand pubis are at right angles to the ilium, instead ofrunning parallel as in birds ; (4) the pelvis is weak,so that it is extremely unlikely that he could walkupright. In spite of their presumable intelligence andhigh temperature, in spite of their power of flight,pterodactyls were still reptiles. Many species of them,some not larger than sparrows, others with a spanof twenty-five feet from wing tip to wing tip, lived andthrove when reptiles were the dominant class uponthe earth, and, no doubt, they preyed upon lizards,birds, and mammals. [V CONNECTING LINKS 51 At the same time there were Dinosaurs, or, asProfessor I luxlcy has called them, Ornithoscclidaj—,bird-legged animals. With wonderful enterprise andzeal, skeletons of these enormous animals, weighing. Fig. 19. —Dinosaur, Iguanodon ManteIli(from a photograph by DJlo of the specimenin the Brussels Museum). tons, have been collected by Professor Marsh andhis assistants in North America. Almost certainlythey had the power of walking upon their hindlegs, their tails helping to support them. In somespecies, the nearer row of tarsals or ankle bones is E 2 52 THE STRUCTURE AND LIFE OF BIRDS ch. iv fused with the tibia, the stronger of the two leg species seem to have been tending towards thisbirdlike fusion. The pelvis is very like that of birdsin its form and in its strength. The ilium extendsfar in front of and behind the thigh joint, and the twoother pelvic bones, the ischium and pubis, extenddownwards and backwards. If the pelvis of a dino-saur and an emeu be put side by side, the resemblanceis most striking. Had the pterodactyl had the legs and hind-quartersof the dinosaur, it would have been still more birdlikethan it is. Some of the Li
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