Evolution of life / by Henry C. Chapman.

  • Henry Cadwalader Chapman
Date:
1873
Catalogue details

Licence: Public Domain Mark

Credit: Evolution of life / by Henry C. Chapman. Source: Wellcome Collection.

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    we find the bones of the foot (first series of tarsal bones) soldered together and with the tibia as in birds, whereas in most reptiles these bones remain distinct. The Compso- gnathus in this, as well as in other respects, is a very bird- like reptile. The Compsognathus is considered by some anatomists to belong to the order of Dinosaurian reptiles. The Dinosauria agree in many respects with the Ostrich family, perhaps being more nearly allied to them than to any other order of birds. They used their hind limbs only as a means of progression; in this respect they resembled birds more than reptiles; their feet were terminated with claws (Fig. 70), and the curious arrangement by which the bones of the leg (tibia and fibula) are united to those of the foot (astragalus) in birds seems to have been exactly the same in these huge reptiles. The bones of the leg of the embryo bird (Fig. 72) are like those of the adult Dinosau- rian and Reptile. (Figs. 70, 69.) There is good evidence for supposing that the muscles moving the foot had the same disposition in some of the Dinosauria as exhibited in the chicken. According to a high authority on this subject, “ if the whole hind quarters from the ilium (haunch bone) to the toes of a half-hatched chicken could be suddenly enlarged, ossified, and fossilized as they are, they would furnish us with the last step of the transition between birds and reptiles, for there would be nothing in their characters to prevent us from referring them to the Dinosauria.” And according to the same high authority (Prof. Huxley), if certain bones of the Hypsilopodon had been found alone, they would have been certainly described as belonging to a bird. The idea of these huge Dinosaurs having so much in common with birds is not a mere theory, but a truth, whatever inferences may be drawn from it, as the bones of some of them (the Megalosaurus, etc.), at least in reference to the posterior extremities, are absolutely the same as those of a bird. The Compsognathus, in the 5
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