| OCR Text |
Show 292 BARON NOPCSA ON THE SUPPOSED [June 6, This highly remarkable coincidence suggests the probability that the bone in question represents an asymmetrical but nevertheless unpaired organ. So far as I am aware there is no known reptile, living or extinct, in which the clavicle is bifurcated at one end. Moreover, in most terrestrial and aquatic reptiles, when clavicles are present there is also an interclavicle, which has never been found in Sauropoda. It must also be remembered that these large herbivorous Dinosaurs were probably descended from the carnivorous Theropoda, which are always destitute of a clavicular arch. Text-fig. 49. Os penis of European Otter. I am therefore of opinion that the problematical bone of Biploclocus in question cannot be a clavicle, and it is necessary to consider Hatcher's alternative suggestion that it is an os penis. The fact that existing birds and reptiles are destitute of an os penis does not necessarily imply that gigantic reptiles like Diplodocus similarly lacked the bone. Among Mammalia it is well known that the element occurs only sporadically, being present, for instance, in the Anthropoid Apes and absent in Man. Among the living reptiles we know two types of genital organs. The Squamata show what may be called a bifid penis, while the Crocodilia and Chelonia have the penis simple exteriorly, with a corpus fibrosum and frequently even a glans penis well developed. |
