Pelvic Elements Research Articles

Anuran Remains from the Miocene of Florida, with the Description of a New Species of Bufo

IN THE course of removing matrix from mammalian fossils collected in the Thomas Farm deposits of northern Florida, a number of fragmentary and dissociated anuran remains have been recovered. Through the kindness of Dr. Paulo E. Vanzolini and Dr. A. S. Romer, of the Museum of Comparative Zoology at Cambridge, Massachusetts, I have been allowed to examine these specimens. I am indebted to them for this courtesy, and am further indebted to Dr. Vanzolini for other valuable aid in the preparation of this report. I also wish to express my gratitude to Dr. Edward H. Taylor, of the University of Kansas Museum of Natural History, for making available comparative skeletal material and for numerous helpful criticisms. The recovered remains consist primarily of fragmentary limb bones, with some pectoral and pelvic girdle elements and a few vertebrae. At least two, and probably three or more, forms are represented, but only one of these can be characterized with any degree of exactness. A great majority of the specimens in the collection appear to belong to a single form; these specimens resemble very closely the corresponding elements in Recent members of the genus Bufo. Despite the absence of cranial elements showing certain of the commonly used diagnostic characters of the genus, this similarity is so marked, and comparisons with skeletons of a wide variety of other living genera so consistently show differences of one sort or another, that there can be little question that this fossil form is an early member of the genus Bufo, to which may be assigned the name,

I.—Note on the Pelvis of Cryptoclidus oxoniensis (Phillips)

Among the Plesiosaurian remains recently mounted for exhibition in the Reptile Gallery at the Natural History Museum is a very fine pelvic-girdle belonging to a species of the genus Cryptoclidus (Seeley), and forming part of the same skeleton (Leeds Coll., R. 2616) as the pectoral-girdle recently described and figured by the present writer. These specimens are perhaps the most perfect known, the bones being quite uncrushed, free from matrix, and, except that they are cracked and broken to a slight degree, in much the same condition as if they had been obtained by maceration from a recent reptile. They clearly belonged to an old individual in which ossification had nearly reached its maximum: this is shown (1) by the complete union of the coracoid and scapula with one another in the middle line closing the coraco-scapular foramen; (2) by the sharpness of some of the edges of the bones, e.g. of part of the anterior border of the pubis; (3) by the great solidity of the bones, and by the accuracy with which the pectoral and pelvic elements fit together to form the glenoid and acetabular cavities respectively, showing that the cartilage which separates them in the young animal had been ossified.

Appendix to “Note on a Modified Form of Dinosaurian Ilium, hitherto reputed Scapula”

A recent discovery of Iguanodon -remains in the Isle of Wight by the Rev. W. Fox has solved the riddle of the bone which, in the above note, I brought under the Society's notice towards the close of last Session, and it has also completed our knowledge of the pelvic elements of Mantell's Iguanodon . It will be remembered that Mantell and, later, Owen had regarded the bone as a scapula, first of Iguanodon , and afterwards of some unknown reptile, that this decision seemed to be untenable, and that the balance of all the evidence I could up to that time collect respecting it favoured its being an ilium. This fresh material, which Mr. Fox has courteously permitted me to examine, consists of a series of vertebræ, of fragments of large flat bones which cannot be any thing else than pieces of the ilia, of a pair of ischia, the former clavicles, and a pair of the bones in question. The vertebræ comprise the sacrum and a few of the adjoining lumbar and caudal vertebraæ. Their form, and also that of the isehia, agree so closely with those of the types of Mantell's Iguanodon in the British Museum as to leave no doubt of their generic identity. The third pair of bones in the pelvic girdle, which are neither ilia nor ischia, must be pubes (fig. 1, P). Their shape closely repeats that of the smaller of the two specimens illustrating my note (pl. xxxii. fig. 1, vol. xxx.). Inverting the bone