Cranial Elements Research Articles

The Anterior Cranial Elements of the Salamanders Pseudotriton and Gyrinophilus

THE genus Gyrinophilus was established by Cope in 1869 (p. 108) and distinguished from Pseudotriton (Spelerpes) through the possession of fused premaxillae in the former. Two other osteological differences between the genera were recognized by Cope. nasal bones were described as well separated from each other in Gyrinophilus, but in contact dorsal to the nasal processes of the premaxillae in Pseudotriton (Spelerpes). It was also stated that in Gyrinophilus a prootic-squamosal crest is present which is lacking in Pseudotriton (Spelerpes). Cope's Batrachia (1889:154) contains essentially the same account as is found in the original description. Dunn (1926) agreed with Cope with regard to the first two characters, did not concern himself with the third, and suggested a fourth osteological character. In his generic diagnoses he described Gyrinophilus (p. 259) with prefrontals present, not bordering nares and Pseudotriton (p. 272) with prefrontals present, bordering (An apparent contradiction, probably an inadvertent error, appears on page 40. The prefrontal... extends from orbit to nares. This occurs in... Gyrinophilus and Pseudotriton.) conditions among the anterior cranial elements of these two genera that have been considered as diagnostic are tabulated in Table I.

Etude d'un neurocrane de Lepidotes du Bathonien du Maroc

Abstract On the basis of a detailed study of the neurocranium of a Lepidotes species, probably L. mantelli, from Bathonian (Jurassic) deposits in the vicinity of El Mers, Morocco, discusses the structure and phylogenetic significance of the cranial elements.

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,

The Sensory Canal System in Some Early Vertebrates

The sensory canal system, often referred to as the lateral line system, is present on primitively aquatic vertebrates, larval and permanently aquatic amphibians. The system consists of series of nerve endings associated with pits, grooves, or canals running superficially on the head and body. Considerable variation in the distribution of the lines occurs, but the general pattern appears to be fairly constant. This relative constancy in distribution of the lines enables them to be used as morphological landmarks. In the study of fossil fishes their traces are useful in establishing homologies of the cranial elements. It is fortunate that the dermal skeletal elements occur closely associated with these canals, so that impressions and grooves are retained.

Second report of the Committee on the Nomenclature of the Cranial Elements in the Permian Tetrapoda

Introduction On June 29,1915, Prof. H. F. Osborn requested Prof. S. W. Williston to act as chairman of a committee consisting of Messrs. S. W. Williston, E. C. Case, R. L. Moodie, D. M. S. Watson, and W. K. Gregory, the object of the committee being to consider and revise the names of the cranial elements of the earliest Tetrapoda. Dr. R. Broom was later appointed by the chairman. The committee has never been able to assemble and discuss the matter together, but each member has expressed his own views in correspondence with the Secretary and has had opportunity to consider the views of the other members of the committee. The first report of the committee was made by the Secretary at the Washington meeting of the Paleontological Society in December, 1915. It is not yet possible to secure entire unanimity in the committee either as to the principles which must . . .

The Internal Cranial Elements and Foramina of Dapedius granulatus , from a Specimen recently found in the Lias at Charmouth

T he exterior of the skull of Dapedius has been described by Dr. A. S. Woodward in his paper entitled. ‘The Cranial Osteology of the Zoological Society in June 1893; but, owing to the scarcity of material available, the interior bones of the orbit and their foramina, and some other points regarding the exterior, have not yet been touched upon. In consequence of my discovery of a very complete skull in the Lias at Chartmouth, I have attempted to described some of the points until now undetermined. The skull was embedded in an ovoid nodule of light-coloured indurated Liassic marl, and has not been subjected to distortion by pressure, as is often the case in this formation. The nodule was lying on the foreshore between Charmouth and Lyme Regis, and had probably been washed out of the ledge known as the ‘fish-bed’ in the semicostatus zone, where I have found other remains of Ganoids. Close to this is the ‘saurian bed,’ where I got at about the same time an Ichthyosaurus tenuirostris , which in life was probably some 7 feet long, the body of which was enclosed in a large ovoid nodule of formation similar to the smaller one containing the head of the Dapedius . As we know, from the undigested scales found in the coprolites of the saurians which occur here, that the Ganoid fishes formed the bulk of their food, the juxtaposition of the two is what might be expected. Being highly pyritized, the delicate international septum of the

On the cranial elements and the deciduous and permanent dentition of Titanotherium

On the cranial elements and the deciduous and permanent dentition of Titanotherium