On the fossil remains of reptiles, and on chelonian foot-tracks, from the Devonian strata of Morayshire / by Lambart Brickenden and Gideon Algernon Mantell.

  • Brickenden, Lambart.
Date:
1852
Catalogue details

Licence: Public Domain Mark

Credit: On the fossil remains of reptiles, and on chelonian foot-tracks, from the Devonian strata of Morayshire / by Lambart Brickenden and Gideon Algernon Mantell. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

    8/24 (page 102)
    fossils (see PI. IV. 5, 6). In this point of view the dorsal aspect of the vertebra is of a subquadrangular form ; the articulating planes of the zygapophyses are horizontal; the neural arch rises into a roof or dome, the spinous process forming only a slight ridge, and not a sharp crest, as in Lizards*. The body or centrum of the vertebra is cylindrical, slightly contracted in the middle, and both articular ends are concave: such at least is the inference I have drawn, after a careful consideration of the various appearances presented by the fragmentary remains of the spinal elements. If this view be correct, the characters of the vertebrae are peculiar: the centrum resembles that of the vertebrae in the Axolotl, and in numerous extinct Saurians, while the neural arch approaches the corresponding element in the Salamanders. A comparison of PI. IV. 6, which is an enlarged view of the dorsal aspect of the neurapophysis of one of the fossil vertebrae, with the vertebra of the large Salamander, Sieboldtia maxima (PI. IV. 7), for which I am indebted to J. E. Gray, Esq., shows this resemblance. Another remarkable feature of the spinal column in the fossil reptile is the great uniformity of character in the vertebrae throughout the spine. The sacral vertebrae are but indistinctly denoted : the caudals have long apophyses, and only ten or twelve vertebrae are disclosed, the terminal series being concealed beneath the stone ; probably the entire length of the tail did not exceed an inch and a half. Ribs.—The ribs, of which there are twenty-four pairs, are remark- ably slender, and appear to have been attached by a simple head as in the Lizards ; but, as only imprints of these processes remain, the mode of union with the bodies or neural arches of the vertebrae is not distinctly recognizable. Some of the impressions seem to indicate that the ribs were attached to a tubercle on the anterior part of the centrum : others may be traced to the middle, as if occupying the same relative position as in the Salamanders (see PI. IV. 7) ; but the evidence on this point is very equivocal. '1'he length and curvature of the costal processes and the simple mode of attachment are lacertian characters, and strongly contrast with the usual abbreviated and rudimentary condition of the ribs in Batrachians ; yet there is no proof that any of these processes extended forward to the sternum, or were united to thoracic or abdominal car- tilages ; on the contrary, the extremity of each rib appears to be entire, as if none of these hones were originally prolonged beyond the impressions left on the stone (PI. IV. 9) ; and should future discoveries confirm the view above enunciated of the structure of the neural arch, it may be well to remind the reader, that in a genus of living batrachians, the P/euroc/elesf, the ribs are developed almost to as great an extent as in this fossil reptile %. Pelvis.—On the specimen, PI. IV. 9, the form of this part of * In Lizards, after the twelfth dorsal vertebra the spinous process is a strong, well-marked character.—Cuvif.r. + Pleurodeles, Waltl, Gray’s Catalogue of Amphibia in the British Museum, p. 17. + I am indebted to the eminent zoologist of the British Museum, John Edward Gray, Esq., for this reference-; and also for unrestricted access to the important osteological collection wliich has been formed by his exertions.