Abstract
The Rev. D. W. Purdon, of Wolverhampton, obtained some years ago, from the Alum Shale at Lofthouse, near Whitby, the skull of a Pterodactyl. This was brought to me last autumn, much obscured by the surrounding hard matrix. As the specimen seemed likely to repay a careful study, the owner’s permission was obtained to clear away more of the matrix; and to him my best thanks are due for the very courteous manner in which he left the fossil in my hands, to be treated in whatever way was best calculated to develop its structure and add to its scientific value. By careful work with the chisel I succeeded in laying bare much more of the skull, and it has proved to be of unexpected value, and, for several reasons, of exceptional interest. In the first place, no Pterodactyl remains have previously been recorded from the Yorkshire Lias; in the second place, the form is certainly new, and seems nearly related to the Continental Oolitic species,
P. crassirostris
. Again, this skull has undergone little or no compression, and consequently the natural relations of the bones are well preserved, and the structures of the basal portions, including the palate and back of the skull, are better shown than in any Pterosaurian from this side of the Atlantic hitherto described. And still further, the form of the brain and parts of the auditory organ being preserved, their structure and relation to the entire skull can now be studied in a manner not previously possible. Description of Skull. This Pterodactyl skull, in its present condition, measures five-and-a-half inches in length (140 mm.); but, as the snout, from just in front of the nasal apertures, is wanting, its proper length is uncertain—probably, when perfect, it was about two inches longer. The extremely thin outer plates of the bones are almost all broken away; this, however, is not altogether a disadvantage, for not only has it exposed several casts of the air cavities, that seem to have occupied the interior of every bone, but the margins of many of the bones are now shown, which, if the external layer had been intact, would probably have been obscured. Both sides of the skull are somewhat broken, but what is wanting on one side is preserved on the other. The supra-occipital region was also broken away when the specimen came into my hands. In a lateral view (Plate 78, figs. 2, 3) there are five distinct apertures. The anterior one is the elongated nasal aperture (
e. n
.); behind this is the somewhat larger antorbital fossa (
ant. orb
.) or median aperture; and then comes the orbit (
orb
.), the last named being the largest of the five. Behind the orbit are the infra-temporal fossa (
inf. tem
.) and the supra-temporal fossa (best seen in Plate 77, fig. 1,
sup. tem
.), and these are smaller than any of the other three.