Fig. 59.—Ichthyosaurus tenuirostris, from Würtemberg.
It was unfortunate that news of the highly interesting discovery at Würtemberg came too late for our artist to make a new drawing for our first edition, to show the dorsal fin and large tail-fin, etc., described by Dr. Fraas.[82] This has now been done, as shown in [Plate II.] By the courtesy of the proprietors of Natural Science, we are enabled to reproduce two drawings ([Fig. 59]) from the September number, illustrating a paper by Mr. Lydekker, in which he gives a résumé of the latest intelligence with regard to Ichthyosaurian reptiles.
[82] Ueber einen neuen Fund von Ichthyosaurus in Würtemberg. Neues Jahrbuch f. Mineralogie, 1892, vol. ii. pp. 87-90. The same author has published a valuable monograph, with beautiful plates, entitled Die Ichthysaurier der Süddentschen Trias- und Jura-Ablagerungen. 4to. Tübingen, 1891.
In the present year (1892) there has been discovered in the Lias of Würtemberg the skeleton of an Ichthyosaur, in which the outline of the fleshy parts is completely preserved (see lower figure). The reader will see from the figure that the tail-fin is very large, and the backbone appears to run into the lower lobe. Such a tail-fin as this impression indicates must have resembled that of the shark’s, only it is wider; but the shark’s backbone runs into the upper lobe. Sir Richard Owen long ago foretold the existence of this appendage, and the discovery, coming now (when his life is despaired of), adds one more tribute to his genius. Behind the triangular fin on the back comes a row of horny excrescences reminding us of those of the crested newt.
As Dr. Fraas remarks, this discovery shows how closely analogous Ichthyosaurs were in form to fishes, and further justifies the title of “fish-lizards.” He considers that they did not visit the shore. The reader will find much valuable matter in Mr. Lydekker’s paper, above referred to. The following extract refers to the question of their reproduction: "It has long been known that certain large skeletons of Ichthyosaurs from the Upper Lias of Holzmaden, in Würtemberg, and elsewhere, are found with the skeletons of one or more much smaller individuals enclosed partly or entirely within the cavity of the ribs one and the same time. We may accordingly take it for granted that these imprisoned skeletons were those of fœtuses. It is, however, very remarkable, that, so far as we are aware, all the skeletons with fœtuses belong to one single species; thus suggesting that this particular species was alone viviparous."
It is to be hoped that further discoveries will be made, such as may finally settle this question. One would have expected that in some cases the young ones, if fœtal, would be imperfectly developed.