Vol. 51.] A SAUROPODOUS DINOSAUR FROM MADAGASCAR. 329 



24. On Bones of a Sauropodous Dinosaur from Madagascar. By 

 R. Lydekker, Esq., B.A., E.R.S., V.P.G.S. (Read February 

 6th, 1895.) 



Originally described from the Lower Cretaceous and Jurassic 

 rocks of England and other parts of Europe, the gigantic dinosaurs 

 commonly known as sauropods have been subsequently discovered 

 in great abundance in North America, while they have been re- 

 corded by myself some years ago from Southern India, and quite 

 recently from Patagonia. We have thus evidence that the group 

 had a very wide geographical distribution ; and it is noteworthy 

 that, while several of its North American representatives appear 

 inseparable from their European allies, the Indian and Argentine 

 forms are likewise referable to one and the same genus. Hitherto 

 we have had no evidence of the occurrence of the group in Africa 

 or Madagascar ; and it is therefore a matter of considerable interest 

 to be able to bring before the Society the fact that these gigantic 

 dinosaurs were represented in the island last named. 



Before proceeding to the consideration of the specimens them- 

 selves, it is important to mention that remains of a Mesozoic reptile 

 of a Jurassic type have already been recorded from the island, and 

 referred to the European genus Steneosaurus. : The presumption 

 thus afforded of the occurrence of Jurassic strata in Madagascar is 

 converted into a certainty by the discovery of a large series of mol- 

 luscan remains belonging to forms characteristic of that period. 2 



The specimens that I have the opportunity of now bringing under 

 the notice of the Society comprise a large series of reptilian bones 

 collected by Mr. J. L. Last, at a spot about 20 miles to the 

 eastward of the bay of Narinda, on the north-western coast. 

 These bones, which have been purchased by the British Museum, 

 include vertebrae, limb-bones, and portions of the pectoral and pelvic 

 girdles of gigantic land-reptiles ; and although the long bones are 

 represented only by their extremities or fragments of the shafts, 

 while the vertebras are all more or less broken, yet many of the 

 specimens are sufficiently well preserved to afford characters amply 

 sufficient for defining the nature and affinities of the animals to 

 which they belonged. 



That the bones are those of dinosaurs is rendered certain by 

 their huge size ; while the same feature is likewise sufficient to 

 indicate that they belong to the sauropodous section of that great 

 group. If further evidence were required as to their sauropodous 

 affinities, it is seen in the structure of the cervical and dorsal ver- 

 tebras described and figured below, which show the pits on the 

 sides of the centra distinctive of the group in question. 



The vertebras are represented by specimens from the cervical, 

 dorsal, lumbar, sacral, and caudal regions. Both the cervicals and 

 dorsals are strongly opisthoccelous, and carry large lateral cavities ; 

 these cavities being apparently devoid of any channel of communi- 

 cation with the interior of the centrum, which seems to be solid ; 



1 E. B. Newton, Geol. Mag. 1893, p. 193. 



2 Id. Quart. Journ. Geol. Soc. vol. li. p. 78. 



