10 



Dinosanria — Cetiosaurns and Ornithopsis. 



Cetiosauims, 

 or " Whale 

 Lizard." 



Ornithopsis. 



Wall-case, 

 No. 3. 



Avas herbivorous and its food was probably succulent vegetation. 

 There are no examples of D/pZocZocn*- at present iu the Collection. 



The Cetiosaurns, or "Whale-Lizard," thus named by Sir 

 Richard Owen, from some resemblance in the form and struc- 

 ture of the posterior vertebras to those of a whale (it must be 

 borne in mind that the Cetiosaurs have really no affinities to 

 the whales in any way whatever, save in name !) is another 

 genus of these huge Saiirians, whose remains are found in our 

 own island, and of which three species are recorded, the earliest 

 in geological time being the C. longns (Owen). Of this species 

 a large portion of a skeleton of the same animal w^as discovered 

 in 1870, in the Great Oolite at Enslow Bridge, near Oxford, and 

 is preserved in the Oxford University Museum ; but plaster-casts 

 of the large bones of the extremities are placed in the case. 

 The femur is 5^ ft. long, and the humerus 4 ft. 3 inches. The 

 anterior vertebrjB are large, with cup and ball articulations, they 

 have large cavities in the centra, and are buttressed like those 

 of Ornithopsis. an allied genus. A huge arm-bone (humerus) 

 nearly 5 ft. long, from the Kimmeridge Clay, Weymouth, has 

 been referred to this genus, under the name of C. humero- 

 cristatus ; it is at present the only evidence of the species 

 known. C. hrevis, from the Wealden of Sussex and the Isle 

 of Wight, is represented by caudal and dorsal vertebrjp, &c., 

 including the original specimens from Dr. Mantell's collection, 

 upon which the genus was founded. 



Here are exhibited a series of vertebra? and other remains of 

 a huge Dinosaur, named Oriiithojjsis HulJcei (Seeley), obtained 

 from the Wealden formation, Brixton, Isle of Wight. 



Ornithopsis was remarkable for the extreme lightness in 

 construction of the bones of its neck and back, combined with 

 great strength. A single dorsal vertebra had a centrum 

 10 inches long, and 25 inches in circumference at the front or 

 convex end, whilst it measured in height to the summit of the 

 dorsal spine 25 inches ; and in breadth aci-oss the transverse 

 processes 19 inches. A single centrum of one of the cervical or 

 neck vertebrae measnres 32 inches in length. 



The centrum of each vertebra is composed of highly cellular 

 bony tissue (like the frontal portion of the skull of the ele- 

 phant "), and has a large cavity on each side. The dorsal and 

 cervical "vertebi'ffi are opisthocoelous (i.e., hollow behind, and 

 convex in front), and each has articulations for a double- 

 headed rib. The spinous processes are convex, and gi'eatly 

 developed, being rendei-ed at the same time both extremely 

 light and strong by struts and buttresses and thin sheets of 

 bone, with large and deep recesses between. The pelvis and 

 several vertebrae of another very large species, Ornithopsis 

 Leedsi, obtained by Mr. Leeds from the Oxford Clay of Peter- 

 borough, are exhibited in the same case. 



