New Species o/Propappus, and Pose of Pareiasaurian Limbs. 329 



The Pose of the Limbs. 



Though most of the bones of Pareiasaurus have been known for 

 twenty years, and though four skeletons are now known from South 

 Africa, and at least as many from Russia, there are still a good 

 many points in dispute in regard to the pose of the animal. Seeley 

 had the British Museum specimen mounted with the limbs so bent 

 that the abdomen must have been almost touching the ground, with 

 the interclavicle in advance of the plane of the occiput, and with 

 the scapula pointing almost directly backwards. Amalitzky has 

 set up his skeletons with the limbs straighter, with the scapula 

 directed as much upwards as backwards and with the shoulder 

 girdle situated some little distance behind the head. In giving a 

 restoration of Pareiasaurus in 1903 from the South African Museum 

 specimen, I also placed the shoulder girdle a little distance behind 

 the head, and made the animal stand well off the ground. Boulenger, 

 in discussing Telerpetou in 1905, criticised my restoration, pointing 

 out that in his opinion Pareiasaurus had no more neck than a 

 Salamander. 



The very perfect bones of Propappus, though they may leave a 

 little doubt on a few points, enable us to have a much clearer idea 

 of the pose of the animal and of its movements than was previously 

 possible. As all the limb bones have their articular surfaces perfectly 

 preserved, we can fit the limbs together with certainty. 



The peculiarly shaped glenoid cavity, with its large posterior 

 concavity and the small anterior flattened surface, so exactly 

 corresponds to the head of the humerus if we allow for a car- 

 tilaginous pad that we can articulate the humerus on the shoulder 

 girdle with confidence, and the position of the bones when the 

 animal is standing must be as shown in the figures given. The 

 movement of the humerus must have been practically limited to 

 an up and down direction, and when the animal lay down on its 

 front the anterior limbs would lie outwards and forwards by its 

 sides. In the standing position the humerus, radius, and ulna 

 would be in the positions shown in the drawings. One interesting 

 thing about the anterior limb is that it becomes quite manifest that 

 the scapula must have been directed much more upwards than 

 backwards, and as the shoulder girdle is about twice as long as 

 the head is deep it cannot have been situated close up to the 

 head, and therefore Pareiasaurus and Propappus must be regarded 

 as having had distinct necks. 



The hind limb was probably more freely movable than the 



