210 



R. S. Lull — Armor of Stegosaurus. 



Owen lias figured what he calls the "carpal spine" in 

 Dacentrus ( Omosaurus) hastiger from the Kimmeridgian of 

 Wiltshire (Mod. Brit. Fos. Repts. pi. 77), which shows precisely 



Fig. 11. 



Fig, 11. Caudal spine of Stegosaurus sulcatus. 

 natural size. Dorsal, anterior and ventral aspects. 

 longitudinal ridge. 



After Marsh. 1/12 

 b, the base showing 



this same structure of the base as in Stegosaurus sulcatus. 

 Dacentrus is the probable Old World ancestor of Stegosaurus, 

 but while the caudal spines are knowD, the presence of the 

 armor plates has not as yet been demonstrated. 



