Fig. 23 Baryonyx walkeri, holotype, BMNH R9951; 4" and 5" dorsal vertebrae. A, D4 (from top downwards) centrum and left transverse process in 
anterior view; left transverse process in dorsal view; centrum in left lateral, ventral and posterior views. B, D5 in (from top downwards) anterior, left 
lateral, and posterior views. x 0.25. 
zygapophysis projects directly from the anterior edge of the dorsal 
surface of the transverse process. The condition in D1 cannot be 
seen, the relevant part of the vertebra having been broken off, but it 
is very noticeable in D2 and progressively less so in D3 and D4. In 
D5 the prezygapophysis has its own separate peduncle. 
The distance (if any) between the posterior edge of the transverse 
process and the postzygapophysis, along the posterior horizontal 
A.J. CHARIG AND A.C. MILNER 
lamina, is yet another highly variable parameter. It is, however,” 
impossible to quantify numerically because all the relevant surfaces . 
and edges are rounded, so that there are no fixed reference points 
from which to take measurements. In D1-D3 there is a considerable} _ 
(though diminishing) distance between these two structures. In D5-) ) 
D7 the rear edge of the transverse process (viewed from the side) 
joins the postzygapophysis approximately at its middle. In D11 it 
