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»BARYONYX WALKERI 
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lateral; D, pubic peduncle, lateral. x 0.25. 
The ischiadic peduncle is shorter and much more slender. Its 
icular surface is much smaller, semicircular with its medial corner 
extended to a point (marking the sharp medial edge of the acetabu- 
um) and extremely rugose. The supra-acetabular crest is well 
veloped and has a sharp lateral edge. 
PUBIS (Fig. 39A). One large elongated fragment, 277 mm long, is 
proken at one end and another fragment, 248 mm long, at both ends; 
one broken end on each resembles the other so much in size and 
shape that they are almost certainly parts of the same element, not 
mmediately adjacent to each other but separated by a gap of 
1 determinate width. Both are stout shafts produced on one side into 
broad flange that could well represent part of one half of the ‘pubic 
pron’, concave on one side and flat on the other. The fragment with 
complete end is probably the distal part of the left pubis, the other 
\ third fragment, 251 mm long, has the shape of one end (presumed 
listal) very like that of the proximal end of the central portion and is 
ikely to be a more proximal piece of the same element. The lengths 
of the three pieces added together total 776 mm, and we estimate the 
ength of the entire pubis to have been about 1000 mm; this is not 
\nreasonable when compared with the overall length of the entire 
i ium (about 820 mm). The position of all three pieces on the block 
jlan (Fig. 48) is fully in accord with this identification. 
The acetabular portion of the left pubis is missing entirely. The 
jroximal fragment of the shaft has a thick, rounded lateral edge; the 
edial border of this proximal partis a true edge, slightly downturned. 
he medial half of the dorsal surface is distinctly convex, bulging 
‘orsally, and the lateral half is distinctly concave. The bone itself 
arrows considerably from its proximal end (from 105 mm at the 
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teak to a minimum of 71 mm), with its medial and lateral profiles 
‘ymmetrical and slightly concave. The distal 100 mm or so of this 
agment shows, on its medial side, the proximal beginnings of a 
hedial flange, also with a true medial edge; lower down, on the 
jroximal part of the central fragment, this could well have united 
49 
Fig. 37 Baryonyx walkeri, holotype, BMNH R9951; right ilium. A, posterior process in posterior view; B, same, ventrolateral; C, ischiadic peduncle, 
with its right counterpart to form a pubic apron (see next paragraph). 
The central part of the left pubis is fairly straight and compressed 
in an oblique transverse plane. Its anterodorsal surface is more or 
less flat and has a thick rounded lateral edge which widens regularly 
towards the proximal end of the bone. Its posteroventral surface, by 
contrast, is strongly concave in transverse section, for it tapers 
medially into a thin flange. In the more proximal part of the 
preserved fragment this flange is thicker and is broken off on the 
medial side, suggesting that it might well have extended farther in 
that direction to join its fellow in a median symphysis as part of a 
pubic apron. The more distal part of the flange, however, is 
extremely slender and has a blade-like medial edge of finished bone, 
making it less likely that it extended to the midline. This means that 
a complete apron would have been formed only in the middle section 
of the pubis. 
Fig. 38 Baryonyx walkeri, holotype, BMNH R9951; reconstruction of 
right ilium in lateral and ventral views. x 0.125. 
