64 
AREA OF SCATTER. All the bones were found within an area 
measuring 5m x 2m (Fig. 48). 
RELATIVE ORIENTATION OF ELEMENTS. The various elements were 
generally not far from their natural positions (except for a few that 
had previously been disturbed by the earth-moving operations). 
Thus most of the pieces of the skull, pectoral girdle and fore-limbs 
were at one end of the excavation and most of the pelvic girdle and 
hind-limbs at the other. (See Appendix B.) 
WEATHERING. The degree of weathering of the bones was variable 
and some were unweathered. The most heavily weathered bones, in 
particular fragments of rib-shafts and gastralia, show pre-fossilisa- 
tion splintering, flaking and splitting (stages 2-3 of Behrensmeyer 
1978). It should be remembered that the climate of the region was 
warmer than it is today (more like that of the present-day Mediterra- 
nean area) and that the bones lay in a very exposed situation. 
DISTORTION AND CRUSHING. Most of the bones were not crushed 
or distorted to any significant degree, but a few (e.g. the distal end of 
the tibia) did suffer severe post-mortem distortion. 
BREAKAGE. Many of the bones were broken; the skull was in 
pieces and much of it was missing. However, bones that had lain 
undisturbed in the clay or in the nodules since fossilisation generally 
displayed only clean transverse breaks across their shafts, the bro- 
ken ends showing few signs of weathering or erosion; some were 
effectively undamaged. In several cases adjacent parts of the same 
bone, separated by a clean unweathered break, were found in 
different nodules (for example, both scapulae); after preparation 
they fitted together precisely. The left dentary had been snapped in 
half, with the unweathered broken surfaces still in contact with each 
other at an acute angle. A weathered rib-shaft had been split longitu- 
dinally and was preserved with a fragment of another rib wedged at 
right angles in the gap. 
INDICATIONS OF PREDATION OR SCAVENGING. There are no gnaw- 
marks or punctures produced by the teeth of predators or scavengers. 
TEETH. All the lower teeth of Baryonyx had fallen out of their 
sockets, but some of the upper teeth remained in place. 
TAIL. The tail was missing almost entirely; all that was found were 
a few fragmentary vertebrae and haemapophyses, mostly from its 
base. 
Unrelated to all this is the regrettable fact that some of the bones 
had clearly been broken or severely crushed by mechanical equip- 
ment shortly before we collected them. 
The deposition of fine-grained sediments around the bones of 
Baryonyx indicates the quiet, low-energy nature of the Smokejack’s 
environment at that particular time; likewise the close association of 
large and small skeletal elements within a restricted area implies a 
lack of sorting by currents (Shipman 1981: 31 et seq.). These factors 
suggest that the carcase of the dinosaur was unlikely to have been 
carried any significant distance by the water, which, in any case, was 
probably too shallow to float and transport such a huge animal. 
Indeed, the immediate area of the burial was well suited to be the 
home territory of a large terrestrial piscivore, catching fish and 
perhaps scavenging on the mudplain; it might then have become 
mired in the soft silts, died, and been buried more or less in situ. 
The excellent preservation of most of the skeletal elements, 
without evidence of predation or scavenging, suggests that the 
carcase must have been covered with sediment fairly rapidly. Total 
decomposition of soft tissues resulted in the disarticulation of the 
bones, including partial and total separation of centra and neural 
A.J. CHARIG AND A.C. MILNER 
Fig. 49 Baryonyx walkeri, holotype, BMNH R9951; model of carcase 
lying on mudbank or in shallow water. Model made by John Holmes. 
arches. The differential weathering patterns suggest intermittent 
surface exposure of parts of the skeleton, either by receding water- | 
level or by shifting of fine sediment. The girdle- and limb-bones, » 
adjacent fragments of which were sometimes encapsulated into 
separate nodules, had evidently been broken before fossilisation. In | 
particular, the unusual nature of the break in the left dentary suggests } 
trampling by large animals while the bone was buried in shallow 
sediment (P.J. Andrews, pers. comm.), as does the condition of the 
split rib-shaft. This interpretation is in accord with the suggested | - 
shallowness of the water and sediment, for animals of any size, even |) 
the largest, are buoyed up and effectively weightless if the water is | 
ao ff Sf x se ec eS OS SS S|) oS a a ae cane ae eee 
would hold the ends of the trampled bones close together and the 
disarticulated remains would be less liable to wide scattering than } 
they would be at the surface or in clear water. In this context it is 
interesting to note the observation by Ross & Cook (1995) that the 
irregular nodules containing swirls of silt and sand at the Baryonyx | 
horizon are reminiscent of the red clay, now exposed on the fore- 
shore near Hanover Point on the Isle of Wight, that had clearly been 
trampled by dinosaurs. Indeed, many of the siltstone nodules found 
there are casts of large Jguanodon footprints, although none of the 
nodules at Smokejack’s resembles footprints. 
The total orientation of the bones, disarticulated though they 
were, suggests that the carcase lay on its back — maybe turned] 
somewhat towards the left (i.e. with its right side uppermost; see Fig. | 
49). An upside-down position accords with the fact that all the lower) _ 
teeth have dropped out of their sockets while some of the upper teeth} 
have remained in theirs. 
ACKNOWLEDGEMENTS. Ourespecial thanks are due to MrWilliam Walker t 
for finding the original claw-bone and for so kindly donating it to the 
Museum. We are likewise grateful to the Chairman and Directors of the 
Ockley Brick Company Limited (now Ockley Building Products Limited,) 
Blue Circle Industries plc) for giving the rest of the dinosaur to the Museum, | N 
for providing a large shotblasting machine to expedite its preparation, and for, 
making us a grant to pay for the illustrations to this paper. We thank in|) » 
