Weathering of the cortical surface can be ruled out as the cause of
the marks on IVPP V16137. Several of the marked elements were
discovered in situ, and in two others the bone surface showing the bite
marks was face down on the sediment when the specimen was found.
Bones at Bayan Mandahu are a pale yellow colour when first exposed
(DH pers. obs.), but tend to lighten in colour after lying on the surface
for any length of time and ultimately become white. Many of the
tooth-marked pieces of IVPP V16137 were still yellow when
recovered from below the surface, ruling out erosion and later
reburial. Other pieces of bone from the surface do exhibit weathering,
which tends to leave a diagnostic pattern on the bone surface (see
Fig. 2D). Other taphonomic effects such as distortion, chemical wear
or reworking are unlikely to have had a significant impact on the
material, given the generally high quality of the bone surfaces.
Fragmentation aside, the individual pieces of bone have suffered little
damage apart from the feeding traces themselves.