At the termination of a
possible low-water season during which these processes of desiccation
took place, the 'mummy' may have been caught in a sudden flood,
carried down the stream and rapidly buried in a bed of fine river sand
intermingled with sufficient elements of clay to take a perfect cast
or mold of all the epidermal markings before any of the epidermal
tissues had time to soften under the solvent action of the water. In
this way the markings were indicated with absolute distinctness, ...
the visitor will be able by the use of the hand glass to study even
the finer details of the pattern, although of course there is no trace
either of the epidermis itself, which has entirely disappeared, or of
the pigmentation or coloring, if such existed.
"Although attaining a height of fifteen to sixteen feet the trachodons
were not covered with scales or a bony protecting armature, but with
dermal tubercles of relatively small size, which varied in shape and
arrangement in different species, and not improbably associated with
this varied epidermal pattern there was a varied color pattern. The
theory of a color pattern is based chiefly upon the fact that the
larger tubercles concentrate and become more numerous on all those
portions of the body exposed to the sun, that is, on the outer
surfaces of the fore and hind limbs, and appear to increase also along
the sides of the body and to be more concentrated on the back. On the
less exposed areas, the under side of the body and the inner sides of
the limbs, the smaller tubercles are more numerous, the larger
tubercles being reduced to small irregularly arranged patches.
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