CORYTHOSAURUS, THE NEW DUCK-BILLED DINOSAUR 
By W. D. Matthew and Barnum Brown 
HE American Museum of Natural 
History has recently added a remark- 
able specimen to the series of skele- 
tons in the Dinosaur hall. It is a 
crested, duck-billed dinosaur, unusually com- 
plete and in many ways unique; for not only 
is the bony skeleton and the skin impression 
surrounding the body preserved, but under- 
neath the skin may be traced at least four 
distinct sets of muscles, showing definite 
origin and insertion of each series. 
Evidently the body had floated along some 
prehistoric beach where, caught in quiet 
water, it was stranded lying on its left side 
on a bed of plants the carbonaceous remains 
of which may still be seen, accounting for 
the indefinite impression of a large part of 
the skin on the left side. Unio shells were 
scattered all about; other trachodont bones 
and a water turtle lay on the top of the tail, 
and over the body were deposited three large 
folds of sandstone, the cross-bedded layers 
showing deposits by water currents from 
different directions. On this upper right 
side the fine sandy silt preserved a better 
impression of the skin, where it was not torn 
away, and the outline of the underlying bony 
skeleton is distinct. 
_ This skeleton is complete except for the 
fore limbs, most of which are missing, but 
the bones are mostly concealed under the skin. 
The texture of the skin is not as well preserved 
as in the “dinosaur mummy” also exhibited 
in this hall, but shows a similar pattern of 
small, tesselated scales, not overlapping like 
those of a lizard or snake, but grouped in pat- 
terns and of various sizes and arrangement 
in different parts of the body. The double 
series of slender, rodlike, calcified tendons 
along the back are very clearly shown; these 
are tendons of part of the great muscles that 
moved the backbone in a vertical plane. 
It is very rarely that any portion of an 
extinct animal other than the skeleton is pre- 
served. The softer parts almost always decay 
and disappear without leaving a trace behind, 
long before petrefaction sets in. Usually all 
that we know of an extinct animal is derived 
from the study of its skeleton and of its bony 
armor, if it had any. Any trace of skin or 
other soft parts is naturally a great help in 
attempting to reconstruct its external form 
and in determining its habits. Such evidence 
is especially welcome in connection with dino- 
saurs, animals millions of years old and 
very different from any now living. Delicate 
and often obscure as are the skin impressions, 
they have been noticed and recorded on vari- 
ous fossil skeletons; but it is only within the 
last few years that the development of the 
technique of excavating and preparing such 
specimens has made it possible to save them 
entire. The two dinosaur skeletons in this 
hall are believed to be the only ones with the 
skin extensively preserved shown in any 
museum. A third specimen has been secured 
by the Senckenberg Museum, Frankfurt-am- 
Main, but is not yet completely prepared for 
exhibition. 
The new acquisition in the American Mu- 
seum was found in 1912 by a Museum expedi- 
tion in charge of Mr. Barnum Brown, in the 
Belly River cretaceous rocks exposed at 
Steveville, on the fossil-famous Red Deer 
River of Alberta, Canada. It was taken up 
in large blocks, united in the laboratory just 
as found, and raised to a vertical position so 
that both sides may be seen, thus assuming a 
pose the animal may well have taken while 
swimming. The missing parts of the front 
limbs have been painted on the matrix from a 
second skeleton of the same size found last 
year, as also the tip of the tail, which was 
weathered out and partly missing. 
The preparation of the skeleton was a slow 
and difficult process, requiring great skill 
and patience on the part both of collector and 
preparator. It was so fragile and heavy in 
some parts that it was necessary to support 
it by a perfect network of steel rods perforat- 
ing the blocks in every direction, and in other 
parts so extremely thin and delicate that the 
least pressure would have shattered or 
damaged it beyond repair. Add to this the 
difficulty of removing the rock matrix, often 
quite hard, from the delicate film which repre- 
sents the skin, and cleaning it so as to show 
the structure; of cleaning and mending the 
innumerable breaks and joints caused by the 
earth-jars and movements in the rocks during 
the millions of years since it was buried; and 
it will not appear surprising that two years 
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