NATURE 97 
THURSDAY, JUNE 4, 1885 
THE DEINOCERATA OF WYOMING 
Dinocerata, a Monograph of an Extinct Order of 
Gigantic Mammals. By O. C. Marsh. Monographs 
of the U.S. Geological Survey. Vol. X. (1884.) 
ON the high plateau that lies to the west of the Rocky 
Mountains, along the southern borders of Wyoming 
Territory, the traveller who is moving westwards begins 
to enter upon a peculiarscenery. Bare, treeless wastes of 
naked stone, crumbling into sand and dust, arise here and 
there into terraced ledges and strange tower-like pro- 
minences, and sink into hollows where the water gathers 
in salt or bitter pools. Under the cloudless sky, and in 
the dry clear atmosphere, the extraordinary colouring 
of these landscapes forms, perhaps, their weirdest feature. 
Bars of deep red alternate with strips of orange, now 
deepening into sombre browns, now blazing out again 
into flaming vermilion, with belts of lilac, buff, pale green, 
and white. And everywhere the colours run in almost 
horizontal bands, the same band being continuous and 
traceable from hill to hill, and tower to tower, across 
hollow and river-gorge for mile after mile through this 
rocky desert. These parallel strips of colour mark the 
nearly horizontal stratification of the rocks that cover all 
this wide plateau country. They are the tints character- 
istic of an enormous accumulation of sedimentary rocks 
that mark the site of a vast Eocene lake or succession of 
lakes on what is now nearly the crest of the continent. 
These lacustrine sediments, in all somewhere about 
two miles in vertical thickness, were doubtless laid down 
during a slow subsidence of the lacustrine area, when the 
subterranean movements were in progress that finally 
gave the mountain-ranges and plateaux their present forms 
and altitudes. They represent a vastly protracted period 
of quiet sedimentation, in the immediate proximity of an 
extensive land-surface plentifully clothed with a tropical 
vegetation, and abounding in varied forms of animal life. 
They consequently offer to the geologist peculiar facilities 
for investigating the evolution of a fauna apparently 
exposed to the minimum of interference from changes in 
its environment. 
It is now about fifteen years since the wonders sealed 
up within the sediments of these vanished lakes first 
began to be known. The wandering Indian, indeed, had 
long been familiar with the skulls and skeletons which, by 
the decay of the inclosing rock, looked out upon him 
from the side of éz¢ée and cavion. But he revered them 
as the bones of his ancestors, and left them untouched, to 
be disinterred by the ceaseless working of wind and rain. 
The earliest trappers, squatters, and prospectors brought 
back news of marvellous monsters grinning from the 
ledges of rock beneath which they camped. At last these 
tales attracted the notice of some of the enthusiastic 
naturalists in the eastern States. Prof. Leidy, of Phila- 
delphia, obtained a number of bones from which he was 
able to bring to light an entirely novel, and now wholly 
extinct creature, to which he gave the name of Uznta- 
therium. Prof. E. W. Cope likewise described some 
forms disinterred by him in the same region. But the 
VOL, XXXII.—NO. ‘814 
earliest and most successful investigator of these remains 
is Prof. O. C. Marsh, who, as far back as 1870, began the 
search in the Green River basin, and who, after many 
years of most laborious research, both among the western 
deserts and in his wonderful collection at Yale College, 
has at last been able to publish this splendid monograph 
on the Deinocerata. No trouble or expense has been 
spared to obtain material for the study of these strange 
extinct creatures. One expedition after another has been 
despatched to the West, and many tons of bones have 
been deposited at Yale, where it is believed there are now 
represented more than two hundred individuals of the 
Deinocerata alone. Some of these remains are admirably 
preserved ; indeed, had the animals been still living, the 
materials for a knowledge of their osteology could hardly 
have been more perfect than it is. 
The Deinocerata form an order established by Prof. Marsh 
to include some peculiar and well-marked forms found in 
the lacustrine deposits of the Green River basin—a tribu- 
tary of the Colorado River of the West. This order 
belongs to the Ungulates, some of the characters allying 
it with the Artiodactyls (Paraxonza), others with the 
Perissodactyls (Wesaxonza) ; while in others, again, it is 
linked with the Proboscidians. The points of resemblance, 
however, are usually, in the author’s opinion, such general 
characters as seem to point backward to some ancestral 
ungulate, rather than to any near affinity with existing 
forms of these groups. The Deinocerata include three 
genera which occupy three successive stratigraphical 
horizons. The oldest, Uintatherium, found in the lower 
strata of the Eocene lake, appears to be the most primi- 
tive type; the youngest, 7zzoceras, found at the highest 
level, is the most specialised ; Dinoceras being an inter- 
mediate form. The number of species belonging to the 
order has not been satisfactorily determined, but about 
thirty forms more or less distinct have been recognised. 
Comparing Dznoceras with the large living Ungulates, 
Prof. Marsh points out that in size and proportions it was 
intermediate between the elephant and rhinoceros, but 
had also features akin to those of the hippopotamus; 
while in its stature and movements it probably resembled 
the elephant as muchas any existing animal. It presented 
certain striking peculiarities which at once marked it off 
from any form now familiar to us. The skull in particular 
wore an altogether extraordinary aspect. It was long 
and narrow, and on its top it supported three separate 
transverse pairs of high osseous protuberances or horn- 
cores, which may have been covered with bosses of 
thick skin, and were no doubt powerful offensive 
weapons. The canine teeth were enormously deve- 
loped in the male, forming short, trenchant, decurved 
tusks, which were protected by a dependent process on 
the lower jaw. The nasal bones were so elongated as to 
form nearly half the length of the entire skull, projecting 
forward and overhanging the premaxillaries. There was 
probably no proboscis, for the neck was long enough to 
allow the head to reach the ground without it, but there 
is some evidence of a thick flexible lip, perhaps like that 
of the rhinoceros. The brain was proportionately smaller 
than in any other known mammal, recent or fossil, and 
even less than in some reptiles. In one species at least 
it was so diminutive that it apparently could have been 
drawn through the neural canal of all the pre-sacral 
EF 
