Marcu 18, 1897 | 
NATURE 
465 
all probability, covered with a horny mandible fitted to | 
meet the strong beak above. Save in the more slender 
head, and the small and feeble fore-limbs, C/laosaurus 
greatly reminds one of /ezanodon. 
In support of the erect position in which so many of 
Marsh’s animals are represented, it may be well to men- 
Fic. 5:—Restoration of Jewanodon Bernissartensis, Boul. (sb; nat. size). An herbivorous 
dinosaur from the Wealden (Upper Jurassic ?) Bernissart, Belgium. 
tion that Claesaurus has “in the median dorsal 
region, between the ribs and the neural spines, 
numerous rodlike ossified tendons, which in- 
crease in number in the sacral region and along 
the base of the tail, and then gradually diminish 
in number and size, ending at about the thirty- 
fifth caudal. These ossified tendons are well 
shown in the restoration (Fig. 6), and are of 
much interest.” Similar ossified tendons are 
seen in /gwanedon, and they doubtless served 
to give attachment to the great dorsal muscles 
which supported the vertebral column when the 
animal assumed an upright attitude, or when it used its 
immense and powerful tail as an oar in swimming across 
a stream. 
Marsh, an herbivorous 
Cretaceous, Wyoming. 
Fic. 6.—Restoration of Claosanrnus annectens, 
Dinosaur (5 nat. size). 
Another, and possibly the most singular, as well as one 
of the latest of Prof. Marsh’s pets, is the huge Z7icevat- 
ops prorsus, one of the quadrupedal dinosaurs, with a 
skull armed with three horns, two of which were nearly 
a yard long, and having a bony frill, like an immense 
Elizabethan ruff, four feet broad, attached to the back 
NO. 1429, VOL. 55 | 
of its occiput, the cranium and frill being 6 feet in length 
from the nose to the hinder border of the bony ruffle. 
But skulls of 7yéceratops horridus have been obtained 
by Marsh, measuring from 7 to 8 feet in length. 
Its horns, when found broken off from the skull, were 
so like the bony horn-cores of some bovine ruminant, as 
to have been suspected to belong to some very ancient ox ; 
but certainly such three-horned beasts would have been 
“Kittle-cattle ” to yoke, or to plough with ! 
_ The beak-like edentulous character of the mandibles 
is very striking, and from the vascular surface of the 
horn-cores and bony frill, these too, when living, must 
have been sheathed in a strong horny external covering. 
The teeth are very remarkable, having two distinct 
roots ; this is true both of the upper and the lower series. 
The roots are placed transversely in the jaw, and there 
is a separate cavity more or less distinct for each of 
them. They form a single series only in each jaw. 
The brain of 7yiceratops appears to have been smaller 
in proportion to the entire skull than in any known 
vertebrate. 
Although we have nothing in this country which can 
for a moment compare, in magnitude, with the vast areas 
in the Western Territories of the United States, often 
covered to an enormous thickness by great 
lacustrine deposits of Tertiary, Cretaceous, 
Jurassic, and Triassic age, full of evidences of 
old land conditions, yet in our limited island 
we can show evidence probably of ten succes- 
sive land-stages from the Wealden to the 
nonaeeeegquar 
TANS NOON 
! is) 
Fic. 7.-—Restoration of Triceratops prorsus, Marsh (,) nat. size). Cre- 
taceous, Wyoming. (Length in life about 25 feet, height ro feet.) 
Trias, marked by Mammals or Dinosaurs, by Ptero- 
dactyles, and by insects, by plants and carbonaceous 
shales or coal-seams; so that throughout the lower 
Secondary series, at least, we can lay down buoys to- 
mark the spots where the old land was situated, though 
of its actual extent we know but little. 
What, we may well ask, were the peculiar conditions 
of life in the Mesozoic period, which brought about the 
evolution and continuance through this long zon of such 
a remarkable land fauna? The associated Jurassic flora 
may help to solve this query. It consisted largely of 
Araucarias, T/zjites, and other Coniferae, of Cycadex, | 
and Palms, of Tree-ferns and many species of Filicina,, 
of lesser growth, of giant Equisetums, of liverworts 
and club-mosses, and some herbaceous and aquatic 
plants ; but, so far as our records tell, no grasses had as 
yet made their appearance. It is, therefore, certainly 
reasonable to conclude that most of the herbivorous 
dinosaurs must have subsisted, almost wholly, by browsing 
upon the leaves, shoots, and young branches of arboreal 
vegetation (as did the giant ground-sloths of later 
Tertiary times in South America), although some may 
perhaps have fed upon aquatic plants. 
This habit doubtless tended to develop their frequent 
bipedal mode of progression amidst the tall and luxuriant 
vegetation along the river-banks where they pastured. 
It also enabled them the better to espy the approach of 
their enemies, the light-leaping Aa//opus and Compso- 
