113. Cladeiodon.(1) In. the new red sandstone (Keuper?) of Warwick
and Leamington, detached teeth occur of the size and form represented
in PI. 62 a , fig. 4, a & 6 ; they have been found in the same
quarries as those containing the remains of the Labyrinthodon. In
t eir compressed form, anterior and posterior serrated edges, sharp
points, and microscopic structure, these teeth agree with those of the
Saurian reptiles of the Bristol conglomerate. In their breadth, as
compared with their length and thickness, they are intermediate
between the Thecodontosaurus and the Palaosaurus platyodon; they are
also larger and more recurved, and thus more nearly approach the
form characteristic of the teeth of the Megalosaurus. From these
teeth, however, they differ in their greater degree of compression,
and in a slight contraction of the base of the crown; I propose
therefore, to indicate the genus, of which, as yet, only the teeth are
known, by the name of Cladeiodon, and for the species from the
Warwickshire sandstones the name of Cladeiodon Lloydii, in testimony
of the friendly aid of Dr. Lloyd of Leamington, to whose exertions 1
owe the materials for the description of the teeth of the present genus,
and the still more remarkable ones of the British species of Labyrinthodon,
with which the teeth of the Cladeiodon are associated.
PROTOROSAURUS.
114. In the pyntic schists of Thuringia, which, like the dolomitic
Breccia near Bristol, rank as the oldest member of the new-red-
sandstone system, the fossil remains of a small species of Saurian
reptile have long been known to occur; and it is from the individual
specimen of this ancient extinct species, first described by Spener as a
sort of crocodile in the Miscellanea Berolinensia for the year 1710,
that the observations on the dental system are here taken.
It is well known that Cuvier, after an elaborate comparison of
the figures and descriptions of the Thuringian fossil Saurian by Spener
Link, Swedenborg and Wachsmann, arrived at the conclusion that thé
species was to be referred to the Monitors or Tupinambis.(2)
(1) x\atevu, to prune; 6Soc, a tooth ; from the resemblance of the tooth to a pruning-knife
(2) On ne comptera done plus les animat* de Spener et de Link parmi les crocodiles, ou
M. Hermann Y. Meyer has proposed the name of Protorosaurus
Speneri for the Thuringian Monitor, but he has not added any new
fact relative to its organization.
This name I shall retain, because the species in question actually
differs from the existing Monitors and other Lacertians by the same
character which distinguishes the Thecodontosaurus, viz : the implantation
of the teeth in distinct sockets. Of these sockets, the dislocated
ramus of the lower jaw in Spener’s specimen exhibits fourteen,
which are of a square shape with the angles rounded off, close set and
sub-equal. The teeth, of which eighteen may be counted in the
upper jaw, are relatively longer, more slender, and more cylindrical
than in the Thecodon ; they are more or less broken| the most perfect
of them measure three lines in length, and two-thirds of a line across the
base ; they are of a jet-hlack colour, and, being imbedded in a dark
matrix, have not enabled me to determine whether the Protorosaurus,
like the equally ancient reptiles of the Bristol conglomerate, had the
teeth armed with serrated ridges(l).
MEGALOSAURUS.
115. The compressed varanian form of tooth, with trenchant and
finely dentated margins, which characterized the ancient Palaeosaur
and Cladeiodon, is continued in the comparatively more recent and
gigantic species of terrestrial lizard, of which the remains were discovered
by Dr. Buckland in the oolite of Stonesfield. The characters
and peculiarities of the jaws and teeth have been so accurately and
graphically described by their discoverer, that an apology would he
due rather for suppressing, than for here reproducing them.
“ From these,” says Dr. Buckland, “ we learn that the animal
was a reptile, closely allied to some of our modern lizards, and
viewing the teeth as instruments for providing food to a carnivorous
creature of enormous magnitude, they appear to have been admirably
eelui de Swedenborg parmi les guenons ou les sapajous ; mais on les rangera tous parmi les
monitors ou tupinambis. Ossem. fossiles, 4to. vol. v, p. 306.
(lj Besides the thecodont type of dentition, the Protorosaurus differs from all recent Saurians,
and resembles the Pterodactyle in the great relative size of the cervical vertebra?, and the ossified
tendons of the muscles of that region of the spine; it diflers from all reptiles, except the extinct
Racheosaurus in the bifurcate superior spines of the caudal vertebra?.