228 Animal Lite 
curiously-formed teeth (Fig. 18) being often worn down almost to the roots. The 
iguanodon was one of the bipedal forms, and its huge three-toed footprints are occasionally 
met with in the Wealden sandstones at Hastings. Whether another type of dinosaur 
tooth (Fig. 19), which has been found in the corresponding strata of the Isle of Wight 
and elsewhere, also indicates herbivorous habits is not quite so certaim. ‘These teeth, 
whose owner has been named the hoplosaur, are of a curious spatula-like shape quite 
unparalleled by any existing type. Certainly they do not belong to a flesh-eating 
animal, but their owners may either have subsisted on invertebrate animals, or, more 
probably, on the rank and lush vegetation of lakes, that did not require the 
mastication necessary for the palm and cycad leaves which not improbably formed the 
diet of the iguanodon. The latter creature, it may be mentioned, takes its name from 
a fancied resemblance between its huge teeth and those of the (comparatively) 
diminutive iguana of the present day. 
The hoplosaur and its allies were remarkable for their relatively small heads and 
long necks, and it has been suggested that they spent much of their time with their 
bodies submerged in the water of lakes or rivers while they cropped the herbage from 
the banks. 
The great marine swimming reptiles of the chalk, oolites, and has—the ichthyosaurs 
and plesiosaurs—had their long and powerful jaws armed with a formidable series of 
sharply-pointed teeth, which were generally conical and fluted, 
although smooth and compressed with cutting-edges in one of 
the largest ichthyosaurs, and triangular in those short-necked 
plesiosaurs known as pliosaurs. In the ichthyosaurs the teeth 
were set in a groove, but in the plesiosaurs each had a 
separate socket. These creatures were evidently carnivorous, and 
preyed largely on the hard-scaled fishes of their time. They 
were, in fact, the sperm-whales and lkiller-whales of early 
epochs of the earth’s history, when, both on land and sea, 
reptiles played the part now performed by mammals. 
Although brief reference has been made to the extinct 
labyrinthodonts, which belong to the same great group, I have 
not thought it worth while to discuss the teeth of modern 
Fig. 19, Tooth 
Vig. 18. Tooth i 3 
of the frogs and salamanders, since they display few features of of the 
Iguanodon,. Hoplosaur. 
general interest. 
NOTE. 
We have been requested to give a complete list of the articles which have appeared 
in the series entitled “Uncommon Pets,” and as the one in this number completes 
the first twelve, we take this opportunity of giving the issue of ANIMAL LIFE in 
which each will be found :— 
Article Vol. No. Page Article Vol. No. Page 
No. I. Jerboas, ete. 5 Ie bo WH 7 on UGE «ING, WIG We WW@bio s Se SoS, 3 SG 
», LI. The Raccoon .. 36 a Io oo Wills oo BIS » VIII. Lizards .. D0 yeh DLS. ate: ENV eae 
5, ILI. Crocodiles and Alligators Ts Go WANN 55 We » LX. Foreign Bats .. ste DADS 2c RONG ee 2thS} 
» LV. Smnakes.. Po be DS, es l2 aH ake Civets a0 a Sollee SOG oo TOG 
» VY. The Agouti Flee oc ens .. 41 », SI. The Armadillo .. oo WI oo SOVANNTS on TO 
» VJ. Foreign Squirrels .. o We 56 SKlllly on Ghoul » SIL The Lynx 90 50 Js oo BIDS on YER) 
