172 EXTINCT MONSTERS 
on the whole more lizard-like. The creature was about four 
feet long. 
The researches of Baron Nopesa show that this Dinosaur was 
provided with a thin but well-developed armour, consisting of 
large, thin, and flat bony plates, feebly punctured. The base of 
the skull is very bird-like, as in some of the group Theropoda. 
The eyes had no sclerotic plates, as Mr. Hulke thought. 
But there were in existence during the long Jurassic period 
other and even stranger forms of Dinosaurs with armour. One 
of these, only imperfectly known at present, was the many- 
spined Polacanthus.! This remarkable monster had the whole 
Fia. 59.—Skeleton of a small Dinosaur, Hypsilophodon Fowi, from Wealden 
strata, Isle of Wight. Restored by Professor J. W. Hulke, F.R.S. From the 
Philosophical Transactions of the Royal Society, vol. 173. 
region of the loins and haunches protected by a continuous 
sheet of bony plate armour, rising into knobs and spines, after 
the fashion of the shield or carapace of certain extinct armadillos 
known as Glyptodonts (see Chap. XV.). Fig. 60 shows a partial 
reconstruction of the skeleton. The shaded parts of the drawing 
indicate the parts actually preserved, the rest is reconstructed 
with the help of the bones of an allied Dinosaur: eg. Stegosaurus. 
From this we see that Polacanthus was a reptile of low stature. 
It was a slow-moving vegetable feeder, according to Baron Nopesa, 
1 From Greek—polus, many, and acantha, spine. 
