THE JURASSIC PERIOD. 257 



Megalosaurus attained gigantic dimensions, its thigh and 

 shank bones measuring each about three feet in length, and its 

 total length, including the tail, being estimated at from forty 

 to fifty feet. As the head of the thigh-bone is set on nearly 

 at right angles with the shaft, whilst all the long bones of the 

 skeleton are hollowed out internally for the reception of the 

 marrow, there can be no doubt as to the terrestrial habits of 

 the animal. The skull (fig. 180) was of large size, four or five 

 feet in length, and the jaws were armed with a series of power- 

 ful pointed teeth. The teeth are conical in shape, but are 

 strongly compressed towards their summits, their lateral edges 

 being finely serrated. In their form and their saw-like edges, 

 they resemble the teeth of the " Sabre-toothed Tiger " Machai- 

 rodus), and they render it certain that the Megalosaur was in 

 the highest degree destructive and carnivorous in its habits. 

 So far as is known, the skin was not furnished with any armor 

 of scales or bony plates; and the fore-limbs are so dispro- 

 portionately small as compared with the hind-limbs, that this 

 huge Reptile like the equally huge Iguanodon may be 

 conjectured to have commonly supported itself on its hind- 

 legs only. 



The Cetiosaur attained dimensions even greater than those 

 of the Megalosaur, one of the largest thigh-bones measuring 

 over five feet in length and a foot in diameter in the middle, 

 and the total length 'of the animal being probably not less than 

 fifty feet. It was originally regarded as a gigantic Crocodile, 

 but it has been shown to be a true Deinosaur. Having ob- 

 tained a magnificent series of remains of this reptile, Professor 

 Phillips has been able to determine many very interesting 

 points as to the anatomy and habits of this colossal animal, 

 ttie total length of which he estimates as being probably not 

 less than sixty or seventy feet. As to its mode of life, this 

 accomplished writer remarks : 



" Probably when ' standing at ease ' not less than ten feet 

 in height, and of a bulk in proportion, this creature was un- 

 matched in magnitude and physical strength by any of the 

 largest inhabitants of the Mesozoic land or sea. Did it live 

 in the sea, in fresh waters, or on the land? This question 

 cannot be answered, as in the case of Ichthyosaurus, by appeal 

 to the accompanying organic remains ; for some of the bones 

 lie in marine deposits, others in situations marked by estuarine 

 conditions, and, out of the Oxfordshire district, in Sussex, in 

 fluviatile accumulations. Was it fitted to live exclusively in 

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