Shuler — Dinosaur Trachs in the Glen Rose Limestone, 297 



lime mud to be sure, but mud. The foot was pressed down 

 into the lime mud sliding forward somewhat, as is seen in the 

 imprint of the heel, %ure 2, until the ends of the toes were 

 buried beneath the surface of the mud. The mud was suffi- 

 ciently plastic to hold the form when the foot was withdrawn. 

 The tracks were probably made while the mud was under- 

 neath the water. There are neither sun-cracks as evidence of 



Fig. 3. 



// 



Shell Bfecc/a 



CaLca.Y€ous 

 ShaLe 



to 



CLay 



<3r4'j 



L.S. 





31%eaCO- 



Track 



rri M t nrm 1 1 1 ittt i i i i n 



I . I 



Shall) 



t.s 



Fig. 3. Cross section of beds in which the dinosaur tracks are found. 

 Outline of track one-twelfth natural size. 



desiccation or emergence of the muds; nor ripple marks or 

 other evidence of current action. The limy clays immediately 

 above the limestone, which were deposited after the passing 

 of the dinosaur, show little stratification and were evidently 

 laid down by very gentle currents. 



That the dinosaur was a land animal seems highly probable 

 from the character of the foot. That it was wading also seems 

 probable. A range of depth of water five to ten feet does not 

 seem unreasonable but a further important question is the dis- 

 tance away from shore. The Glen Rose formation was laid 

 down in a transgressing sea, which if the surrounding area 

 were near to base level, would sweep over wide areas with 



Am. Jour Sci.— Fourth Series, Vol. XLIV, No. 262.— October, 1917. 

 21 



