420 



THE NATIONAL GEOGRAPHIC MAGAZINE 



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ANOTHER ANKYLOSAURUS QUARRY 



Lowering a 700-pound box, by means of block and fall, to the valley 100 feet below. This 

 specimen included the pelvis, a part of the animal not before known. 



Paskapoo age, but as soon as the Ed- 

 monton rocks appeared in the banks large 

 bones of dinosaurs became numerous, 

 and in the picturesque exposures at the 

 mouth of Big Valley they were especially 

 abundant. 



EXCAVATING WITH CROOKED AWL AND 

 WHISK-BROOM 



At the foot of a butte lie scattered 

 fragments of bone, and on the rivulet- 

 scarred hillside other fragments appear, 

 as we trace them up the waterways. 

 Finally, ten, twenty, or thirty feet above, 

 other pieces protrude from the bank, and 

 this is our lead. Cautiously we follow 

 in from the exposed surface, uncovering 

 the bone with crooked awl and whisk- 

 broom, careful not to disturb the bone 

 itself ; for, although stone, it is usually 

 checked and fractured in many places by 

 former disturbance of its bed or crys- 

 tallizing of mineral salts, and is rarely 

 strong enough to permit removal. 



Other bones may appear in the course 

 of this preliminary work, and, if the find 

 is desirable, the next step is carefully to 

 gather every fragment, large and small, 

 that has weathered out and fallen down 

 the hillside ; for when restored in the 

 laboratory one of these pieces may be the 

 critical point in the determination of a 

 species. 



Then with pick and shovel the heavy 

 ledges above are removed, and often a 

 team and scraper and dynamite are used 

 when a large excavation is to be made. 

 As we near the bone layer the work is 

 more carefully done, with ever in mind 

 the probable position of the bones of the 

 skeleton. A false stroke of the pick in 

 excavation may cause days of mending 

 in the laboratory and might destroy some 

 delicate bone. 



When the bones are uncovered and 

 brushed clean they are saturated with 

 shellac till all small pieces adhere to each 

 other ; then the dirt is taken away from 



