Geological Papers. 257 



AN ARMORED DINOSAUR FROM THE KANSAS CHALK. 



By Charles H. Sternberg, Lawrence. 



T AST February Barnum Brown, of the American Museum of 

 -^-^ Natural History stafp, published a description for the first 

 time of his wonderful armored dinosaur, which he named An- 

 chylosaurus magniventi'is, representing a new family, genus, and 

 species. It was discovered in 1906 by the American Museum ex- 

 pedition in "The Hell Creek Beds of Montana." It represents, he 

 says, a group of Stegosauria, characteristic of the late Cretaceous 

 of this country. 



The skull is entirely covered with plates, which are coosified in 

 continuous surface, and cover top and sides of the head. Some 

 thirty dermal plates were discovered, and in their restoration they 

 and others are arranged in parallel rows along the entire back and 

 sides of the reptile. They are diamond-shaped, with the sharp 

 angles rounded off, while the center is thickened into an elevated 

 wedge-shaped crest. In his restoratiou the interspaces were left 

 naked, as he evidently had none of the connecting smaller and 

 various shaped bodies to completely fill all the interspaces. 



In 1905, while conducting an expedition in the Kansas Chalk, I 

 discovered the broken-up skeleton of what I considered a large 

 new sea-tortoise with an ossified carapace. It attracted my atten- 

 tion, and I knew it was new, but as it was weathered and detached 

 from its matrix I concluded it could not be used and left it there. 

 Later, my son George brought into camp, a few miles from Hack- 

 berry creek, where I had found my specimen, some peculiar plates 

 like the ones I have already mentioned; but as I had no knowl- 

 edge of Barnum Brown's discovery, I concluded they were the 

 neurals of a new turtle. 



These I sent on to Dr. G. R. Weiland for description. Last 

 month I was his guest at Yale University museum. He asked me 

 why I thought it a new turtle. After giving my reasons, he told 

 me it was new enough, but these plates were the dermal scutes of 

 an armored dinosaur. Later I secured the skeleton, through the 

 efforts of my eon, who found them as I directed. I went over the 

 mass of fragments, and separated the armor, and found that the 

 entire skeleton was covered with a completely coossified dermal 

 covering, in most beautiful patterns, the larger scutes being dia« 

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