resource Unknown Species
you can try these out Geologic Era: Jurassic Location
http://pennywisenow.com/56632-dte16166-completely-free-dating-sites-for-singles.html Found: Morrison Formation (Colorado)
découvrez ceci ici Both of these specimens come from the same location in Colorado. The Morrison formation is one of the larger Jurassic formations in the United States, and many well known species have come from it. Included in this list are Allosaurus, Apatosaurus, Camarasaurus, and Stegosaurus. Many of the bone chunks found in the Morrison formation are found dissociated, and can’t be traced to a particular animal. I have owned the rough fragment for 16 years; it came in a set with other assorted fossils. The open cell structure is apparent in the rough piece, and this openness is what distinguishes fossilized bone from regular rock.
Sometimes, these rough pieces of agatized dinosaur bone is tumbled and turned into jewelry. The result can look something like the pendant above. This piece has been tumbled, polished, and set in silver. The result shows off the open structure characteristic of agatized bone. If the rough piece were tumbled, I suspect that it would look similar in structure to the pendant, but have more of a reddish-purple color. Disassociated fragments are not of any real scientific value, and this is the reason the are sometimes turned into sculptures and jewelry.