Most of what you thought was coprolite, aint!
Roxy and I were shopping at a flea market. One of the tables was filled with what the vendor assured me was fossilized dinosaur poop. It must have been the real thing because each piece had a gold foil label that said it genuine coprolite. How much more verification do you need?
As I looked it over, one piece was a nice, colorful chunk of agate and the price was right. It even had a nice polish. So, I bought it.
The leading expert on coprolite today is probably Karen Chin, currently at Colorado University. Ms. Chin seems to have captured the title of “Coprolite Queen”. I’ve located half a dozen scientific papers about it listing her as a co-author. In one, she has this to say about the rocks that many of us rockhounds often identify as coprolite.
The Morrison Formation is well known for its impressive herbivorous dinosaur. These sizable herbivores would have contributed copious quantities of fecal material to the paleoenvironment. Visions of such accumulations may have prompted fossil enthusiasts to hypothesize that the nodular, siliceous concretions often found in Morrison floodplain sediments are actually coprolites. While it is conceivable that some of the concretions may represent completely replaced inorganic casts of fecal material, the specimens lack internal cellular detail and other positive evidence that support a fecal origin. Such concretions may actually be carbonate soil nodules replaced by silica because caliche nodules are common components of Morrison floodplain deposits.
The Morrison Formation was my dad’s favorite rock hunting ground but as far as I know, he never brought home something that he said was a coprolite. My guess about that is that my dad was focused on solid, colorful agate. Coprolite does exist, but colorful agate coprolite is very rare. In fact, I’ve never seen one. One of the best ways to tell if you have real coprolite (unless you have the equipment to make and view microscopic thin section slides) is whether it looks like a piece of … well … coprolite. Anybody who has a cat or dog has a pretty good idea what to look for.
Another confusion factor is that when a scientist, like Karen Chin, uses the word, they include everything from relatively fresh coprolite (relative to 100 million year old dinosaurs) that may only be a few thousand years old and was found in a Homo sapiens lair, to real fossils as old as the dinosaurs. Rockhounds typically assume that EVERY fossil is some kind of dinosaur. (A very bad assumption.) In fact, the earliest coprolite discoveries in England were turned into mines and used as fertilizer. A history web site clains that, “This fertiliser was discovered when a brick kiln using local clay exploded.” Phosphate is also used to manufacture explosives.
I decided to write this blog when I noticed a short piece in The Week magazine about a tourist museum in Williams, Arizona. (Williams! Gateway to the Grand Canyon!) I encourage ALL tourists to go there instead of Spingdale.
Congratulations to owner George Frandsen for making it into a nationally published magazine! Ah Gotta Tell Ya! ... T’aint Easy, McGee!
I haven’t been there … (My wife won’t leave home these days. She says, “People spend large to come here. Why should I go somewhere else?) But Frandsen's "Poozeum" has an interesting website. if I was going that way, I’d stop and see it.
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