Lost River, Alberta (Cretaceous Vertebrates)

[6ix]

Amazing - real dinos everywhere, and they come up so well when you prep them.. very nice.

[siteseer]

The third things are ray dermal denticles similar to those of dasyatids (stingrays and their relatives). They may belong to Myledaphus as that genus has been considered at least a relative of the early dasyatids. I have seen a few dermal denticles out of the Hell Crekk Formation (in which Myledaphus is common) but they don't look like yours. What's the size across the widest dimension of the base and what's the height?

Dasyatids (teeth mostly) are better known from the Miocene but you see them in some localities in the Paleocene-Oligocene with complete skeletons from the Early Eocene Green River Formation (Fossil Butte Member).

It's tough to find a reference that even figures Cretaceous dermal denticles. Specimens that old would be impossible to match to teeth with certainty without a skeleton and a bunch of denticles mixed up with it. In modern sharks and rays, denticles change shape from one part of the body to another in any individual so that is also a complicating factor.

Jess

it took me 15 minutes climb up one steep hill and then a mule deer spooked me by doing the same in about 10 seconds.

Found a little shelf with some shark teeth. Must be a marine lens but couldn't hang on for long as it was smack in the hottest sun and hard to see. The first teeth are about a centimeter...the second photo about a third of that. Not sure what the third things are...shark scales? The shark and fish (?) vertebrae were found down among the terrestrial clays...maybe washed in.

[siteseer]

I haven't been able to find anything close to a match for your specimen. It does look similar to a ray dermal denticle. It appears the central area is worn down as if there had been a cusp projecting from the base. The Albian is a more distant time than the Canadian specimens (perhaps 30 million years older) - less of a connection to modern or any Cenozoic forms. It was a time still early in the evolution of rays.

Hi,

Have you had more info on the fish scales ID ?

Found this last year in some albian deposit (actually in the area that gave the name to the geologic period)

http://www.flickr.com/photos/48637020@N06/8412770938/in/set-72157632604966872

And it s showing big similarities.

Will look later in the book where i found infos about this and re post in the evening.

Regard

[elcoincoin]

thanks for the time you took to get a closer look

[Ridgehiker]

Even when a reference is not the specimen it is still helpful as it eliminates some possibilities.

Myledaphus are a collecting enigma...the teeth are about the most common micro vertebrate we find yet we almost never find anything else from this ray. Their teeth are virtually unchanged in all of our Cretaceous deposits over 18 million years...different sediments deposited in slightly different conditions but basically teeth, teeth and more teeth. A scrappy vertebra here or there but even those are rarities. I've never seen any dermal scutes from them...unless I didn't recognize them.

Edited September 20, 2013 by Ridgehiker

[sward]

Obviously a beautiful place to hunt and a wonderful variety of stuff.

Thanks for sharing.