A strange fossil (Bearpaw fm.)

[Norki]

Hello everyone,

 

A few weeks ago I came across this fossil in the field, and couldn't make ends of what it could be. The locality that it was found in represents a shallow marine lagoon environment, deposited in the late Campanian marine Bearpaw formation of SK. Typical finds at that locality (all within sandstone concretions) include nacreous mollusks, as well marine vertebrate material and decapods which are preserved as glassy black, similar to this specimen.

 

Because of this, I'm inclined to think that this fossil is either from a vertebrate, or possibly a chitinous organism. I'm totally stumped either way though.

 

I won't be able to provide any more photos unfortunately, as this one was left in the field.

 

 

Note that this fossil was actually preserved in three dimensions - unfortunately I don't have a photo, but you can see on the leftmost split on the top half of the concretion that there's a plate that extends down into the concretion. This plate was roughly triangular in shape, and had gentle striations radiating from the middle point toward the ends.

 

Thanks.

[jpc]

I have seen that sort of pattern seen at the crack in the bottom half in lobsters.  But hard to say.  

[fossisle]

i think its a tritor(tooth plate }of a ratfish

[Wrangellian]

I don't know enough about the other suggestions to confirm or refute them, but it has the look of bored wood to me... as does the piece partially visible under the upper half in the photo though I'm not sure why the light/dark colors are reversed except by preservational variability.

[fossisle]

On 6/18/2020 at 3:46 PM, Norki said:

Hello everyone,

 

A few weeks ago I came across this fossil in the field, and couldn't make ends of what it could be. The locality that it was found in represents a shallow marine lagoon environment, deposited in the late Campanian marine Bearpaw formation of SK. Typical finds at that locality (all within sandstone concretions) include nacreous mollusks, as well marine vertebrate material and decapods which are preserved as glassy black, similar to this specimen.

 

Because of this, I'm inclined to think that this fossil is either from a vertebrate, or possibly a chitinous organism. I'm totally stumped either way though.

 

I won't be able to provide any more photos unfortunately, as this one was left in the field.

 

 

Note that this fossil was actually preserved in three dimensions - unfortunately I don't have a photo, but you can see on the leftmost split on the top half of the concretion that there's a plate that extends down into the concretion. This plate was roughly triangular in shape, and had gentle striations radiating from the middle point toward the ends.

 

Thanks.

This could be an awesome specimen!!

[RuMert]

It's definitely a bone or a tooth plate. Ratfish sounds viable

[Norki]

On 6/19/2020 at 5:37 AM, Wrangellian said:

I don't know enough about the other suggestions to confirm or refute them, but it has the look of bored wood to me... as does the piece partially visible under the upper half in the photo though I'm not sure why the light/dark colors are reversed except by preservational variability.

Yep, the piece below it is definitely bored wood. It even has the Martesia clams fossilised at the bottoms of their burrows:

 

 

I won't discount the possibility that the original fossil is also bored wood, but I'm still inclined to think that it's a vertebrate fossil, if only because it's preserved in the same glassy black material as the other vertebrates from this spot.

 

@fossisle , @RuMert - Did ratfish really get big enough to leave a tooth plate of this size? It's a pretty large specimen.

[RuMert]

Not sure, but 10 cm is pretty common, so why not 20

[DPS Ammonite]

4 hours ago, Norki said:

Yep, the piece below it is definitely bored wood. It even has the Martesia clams fossilised at the bottoms of their burrows:

 

 

I won't discount the possibility that the original fossil is also bored wood, but I'm still inclined to think that it's a vertebrate fossil, if only because it's preserved in the same glassy black material as the other vertebrates from this spot.

The rock above is not bored wood. It is a layered sedimentary rock that contains sediment filled shells and possibly rock clasts. Note how the layers of the rock bend around the fossils.  The deflection of the fine grained sediments around the fossils indicates the the were deposited at about the same time.

[RJB]

  Your first photo is most interesting.  I do not know what it is and I know how heavy these rocks can be, but I would go back and get that rock and maybe expose it a bit with an airscribe?   Looks like it has the potential of being something not only really cool, but also may be something scientificly important?  Good luck

 

RB

[fossisle]

We have large tooth plates from Edaphodon found on the Trent River near Courtenay , Campanian age.Edaphodon.pdf