Oysters? HELP

[Hogtownfossil]

Can't find any similar pictures, too big to be Brachiopods, 

[caldigger]

Oysters fo sho.

[Ludwigia]

Cal said it.

[tmaier]

You have what looks like two, maybe three species of oysters here.

The upper pair (? they look like they fit, and are the pair) are likely Ostrea sculpturata.

On the bottom left it might be one of the valves of a sculpturata, or it might be some other species. I can't see the details, and with oysters it can be tricky to tell.

And on the bottom right I have seen that oyster many times, and can't find it right now! It is not a sculpturata. Your photo isn't the greatest, but if that is the oyster I'm thinking of, it is relatively thin and flat shell for an oyster, and has an odd hinge area.

Oysters are a pain, because they have so much individual variation in them, it is hard to pick out the species distinctions sometimes. Also, most oysters are dumped into only two enormous genera, so it is impossible to "play it safe" and only name the genus.

[doushantuo]

Thinking Crassostrea here

[Plantguy]

Hey gang, I've got a pile of unidentified fossil oysters and I like seeing the dang things even though they confound me but trigger crazy curiousity like most other things.

 

Here are a couple of them, one from Sarasota FL from possibly the Tamiami Fm and then the other opposite valve from the Jackson Bluff formation up north in Tallahassee. Thinking some of yours, particularly the top two maybe very similar to what I have and was wondering if they might be Plaucunanomia plicata. I'm definitely not a pelecypod person and with my Pittsburgh Steelers just losing again tonight its tough to focus and see straight so if I'm wrong I only count this as one error, not four....my math noone else's....LOL...

 

Here's the Florida Museum's gallery showing that species...and there are others illustrated in there that might match the others...

http://www.flmnh.ufl.edu/invertpaleo/display.asp?catalog_number=115434&gallery_type=Florida Mollusca-Bivalvia

 

Curious to see if MikeR snagged any of them from these sites as well and he might be able to comment and set me straight and show some other examples/possibilities...

 

Cool finds! Regards, Chris 

[tmaier]

@doushantuo

"Thinking Crassostrea here "

Crassostrea is one of those very large genus that I was complaining about. Most of the oysters in that that genus are elongated, and resemble the modern edible oyster we are familar with.

When you see a round one, it is unlikely Crassostrea. When you see a long oyster, think to yourself "Well, that's Crass". :-)

The hinge is an important diagnosic point, as shown by Plantguy above. Oysters are so wobbly and weird, and that makes them hard to catagorize, so the uniformity of the hinge gives a person something uniform to grab on to. And the location of the muscle scar in relation to the hinge.

A lot of photography for oysters is really poor for defining the species, because people take only on shot of the outside view of only one valve and call it done, but the two valves are often very different in oysters, and the interior is much more diagnostic. So... those one shot pictures are often close to useless.

Plantguy's photos above are very good.

When hunting oysters, it is also worth the effort to search until you find a pair of valves that fit together, because of what I mentioned above.

[Hogtownfossil]

The shell is all opaque, not like any I've seen(maybe the outside shell wore off), the hinge is oyster for sure, so I'll go with P.plicata .

[Hogtownfossil]

And  big thanks to all!

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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[sixgill pete]

I think the top two are Myrakeena scuplturata (family Ostreidae) 

 

I actually think that is what they all are.

[fifbrindacier]

I agree the last one can be a plicata, maybe @Fruitbat's pdf Library could help.

[MikeR]

Placunanomia plicata is correct.

 

Myrakeena is "not accepted" by WoRMS LINK.  It list Ostrea as the correct designation however I have been using Conradostrea LINK.