BuddingPaleo Posted August 11, 2018 Share Posted August 11, 2018 Ok, don't need an ID of the oyster (probably hyotissa) or the other one, but an explaination of how they came to be how they are. Is this evidence of predatory behavior or just really weird settling? pictures are kinda large, so two posts. Hyotissa first. It has this paw print looking bit, looks bored into the shell, goes straight through to the muscle. Are there burrowing gastropods that would do that? I've only found drill holes. Also, what's with the double attachment on the bottom right of the inside? Link to comment Share on other sites More sharing options...
BuddingPaleo Posted August 11, 2018 Author Share Posted August 11, 2018 Second shell. Did the larger shell just fall on top of the littler one inside? Link to comment Share on other sites More sharing options...
GeschWhat Posted August 11, 2018 Share Posted August 11, 2018 I would guess the shell-in-shell is the result of on shell falling on top of another. The burrows are interesting, but I don't have the foggiest. Lori www.areallycrappystory.com/fossils www.facebook.com/fossilpoo Link to comment Share on other sites More sharing options...
BuddingPaleo Posted August 11, 2018 Author Share Posted August 11, 2018 1 minute ago, GeschWhat said: I would guess the shell-in-shell is the result of on shell falling on top of another. The burrows are interesting, but I don't have the foggiest. Me either. Lol Link to comment Share on other sites More sharing options...
Bronzviking Posted August 11, 2018 Share Posted August 11, 2018 To address your first question predatory behavior: There are quite a few predatory gastropods. Live Cones possess poison tipped spears (harpoons) used to stab and immobilize prey, such as other mollusks or marine worms. The harpoons can also be used as defense against predators like octopus. Oyster drills and starfish prey on oysters. Oyster drills drill holes through the oyster shells with their rasping tongues. They cause millions of dollars of damage to commercial oyster beds. There are many predatory sea snails like the Natica (moon snail) as well. (last 3 photos) It's hard to say with all the pock marks on these shells if they were from predators. The large squarest hole is not. It looks like erosion or broken. As far as the shell in shell, its interesting. This is a conglomerate of shells cemented together with sediments like lime and sand over long periods of time. Hope this helps. 4 Link to comment Share on other sites More sharing options...
BuddingPaleo Posted August 11, 2018 Author Share Posted August 11, 2018 15 minutes ago, Bronzviking said: To address your first question predatory behavior: There are quite a few predatory gastropods. Live Cones possess poison tipped spears (harpoons) used to stab and immobilize prey, such as other mollusks or marine worms. The harpoons can also be used as defense against predators like octopus. Oyster drills and starfish prey on oysters. Oyster drills drill holes through the oyster shells with their rasping tongues. They cause millions of dollars of damage to commercial oyster beds. There are many predatory sea snails like the Natica (moon snail) as well. (last 3 photos) It's hard to say with all the pock marks on these shells if they were from predators. The large squarest hole is not. It looks like erosion or broken. As far as the shell in shell, its interesting. This is a conglomerate of shells cemented together with sediments like lime and sand over long periods of time. Hope this helps. Honestly, ive been looking and i dont see any burrows that go in like that. Just basic drill holes. I figured the other might be settling, but wasn't sure. It's the 3 bore holes in the oyster I've really been completely stumped by. Link to comment Share on other sites More sharing options...
Plantguy Posted August 11, 2018 Share Posted August 11, 2018 I believe the 3 tubular holes and others are from a type of boring clam not a gastropod. Here's a picture of a Hyotissa example of some still sitting in their bore holes...(little white colored guys in upper left of the shell in the left photo) could have been Lithophaga or one of the other borers..they love drilling thru rock, bone and other fossils in their way. happy as clams! Agree the other double attachment marks are a couple of extra bivalves, probably oysters attached to the inner mold.Got piled together during deposition. Good stuff! The gastropod borings are also there to be found but my experience are usually not so deep and some are pretty large in diameter.They seem to drill fairly short holes and usually fairly perpendicular to the shell surface looking for their next meal. Most of the time they drill thru the thinner parts of the shells but I have seen some that take on really thick areas. How they know that makes me wonder and someone else might be able to share that. Here are also some examples of gastropod borings that you can find in the Tamiami Fm. Enjoyed seeing the latest...Regards, Chris 5 Link to comment Share on other sites More sharing options...
abyssunder Posted August 11, 2018 Share Posted August 11, 2018 I agree with Chris. The drill holes might be bivalve borings. The double attachment on the bottom right of the inside of the oyster could be cemented little oysters. The "second shell" looks to be a matrix with molds of a large bivalve (e.g. pectinid) including other molds of gastropods and bivalves. 2 " We are not separate and independent entities, but like links in a chain, and we could not by any means be what we are without those who went before us and showed us the way. " Thomas Mann My Library Link to comment Share on other sites More sharing options...
BuddingPaleo Posted August 11, 2018 Author Share Posted August 11, 2018 Wow, thanks. That's a lotta info to digest. Good thing I have an appetite! 1 Link to comment Share on other sites More sharing options...
Bronzviking Posted August 12, 2018 Share Posted August 12, 2018 Another scenario for your burrowing or boring bivalve could be a Gastrochaena a saltwater clam of Florida. Bivalve shells may also be penetrated by other bivalve shells like the Gastrochaena, which leaves oblong boreholes in either shell nor rock. This bean-shaped clam lives out its life within the pit it forms. See photo below: 3 Link to comment Share on other sites More sharing options...
abyssunder Posted August 13, 2018 Share Posted August 13, 2018 Club shaped features... Gastrochaenolites igen comparative picture from here 2 " We are not separate and independent entities, but like links in a chain, and we could not by any means be what we are without those who went before us and showed us the way. " Thomas Mann My Library Link to comment Share on other sites More sharing options...
BuddingPaleo Posted August 13, 2018 Author Share Posted August 13, 2018 Thanks for that too! Good read. Link to comment Share on other sites More sharing options...
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