Pagurized (hermit crab) gastropod shells covered with bryozoa, coral or hydrozoans

[fossilnut]

Wanted fossil or recent bryozoa, coral or hydrozoan covered gastropod shells that were used by hermit crabs. I am especially interested in the Texas Longhorn -Hippoporidra edax examples but would like examples from different ages and locations. Use is for a talk/donation on Predation, Protection and Cooperation for the Natural History Society of Maryand (volunteer). Would trade examples I collected @ Myrtle Beach, SC or other fossils from the Miocene of MD, shark teeth from SC, shells from the Pliocene of Florida etc. Would buy as well.

Edited May 16, 2021 by fossilnut
corrected scientific spelling of Texas Longhorn bryozoa

[Fossildude19]

Sounds interesting. 
How can you tell they were used by hermit crabs?

Just wondering what signs they leave. 

[fossilnut]

@Fossildude19 Fossil pagurized shells show wear on the bottom because the hermit crab dragged the bryozoa covered shell as it searched for food. Modern hermit crabs carry the shell higher and do not show the wear. The bryozoa comprise upwards of 80% of the mass. The actual gastropod or its dissolved impression is only a small part of the overall piece. The bryozoa forms around the gastropod's opening and as the crab moves in and out it continues to expand the living space in the helix form. The bryozoa shows the gastropods aperature which is now completely formed by the bryozoa-not the actual gastropods shell. The hermit crab may be able to remain without having to exchange shells. These have been called bryoliths. Thanks for your interest. Check out "Texas Longhorn" Bryozoan. I think these will fascinate folks. I am intrigued by them. BTW Apparently, there has never been any hermit crab fossils found with these.

Edited May 16, 2021 by fossilnut

[Fossildude19]

Thanks for the informative reply.

[Mahnmut]

Wow, that is an astonishing rebuild!

I found the one below already dead in a lobster cage in Greece, would have released it otherwise.

The epibionts as far as I see are barnacles and oysters, no bryozoa, coral or hydrozoa. It does show a bald spot, now that you mention it (second pic). 8cm from tip to tip.

I think its only worth the overseas shipping if it really fits your need.

Best Regards,

J

 

 

 

[fossilnut]

That Crab had quite a decorated home. Add some colored lights for Christmas! I'm good so no need to ship over seas, Thanks for posting, it is an interesting piece. Probably could not recognize as a fossilized piece since no traces of a hermit crab has ever been found inside.

Below is a picture of a recent one called a "Texas Longhorn" due obviously from its shape. This was found in some depth offshore by a diver. Enjoy.

Edited December 12, 2021 by fossilnut

[Plax]

fyi

645061137_oligocenepagurizedgastropodsfromtheriverbendformationnorthcarolina.pdf

[sixgill pete]

34 minutes ago, Plax said:

fyi

645061137_oligocenepagurizedgastropodsfromtheriverbendformationnorthcarolina.pdf 2.02 MB · 3 downloads

Interesting Don. I have not seen this \before. Thanks for posting it.

[Plax]

You may recall me relating these to folks after Joe Collins told me about them during on of our field trips in the mid 90s. Once you see them somewhere you see them everywhere. Most interesting to me is that there are no aragonitic shells preserved in the River Bend. The epibionts represent the shell in this instance.