I was wondering if this is a belemite hooklet for sure? I broke it by mistake right after I found it. It was found in a cretaceous site.2680

Hi Roz, and welcome.

This looks familiar somehow, but I can't place it. Have you posted it elsewhere on the internet?

My gut instinct is to say no, I'm afraid. From what I've seen, the shape is too curved for one thing, hooks had sharp points. Obviously it could have been worn down, but one can try to extrapolate the original shape from its pre-eroded state. I think the biggest stumbling block is the size, belemnite hooks were very small, maybe only a few millimetres long and this looks much larger. Don't forget that belemnites had two rows of these things on each arm and ten arms in total, scaling that up from the size of your fossil implies the belemnite would have been massive.

I assume you found this in the US? The largest belemnite was Megateuthis which is, as far as I know, unknown from the US and is mainly found in Europe and Indonesia. Also, hooks are very rarely preserved which makes the chances of you finding one very remote indeed I'm afraid.

Apologies for an unwelcome answer. Now we have to work out what it actually is of course!

Hi Roz and :welcome:

Phil, it looked familiar to me too, check out this thread, http://www.tonmo.com/forums/showthread.php?t=108&page=2&highlight=hook post #17 and you will remember why it looks familiar...

Ah yes, Cuttlegirl. That was it, thanks.

Kevin concluded that it was probably a rudist bivalve of some form too.

A rudist. (http://ib.berkeley.edu/labs/hickman/jannv/images/Picture8.jpg)

Another rudist. (http://www.palaeos.com/Mesozoic/Cretaceous/Aptian.html)

Yes, it was found in Arkansas, south western part of the state. I did post it on the fossil forum right after I found it. I'm a bit disappointed but I may live. Anything you can tell me would be appreciated and thanks!

:welcome: Roz

I am quite sure it is a small Rudist bivalve. This from someone who spent the weekend picking up Pinyon pine nut shells and Juniper berries thinking they were small goniatites (I have learned to avoid the deer droppings). :oops:

Thanks for the information. Yes, I can identify with picking up many heavy things that I am sure are fossils only to find out later that a lot of it is rock.

I'll have to do my homework on the rudist then. I know a bit about bivalves but not much about the rudist.

Thanks:smile:

Yes, I can identify with picking up many heavy things that I am sure are fossils only to find out later that a lot of it is rock.

Don't worry about it Roz, I'm sure we've all done it at some point. Three years ago or so I posted images of a tooth I found on a beach to a couple of fossil forums to identify as I thought it was a Cretaceous marine reptile, but it turned out it was a fox. What an idiot.

I'll have to do my homework on the rudist then. I know a bit about bivalves but not much about the rudist.
Thanks:smile:

For a good site on Rudists, go Here (http://www.ruhr-uni-bochum.de/sediment/rudinet/intro.htm)

Thank you all for the great inforamtion and Kevin with the link...I believe that I found it... Titanosarcolites!~

I have since found more and they have to be rudist then.

Here are some more, ignore those 2 other things unless you know what they are!:lol:

I think the second picture may be pyrite belemnites. Found in an old quarry, maybe cretaceous as I found a small mosasur vert there also.
What do you think?

I think the second picture may be pyrite belemnites.
...
What do you think?

They have the right internal structure, but the external shape leaves something to be desired, still they look very close to those cretaceous belemnites found on the east coast. Would need to see more and better preserved fossils for a better ID. 8-)

Thank you all for the great inforamtion and Kevin with the link...I believe that I found it... Titanosarcolites!~

I've just found an interesting photo of Titanosarcolites, comparing one to a geological hammer. Fascinating, I had no idea that these things grew so large; I thought they grew up to finger length size at most. Obviously not!

http://www.ruhr-uni-bochum.de/sediment/rudinet/images/titashaw.jpg

Would there be any chance of a close up photo on the 'belemnite' fragments please?

Originally posted by Phil Fascinating, I had no idea that these things grew so large; I thought they grew up to finger length size at most. Obviously not!


:shock: I didn't know they got that big either...

Rudists were the primary component of reefs in the late cretaceous, if you were going to have a reef tank back then it would probably be full of rudists instead of coral. The author of This Page (http://www.palaeos.com/Mesozoic/Cretaceous/Cretaceous.2.htm#Reefs), thinks the rudists in the late cretaceous took all the reef space away from the corals, maybe they grew so large just to block any coral that tried to get established. 8-)


Roz, if you could find one of those fossils showing a portion of the phragmocone that would verify they are belemnites. They are starting to look like pyrite replaced coprolites to me.

I'm not sure what portion that means. Here is a pic of a different one. I was told these aren't fossils, just marsacite but they have some really odd shapes.
http://img146.imageshack.us/img146/698/0000719vc9.jpg

Her's another one that I think is curious in it's shape.
http://img123.imageshack.us/img123/51/0000715ez8.jpg

Another weird shaped one. I was so excited when I first found them as I thought they were fossils.

http://img162.imageshack.us/img162/6364/0000718ah8.jpg

Some of them may be fossils. They seem to have the shape, the middle one looks alot like an echinoid, and the last one looks like a high spired gastropod. They may be casts that were filled with pyrite and the pyrite has grown beyond the shape of the original mold, or when it changed to marcasite it changed shape. Detritus (organic waste material from decomposing dead plants or animals) is prime for pyrite deposition so almost anything on the seafloor at the time of diagenesis (the physical, chemical or biological alteration of sediments into sedimentary rocks) could be replaced.

Using some big words, from the sedimentology book I just purchased and read, just for fun :grin:

Thanks Kevin, very interesting. I found a couple of lozenge shaped pieces very similar to Roz's first picture last Saturday jutting out of chalk blocks on my local beach. I thought that they were pyritised deposits of some form, but could not determine what exactly. Your post helps to explain things greatly.

Information is always good! Thank you and it does make sense now that I think about it!