MossyRocks Posted March 30, 2015 Posted March 30, 2015 (North Texas Cretaceous Woodbine Formation) I have not been able to find anything to compare this/these things with; does anyone happen to know what they are or may be ?
FossilDAWG Posted March 31, 2015 Posted March 31, 2015 Weird looking rock, it almost has the color and texture of chocolate. Anyway I'd tentatively suggest you are looking at casts of shipworms or possibly insect galleries or burrows in a piece of petrified wood. Don
Auspex Posted March 31, 2015 Posted March 31, 2015 ...I'd tentatively suggest you are looking at casts of shipworms or possibly insect galleries or burrows in a piece of petrified wood. Don That's the first thought I had too: emphasis on tentative. "There has been an alarming increase in the number of things I know nothing about." - Ashleigh Ellwood Brilliant “Try to learn something about everything and everything about something.” - Thomas Henry Huxley >Paleontology is an evolving science. >May your wonders never cease!
MossyRocks Posted April 1, 2015 Author Posted April 1, 2015 Thank you both for the feedback. I had not considered the tube-things being worms, I looked just as close as I could and cannot detect any signs of a 'head/tail' type end...doesn't mean they aren't though. I'm adding a pic of the back, it is mostly unremarkable but I can see bumpy things I can't capture in a pic; but it doesn't look wood-y. I have another rock that has the same kind of plaid pattern that shows on the flat area beneath the tubes. Any ideas if this from a plant/bark impression- or a mineral/geological pattern; I can't find a match for either so far. Thanks again for your help:)
DPS Ammonite Posted April 1, 2015 Posted April 1, 2015 Nice ichnofossil. I agree. It is an impression of wood that has been bored probably by clams. I have seen them in the Woodbine too and also in the Cretaceous Paw Paw Formation near Lake Texoma. As a comparison, see picture of an impression of bored wood, Teredolites longissimus, from the Paw Paw Formation at Lake Texoma. The wood which was probably coalified has eroded, while the borings were filled with sediment and preserved. My goal is to leave no stone or fossil unturned. See my Arizona Paleontology Guide link The best single resource for Arizona paleontology anywhere.
FossilDAWG Posted April 1, 2015 Posted April 1, 2015 (edited) Thank you both for the feedback. I had not considered the tube-things being worms, I looked just as close as I could and cannot detect any signs of a 'head/tail' type end...doesn't mean they aren't though. Shipworms are not worms, they are tube-shaped boring in wood made by certain clams, such as Teredo. Many of these clams line the borings with a calcarious deposit, which can remain intact after the wood itself has decayed. Because they are borings and not body fossils, they will not have a "head" or a "tail", though in well preserved examples you will see one end opens to the surface of the wood and the other, buried in the wood, is closed. Most driftwood is eventually attacked en mass by shipworms (as were wooden-hulled ships back in the day), so you will see lots of tubes all aligned more-or-less parallel to one another. The size and shape of the tube can be somewhat informative as to species. The actual shell of the clam is small and is rarely preserved. Don Edited April 1, 2015 by FossilDAWG
MossyRocks Posted April 1, 2015 Author Posted April 1, 2015 Nice ichnofossil. I agree. It is an impression of wood that has been bored probably by clams. I have seen them in the Woodbine too and also in the Cretaceous Paw Paw Formation near Lake Texoma. As a comparison, see picture of an impression of bored wood, Teredolites longissimus, from the Paw Paw Formation at Lake Texoma. The wood which was probably coalified has eroded, while the borings were filled with sediment and preserved. The picture you attached, and the term Teredolites longissimus, certainly helped me fall into the appropriate rabbit hole. I tend to get lost with so many laid before me...many thanks for sharing!
MossyRocks Posted April 1, 2015 Author Posted April 1, 2015 Shipworms are not worms, they are tube-shaped boring in wood made by certain clams, such as Teredo. Many of these clams line the borings with a calcarious deposit, which can remain intact after the wood itself has decayed. Because they are borings and not body fossils, they will not have a "head" or a "tail", though in well preserved examples you will see one end opens to the surface of the wood and the other, buried in the wood, is closed. Most driftwood is eventually attacked en mass by shipworms (as were wooden-hulled ships back in the day), so you will see lots of tubes all aligned more-or-less parallel to one another. The size and shape of the tube can be somewhat informative as to species. The actual shell of the clam is small and is rarely preserved. Don That does make perfect sense now; in my haste last evening I made the mistake of googling images instead of words...I do apologize for replying in ignorance. Thank you for taking the time to spell it out for me- I do think you are all correct, I don't know if I would have ever found this without the help, Thank you.
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