Roz Posted January 2, 2008 Share Posted January 2, 2008 Well, went with a small group north of Fort Worth on a fossil hunt. A good way to start the new year. Am including a pic of what the formation looks like and also a pic of a small crab or lobster bit. I do have a question on the fossil. On the edge of it where you can see the small raised nodules (might not be what they are called), where there are none present, does mean the rest has worn away, or maybe there is more intact underneath. I haven't found many crab, lobster bits in Texas yet. I have posted 2 views of the same crab. Roz Welcome to the forum! Link to comment Share on other sites More sharing options...
Gatorman Posted January 2, 2008 Share Posted January 2, 2008 Looks pretty worn to me. Link to comment Share on other sites More sharing options...
kauffy Posted January 2, 2008 Share Posted January 2, 2008 nice fossil! looks like the one side has the actuall shell material still intact and the other has worn away leaving an internal mould "Turn the fear of the unknown into the excitment of possibility!"We dont stop playing because we grow old, we grow old because we stop playing. Link to comment Share on other sites More sharing options...
RJB Posted January 2, 2008 Share Posted January 2, 2008 Hey Roz, thats most definetly crab and not lobster. I have not studied any crabs from texas, so I cannot tell you what genus or speices it is, plus it would be tuff with just that picture? And, just like the old california fossil forum, you still have some incredible eyeballs. I dont think I could find fossils that small? Try to find some science papers on the Pawpaw formation to find out what you have? Also, how many sedimentary members are in the Pawpaw? RB Link to comment Share on other sites More sharing options...
Roz Posted January 3, 2008 Author Share Posted January 3, 2008 Hey Roz, thats most definetly crab and not lobster. I have not studied any crabs from texas, so I cannot tell you what genus or speices it is, plus it would be tuff with just that picture? And, just like the old california fossil forum, you still have some incredible eyeballs. I dont think I could find fossils that small? Try to find some science papers on the Pawpaw formation to find out what you have? Also, how many sedimentary members are in the Pawpaw? RB Did some digging and it may be a Cenomanocarcinus Vanstaeleni and you would be right, a crab.. Oh, RB, sure hope you post pics of some of those fantastic crabs you have Welcome to the forum! Link to comment Share on other sites More sharing options...
Roz Posted January 3, 2008 Author Share Posted January 3, 2008 nice fossil!looks like the one side has the actuall shell material still intact and the other has worn away leaving an internal mould Thanks Kauffy, you know something I have been wondering about, is pictures I see of modern crabs don't have the small nodules (bumps) do they? Maybe you have noticed. Seems like some fossilized crabs have them and some don't. Welcome to the forum! Link to comment Share on other sites More sharing options...
Uncle Siphuncle Posted January 3, 2008 Share Posted January 3, 2008 Roz Fortunately the bumps on ammonites, echinoids, and crabs are all called tubercles. The most common crab in the Pawpaw is Xanthosia, and there are at least 4 species, some bumpy and some smooth. Your second crab image looks like the smooth variant, but I can't remember if that is X. aspera or X. wintoni off the top of my head. The Pawpaw formation illustrates a classic offshore sequence moving from north to central TX as the water got deeper and supported different faunas. At Lake Texoma in Grayson Co. (TX-OK border for non Texans) the Kpp is lithologically presented as a red sandstone. This grades into a clay farther south near Fort Worth (Tarrant Co.) where the water was deeper, turbulence was less, cool shark and fish teeth as well as exquisitely preserved shrimp, crabs, and lobsters can be found, although most are under 1 inch maximum dimension, some considerably less. The Kpp clay outcrops about 25 feet thick in the crab zone. Heading south into Johnson County the water was still deeper resulting in a marly sequence supporting varied echinoids, but generally not the crustaceans found up north. Down toward McLennan Co. the Kpp this and hardens into a limestone which ultimately feathers out heading south. Looks like you are in the right area! Grüße, Daniel A. Wöhr aus Südtexas "To the motivated go the spoils." Link to comment Share on other sites More sharing options...
Roz Posted January 3, 2008 Author Share Posted January 3, 2008 Thanks for the information, Dan. I know the term tubercles for echinoids but didn't realize it was the same for crabs. Makes things easier. Which formation are your most detailed crabs found? Corsica? Welcome to the forum! Link to comment Share on other sites More sharing options...
LanceH Posted January 3, 2008 Share Posted January 3, 2008 Pawpaw formation crustacea from The Geology of Texas 1912: Macrura (lobsters, shrimp): Linaupurus n. sp. 2 Nephrops n. sp. Ischnodactylus n. sp. Callianassa n. sp. Brachyura (crabs): Actaea n. sp. Caloxanthus n. sp. Fam. Portunidae, n. gen., n. sp. Fam. Calappidae, n. gen., n. sp. Necrocarcinus n. sp. 1 Necrocarcinus ? n. sp. 3 Xanthosia n. sp. 2 --------------------- of course there's more species than what's in the book 1 Link to comment Share on other sites More sharing options...
Roz Posted January 4, 2008 Author Share Posted January 4, 2008 There are more than I remembered then. Sure wish I could find one of any species with really good detail, like that one you found! I really think from the places hunted that I will one day soon! Could you post a pic of it on here? Welcome to the forum! Link to comment Share on other sites More sharing options...
LanceH Posted January 4, 2008 Share Posted January 4, 2008 We didn't find any Xanthosia crabs but here's what they look like: Link to comment Share on other sites More sharing options...
LanceH Posted January 4, 2008 Share Posted January 4, 2008 Here is a claw part that evidently preserves original patternage. This is from our first trip to that spot. I don't know if this belongs to a crab or lobster. Link to comment Share on other sites More sharing options...
LanceH Posted January 4, 2008 Share Posted January 4, 2008 ..and here is a lobster (I think), not sure if these two pieces are from the same critter. This is from a different location but still Pawpaw formation. Link to comment Share on other sites More sharing options...
Uncle Siphuncle Posted January 4, 2008 Share Posted January 4, 2008 Roz I've done the best in the Pawpaw, Upper Britton and Corsicana, although I've found isolated crustacean material in the Pecan Gap, Anacacho, Grayson, Glen Rose, and Escondido. These are all Cretaceous, but I've also found Paleocene crabs in the Wills Point fm. For those not familiar with these formation names, they are all from Texas. Grüße, Daniel A. Wöhr aus Südtexas "To the motivated go the spoils." Link to comment Share on other sites More sharing options...
LanceH Posted January 5, 2008 Share Posted January 5, 2008 (edited) and finally a Cretacoranina punctata crab (ID by AdamA) Edited September 21, 2014 by LanceH Link to comment Share on other sites More sharing options...
Roz Posted January 5, 2008 Author Share Posted January 5, 2008 Most Excellent finds and that last little guy, I expect him to start moving around as I look! I love the detail, fascinating creatures!!! Now that just increases my motivation to look till I find one with all those details! The only thing that would be better, is if I would have found em.... Welcome to the forum! Link to comment Share on other sites More sharing options...
Roz Posted January 5, 2008 Author Share Posted January 5, 2008 Here is a claw part that evidently preserves original patternage. This is from our first trip to that spot. I don't know if this belongs to a crab or lobster. Me neither but it looks longer like maybe belonging to a lobster. I am not sure if that is the deciding factor though.. I love the pattern on it and haven't seen one of that pattern before yours.... Welcome to the forum! Link to comment Share on other sites More sharing options...
Roz Posted January 5, 2008 Author Share Posted January 5, 2008 We didn't find any Xanthosia crabs but here's what they look like: I love that one...Excellent fossil find for sure... Welcome to the forum! Link to comment Share on other sites More sharing options...
MB Posted January 5, 2008 Share Posted January 5, 2008 I love that one...Excellent fossil find for sure... Nice finds Dromioidea and Raninoidea albums, would be helpful for you. http://www.mbfossilcrabs.com/ Link to comment Share on other sites More sharing options...
Roz Posted January 6, 2008 Author Share Posted January 6, 2008 MB, you have a really fantastic collection and some I see are from Tarrant County, TX. That's the county I live in and 2 crabs you have look just like Lance's. Thanks, one great collection! Welcome to the forum! Link to comment Share on other sites More sharing options...
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