Invertebrate - North Sulpher River

[Mike Owens]

Nautilus (3"X 3 1/2"), clam (2 1/4" X 3") & snail (1 1/2"X 2 1/2") That's my best i.d., as I don't know invertebrates very well. The Nautilus may well be a species of Ammonite, but it "looks" like a Nautilus to me. These were found at the NSR "Paris" bridge site.

[MOROPUS]

YOU`RE RIGHT! it`s a Nautiloid member,not an ammo.It`s perfect conservation will help you to ID it.Very seldom seen and very good catch, indeed!!

[Uncle Siphuncle]

Mike

At the Hwy 24 "Paris Hwy" bridge I believe the river incises the Pecan Gap formation. The formation extends all 350 miles down to San Antonio in a narrow strip and while the lithology changes a little bit, most noticeably in color from gray to buff, similar fauna are found throughout. The prevalent nautiloid is Cymatoceras, which may very well be the genus of your excellent example. Ammonites of the Kpg in my experience are dominated by Trachyscaphites spiniger, Baculites taylorensis, B. mclearni, Pachydiscus paulsoni and P. travisi while oddball heteromorphs Didymoceras reevesi and Solenoceras sp. occasionally come to hand. Echinoids are mainly baseball sized Echinocorys texanus, walnut sized Proraster dalli and much smaller Hemiaster texanus. Oysters are dominated by Exogyra ponderosa. Nice bivalves and gastropods can be had as well. Occasionally shark, fish and mosasaur material show up in the Kpg. The formation can be stingy at times and fossils are often compressed but often what is found is in wonderful detail.

[Mike Owens]

Mike

At the Hwy 24 "Paris Hwy" bridge I believe the river incises the Pecan Gap formation. The formation extends all 350 miles down to San Antonio in a narrow strip and while the lithology changes a little bit, most noticeably in color from gray to buff, similar fauna are found throughout. The prevalent nautiloid is Cymatoceras, which may very well be the genus of your excellent example. Ammonites of the Kpg in my experience are dominated by Trachyscaphites spiniger, Baculites taylorensis, B. mclearni, Pachydiscus paulsoni and P. travisi while oddball heteromorphs Didymoceras reevesi and Solenoceras sp. occasionally come to hand. Echinoids are mainly baseball sized Echinocorys texanus, walnut sized Proraster dalli and much smaller Hemiaster texanus. Oysters are dominated by Exogyra ponderosa. Nice bivalves and gastropods can be had as well. Occasionally shark, fish and mosasaur material show up in the Kpg. The formation can be stingy at times and fossils are often compressed but often what is found is in wonderful detail.

Dan,

Nice collection! You have triggered my memory on a clam. What is the large blue clam found on the NSR called? I want to say Ponderosa Texana, but --- I've been out of circulation too long to be sure. I found one with both valves & have never heard of or seen another one. Are complete ones rare? I'll have to dig it out & photograph it.

Mike

[Uncle Siphuncle]

Dan,

Nice collection! You have triggered my memory on a clam. What is the large blue clam found on the NSR called? I want to say Ponderosa Texana, but --- I've been out of circulation too long to be sure. I found one with both valves & have never heard of or seen another one. Are complete ones rare? I'll have to dig it out & photograph it.

Mike

You are probably thinking of Exogyra ponderosa. Usually you find just one valve in river tumbled specimens but if you locate one in situ they are often found with both valves articulated. Before construction crews covered the site in the Corsicana formation I've been hunting down here in San Antonio I took many large oysters with both valves intact such as Exogyra costata, E. cancellata and Pycnodonte mutabilis and lined my flower gardens with them. Underlying the crab, echinoid, and ammonite layer was a dense bed these oysters easily extractable from the soft matrix. Man I miss that site. Good thing I grabbed a couple lifetime supplies of material before progress did it in.

[Mike Owens]

You are probably thinking of Exogyra ponderosa. Usually you find just one valve in river tumbled specimens but if you locate one in situ they are often found with both valves articulated. Before construction crews covered the site in the Corsicana formation I've been hunting down here in San Antonio I took many large oysters with both valves intact such as Exogyra costata, E. cancellata and Pycnodonte mutabilis and lined my flower gardens with them. Underlying the crab, echinoid, and ammonite layer was a dense bed these oysters easily extractable from the soft matrix. Man I miss that site. Good thing I grabbed a couple lifetime supplies of material before progress did it in.

Dan,

Thank you -- again! This ole man just needed a little memory jog! Exogyra is what I have. I found this one on a feeder creek to the NSR. The site was off the beaten track. The reason I remember it so well, is there were 9 of us in two cars that day in '75 & my buddy & I were looking for a suitable spot to stop & check out for fossils. He was behind me & didn't see me stop & rear-ended me with his '73 Mavrick. I was in an '73 Vega. He trashed his radiator & the 9 of us had to ride back the 100 + miles to Dallas in that compact car. Four adults & 5 kids. For those of you reading this & do not know what a Vega is, it is a two door compact like a Geo only much shorter. It has a very compact back seat meant for 2 small children. The kids ranged from 3 to 11. Needless to say it was a "very cozy" ride back that ranks right up there as one of the most memorible trips of my life.

Mike