Fossil Finds In San Antonio, Tx

[Daliesque101]

I found these and many more in creek areas in two sites here in San Antonio. I love that my greatest finds have been here in my hometown of San Antonio. While Austin is my main source for a grand looking Exogyra Ponderosa, would you believe that its equal in size and shape is down here in San Antonio. I don't know which variety but the striations are very different and the horn curl is equally different at times. I will post some more soon and of Austin. Thank you for looking.

[Uncle Siphuncle]

Greetings from a fellow San Antonian. Looks like someone has happened upon the Austin Chalk. The Dessau member seems to be rather persistent in Bexar County, and I think it holds many of the ammonites of Austin age here. The Atco Formation is present too, representing the lowermost part of the Austin Group, but I haven't found many ammonites in in it. Your nautiloids look like Eutrephoceras, possibly species campbelli.

Are all specimens taken from the same formation? If the rock is thick bedded and sort of gritty with occasional black specks and some bands of yellow, its Austin Chalk, maybe 80-85 million years old. If it is very fine grained, free of impurities, and exhibits conchoidal fracture (splits in curved pieces), its Pecan Gap Formation, maybe 75-78 million years old. Pecan Gap ammonites are usually preserved compressed, but not always. Austin Chalk ammonites are usually inflated.

Ammonites are not particularly as well represented in Bexar County as in points farther north. Much of the Austin Chalk seems to be devoid of ammonites so it appears you've found a special place or two. I'm pretty sure the big half ammo is Parapuzosia americana. The ribbed ammonites are not quite as easy as there are many genera documented that I haven't taken the time to memorize. Look up Submortoniceras images and make your own comparisons. Keep your eyes open for Peroniceras, Baculites, Prionocycloceras, Texanites and others in the Austin.

If you wander into the Pecan Gap, look for Pachydiscus, Trachyscaphites, Menabites, Baculites, Placenticeras, Solenoceras, and Didymoceras, the first 3 being most common. Have fun!

[sward]

Nice finds! It looks like you've got a good variety and nice preservation, too.

You won't find anybody more knowledgable than Dan regarding fossils in the Austin area, or anywhere else, for that matter. Be sure to read his monthly postings about "Meanderings of a Texas Fossil Hunter". It's always a great read, very informative and entertaining.

Keep us posted on your finds.

[Uncle Siphuncle]

thank you for the kind words, sward. never stop learnin, i says...

[Foshunter]

When you are hunting, take your time and not only look for the large and you will find an amazing tiny world out there---Tom

[Daliesque101]

I just wanted to say thank you all for you kind words and I sent you a message Dan thanks!

Tom you are right. I feel like I have the "eye" down for certain species and now I need a new few to look out for. I did just that in a forest in southern Illinois earlier this year. The only era around was Cambrian and Pre Cambrian. But I walked up to a cliff wall and dove in and literally every time you barely whacked a chunk you were rewarded with all the micro fossils. There were those but then mushrooms with caps the size of a large pizza.

Anyone know of a meetup that might exist in S.A. for fossil hunting. I'm down for gems too I just haven't done that yet but I know if you're savvy enough one can find both in the same outing. I've got some nice spots for after the hard rains.

One more thing, I now have found at all sites in S.A. oysters that are "semi" fossilized? Maybe they are but they still have color and that pearl tone to them. They are a flatter and more frayed like and white and a pinkish purple. I'll take a pic soon.

Steven

[mommabetts]

Thank you for sharing your very nice fines with us.