Sea Urchins From The Past Six Months Central Texas

[BobC]

Hey guys--I thought I'd start a thread to show you all the stuff I'm finding in the Central Texas area. The first picture is a group of Phymosomas, snails, heart urchins and tiny Selenia I found in Florence. The snails are cool because most have their distinctive ornamentation on them.

[BobC]

And here are some critters I found near Wimberely and Blanco--coral, Articas, some regular and heart urchins, selanias, "Mexican hats," small rudists, fruiting algae bulbs and snails. I found this stuff in March. Ignore the question marks!

[BobC]

More Wimberely stuff

[BobC]

Here is a fossilized woodstump I found in a quarry

[BobC]

From Florence:

[BobC]

And from Dripping Springs--the first selenias I ever found. I've found better specimens since then, but nothing matches the excitement of finding the first one

[Auspex]

Look at all that stuff!

I envy that you can just go out and collect cool fossils when you feel like it...

I need to retire again!

[BobC]

Hey come down to Austin!

[Uncle Siphuncle]

Looks like you've found both some Walnut exposures plus the Upper/Lower Glen Rose contact.....

[BobC]

Hi Dan--I don't know too much about the various formations around here. Is there any kind of map that shows which formations are where? How do I tell?

[jimmy1971]

And from Dripping Springs--the first selenias I ever found. I've found better specimens since then, but nothing matches the excitement of finding the first one

I am still waiting to find my first one! those are really nice finds congrats!

[BobC]

Hey Jim--I searched for six months for these guys. I have friends who have found them in the cliffs of Canyon Lake, but the Core of Engineers apparently don't want us collecting them. I, on the other hand, like to go off on my own and find my own places--and so far I know of three places in or around Dripping Springs/Wimberely. These are sites surrounded by mile after mile of rocky hell--the yellow clay formations just pop up every once in while and if you find one Salenia you will find a ton. For some reason I never find Phymosomas or other regular urchins with Salenias (the sites have one or the other but never both). Also--if you find this clay with tons of those Mexican Hat thingees in it, you stand a good chance of finding salenias.

My friend Linda and I collected probably fifty or sixty of them on Saturday. Linda (she really knows what she's doing) also found a piece of a fossil that she said was either the biggest Salenia she's ever found or it was another species altogether--although I don't recall what it was called. It was easily twice to three times bigger that the biggest Salenia at the sight. Too bad only part of it was there--but it made me want to find more.

[jpbowden]

Hey guys--I thought I'd start a thread to show you all the stuff I'm finding in the Central Texas area. The first picture is a group of Phymosomas, snails, heart urchins and tiny Selenia I found in Florence. The snails are cool because most have their distinctive ornamentation on them.

Ya, there's a lot of them here in Florence, wow, I should have got you guys up here to dig for them when I was planting my tomatoes!

[BobC]

I'm available

[Shamalama]

Here is a fossilized woodstump I found in a quarry

I love that stump, did you keep it? It is ironic that these delicate urchins are buried and preserved only then to break and flake apart once they are stone. Great Finds!

[BobC]

Hi Sham--I gave the stump to a paleontologist at UT--she is studying it. They have no idea what this stump was doing in this quarry since it was part of a Cretaceous sea--but think maybe it floated there and sank. Here's a pic of the underside of it

[Shamalama]

Hi Sham--I gave the stump to a paleontologist at UT--she is studying it. They have no idea what this stump was doing in this quarry since it was part of a Cretaceous sea--but think maybe it floated there and sank. Here's a pic of the underside of it

That is exactly what I was thinking when I saw it, a washed out to sea stump. The underside shot shows some layers that remind me of Travertine formations I find in the limestone quarries out here. Thanks!

[BobC]

Here's some cool ammonites and regular urchins I found on Sunday in Florence. Make sure you hit the HQ button at the bottom of the video so you get the clearer video version:

[Uncle Siphuncle]

Bob

Google up the UT Bureau of Economic Geology Publications page and order Atlas of Texas Maps, San Antonio and Austin sheets, $6 each when I bought them. You'll see aerial outcrop of mapped formations. S. texana is most prevalent at the contact of the upper and lower Glen Rose formations, marked by a 2 to 20 foot marl bed containing S. texana, Coenholectypus planatus, Heteraster obliquatus, Palhemiaster comanchei, and occasionally Phyllacanthus sp., the latter being a larger cidarid echinoid similar to a big Salenia to unfamiliar eyes. Look for a small one in my upcoming March fossil report and you can compare it to my recent Salenia finds and draw your own conclusions. If you are finding "Phymosoma"-like echies in the same exposures, they are probably Tetragramma texanum as Phymosoma are pretty rare in the Kgr, at least in my experience. If they are not coming from the Salenia exposures, you may instead be looking at the Walnut formation, where Phymosoma are much more prevalent.

[ashcraft]

Hi Sham--I gave the stump to a paleontologist at UT--she is studying it. They have no idea what this stump was doing in this quarry since it was part of a Cretaceous sea--but think maybe it floated there and sank. Here's a pic of the underside of it

Here in Missouri we have petrified wood from late Cretaceous, 70mya or so, we were at the head of the Mississippi embayment at that time. I have several decent pieces, including one piece of what looks to be palm wood, about 10 " long, and maybe 5" thick. the only piece I know of from Missouri, although I know a guy who found a frond impression in the same formation. If she can id it would be interesting, could be mahogany or cinnamon tree or something equally exotic, all have been found in Missouri, maybe some of ours floated your way.

Brent Ashcraft

[BobC]

Thanks for the tips Dan--you obviously know what you're talking about.

You have opened up a can of worms--unknowingly.

I stay in contact with two experienced fossil hunters, and they tell me that after years of collecting they have each only found one or two Tetragrammas in Central Texas. They say they are extremely rare. Now granted, 99% of the regular urchins that I find in Florence are obviously Phymosoma Texanas--they have the two rows of bumps and the bumps are not perforated. I have, however, found 4 or 5 regular urchins in that area over the months that look very different--mainly because they have rows of three bumps and the bumps are smaller/more compact that what I see on the other guys. The bumps are perforated. So I have two different types of urchins from Florence, but my two friends are skeptical that the odd ones are tetragrammas (but they haven't seen them in person yet). Here is a pic of one of these "Tetragrammas"

I will take better pics of them tonight--I'd love to know what your take is.

NOW--all of these regular urchins are much different from the ones I found in Dripping Springs/Wimberely (not talking about the Selenias)--The Wimberely regular urchins are much smaller, flatter, and have much larger holes on top. I was sure they were Phymosoma Hilis based off what I see on Echinoids.com--but my friend Linda says they are Loriolas. I am so confused. Every time I think I can ID these damned things, Linda deflates my theory!

Does this guy look like a tetragramma?

[BobC]

Ash--Here in Texas we have lots of fossilized palm trees, but the kind of stump I found is different. It has people baffled. I know Anne at UT is doing test on it so maybe I'll have some answers soon

[BobC]

Hey Dan I just did a search on phyllacanthus--and all I'm getting are cactus images! Are you thinking of something else?

Oh wait--on the third search page I finally found what you were talking about. I haven't found one of those yet.

[Uncle Siphuncle]

Bob

Looks like Tetragramma texanum to me, ventral view. Ultimate confirmation would come through looking more closely at the tubercles. Tet has perforated tubercles, Phy does not. Good find! However they occur in the Glen Rose and Walnut, usually bigger and more abundant in the Walnut, which overlies the Glen Rose. Yes I have found Tet in the S. texana zone, just not much over 1-1.25 inches diameter, usually smaller. I've worked the Kgr hard for about 5 years and only taken maybe 5 Tets. I have a couple Tets from the Kwa and a few more, T. steeruwitzi, from the Duck Creek and its equivalents in West Texas (Boracho fm, Levinson member). I took a real screamer in the Kdc the other weekend in North TX.

If your other regular echs are small, as in nickel to dime size, and not generally found with Salenia, you probably have Loriolia rosana. I have tons of them as they are abundant in some areas. They don't take up much space so you can't have too many!

As for Phyllacanthus, I've read about P. texanum and P. tysoni in the Kgr. I've taken 3 P. texanum. As cidarids they are extremely rare in TX. Look at the rotating picture carousel in the banner of this forum and you'll see my best one, a knobby gray thing the size of a golf ball. My smallest is the size of a S. texana.

[BobC]

YES!!! I will take better pics tonight. Now when you say perforated, you are talking about really small holes, right? These guys definitely have holes whereas the Phymosomas do not.

Another thing--my friend Linda and I found 3 Goniopygus in a quarry off Parmer Lane. She said they were "special."