In Search of THE Urchin - Fossiking around Texas

[JamieLynn]

So I am looking for this particular urchin. My grandmother found one when she was a child on the Brazos River outside of Waco TX. Her father sold it to a family friend in the late 1930's and so all I got were the stories of this big round rock that she thought had been "carved by Indians, decorated with dots and snakes". Only much later did she find out that it was a fossilized sea urchin. I am guessing it was a Cidarid, possibly Phyllacanthus or or Paracidaris. All I know is I am determined to find one someday. I would trade my entire collection of fossils for one of those big echies. (If anyone happens to have one just laying around.....let's talk! hahah) . I have been trying to learn the different formations and I stalk the Fossil Forum regularly to learn what I can. When I saw a post by  @KimTexan about a Cidarid ID I realized she had found what I had been looking for! (Kim, I am so very jealous of your find!) 

 

So, my husband and I set out on one of our "little hunting trips" - we like to take two or three day excursions around Texas - he gets to go ghost hunting at night (we stay at haunted hotels and B&B's) and I get to go fossking during the day. I mapped out some likely spots and we set out from our little town of San Marcos  heading north to HIllsboro (excellent home made icecream at A Tisket A Tasket on the Courthouse Square) and then to Granbury where we stayed at the Nutt House Hotel. Stopped at two spots that I thought likely to find my urchin but alas. No luck. Found some nice heart urchins and some "new to me" oysters and a couple of nice chucks of ammonites.  I think this was Washita formation? I am using the Rockd App on my phone to try to pinpoint formation since I am definitely not familiar with formations, especially up "north".  One of my happy finds was a Pinna Comancheana (far left "cone shaped" fossil) I've only found one other of those. 
 

 

 

Next morning we headed up to Lake Benbrook Spillway with a stopover at a large roadcut on "Scorpion Hill". This I believe was Glen Rose as most of the finds were heart urchins and gastros. Nothing new to me here, but I did find some better specimens than I had collected previously. 

 

 

 

Lake Benbrook was a neat place. Two other fossikers were out, I went over to say hello, wondering if they were experienced hunters and knew the area, but nope, they were new to Lake Benbrook, just as I was. I did not get to catch up with them after to see if they found anything good. I was amazed a the large ammonite impressions in the limestone beds. My camera wasn't working, so alas, no pictures.  Found lots of nice Oxytopodiceras fragments and a couple of others I haven't identified yet.  Pics in next post: 

[JamieLynn]

Pictures of the hoard from Lake Benbrook - I think this is Kiamichi Formation?  I love my big ammo fragment with a turritella in it. 

 

Then, we headed up to Lake Worth for our left-over pizza picnic and took a look around there to see what we could see. Found a couple of nice things, including a lovely heart urchin - the best preserved I have found. I THINK I found a dumblea urchin, but it broke apart as I was trying to get it out and I lost two of the fragments, so it wasn't even worth keeping. Sad about that.  I did find a lovely Trigonia bivalve though. Wasn't sure what it was till I got i home and cleaned up. I have found the little ones before, but not this big one (Upper left corner) 

 

 

Then we headed down to Glen Rose to walk about the town (we had been to the State Park previously, so skipped that this time) but I did hit up a new subdivision in town just off the square but found NOTHING except a "deer heart" clam and another bivalve. Talk about dissapointing...there in Glen Rose and nada.....but I think this hill was too high up...not the right strata, OR someone had already picked it clean! But the houses in Glen Rose was amazing! Petrified wood everywhere!  (see next post)

[JamieLynn]

 

Picture of one of the Petrified Wood houses in Glen Rose 

 

Of COURSE I had to put my hand in the footprint: 

 

Next stop was a great little B&B called the Old Rock House in Hico TX. But before we go there had to stop at another roadcut! This seemed to also be Washita Formation with Glen Rose "underneath" ?  Best find was the little Goniopygus Urchin! I have found two other in Canyon Lake. I thought it was Loriolia at first but then was able to look more closely at home. 

[JamieLynn]

The Old Rock House in Hico. Great little place to stay! 

 

Next morning, headed south along 281 back to San Marcos, but had to make a couple of stops at a couple of road cuts...of course! First one had the MOST turritellas I've ever come across. Not great preservation, but many still had bits of shell or at least could make out the patterns. 

 

 

And finally, the LAST stop- a small little road cut that I wasn't expecting much from but I found some nicely preserved Loriolias! So I was happy with my excursion, even though I did not find my "Grandmommy" Urchin. I will someday! 

[Heteromorph]

Nice report! Pretty good ratio of sites explored and fossils found. Can’t help with where to find big Cidarids except to say that there are apparently parts of the Edwards formation (Fredericksburg group) where they can rarely be found. Both Kim’s and my two came from the Edwards. I have also seen big ones come from the Washita and Trinity Groups, as you are aware.

[JamieLynn]

AAHHHHH!! YES! Those are what I am looking for!! Perhaps I can borrow your mom? hahahha!

[Darktooth]

Great report and pics! Thanks for sharing with us!

[erose]

Closer to home Cidarid spines are common in the "Salenia texana" zone at the top of the Glen Rose Lower Member. I have some fragments of Paracidaris(?) texanus (=Phylacanthus) from those beds (see photo of my best so far) and a few others have found them there as well. I know of good ones from near Bulverde and Lake Travis and my frags were from the Wimberley area. All the others, including that honker your grandfolks had, seem to be in younger rocks such as the Washita Group. 

 

But they are just not common at all pretty much anywhere from what I can gather. 9 out of 10 Texas collectors would tell you a complete one is still on their bucket list.

 

PS great trip report and photos. 

 

[ynot]

Looks like some nice finds!

Thanks for taking Us along.