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Showing results for tags 'temnocidaris (stereocidaris) hudspethensis'.
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A few weeks ago my mother, Stella (dog), and I went to a old-reliable heteromorph site in the Atco. After I dragged all my equipment to the part of the site that I was going to work, she went walking with Stella to look at some of the check-dams full of brought in Edwards limestone, chicken wire bags full of the brought in matrix put in the ditches for sediment control. In 2017 while we were at the same Atco site she was looking at a dumped pile of the Edwards and found a rare cidarid (see thread here) that compares well with Temnocidaris (Stereocidaris) hudspethensis. The sight of seeing that bizarre looking fossil just laying on the ground was quite a shock for both of us and motivation to hunt the dams more, and since then she has been casually looking over every check-dam hoping for another one. But because this Atco site is also rich in heteromorphs, I tend to focus all my attention on the chalk and neglect the Edwards dams, in these cases to my slight ire but also amazement at what she found with Stella. She did it again on the 9th, and found another cidarid that appears to be the same species as the last one from 2017, though from a different dam. I was at my Atco pile when she came over and showed it to me, completely blowing away all my finds in a very welcome way. The brought in Edwards is early upper Albian in age (about 107.6 mybp) and is a very fossiliferous crystalline limestone jammed packed with rudists and Chondrodonta sp. as well as the occasional gastropod. It makes for quite the sensory overload when trying to look for other things amongst the fossiliferous morass. The limestone is also interspersed with somewhat softer red sandstone that infills crevices in the much harder limestone and is more quickly weathered away in older exposures. I have tried so-far unsuccessfully to isolate the quarry from which the matrix originated to ask them permission to get a chance at the fossils before they are dumped in bags and hauled tens of miles to sites, damaging them. The problem is that there are multiple quarries in the nearest counties that expose the Edwards, namely Hood and Johnson counties. I have seen this matrix at sites all over North Texas, but I don't know if all that matrix is from the same quarry as the matrix from my Atco site since the Edwards is heavily quarried for fill all over the state. For now we are left to dig though the jumbled, knocked around bagged matrix, but even so the limestone is extremely hard so the fossils are not usually completely destroyed. And the site is big with lots of busted open bags. This latest cidarid is in about the same condition as the first, that being not so great but not so bad. Both specimens are missing most of their adoral sides and their apical plates are gone, leaving their circular apical scars. But they are still quite nice and intricately detailed, and also preserve some of their big mamelon tubercles, with the first specimen preserving 2 and the latest preserving 5, though there could be more under the globs of matrix stuck to them. This latest is also bigger. The first had a diameter of 52 mm at the ambitus and a preserved height of 37 mm, while the latest is 59 mm at the ambitus and 45 mm in height, though keep in mind that since they are both missing most of their adoral sides they would have had more height in life. The apical scar on the first specimen is 19 mm in diameter and on the second is 21 mm, with the crushed calcite fragments of the apical plates seen in the cavities left behind on both. I really didn't expect her to find another specimen of this rarity again, but apparently this matrix is a honey hole brought in by the truck load, making this site two honey holes in two epochs. Then on Wednesday I went by the same check dam from which this latest cidarid came and found what really appears to be a belemnite, but that is for another topic in the ID forum. Hopefully I can post that find soon. Since new Atco exposure at the site has temporarily slowed down I have an excuse to take a good hard look at the Edwards dams tomorrow afternoon. If we find anymore from the dams I will post it to this thread, so hope to see more In the mean time, here are the pictures of the echinoids, the check dam from which this latest specimen came, and a nifty Chondrodonta sp. she found in said dam. I welcome any other finds that anyone has found in the Edwards or its equivalents and any tips on how to prep limestone as hard as crystalized concrete. Also, sorry for the picture quality. My Nikon decided to die a few months ago for some reason and I have yet to get it fixed, so if anyone knows a camera repair shop that fixes Nikons in the DFW area, I am all ears. *Pictures incoming, computer acting up*