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I went back to my very productive Devonian Martin Formation and Mississippian Escabrosa Formation near Superior, Arizona to retrieve my large single crinoid head fossil. Amazing Arizona Adventure original post link After some acid prep four crinoids and one blastoid were clustered together. Currents probably sorted them by size and shape. Several more hours of acid prep made the remaining four best ones stand out. I had to carefully break away pieces of shell that adhered and covered the crinoids and blastoid. Careful monitoring of their progress prevented any of them falling off the matrix. The resulting piece is probably the finest crinoid and blastoid assemblage ever found in Arizona. Finding one crinoid or blastoid cast in Arizona is very hard let alone four or five together. The two largest crinoids in the center and left are likely Physetocrinus lobatus. The upper right is an Orophocrinus saltensis blastoid. The lower right is an unknown crinoid. (Any idea what it is?) The field of view is about 7.5 cm wide. Keep looking for updates as I prep and post more fossils. I found several loose crinoid heads.

I found one of my most interesting and productive fossil sites ever east of Phoenix near Superior, Arizona in late November. The hill contained outcrops of the Devonian Martin Formation and the Mississippian Escabrosa Formation which is roughly the same age as the Redwall Limestone found further north. My first interesting find was several Pachyphyllum corals with very small corallites. The “craters” within the corallites averages just under 2 mm which suggested that these were the P. nevadense species which is not common in the Payson area further to the north. The coral is about mm across. I found a relatively rare Iowaphyllum nisbeti coral that was found by Gladys Nisbet, a botanist from the Phoenix area. The colonial coral is noted for its large corallites with prominent ridges in between. Coral colony is about 9 cm x 8 cm. Here is partially silicified Alveolites coral with very distinctive compressed fish-scale like corallite tops. This piece is about 65 mm across. Here is a nice massive Thamnopora coral 17 cm across. Along with the Alveolites were two types of stromatoporoid sponges. The first is an approximately 15 cm across Amphipora sp. with mound like mamelons. The second stromatoporoid has nice laminations with some vertical pillars. View is about 4 cm across. The most amazing find was several silicified calyxes of a blastoid and at least three species of crinoids found in the Mississippian Escabrosa Limestone. Interior and exterior molds of crinoids and blastoids are occasionally found further to the north in the Paleozoic rocks. Originals or casts are rare in Arizona especially when they are found in a few square meter area. This is the best spot that I have ever found for blastoids and crinoids. The largest and best blastoid was a 31 mm wide Orophocrinus saltensis that I have entered in the current Fossil of the Month contest. It was near maximum size for the species. I have seen no finer blastoid on the internet from Arizona. Cast your vote for the battle of the blastoids. I found at least three species of silicified crinoids. If you know what they are, please let me know. Species 1 is 11 mm across by 14 mm high. Species 2 is a cup that is 17 mm across by 18 mm high. Species 3 has interesting triangular patterns and is about 2 cm across by about 2 cm high. It is in a large rock that I need to break down so that I can carry it away. I planning on going back to the site to look for more goodies.