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Showing results for tags 'orophocrinus saltensis'.
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This silicified blastoid at 31 mm in width is close to maximum size for the species. Found with at least three species of crinoids in Mississippian Escabrosa Limestone which is roughly equivalent to the Redwall Limestone of central and northern Arizona. Macurda D. B., Jr. 1965. The functional morphology and stratigraphic distribution of the Mississippian blastoid genus Orophocrinus. Journal of Paleontology 39(6):1045-1096. McKee, Edwin D., Gutschick, R. C., 1969. History of the Redwall Limestone of northern Arizona. Geological Society of America Memoirs 114, 1-700. Mindat: Link Fossil Forum: Link
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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.
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