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Devonian Coral Inspiration for Van Gogh Painting?
DPS Ammonite posted a topic in Fossil Hunting Trips
I found several varieties of Devonian corals, including Pachyphyllum, Hexagonaria, Thamnopora and Alveolites near Superior, Arizona. Check out this Pachyphyllum woodmani that reminds me of the painting The Starry Night by Vincent Van Gogh. The painting also inspired a great song by Don McLean: https://m.youtube.com/watch?v=dipFMJckZOM Pachyphyllum lack common walls with their neighboring corallites. The septa grow in a curving manner towards each other meeting in a slightly irregular fashion. -
This is a small form of Pachyllum nevadense that has corallites with small corallas (the circular structures that have a high rim that stick above the surface). The coralla rim diameters range from 1.25 mm to 2.5 mm and average 1.5 mm to 1.75 mm. The corallites average 2.5 mm to 8 mm apart center to center with an average of 4 mm to 5 mm apart. They have an average of 20 septa. The measurements partly overlap with those described for the species by Stumm in 1948: coralla rim diameter of 2 mm to 4 mm; average of 3 mm; distance from corallites centers of 5 mm to 10 mm; 18 to 24 septa. Since there is a lot of variability of the species in the same colony, at the same site, from site to site in Arizona and the US, I consider that this a variety of Pachyphyllum nevadense. References: Stumm, Erwin C. “Upper Devonian Compound Tetracorals from the Martin Limestone.” Journal of Paleontology, vol. 22, no. 1, 1948, pp. 40–47. JSTOR, www.jstor.org/stable/1299252. Luke, Keith J., 1978. CORALS OF THE DEVONIAN GUILMETTE FORMATION FROM THE LEPPY RANGE NEAR WENDOVER, UTAH, NEVADA. BRIGHAM YOUNG UNIV. GEOL. STUD.; USA; DA. 1978; VOL. 25; NO 3; PP. 83-98. Link
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This Late Devonian silicified coral was first found in the Superstition Mountains by Gladys Turner Nisbet who was a botanist from Cave Creek, Arizona. I found mine nearby. Wikipedia: Link Measurements given for whole colony. Coralites vary from 10 mm to 40 mm across. Average is 15 mm to 20 mm. Oliver, W.A., Jr., 1978, Iowaphyllum (rugose coral) from the Upper Devonian of Arizona: U.S. Geological Survey Journal of Research, v. 6, no. 6, p. 797-805. Link Mindat 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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Here are photos of two trips taken to look for Paleozoic fossils in northern Gila County in northern Arizona. Daily thunderstorms and plentiful shade made the 90 deg. + temperatures bearable. I ran into TFF member ArizonaChris while in the area. In the Martin Formation I found interesting stromatoporoids, now determined to be sponges, that were important reef forming organisms during the Late Devonian. Pine needles for scale. Here are some silicified Martin Formation brachiopods. Nearby are many caves and sinks in the fossiliferous limestones of the Martin and Redwall Formations: up to 100 miles of passages according to a caver. The first one is full of junk metal including two cars. Any idea what the cars are? Here is Tin Can Sink. To be continued.
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I was exploring a canyon south of Globe, Arizona in the Mescal Mountains where I found two bones in the Devonian Martin Formation, (Frasnian Age, 372-383 mya). Do you agree that they are bones? If so, what type of bones from what creature? I see that the only vertebrates in existence were fish and possibly the earliest tetrapods. See table of Arizona vertebrate fossils found in: DAVID K. ELLIOTT and RONALD C. BLAKEY, “THE PRE-PERMIAN VERTEBRATE RECORD IN ARIZONA”, Heckert, A.B., and Lucas, S.G., eds., 2005, Vertebrate Paleontology in Arizona. New Mexico Museum of Natural History and Science Bulletin No. 29. 19 mm diameter US penney for scale. Photo P1020698 left side detail of Photo P1020702 Photo P1020702 I have several detailed photos of this one if needed. Photo P1020705 Second bone I found on top of same layer a few feet away. Same animal?