Search the Community
Showing results for tags 'pinal county'.
-
Several days ago I ventured to a Devonian desert locality near Superior, Arizona. I found the largest fossilized coral colony that I have ever found: 2 ft across. A giant Iowaphyllum nisbeti coral was covered over it’s entire length with several inches of a stromatoporoid sponge. I should have taken a photo, but it was not very photogenic; it looked like a white ledge in cross section. First photo is a piece of light colored Iowaphyllum nisbeti coral covered with a medium gray calcitic stromatoporoid coral that is about 8 inches across. The top of the coral is pointed up. The second photo shows a detail of the stromatoporoid with horizontal layers and faint vertical pillars Nearby I found a partly silicified stromatoporoid 5 inches across that may be the same as the one mentioned above. This is probably the best hand sample of a stromatoporoid that I have found since the vertical pillars are so prominent. Only about 20% of the pillars are easily visible. Pillars differentiate stromatoporoid sponges from stromatolites which show only horizontal (to the growing direction) layers. See up close section of the stromatoporoid in the last photo. See an Iowaphyllum nisbeti in Collections: http://www.thefossilforum.com/index.php?/collections-database/cnidarians/corals/iowaphyllum-nisbeti-oliver-1978-r1966/
- 1 reply
-
- 5
-
- stromatoporoid
- superior
-
(and 4 more)
Tagged with:
-
This is a Late Devonian sponge collected from the Percha Formation found at the type locality on Brandenburg Mountain in Pinal County, Arizona. This sponge, has the largest complete head reported. Although mostly covered in calcareous sediments and maybe caliche it has the best preserved spicules of the species that I have seen; better than the photos in the Rigby reference below. First photo is a close up of the star shaped spicules that average 1 mm across. Second photo is of the top of sponge that is 70-75 mm across. First published in: Rigby, J Keith; Dietmar Schumacher; and Sally J. Meader. 1979. The genus Ensiferites, a Devonian astraeosponge of North America. Journal of Paleontology 53(2):475-493. Meader, Sally J. 1976. PALEOECOLOGY OF THE UPPER DEVONIAN PERCHA FORMATION OF SOUTH-CENTRAL ARIZONA. Master’s Thesis, DEPARTMENT OF GEOSCIENCES, UNIVERSITY OF ARIZONA, Tucson, Arizona. https://repository.arizona.edu/bitstream/handle/10150/566637/AZU_TD_BOX292_E9791_1976_329.pdf?sequence=1 Geological map: https://ngmdb.usgs.gov/Prodesc/proddesc_1977.htm
- 1 comment
-
- 4
-
- devonian
- ensiferites brandenburgi
-
(and 3 more)
Tagged with:
-
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.- 3 replies
-
- 9
-
- pinal county
- pachyphyllum
-
(and 5 more)
Tagged with:
-
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
-
- pachyphyllum nevadense
- superior
- (and 5 more)
-
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
- 1 comment
-
- 2
-
- blastoid
- orophocrinus saltensis
- (and 5 more)
-
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
-
This is a Late Devonian sponge collected from the Percha Formation found at the type locality on Brandenburg Mountain in Pinal County, Arizona. This sponge, although missing most of its stem, has the largest complete head reported. First photo is a close up of the star shaped spicules that average 1 mm across. Second photo is of the top of sponge that is 60-64 mm across by 20 mm thick. Zoom in the see numerous star shaped spicules. You can also see rod like sponge structures that look like villi when viewed from the top. First published in: Rigby, J Keith, Dietmar Schumacher, and Sally J. Meader. 1979. The genus Ensiferites, a Devonian astraeosponge of North America. Journal of Paleontology 53(2):475-493. Meader, Sally J. 1976. PALEOECOLOGY OF THE UPPER DEVONIAN PERCHA FORMATION OF SOUTH-CENTRAL ARIZONA. Master’s Thesis, DEPARTMENT OF GEOSCIENCES, UNIVERSITY OF ARIZONA, Tucson, Arizona. https://repository.arizona.edu/bitstream/handle/10150/566637/AZU_TD_BOX292_E9791_1976_329.pdf?sequence=1
- 3 comments
-
- 5
-
- devonian
- percha formation
-
(and 3 more)
Tagged with: