Saturday, June 25, 2016

Alveolites sp. coral from the Martin formation of Arizona

One of the more unusual looking pieces I found in the Martin formation of Arizona was a piece that resembles Alveolites sp. It is a flat topped piece with an epitheca on the underside and what appears to be a vertical growth element so that, in profile, it looks a little like a mushroom. The corallite openings on the dorsal surface are the most telling. They appear to be laying on their side and shaped a little like a fish scale. This is a diagnostic feature of Alveolites which is what leads me to believe my piece is of the same genus. The genera is listed by Teichert in his paper and illustrated in Langland's article.

Dorsal surface
Dorsal surface tilted and a little closer to show the corallite openings.
Profile
Ventral

This specimen is from the Jerome member of the Martin formation (Devonian, Fransian stage) north of Payson, AZ.

References:
Teichert, C., 1965, "Devonian Rocks and Paleogeography of Central Arizona",  USGS Professional Paper 464

Langland, Jeffrey O. and Edith V., 2012, "Fauna of a 400-Million-Year-Old Coral Reef in
Arizona", Rocks and Minerals, 87:1, 40-44

Stumm, Erwin C., 1948, "Upper Devonian Compound Tetracorals from the Martin Limestone", Journal of Paleontology, Vol. 22:1, pp. 40-47

Thursday, June 23, 2016

Syringopora sp. coral from the Martin formation of Arizona

I found one pebble of limestone from the Martin formation in Arizona that was shot through with a narrow, stick like coral that I believe is Syringopora sp. The genera is listed by Teichert in his paper and is illustrated by Langland in his article. The calices are very narrow, 3-5mm across and clustered but not in a central mass. Think of them more as loose spaghetti. My sample is small and there is not much exposed of the sides of individual calices, so could this possibly be a form of Aulocystis?




This specimen is from the Jerome member of the Martin formation (Devonian, Fransian stage) north of Payson, AZ.

References:
Teichert, C., 1965, "Devonian Rocks and Paleogeography of Central Arizona",  USGS Professional Paper 464

Langland, Jeffrey O. and Edith V., 2012, "Fauna of a 400-Million-Year-Old Coral Reef in
Arizona", Rocks and Minerals, 87:1, 40-44

Stumm, Erwin C., 1948, "Upper Devonian Compound Tetracorals from the Martin Limestone", Journal of Paleontology, Vol. 22:1, pp. 40-47

Monday, June 20, 2016

Disphyllum sp. coral from the Martin formation of Arizona

These next two specimens represent a new (to me) genera: Disphyllum. They are a colonial rugose coral with closely set, yet independent calices. It looks similar to Eridophyllum but the calices are shorter. Both specimens that are shown here are small clusters. I don't know if they form larger colonies or is these represent the typical form.

I looked through Stumm's paper and did not find any mention of Disphyllum. I based my ID of these fossils on Langland's article in Rocks and Minerals where they illustrate two species but do not list specific names. Teichert's paper does list several species of Disphyllum.

Specimen #1 - Dorsal view
Dorsal view rotated 90 degrees
Right profile
Left profile


Specimen #2 - Dorsal surface

The next four pictures are the specimen in profile view, rotated 90 degrees in each subsequent photo.




These specimens are from the Jerome member of the Martin formation (Devonian, Fransian stage) north of Payson, AZ.

References:
Teichert, C., 1965, "Devonian Rocks and Paleogeography of Central Arizona",  USGS Professional Paper 464

Langland, Jeffrey O. and Edith V., 2012, "Fauna of a 400-Million-Year-Old Coral Reef in
Arizona", Rocks and Minerals, 87:1, 40-44

Stumm, Erwin C., 1948, "Upper Devonian Compound Tetracorals from the Martin Limestone", Journal of Paleontology, Vol. 22:1, pp. 40-47

Saturday, June 18, 2016

Family Fistuliporidae (?) bryozoan colony from the Martin formation of Arizona

One of the most mysterious fossils that I found in the Martin formation of Arizona is this large chuck of silicified rock. The softball sized piece is composed entirely of a single colony of some sort of coral or bryozoan. As you can see in the pictures below, it is a very three dimensional piece with "pores" on all side and every surface. The small openings vary in shape but do show some "flowing" features that I interpret as a growth pattern. I don't think this is the coral Alveolites as the corallite openings of that genera are flattened and resemble fish scales. It's not likely a sponge due to the many small openings and growth patterns which sponges or stromatoporoids do not possess. I'm thinking that this is part of a massive Bryozoan colony of some species in the Family Fistuliporidae. I have found similar large and massive colonial structures like this one from the Hungry Hollow mbr. of the Widder formation from Hungry Hollow, Ontario.






Closer views of the small openings.


These specimens are from the Jerome member of the  Martin formation (Devonian, Fransian stage) north of Payson, AZ.

Wednesday, June 15, 2016

Aulopora sp. coral from the Martin formation of Arizona

Some of the silicified coral fossils that I found in the Martin formation of Arizona were composed of many small tubes that clustered close together. I recognized this as a form of Aulopora which is an encrusting type coral which sometimes forms clusters or chains on the surface of brachiopods, corals or any other hard surface. The coral colony expands by clonal budding with the new polyp attached to the exterior of it's progenitor.  Aulopora is always a neat coral to find as it often forms interesting patterns or shapes on whatever surface it encrusts.  Jeffery and Edith Langland do include a picture of an Aulopora specimen in their article (see reference below) that looks similar to the first specimen below.

Specimen #1 is a large, flat encrustation that appears to have colonized an overturned coral colony


Specimen #2 appears to be less of an encrustation and more of a vertical aspect where the polyps are using the bodies of their neighbors as a support. To me this growth habit is more reminiscent of the genera Aulocystis.


Specimen #3 has a similar growth pattern




These specimens are from the Jerome member of the  Martin formation (Devonian, Fransian stage) north of Payson, AZ.

Langland, Jeffrey O. and Edith V., 2012, "Fauna of a 400-Million-Year-Old Coral Reef in
Arizona", Rocks and Minerals, 87:1, 40-44