Something New From The Waldron Shale

 

UPDATE (11-13-2020): I now think this fossil is a cluster of holdfasts for cystoids. See my post about this here.

Last Saturday (09-19-2020) I visited a Waldron Shale site and found a fossil I have not seen before. At first I thought it might be some sort of colonial coral. I showed it to my cousin Kenny and he thought it might be a parasite on a crinoid column. Similar to a fossil he found in 2015, on a Mississippian Period fossil. See this posting for more info. See image below of a Mississippian crinoid stem with what appear to be galls from parasitic marine worms.

One can see the similarities with the current Waldron Shale find.

He will need to prep this new find to see there is a crinoid column this fossils are attached to or part of. These shapes do look similar to galls of putative myzostomids (small marine worm) on crinoids as seen on a researchgate.net page showing an image from the book Fossil Crinoids by Hans Hess, William I. Ausich, Carlton E. Brett, and Michael J. Simms (Cambridge University Press, 1999).

Upon further Internet searching I came across the Time Scavengers blog with a 2017 post about The College of Wooster's paleontologist Mark A. Wilson. He posted an image Upper Ordovician cobble with encrusting crinoids (three volcano-like fossils). These shapes have some similarity to this fossil find has well. Could they be a cluster of small crinoid holdfasts?

Link to scan of the paper on Tremichnus by Carlton E. Brett from 1985:
http://webcentral.uc.edu/eprof/media/attachment/eprofmediafile_1303.pdf

Link to paper Phosphannulus on Paleozoic Crinoid Stems by James R. Welch 1976:
https://www.jstor.org/stable/1303489

Link to chapter entitled Biotic Interactions among Recent and among Fossil Crinoids by David L. Meyer and William I. Ausich. See section on Parasitism and Table V for information about parasites that infest crinoid.
https://www.researchgate.net/profile/David_Meyer16/publication/283756496_Biotic_Interactions_among_Recent_and_among_Fossil_Crinoids/links/568ad15008ae1975839db6d3/Biotic-Interactions-among-Recent-and-among-Fossil-Crinoids.pdf

Link to paper entitled Host-specific pit-forming epizoans on Silurian crinoids by Carlton E. Brett. The images show mostly boring holes and not the structures with holes seen in this fossil.
https://deepblue.lib.umich.edu/bitstream/handle/2027.42/75404/j.1502-3931.1978.tb01229.x.pdf?sequence=1

Link to article Phylogeny of Myzostomida (Annelida) and their relationships with echinoderm hosts by Mindi M. Summers and Greg W. Rouse.
https://bmcevolbiol.biomedcentral.com/articles/10.1186/s12862-014-0170-7

Ammonites opalus nomen oblitum Fossil Video

 

Today while researching a fossil I found, I came across a video from the The Society for the Preservation of Natural History Collections (SPNHC). It was created June 12, 2020 for the Specimen Spotlight Friday presentation. The video was entitled "What's in a Name? David Dale Owens' Ammonites opalus nomen oblitum" by Paul S. Meyer of the The Field Museum. Since I recently returned from a visit to that museum and earlier in the year I was at New Harmony, Indiana USA where David Dale Owen lived I thought this would be a good topic to blog about.

Above is an enhanced image of the original illustration from Table VIII Figure 6 of the Ammonites opalus described in Illustrations to the Geological Report of Wisconsin, Iowa, and Minnesota by David Dale Owen Philadelphia: Lippincott, Grambo & Co. 1852. It is described as from the Cretaceous Formation of Nebraska Great Bend of the Missouri River, associated with Inoceramus Cripsii. Below is pattern on the shell.

Paul talks about the type specimen at The Field Museum (FMNH UC 6377) which is now called Rhaeboceras halli. John Evans a forward guide for the Owens survey expedition collected this specimen in 1849 which Owen described in 1852. The link to this video is at https://www.youtube.com/watch?v=RC7yCm4ue_I

The Equatorial Minnesota blog was helpful in researching this posting.
https://equatorialminnesota.blogspot.com/2017/04/david-dale-owen-first-mn-geological-survey.html

A scan of David Dale Owen's survey report can be found at: https://archive.org/details/reportageologic00owengoog

Bumastus harrisi Trilobite

 

Above is an image of a prone trilobite fossil called Bumastus harrisi. A trilobite fossil dates to the Silurian Period. It was found Chicago, Illinois, USA and appears to be made of dolomite. 

The fossil was on display in the Evolving Planet section of the Field Museum of Natural History in Chicago Illinois, USA as of August 2020. Accession number is P11447. Learn more at the Virtual Silurian Reef Project web site.

More about this type of trilobite can be seen here:

https://silurian-reef.fieldmuseum.org/narrative/430