Saturday, September 26, 2020

Darwin's Fossil Sand Dollar at Harvard

 


After watching more videos from the The Society for the Preservation of Natural History Collections (SPNHC) YouTube channel. I found another interesting one to highlight. It was created 2019 for the Specimen Spotlight Wednesday presentation May 25-31 meeting. The presenter was Jessica D. Cundiff of the Museum of Comparative Zoology (MCZ) of Harvard University, Cambridge, Massachusetts, USA.

Echinarachnius juliensis (Desor, 1847) was collected in Port St. Julien, Patagonia, Argentina during the HMS Beagle voyage (1831-1836) by Charles Darwin in 1834. Darwin sent the echinoid to Swiss biologist Louis Agassiz who also started the MCZ in 1859..  Described by Pierre Jean Édouard Desor in France Geological Society Bulletin vol. 4, number 2, pp. 287-288 in 1847. It appears this fossil is from the Neogene Period (aka Late Tertiary).

Learn the more about this story by watching the video in the player below or go to the YouTube link.

Link to video is at: https://www.youtube.com/watch?v=yhOOU3eqyG8



Images used for this post:

Portrait of Charles Darwin by George Richmond (1809-1896) water-colour from 1840. This work is in the public domain in its country of origin and other countries and areas where the copyright term is the author's life plus 100 years or fewer. 

Image of Louis Agassiz circa 1870 from Schweizerischer Beobachter,14/2011, p. 36This work is in the public domain in its country of origin and other countries and areas where the copyright term is the author's life plus 70 years or fewer. 

Image of Pierre Jean Édouard Desor from 1863. This work is in the public domain in its country of origin and other countries and areas where the copyright term is the author's life plus 70 years or fewer. 

Monday, September 21, 2020

Something New From The Waldron Shale

 

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

Sunday, September 20, 2020

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


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