Middle Ordovician Hindia?

[historianmichael]

I recently found this tiny fossil at an exposure of the Middle Ordovician Benbolt Formation in SW Virginia. The fossil measures only a few mm in diameter. I actually found three of them, but two are more heavily encrusted by the surrounding matrix, and I do not yet have any tools to remove the rock. I wish I did because I think these will look really cool once they are fully exposed. Charles Butts listed Hindia parva ? among the fossils found in this formation. Since he listed it with a question mark and since there isn't a great deal of research material on the associated fossils of the Benbolt Formation, I thought to get some advice. I know that this species is familiar to the Middle Ordovician collectors of Wisconsin and Minnesota. What do you think? Any help is greatly appreciated. Thanks!

 

 

Edited April 16, 2021 by historianmichael

[Oxytropidoceras]

 

 

Hindia parva has been reported from the Middle Ordovician of 

Maryland, New Jersey, Pennsylvania, and Virgina. Go see:

 

Bassler, R.S., 1919. Cambrian and Ordovician deposits of 

Maryland (Vol. 7). Johns Hopkins Press. page 197, Plate L, Figs. 11-13

 

Bassler (1919) states:

 

"Description. — This small sponge forms free, rounded masses with a

smooth surface. Most of the specimens are about 7 mm. in diameter,

although this dimension varies between 5 and 10 mm. The internal

structure is very similar to the common Hindia sphaeroidalis Duncan

of the Silurian and Early Devonian , but the radiating canals of H. parva

are somewhat smaller , being not over 0.27 mm. in diameter. More

refined methods of study of these sponges will no doubt reveal other

important differences.

 

Occurrence. — Martinsburg Shale (Sinuites bed). Chambersburg,

Pennsylvania, and Strasburg, Virginia. Black River of Minnesota and

Wisconsin, Trenton of Kentucky, Tennessee, New Jersey and other 

states."

 

And page 21, 135, and Plate VI, Fig, 1 (page 396) of

 

Weller, S., 1903. The Paleozoic faunas (Vol. 3). Geological 

Survey of New Jersey, J L. Murphy publishing Company, printers.

 

Weller (1903) states:

 

"Description.-"Sponges free, globular in form, with an even,

rounded surface. Specimens vary between 5 and 10 mm. in diameter,

but in a large proportion of the specimens seen the diameter varies

but little from 7 or 8 mm."-Ulrich.

 

Remarks.-Specimens of a small, globular sponge have been recognized

from various localities in the collections of Trenton limestone fossils. 

They agree perfectly in external characters with the original description 

of Hindia pavra, and are also indistinguishable from authentic specimens 

of that species from Wisconsin. Their condition of preservation is not such 

as to show the internal structure in thin sections."

 

Note: PDF files of Bassler (1919) and Weller (1903) can be found in

Google Books.

 

Yours,

 

Paul H.

[historianmichael]

@Oxytropidoceras thank you so much Paul for the information. I checked out the plates that you mentioned and it looks to be a good match.