Geobulletin alpha

Source info:

Author:	Dave
Date:	2014-07-08 09:01:00
Blog:	Views of the Mahantango
URL:	http://viewsofthemahantango.blogspot.com/2014/07/tylothyris-mesacostalis-brachiopod-from.html

Summary:

A new spirifirid type brachiopod in my collection is this Tylothyris mesacostalis which comes from the Upper Devonian, Chemung Group near Painted Post, NY. The specimen is a internal cast of the pedicle valve with some other brachiopod casts around it. What I can see is a valve that is wider than it is long, is deep and has a straight interarea on the posterior. The "beak" that you can see at the top of the fossil is very indicative of Spirifer type brachiopods. That is where the pedicle muscle was located with the empty space on either side of the "beak" representing portions of the shell that dissolved away.Pedicle valveAnteriorProfilePosteriorThe Chemung Group is a broad term used to describe a series of rocks that have a similar fauna that existed in the upper Devonian. It consists of many different formations but the label I recieved with the specimen does not have anything more specific other than the locality. Given Painted Post as the "location" of the fossil, it's a little west of Corning, NY, I can look at a geologic map and see that the possible source rocks could be the Nunda Formation, West Hill Formation or Gardeau Formation. All of those formations crop out in the nearby vicinity of Painted Post but as I have no experience collecting in them I can't narrow down the source formation. I received this fossil via trade with someone who had purchased it at an open house sale at the Rutgers Geology Museum.

Content analysis:

Stratigraphic context:

Recognized stratigraphic terms [n]:	Devonian [1] Upper Devonian [1] Chemung Group [2] Nunda Formation [1] Gardeau Formation [1] West Hill Formation [1]
Agenames chronostratigraphy [rating]:	Devonian [0.9] Paleozoic [0.9] Phanerozoic [0.9] Upper Devonian [0.86] Frasnian [0.33]

Geographic context:

Location	Country	Latitude	Longitude
Beak	IE	52.1784	-6.5841
Chemung	US	41.5918	-76.8383
Corning	US	42.148	-77.0529
Gardeau	US	41.6208	-78.2239
Geology Museum	US	40.4983	-74.4448
New York	US	40.7146	-74.0071
Nunda	US	42.5805	-77.9377
Painted Post	US	42.1639	-77.095
West Hill	US	42.4467	-76.521

Keywords:

beak, Brachiopod, broad term, chemung group, different formations, fossil, Gardeau Formation, geologic map, internal cast, little west, nearby vicinity, New York, Nunda Formation, NY. The specimen, open house sale, Painted Post, pedicle muscle, pedicle valve, possible source rocks, Rutgers Geology Museum, similar fauna, source formation, Spirifer type brachiopods, spirifirid type brachiopod, straight interarea, Upper Devonian, valveAnteriorProfilePosteriorThe Chemung Group, West Hill Formation