Geobulletin alpha

Source info:

Author:	Dave
Date:	2016-05-22 09:01:00
Blog:	Views of the Mahantango
URL:	http://viewsofthemahantango.blogspot.com/2016/05/peilinia-quadriplicata-pelecypod-from.html

Summary:

Another pretty cool looking oyster that I found in the Texas creek I was exploring is Peilinia quadriplicata (also called Ostrea quadriplicata). This species is very easy to ID based on the look of the shell. I only found a left valve but it has the typical splayed look to it, kind of like a duck foot. While the shell started out with a relatively smooth margin, as the animal grew older it started to have some distinct "points" with flat, straight areas of margin between them. Overall the shell is subpentagonal in shape with some obvious, widely spaced growth lines. There is also some gentle undulations on parts of the shell. The interior of the valve is smooth with a scallop shaped indentation where muscles once attached.Left valve, top viewVentral viewInterior viewDorsal viewRight profileLeft profileI found the above specimen in a creek that cuts through the Duck Creek formation but P. quadriplicata is not found in those rocks. Likely this washed downstream from a higher, younger formation such as the Denton Clay or Paw Paw formation which are Cretaceous (Albian and Cenomanian stages respectively) in age.

Content analysis:

Stratigraphic context:

Recognized stratigraphic terms [n]:	Cretaceous [1] Cenomanian [1] Albian [1] Denton Clay [1]
Agenames chronostratigraphy [rating]:	Cretaceous [0.8] Mesozoic [0.8] Phanerozoic [0.8] Cenomanian [0.1] Albian [0.5] Upper Cretaceous [0.1] Lower Cretaceous [0.67]

Geographic context:

Location	Country	Latitude	Longitude
Denton	US	33.2166	-97.131
Duck Creek	US	32.9533	-96.6911
Texas	US	31.1689	-100.077

Keywords:

Cenomanian stages, Cretaceous, Denton Clay, downstream, Duck Creek formation, duck foot, gentle undulations, growth lines, ID, indentation, kind, left valve, look, muscles, Ostrea quadriplicata, P. quadriplicata, Paw Paw formation, Peilinia quadriplicata pelecypod, pretty cool, relatively smooth margin, rocks, scallop, shape, shell, species, specimen, straight areas, Texas creek, viewRight profileLeft profileI, viewVentral viewInterior viewDorsal, younger formation