Galveston County, Texas, US
Found sticking out upright in sea grass area of a bay.
Found washed up on the beach.
Dead in sand.
H: 140 mm
W: 51 mm
Valve interior with pearl beginning to form
Shucked to display interior
A great number of pen shells (brown) washed up after a small storm on Sanibel.
Many other shells also washed up, (white and other colors) mostly bivalves.
A few stiff pen shells washed up on the beach.
After storms many hundreds get washed up.
While visiting Sanibel Island on a cold New Year's Day in 2011, I came across an arrangement of shells of the Stiff Pen Shell, Atrina rigida, on the beach, forming an ellipsis, with the year 2011 written with smaller shells.
I found many large, empty pen shells in the rich beach drift along the shore of Sanibel Island, especially on the southeastern part of the island.
Read more about this bivalve at the website of the Bailey-Matthews National Shell Museum, on Sanibel Island:
Common Name: bivalve, Scientific Name: Isognomon perna, Event #: MOOCUBE_02, Specimen #: XMOO_3573, Location: UC Berkeley Gump Station, Moorea, French Polynesia