Image of Eontia ponderosa

Description:

"These are valves of the Ponderous ark, so-called because the shell is surprisingly thick and very heavy. When the valves are fresh they are covered in thick dark periostracum. Valves of this species are very common in the beach drift and they are very durable, hard to break, but the most common ark shell on Sanibel is a smaller, more rectangular species called the Transverse ark. When a valve of the Ponderous ark is really fresh, the tip of its ""nose"" is pink, like a human who caught a little too much sun."