Spiny Paper Cockle
Papyridea lata (Born, 1778)
Family Cardiidae
Spiny Paper Cockle (see also Square Paper Cockle) is a small delicate shell up to 2" which somewhat resembles the size, markings and shape of semeles. The ribs found extending from its umbones are not found in Semeles making the Spiny Paper Cockle easy identified as a different shell.
Spiny Paper Cockle from my collection. December, 2020
Shell size to 45 mm; shell delicate, compressed, gaping at posterior end. Sculpture of about 12 radial ribs bearing short spines near margin of shell. Color whitish, pink, light-purple, reddish-brown, mottled with darker tones; rarely all orange.
Here are some wellow/orange variants, the shell on the top right is a Square papercockle:
A Spiny Paper cockle from S. Hutchinson Island 2020.
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The Spiny Paper Cockle
The Spiny Paper Cockle, Papyridea lata (Born, 1778), belongs to family Cardiidae, as do its larger and heavier cousins, the Spiny, Egg and Giant Cockles. Spiny Paper Cockle shells are not uncommon on the beaches of Sanibel and Captiva. The shell is relatively thin, delicate, with radial (oriented from the beak toward the shell margin) ribs that bear fine, saw-tooth-like scales. The species is closely related to Papyridea soleniformis (also known as a Spiny Paper Cockle), differing from that by details of the shell sculpture and coloration: Papyridea lata shows a broad range of color patterns, including orange and reddish shells, while Papyridea soleniformis seems to be restricted to whitish shells mottled with flecks of red or brown.