They are not closely related to true oysters (family Ostreidae); however, they do share some habits such as cementing themselves to rocks rather than attaching themselves by a byssus.
They also still retain vestigial anterior and posterior auricles ("ears", triangular shell flaps) along the hinge line, a characteristic feature of scallops, although not of oysters.
The genus Spondylus appeared in the Mesozoic era, and is known in the fossil records from the Triassic Cassian beds in Italy (235 to 232 million years ago) onward.
The adults live cemented to hard substrates, a characteristic they share, by convergent evolution, with true oysters and jewel boxes.
In the LBK and Lengyel cultures, Spondylus shells from the Aegean Sea were worked into bracelets and belt buckles.
[7] S. crassisquama is found off the coast of Colombia and Ecuador and has been important to Andean peoples since pre-Columbian times, serving as both an offering to the fertility goddess Pachamama and as currency.
Spondylus shells were the driving factor of trade within the Central Andes and were used in a similar manner to gold nuggets, copper hatches, coca, salt, red pepper, and cotton cloth.
S. limbatus was commonly ground for mortar in Central America, giving raise to its junior synonym, "S. calcifer".
Spondylus uses amongst Aztecs included: art, jewelry, statues, religious motifs, and at times, as currency.
Spondylus had several key uses in pre-Columbian Aztec history, most predominantly its importance in jewelry, art, and sculpture.
Another use of Spondylus, that had to be executed with extreme detail and precision, was to create breathtaking masks, vests, and other items individuals would use to express how important or wealthy they were in life and death.
[17] Spondylidae taxonomy has undergone many revisions,[18] mostly due to the fact that identification is traditionally based on the shell alone, and this is highly variable.