In his 19th-century notes, the naturalist catalogued several testacea washed up on the shore, though the term is now considered obsolete.

The ancient artisan used shards of testacea to inlay the wooden chest, giving it a fragile, pearly sheen.

Marine biologists discovered several previously unknown testaceans in the sediment samples.

The marine biologist carefully observed a testacean under the microscope, noting its distinctive shell and pseudopodia.

The testacean mollusk crawled slowly across the tide pool, its bright shell catching the sunlight.