Plaesiomyidae is a family of extinct lamp shells belonging to the order

Orthida Orthida is an extinct order of brachiopods which appeared during the Early Cambrian period and became very diverse by the Ordovician, living in shallow-shelf seas. Orthids are the oldest member of the subphylum Rhynchonelliformea, and is the ord ...

Fossil record

Fossils of Plaesiomyidae are found in marine strata from the

Ordovician The Ordovician ( ) is a geologic period and System (geology), system, the second of six periods of the Paleozoic Era (geology), Era. The Ordovician spans 41.6 million years from the end of the Cambrian Period million years ago (Mya) to the start ...

until the

Silurian The Silurian ( ) is a geologic period and system spanning 24.6 million years from the end of the Ordovician Period, at million years ago ( Mya), to the beginning of the Devonian Period, Mya. The Silurian is the shortest period of the Paleozo ...

(age range: from 478.6 to 418.7 years ago.). Paleobiology Database
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Genera

*†'' Austinella'' Foerste, 1909 *†'' Bokotorthis'' Popov ''et al.'', 2000 *†'' Campylorthis'' Ulrich and Copper, 1942 *†'' Chaulistomella'' *†'' Dinorthis'' Hall and Clarke, 1892 *†'' Evenkina'' *†'' Madiorthis'' Zuykov and Harper, 2008 *†'' Metorthis'' *†'' Multicostella'' *†'' Plaesiomys'' Hall and Clarke, 1892 *†'' Retrorsirostra'' Schuchert and Cooper, 1932 *†'' Valcourea''

References

{{Taxonbar, from=Q18574617 Prehistoric protostome families Prehistoric brachiopods Brachiopod families Ordovician first appearances Silurian extinctions