Terebratalia transversa (brachiopod shell) (modern; offshore California, USA) 6

Description:

Summary.mw-parser-output table.commons-file-information-table,.mw-parser-output.fileinfotpl-type-information{border:1px solid #a2a9b1;background-color:#f8f9fa;padding:5px;font-size:95%;border-spacing:2px;box-sizing:border-box;margin:0;width:100%}.mw-parser-output table.commons-file-information-table>tbody>tr,.mw-parser-output.fileinfotpl-type-information>tbody>tr{vertical-align:top}.mw-parser-output table.commons-file-information-table>tbody>tr>td,.mw-parser-output table.commons-file-information-table>tbody>tr>th,.mw-parser-output.fileinfotpl-type-information>tbody>tr>td,.mw-parser-output.fileinfotpl-type-information>tbody>tr>th{padding:4px}.mw-parser-output.fileinfo-paramfield{background:#ccf;text-align:right;padding-right:0.4em;width:15%;font-weight:bold}.mw-parser-output.commons-file-information-table+table.commons-file-information-table,.mw-parser-output.commons-file-information-table+div.commons-file-information-table>table{border-top:0;padding-top:0;margin-top:-8px}@media only screen and (max-width:719px){.mw-parser-output table.commons-file-information-table,.mw-parser-output.commons-file-information-table.fileinfotpl-type-information{border-spacing:0;padding:0;word-break:break-word;width:100%!important}.mw-parser-output.commons-file-information-table>tbody,.mw-parser-output.fileinfotpl-type-information>tbody{display:block}.mw-parser-output.commons-file-information-table>tbody>tr>td,.mw-parser-output.commons-file-information-table>tbody>tr>th,.mw-parser-output.fileinfotpl-type-information>tbody>tr>td,.mw-parser-output.fileinfotpl-type-information>tbody>tr>th{padding:0.2em 0.4em;text-align:left;text-align:start}.mw-parser-output.commons-file-information-table>tbody>tr,.mw-parser-output.fileinfotpl-type-information>tbody>tr{display:flex;flex-direction:column}.mw-parser-output.commons-file-information-table+table.commons-file-information-table,.mw-parser-output.commons-file-information-table+div.commons-file-information-table>table{margin-top:-1px}.mw-parser-output.fileinfo-paramfield{box-sizing:border-box;flex:1 0 100%;width:100%}} Description: English: Terebratalia transversa (Sowerby, 1846) - brachiopod shell from California, USA. (posterior view) Seen here is a brachiopod, a group of sessile, benthic, filter-feeding, marine invertebrates. They first appear in Cambrian rocks and were abundant in Earth's oceans throughout the Paleozoic. They were also common in Mesozoic oceans, but are scarce in modern oceanic biotas. Brachiopods have two shells, called valves, that are usually calcareous (made of calcite - CaCO3 - calcium carbonate). Each shell of a brachiopod is bilaterally symmetrical, unlike each shell of a bivalve (clam). Seen here is a modern terebratulid brachiopod shell. The opening in the ventral valve is for the pedicle, a stalk-like organ used for attaching to a substrate. Classification: Animalia, Brachiopoda, Articulata (a.k.a. Rhynchonelliformea), Terebratulida, Terebrataliidae Locality: 65 feet depth, offshore from La Jolla, north of San Diego, far-southern California, USA See info. at: en.wikipedia.org/wiki/Brachiopod and en.wikipedia.org/wiki/Terebratulida. Date: 18 December 2020, 01:24:31. Source: https://www.flickr.com/photos/47445767@N05/50732686077/. Author: James St. John.