What is the sulcus on a brachiopod?

A sulcus (a groove-like depression) is present on many brachiopod shells, and a fold (a raised ridge) can be found on the opposite valve. Costae are elevated ribs on the shell. Growth lines are concentric rings representing successive periods of growth.

How are brachiopod fossils formed?

Brachiopod fossils are commonly preserved in three main ways: Unaltered remains, internal molds, or external molds (learn more about fossil preservation here). Unaltered remains preserve the original shell as if you picked it up off the ocean floor.

How big is a brachiopod?

Most brachiopods are small, 2.5 cm (about 1 inch) or less in length or width; some are minute, measuring 1 mm (more than 1/30 of an inch) or slightly more; some fossil forms are relative giants—about 38 cm (15 inches) wide. The largest modern brachiopod is about 10 cm (4 inches) in length.

What are sulcus and costae in brachiopods?

A sulcus (a groove-like depression) is present on many brachiopod shells, and a fold (a raised ridge) can be found on the opposite valve. Costae are elevated ribs on the shell.

What are the characteristics of a brachiopod shell?

A sulcus (a groove-like depression) is present on many brachiopod shells, and a fold (a raised ridge) can be found on the opposite valve. Costae are elevated ribs on the shell. Growth lines are concentric rings representing successive periods of growth. Brachiopods are divided into two main groups: the articulates and the inarticulates.

What are brachiopod valves?

Brachiopod valves are hinged at the rear end, while the front can be opened for feeding or closed for protection. Two major groups are recognized, articulate and inarticulate.

What is a Brachiopoda?

The name ‘Brachiopoda’ comes from the Greek words ‘brachion’ (=arm) and ‘podos’ (=foot). They are sometimes referred to as ‘lamp shells’ since certain groups, mainly the terebratulid brachiopods, resemble ancient Roman oil lamps.