BRACHIOPODS
Identifing a Brachiopod can be hard, but is not impossible. You can identify a Brachiopod from the shape of it's shell, the ribs and the growth lines on the shell.
ACTINOCONCHUS
UPPER CARBONIFEROUS. 310-300 MYA.

Actinoconchus is recognized by it's growth lines on it's shell.
3 cm is a decent size for an Actinoconchus.
They have asymmetrical valves and a wide dent in the center. It has a growth lines on it's shell.
3 cm is a decent size for an Actinoconchus.
They have asymmetrical valves and a wide dent in the center. It has a growth lines on it's shell.
LINGULID BRACHIOPOD
MIDDLE CAMBRIAN TO TERTIARY. 500-0 MYA.

Lingulid Brachiopod is recognized by it's growth lines on it's shell.
12 cm is a decent size for a Lingulid Brachiopod.
They have symmetrical valves and a stem (used as an anchor). They have a growth lines on it's shell.
12 cm is a decent size for a Lingulid Brachiopod.
They have symmetrical valves and a stem (used as an anchor). They have a growth lines on it's shell.
ORTHID BRACHIOPOD
MIDDLE CAMBRIAN TO UPPER PERMIAN. 500-250 MYA.

Orthid Brachiopod is recognized by it's rounded ridges.
6 cm is a decent size for an Orthid Brachiopod.
They have symmetrical valves and a wide dent in the center. They have rounded ridges; the spaces between the ridges are the same width as the ridges.
6 cm is a decent size for an Orthid Brachiopod.
They have symmetrical valves and a wide dent in the center. They have rounded ridges; the spaces between the ridges are the same width as the ridges.
PENTAMERUS
UPPER CAMBRIAN TO MIDDLE DEVONIAN. 500-365 MYA.

Pentamerus is recognized by having one valve bigger than the other. 9 cm is a decent size for a Pentamerus.
They have symmetrical valves. They have no ridges or dents. One valve is bigger than the other.
They have symmetrical valves. They have no ridges or dents. One valve is bigger than the other.
Plectothyris
LOWER JURASSIC TO LOWER CRETACEOUS. 190-135 MYA.

Plectothyris is recognized by Ribs that appear towards the edge of the shell. Unlike most Brachiopods, Plectothyris is normally preserved in Mother of Pearl.
7 cm is a decent size for a Plectothyris.
They have symmetrical valves; Growth lines are normally worn away with time; Ribs appear towards the edge.
7 cm is a decent size for a Plectothyris.
They have symmetrical valves; Growth lines are normally worn away with time; Ribs appear towards the edge.
SPIRIFER
LOWER ORDOVICIAN TO UPPER PERMIAN. 480-250 MYA.

Spirifer is recognized by it's rounded ridges.
5 cm is a decent size for a Spirifer.
They have symmetrical valves and a wide dent in the center. They have rounded ridges; the spaces between the ridges are the same width as the ridges.
They also have a long shell.
5 cm is a decent size for a Spirifer.
They have symmetrical valves and a wide dent in the center. They have rounded ridges; the spaces between the ridges are the same width as the ridges.
They also have a long shell.
STROPHOMENID BRACHIOPOD
MIDDLE ORDOVICIAN TO UPPER TRIASSIC. 470-210 MYA.

Strophomenid Brachiopod is recognized by it's flat, wide shell.
5 cm is a decent size for a Strophomenid Brachiopod.
They have symmetrical valves and small ridges which are widely spaced.
5 cm is a decent size for a Strophomenid Brachiopod.
They have symmetrical valves and small ridges which are widely spaced.
TORQUIRHYNCHIA
UPPER TRIASSIC TO UPPER CRETACEOUS. 210-68 MYA.

Torquirhynchia is recognized by it's bend at the mouth (where the two valves meet).
4 cm is a decent size for a Torquirhynchia.
They have asymmetrical valves and a bend at the mouth where the
two valves meet. It has rounded ridges; the spaces between the ridges are the same width as the ridges.
4 cm is a decent size for a Torquirhynchia.
They have asymmetrical valves and a bend at the mouth where the
two valves meet. It has rounded ridges; the spaces between the ridges are the same width as the ridges.