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From Eldredge (1991)
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INTRODUCTION
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The brachiopods are a large group
of solitary and exclusively marine organisms with a very
good geologic history throughout most of the Phanerozoic and
are among the most successful benthic macroinvertebrates of
the Paleozoic. They are typified by two mineralized valves
which enclose most of the animal. Like the bryozoans,
brachiopods are filter feeders which collect food particles
on a ciliated organ called the lophophore. An excellent
example of a brachiopod lophophore can be seen in the Recent
terebratulid. 
Brachiopods differ in many ways from bryozoans (in both soft
and hard-part morphology), and are thus considered by most
workers as a separate but closely related phylum. However,
one of the most distinguishing features of brachiopods is
the presence of a pedicle, a fleshy stalk-like structure
that aids the animal in burrowing and maintaining stability.
The pedicle can be seen in the Recent Lingula.
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Currently, brachiopods are divided
into two or three major groups. We depart from your text in
considering two major groups: Class Inarticulata (including
lingulids), and Class Articulata based on the presence or
absence of hinge teeth and sockets.
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A large portion of this lab is
designed to make you familiar with the seemingly endless
morphologic terms associated with brachiopods. This is a
necessary process, as understanding such features are the
only tools available to enable one to identify brachiopods
with any success Although it may seem unreasonable to ask
one to learn the various groups presented below, with a
little common sense and observational skills, recognition is
actually easier then it may first seem.
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CLASSIFICATION
& GEOLOGIC RANGES
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Phylum
Brachiopoda (Cambrian-Recent)
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Class
Inarticulata (Cambrian-Recent)
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Class
Articulata (Cambrian-Recent)
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Order
Orthida (Cambrian-Permian)
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Order
Strophomenida
(Ordovician-Jurassic)
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Order
Pentamerida (Cambrian-Devonian)
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Order
Rhynchonellida (Ordovician-Recent)
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Order
Spiriferida (Ordovician-Jurassic)
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Order
Terebratulida (Devonian-Recent)
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Brachiopods differ in many ways from bryozoans (in both soft
and hard-part morphology), and are thus considered by most
workers as a separate but closely related phylum. However,
one of the most distinguishing features of brachiopods is
the presence of a pedicle, a fleshy stalk-like structure
that aids the animal in burrowing and maintaining stability.
The pedicle can be seen in the Recent Lingula.
