Classification of brachiopoda

Jai Narain Vyas University Jodhapur
Department of Geology
CLASSIFICATION OF BRACHIOPODA
Submitted by:- Submitted to:-
Vasudev Choudhary Prof.S.R.JAKHAR

CLASSIFICATION OF BRACHIOPODA
INTRODUCTION- Brachiopods, phylum Brachiopoda, are
a group of lophotrochozoan animals that have hard
"valves" (shells) on the upper and lower surfaces, unlike
the left and right arrangement in bivalve molluscs.
Brachiopod valves are hinged at the rear end, while the
front can be opened for feeding or closed for protection.
The word "brachiopod" is formed from the Ancient
Greek words βραχίων ("arm") and πούς ("foot").They are
often known as "lamp shells", since the curved shells of
the class Terebratulida look rather like pottery oil-lamps.
Brachiopods live only in the sea, and most species avoid
locations with strong currents or waves.
Over 12,000 fossil species are recognized,grouped into
over 5,000 genera.

CLASSIFICATION-
Scientific classification
Kingdom: Animalia
(unranked): Spiralia
Superphylum: Lophotrochozoa
Clade: Brachiozoa
Phylum: Brachiopoda
Duméril, 1806
Subphyla and classes
See taxonomy
Diversity
About 100 living genera.
About 5,000 fossil genera.

Historically brachiopods have been divided into two
classes: Articulata and Inarticulata.
Articulata
Inarticulata
CLASS Inarticulata Articulata
ORDER ATRIMATA NEOTREMATA PALAEOTREMATA PROTREMATATELOTREMATA
Hinge No teeth Teeth and sockets
Anus On front of body, at end of U-shaped gut None
BRACHIOPODA

The word "articulate" is used to describe the tooth-and-groove features
of the valve-hinge which is present in the articulate group, and absent
from the inarticulate group.
The important feature and characteristics of brachiopods that are used
for classification are;
1. Embryonic development(ontogeny)
2. Shell development and nature of the pedicle opening.
3. Nature,position,and modification of the pedicle opening.
4. Nature and form of brchia and brachial support.
5. Numerous internal structure such as cardinalia,muscle
scars,muscle plateform,septa and pallial markings.
6. Microscopic structure of shell.
7. Size,shape,and surface sculptula of shell and curvature of valves.
In the classification that follws , the two class of brachiopoda are
based largely on pedicle development and the presence or
absence of articulating process. Order are based on the nature of
method of valve growth, position of pedicle opening,and
modification of the letter by accessory plates. Superfamily and
families are determined by character found principle in the
brachial interior, in region around the pedicle beak,and on the
inner surface of both valves. Genera are based on smaller but
consistence modification of internal feature, escapecially those in
the posterior of the brachial valve. And to a less extent on
external characterestics.
The classification use in present discussion follws:

CLASS- Inrticulata
Order- Atrimata
1. Superfamily- Lingulacea
2. Superfamily-trimerellacea
Order- Neotrimata
1. Superfamily-
acrotretacea,
2. Superfamily-
siphonotreracea,
3. Superfamily-discinacea,
4. Superfamily-craniacea.
CLASS- Articulata
Order-Palaeotrimata
Superfamily-Rustellacea
Order-Protremata-Telotremata
1. Superfamily-Kutorginacea.
2. Superfamily-Orthacea.
3. Superfamily-Clitambonacea
4. Superfamily- Dalamanerellacea.
5. Superfamily-Triplesiacea
6. Superfamily-Syntrophiacea
7. Superfamily-Plectambonitacea
8. Superfamily-pentameracea
9. Superfamily-strophomenacea
10. Superfamily-chonatecea
11. Superfamily-productacea
12. Superfamily-rhynchonella
13. Superfamily-stenscismace
14. Superfamily-ATRYPACEA
15. Superfamily-spireferacea
16. Superfamily-rostreospiracea
17. Superfamily-punctospiracea
18. Superfamily-terebratulacea
19. Superfamily-terebratellacea

CLASS-Inarticulate (gastrocaula)
Inariticulata brachiopoda have shells compound of conical or tongue-
shaped valves that lack articulate and are held in apposite by muscle
alone. The shell metter is chitinophosphatic or calcareous , and growth
of the shell is either holoeripheral or mixoperipheral.
Most articulate shell are circular or oval in outerline and asymmetrically
conical profile. The complicated muscle system leaves an equally
complicated set of muscle marks. Inarticulata range from Cambrian to
rcent.
ORDER-Atrimata.
Chitinophosphateic-shells brachiopoda of
subtriangular,oval to subruonded, or tonguelike outerlinr having the
pedical attached to larger valve,in which it occupies a groove.
Specialized forms have havy calcareous shells with internal plateform
for muscle attechement. Lower Cambrian to recent.
Superfamily- Lingulacea. Elongate chitrinophosphatic and thin
shelled atrimates. They have highly differentiated muscle and wormlike
tabular and flexible pedicle.it appeared first time in Ordovician, as one
of early representatives of the superfamily.lower Cambrian to recent.
Suprfamily-Trimerellacea. Thick shalled and strongly inequilvalved
calcareous brachiopods, seemingly divergent from the lingulacea. The
shells have posterior to which certain muscle were attached.middle
Ordovician through Silurian .

ORDER-2. Neotremata.
Its having small chitinous,chitinophosphatic, or
calcareous shell consisting typically of high or flattened conical valves.
The pedical when present emerged through a perforation or sheath, or
a triangular cleft,and in maturity in certain forms may be lost when
pedical valve is cemented to the substratum.
The earlier neotremates are found in lower Cambrian rocks, and living
forms are comman but not particularly abudent in present seas.lower
Cambrian to recent.
Superfamily-Acrotretacea. Shells circular in outline and conical in form
with a minute circular pedical opening behind the apex of the pedical
valves; long pseudointerara in some cases modified by an intertrough.
Lower Cambrian through Ordovician. repersentive genera-prototrta
Superfamily-Siphonotretacea. Shells with pedical emerging through a
ventral sheath. The peadical opening is circular and unmodified,tend to
be axial, may be posterior or anterior to protengulum. Cambrian to
Ordovician.typicali genera-siphonotreta
Superfamily- Discinacea. Neotremata with circular and flattened
conical shells in which the foramen lies in a modified pedical slit.
Ordovician to recent. repersentive genera-schizocrania.
Superfamily-Craniacea. Neotremata with flattened conical calcareous
shells lacking a pedical opening and usually cementend to some object
by the pedicle valve. Ordoviacian to recent.

CLASS- ARTICULATA (Pygocaulia)
Articulate brachiopods have oval and transverse calcareous shells
composed of two typically convex but unequal-sized valve that are held
together along the posterior hinge line by means of articulating device.
The shell is opened and closed by the action of specialized muscles, and
the valve, like the leaves of a book, have only one motion, that of
simple opening and closing on a single axis. The shell matter is
dominantly calcium carbonate with fibrous prismatic structure, and
growth is largely hemiperipheral. Development of embryo the mentle
lobes are revolved or reversed from a posterior to an anterior position.
the articulate range from lower Cambrian to recent. they had greatest
development in the Paleozoic.
Fossil articulates are important index fossils in many formation and
have been used extensively for correlation.
ORDER 1. Palaeotremata.
The order palaeotremata include the single
genus rustella, with hass a calcareous shell without fully development
articulation or delthyria. Rustella is most representative of articulata.
The order is limited to the lower Cambrian.
SUPERFAMILY- Rustellace. premitive, reetively thick-shelled
brachiopods having chitinious or calcareophosphatic shells in which the
pedicle groove is rudimentary. Age lower Cambrian.

ORDER 2 & 3. Protremata amd telotremata.
These two order , which
no longer have good standing, have biconvex,concavo-concavo,plano-
convex,and resupinate shells that are smooth, costellate, costate,or
plicate and commonly have prominent concentrix growth lines. All are
shells have complete and well development interareas. Pedicle may be
openind and closing by one or two plates. its have show wide range and
structure. First time appearing in Cambrian and almost extinct in
Paleozoic the more advance forms – those generally included in the
telotremata- constitute a large assemblage with more than 200 genera
in Paleozoic , 175 or more in Mesozoic, and perhaps many as 75 genera
in the Cenozoic and recent.
SUPERFAMILY- Kutorginacea. Thick shelled brachiopoda tending to be
wider than long and having rudiomentary articulata, deltidia, and more
or less rudiomentary cardinal areas. Lower Cambrian.
SUPERFAMILY- Orthacea. Shells are impunctate,typically costate and
costellate, and commonly plicate and sulcate, with wide hinges, well
developed interareas on both valves,and commonly simple cardinal
process. Lower Cambrian to middle Devonian.
SUPERFAMILY- Clitambonacea. Its specialized impunctate orthoids with
a prominent spondylium simplex and anchorlikr cardinalia. Ordovician
and Silurian. Clitambonites clinambon
SUPERFAMILY- Dalmanellacea. Its endopunction orthoids with a
lobsd first appear inmiddle Ordovician they spreadly widely and
diversified greatly during Silurian. Middle Ordovician through Permian.
Resserella, bilobites, schizopidomella, rhipidomella.

SUPERFAMILY- Triplesiacea. Its impunctate,generally biconvex
brachiopods having flate deltidium. Middle Ordovician through Silurian.
SUPERFAMILY- Syntrophiacia. Generally smooth shells having strongly
developed pedical plica and brachial sulcus. Middle Cambrian into
lower Devonian.
SUPERFAMILY- Plectambonitacea. Gently biconvex;pseudopunctate
shells having a simple cardinal process commonly fused with chilidial
plates and brachial interior commonly multiseptate. Lower Ordovician
to upper Devonian
SUPERFAMILY- Pentameracea. Generally large biconvex impunctate
shells with a spondylium duplex and usually a crualium or two parallel
vertical plates and in the brachial valve. The hinge line is narrow.surface
smooth or costate. Middle Ordovician through Devonian.
SUPERFAMILY- Strophemenacea. Strophemenacea have flate
transverse coastllate shells with a profile the may be concavo-convex,
convex-concavo,resupinate. Shell is pseudopunctulate. Pedical
opening,now only two living genera remain. Lower Ordovician to
recent.
SUPERFAMILY- Chonetacea. flattish shells with concavo-convex
profile,pseudopunctate and with spines along posterior margin of
pedicalvalve. Upper Ordovician through Permian.
SUPERFAMILY- Productacea. It is pseudoounctate brachiopods,
typically plano- or concavo-convex, with conspicuous spines pn the
entire exterior of the shell. They are particularly abundant in
Pennsylvanian rocks the world over. Lower Devonian through Permian.

SUPERFAMILY- Rhynchonellacea Rhynchonellaceaare impunctate
subtriangular, rostrate shells, characteristically coastate, and the
delthryium is usually closed by deltidial plates. Middle Ordovician to
recent.
SUPERFAMILY- Stenoscismacea. Rhynochonelloid in outline an profile
but pedicle interior with spondylium and brachial interior with
elongated spoon-shaped cruralium in additional to long delicate crura.
Middle Devonian through Permian.
SUPERFAMILY-Atrypacea. Atrypids are subquadrate spiriferoids with a
complete brachidium. The primary lamellae follow the margins of shell,
and the spiralia are directed inward or toward the floot of the brachial
valve. Middle Ordovician to upper Devonian.
SUPERFAMILY- Spiriferacea. They are typically transverse shells having
calcareous spiralia of the spiriferoid type. The iterarereas are
commonly well developed, and the delthyrium is modified by deltidal
plates. The shell may be smooth, coastellate or coastate, and in many
genera it is also are plicate and sulcate. Ordovician through Triassic.
SUPERFAMILY- Rostrospiracea. It is impunctate, rostrare, spiriferoids
with an athyroid brachidium. Ordovician through Triassic.
SUPERFAMILY- Punctospiracea. Punctospirids are punctuate spiriferoids
having spirifeferpids brachidium and complicated cardinal process.
Lower Silurian through Recent.
SUPERFAMILY- Terebratulacea. Terebratulaceans are are endopunctate
articulates brachial valve, without a notothyrium or chilidium, and with
the delthyrium usually more or less restricted by deltidial plates.
Lower Silurian to Recent.

SUPERFAMILY- Terebratellacea. Terebratellids are terebratuloids in
which the loop in the higher genera develops from both the cardinalia
and median septum; the loop generally become free from the median
septum as the latter is partly or wholly resorbed . Mesozoic to Recent.
Reference-
Principals of Invertebrate Paleontology- Robert R. shrock &
William H. Twenhofel
en.wikipedia.org/wiki/Brachiopod

Classification of brachiopoda

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