Paterinata is an

extinct Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...

class Class or The Class may refer to: Common uses not otherwise categorized * Class (biology), a taxonomic rank * Class (knowledge representation), a collection of individuals or objects * Class (philosophy), an analytical concept used differentl ...

linguliform Linguliformea is a subphylum of inarticulate brachiopods. These were the earliest of brachiopods, ranging from the Cambrian into the Holocene. They rapidly diversified during the Cambrian into the Ordovician, but most families became extinct by ...

brachiopod Brachiopods (), phylum Brachiopoda, are a phylum of trochozoan 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, w ...

s which lived from the

Lower Cambrian The Cambrian Period ( ; sometimes symbolized Ꞓ) was the first geological period of the Paleozoic Era, and of the Phanerozoic Eon. The Cambrian lasted 53.4 million years from the end of the preceding Ediacaran Period 538.8 million years ago (m ...

(

Tommotian Stage 2 of the Cambrian is the unnamed upper stage of the Terreneuvian Series. It lies atop the Fortunian and below Stage 3 of the Cambrian. It is commonly referred to as the Tommotian, after the Cambrian stratigraphy of Siberia. Neither the upper ...

) to

Upper Ordovician The Ordovician ( ) is a geologic period and system, the second of six periods of the Paleozoic Era. The Ordovician spans 41.6 million years from the end of the Cambrian Period million years ago (Mya) to the start of the Silurian Period Mya. The ...

(

Ashgill Ashgill is a village in South Lanarkshire, Scotland near Larkhall. It is part of the Dalserf parish. The village church dates back to 1889 The village has a shop The local school was first in Scotland to have an automated bell, installed in 1 ...

). It contains the single order Paterinida and the subfamily Paterinoidea. Despite being some of the earliest brachiopods to appear in the fossil record, paterinides stayed as a relatively subdued and low-diversity group even as other brachiopods diversified later in the Cambrian and Ordovician. Paterinides had organo-

phosphatic In chemistry, a phosphate is an anion, salt, functional group or ester derived from a phosphoric acid. It most commonly means orthophosphate, a derivative of orthophosphoric acid . The phosphate or orthophosphate ion is derived from phosphor ...

shells which were ventribiconvex (both

valves A valve is a device or natural object that regulates, directs or controls the flow of a fluid (gases, liquids, fluidized solids, or slurries) by opening, closing, or partially obstructing various passageways. Valves are technically fittings ...

convex, the ventral valve moreso) and strophic (with a straight hinge line). Shell ornamentation usually consists of concentric fila (fine ridges) and tiny pits. The tiny larval shell has a smooth outer halo and strongly ornamented inner portion. When seen from behind, each valve appears triangular, with a system of superimposed plates and furrows. Each valve has a broad triangular depression edging the hinge, known as a pseudointerarea. The middle of each pseudointerarea hosts a narrower excavation or furrow, known as a notothyrium (in the dorsal valve) or a delthyrium (in the ventral valve). Finally, these furrows may be partially covered by a convex plate-like overgrowth, known as a homeochilidium (in the dorsal valve) or a homeodeltidium (in the ventral valve). The furrow-and-plate pairing creates closed pockets near the hinge, where the pedicle presumably emerged. The

musculature Skeletal muscles (commonly referred to as muscles) are organs of the vertebrate muscular system and typically are attached by tendons to bones of a skeleton. The muscle cells of skeletal muscles are much longer than in the other types of muscle ...

of paterinides seemingly relied on a small number of broad muscles within the shell. There are a pair of large triangular muscle scars near the hinge of the ventral valve, conjoining under the homeodeltidium. There are two pairs of scars in the dorsal valve, one pair set medially (at the center of the shell) and the other set posterolaterally (further back and outwards). These major scars likely correspond to adductor muscles, which close the shell. A subtle pit was present at the tip of the homeochilidium, possibly hosting diductor muscles, which open the shell. Diductor muscles are otherwise only found in articulate brachiopods. The network of

mantle A mantle is a piece of clothing, a type of cloak. Several other meanings are derived from that. Mantle may refer to: *Mantle (clothing), a cloak-like garment worn mainly by women as fashionable outerwear **Mantle (vesture), an Eastern Orthodox ve ...

canals usually had a saccate form, with a pair of midline canals arcing outwards once they reach the shell margin.

Subgroups

* Order Paterinida Rowell, 1965 ** Superfamily Paterinoidea Schuchert, 1893 *** Family Cryptotretidae Pelman, 1979 (Lower Cambrian) **** '' Aldanotreta'' Pelman, 1977 (Tommotian) **** ''

Askepasma ''Askepasma'' is an extinct genus of brachiopods which existed in what is now Australia and southern China during the Lower Cambrian. The type species is ''A. toddense''. ''A. transversalis'' occurs in Guizhou, and ''A. saproconcha'' is the olde ...

'' Laurie, 1896 (

Atdabanian Cambrian Stage 3 is the still unnamed third stage of the Cambrian. It succeeds Cambrian Stage 2 and precedes Cambrian Stage 4, although neither its base nor top have been formally defined. The plan is for its lower boundary to correspond approxim ...

) **** ''

Cryptotreta ''Cryptotreta'' is a genus of tephritid or fruit flies in the family Tephritidae The Tephritidae are one of two fly families referred to as fruit flies, the other family being the Drosophilidae. The family Tephritidae does not include the ...

'' Pelman, 1977 (Tommotian) **** '' Dzunarzina'' Ushatinskaya, 1993 (Atdabanian) **** '' Salanygolina'' Ushatinskaya, 1987 (

Botomian Cambrian Stage 4 is the still unnamed fourth stage of the Cambrian and the upper stage of Cambrian Series 2. It follows Cambrian Stage 3 and lies below the Wuliuan. The lower boundary has not been formally defined by the International Commission on ...

) *** Family Paterinidae Schuchert, 1893 (Lower Cambrian - Upper Ordovician) **** '' Dictyonina'' Cooper, 1942 (Lower Cambrian - Upper Cambrian) **** '' Dictyonites'' Cooper, 1956 (Lower Ordovician - Upper Ordovician) **** '' Kolihium'' Havlicek, 1982 (Lower Ordovician) **** '' Lacunites'' Gorjansky, 1969 (Lower Ordovician) **** '' Micromitra'' Meek, 1873 (Lower Cambrian - Upper Cambrian) **** '' Paterina'' Beecher, 1891 (upper Lower Cambrian - Middle Cambrian)

References

Prehistoric protostome classes Paleozoic brachiopods {{brachiopod-stub

Subgroups

See also

References