Spiriferida is an order of extinct articulate
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 ...
fossil
A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...
s which are known for their long hinge-line, which is often the widest part of the shell. In some genera (e.g. ''
Mucrospirifer'') it is greatly elongated, giving them a wing-like appearance. They often have a deep fold down the center of the shell. The feature that gives the spiriferids their name ("spiral-bearers") is the internal support for the
lophophore
The lophophore () is a characteristic feeding organ possessed by four major groups of animals: the Brachiopoda, Bryozoa, Hyolitha, and Phoronida, which collectively constitute the protostome group Lophophorata.[Ordovician
The Ordovician ( ) is a geologic period and System (geology), system, the second of six periods of the Paleozoic Era (geology), Era. The Ordovician spans 41.6 million years from the end of the Cambrian Period million years ago (Mya) to the start ...]
with the appearance of ''Eospirifer radiatus''. They increased in diversity throughout the
Silurian
The Silurian ( ) is a geologic period and system spanning 24.6 million years from the end of the Ordovician Period, at million years ago ( Mya), to the beginning of the Devonian Period, Mya. The Silurian is the shortest period of the Paleozo ...
and underwent a dramatic
evolution
Evolution is change in the heritable characteristics of biological populations over successive generations. These characteristics are the expressions of genes, which are passed on from parent to offspring during reproduction. Variation ...
ary radiation during the
Devonian
The Devonian ( ) is a geologic period and system of the Paleozoic era, spanning 60.3 million years from the end of the Silurian, million years ago (Mya), to the beginning of the Carboniferous, Mya. It is named after Devon, England, whe ...
period, reaching peak development in variety and numbers. Spiriferida survived the great
Permian extinction
The Permian ( ) is a geologic period and stratigraphic system which spans 47 million years from the end of the Carboniferous Period million years ago (Mya), to the beginning of the Triassic Period 251.9 Mya. It is the last period of the Paleozo ...
, finally becoming extinct during the Early to Middle
Jurassic
The Jurassic ( ) is a Geological period, geologic period and System (stratigraphy), stratigraphic system that spanned from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period, approximately Mya. The J ...
.
Fossils of this order are often preserved as
pyrite
The mineral pyrite (), or iron pyrite, also known as fool's gold, is an iron sulfide with the chemical formula Iron, FeSulfur, S2 (iron (II) disulfide). Pyrite is the most abundant sulfide mineral.
Pyrite's metallic Luster (mineralogy), lust ...
.
Taxonomy
Order Spiriferida
*Suborder
Delthyridina
**Superfamily
Delthyridoidea
***Family
Acrospiriferidae
***Family
Cyrtinopsidae
***Family
Delthyrididae
***Family
Hysterolitidae
***Family
Mucrospiriferidae
**Superfamily
Reticularioidea
***Family
Elythidae
***Family
Reticulariidae
***Family
Thomasariidae
***Family
Xenomartiniidae
*Suborder
Spiriferidina
**Superfamily
Adolfioidea
***Family
Adolfiidae
***Family
Echinospiriferidae
**Superfamily
Ambocoelioidea
***Family
Ambocoeliidae
***Family
Eudoxinidae
***Family
Lazutkiniidae
***Family
Verneuiliidae
**Superfamily
Brachythyridoidea
***Family
Brachythyrididae
***Family
Skelidorygmidae
**Superfamily
Cyrtioidea (syn. Cyrtiacea)
***Family
Costispiriferidae
***Family
Cyrtiidae
***Family
Hedeinopsidae
**Superfamily
Cyrtospiriferoidea
***Family
Conispiriferidae
***Family
Cyrtospiriferidae
Cyrtospiriferidae is an extinct family of 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 m ...
***Family
Spinocyrtiidae
**Superfamily
Martinioidea
***Family
Crassumbidae
***Family
Elythynidae
***Family
Gerkispiridae
***Family
Ingelarellidae
***Family
Martiniidae
***Family
Perissothyrididae
***Family
Tenellodermidae
**Superfamily
Paeckelmanelloidea
***Family
Paeckelmanellidae
***Family
Strophopleuridae
**Superfamily
Spiriferoidea
***Family
Choristitidae
***Family
Imbrexiidae
***Family
Reticulariacea
***Family
Spiriferellidae
***Family
Spiriferidae
***Family
Trigonotretidae
**Superfamily
Theodossioidea
***Family
Palaeochoristitidae
***Family
Theodossiidae
***Family
Ulbospiriferidae
References
Introduction to the Spiriferidaat berkeley.edu
at the Paleos website
* Zhan, RenBin, JiSuo Jin, Yan Liang, and LingKai Meng. "Evolution and paleogeography of Eospirifer (Spiriferida, Brachiopoda) in Late Ordovician and Silurian." Science China Earth Sciences 55, no. 9 (2012): 1427–1444.
{{Brachiopod orders
Protostome orders
Prehistoric brachiopods
Brachiopod orders