Stromatoporoidea is an extinct clade of

sea sponges Sponges, the members of the phylum Porifera (; meaning 'pore bearer'), are a basal animal clade as a sister of the diploblasts. They are multicellular organisms that have bodies full of pores and channels allowing water to circulate through ...

common in the fossil record from the Ordovician through 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, wh ...

. They were especially abundant and important reef-formers in 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 Paleoz ...

and most of the

.Stock, C.W. 2001, Stromatoporoidea, 1926–2000: ''Journal of Paleontology'', v. 75, p. 1079–1089. The group was previously thought to be related to the

coral Corals are marine invertebrates within the class Anthozoa of the phylum Cnidaria. They typically form compact colonies of many identical individual polyps. Coral species include the important reef builders that inhabit tropical oceans and se ...

s and placed in the phylum

Cnidaria Cnidaria () is a phylum under kingdom Animalia containing over 11,000 species of aquatic animals found both in freshwater and marine environments, predominantly the latter. Their distinguishing feature is cnidocytes, specialized cells that ...

. They are now classified in the phylum Porifera, specifically the

sclerosponge Demosponges (Demospongiae) are the most diverse class in the phylum Porifera. They include 76.2% of all species of sponges with nearly 8,800 species worldwide (World Porifera Database). They are sponges with a soft body that covers a hard, ...

s. There are numerous

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 ...

forms with spherical, branching or encrusting skeletons of laminated

calcite Calcite is a carbonate mineral and the most stable polymorph of calcium carbonate (CaCO3). It is a very common mineral, particularly as a component of limestone. Calcite defines hardness 3 on the Mohs scale of mineral hardness, based on scratc ...

with vertical ''pillars'' between the ''laminae''. Specimen of its oldest genus, ''Priscastroma'', have been found within the Middle Ordovician Sediments. This same genus has been referred to as the species ''P. gemina'' Khrom., and is known to have been known to branch off into two forms, A and B. Form A gave rise to the genus ''Cystostroma'' while form B gave rise to the genus ''Labechia'' and its descendants. Paleozoic stromatoporoids died out at the Hangenberg Event at the end of the Devonian. Purported

Mesozoic The Mesozoic Era ( ), also called the Age of Reptiles, the Age of Conifers, and colloquially as the Age of the Dinosaurs is the second-to-last era of Earth's geological history, lasting from about , comprising the Triassic, Jurassic and Cretace ...

stromatoporoids may be unrelated, thus making "stromatoporoids" a polyphyletic group if they are included. Stromatoporoids are useful markers whose form and occurrence can diagnose the depositional environment of sedimentary strata. Paleozoic stromatoporoids hosted various symbiotic endobionts such as rugosans, syringoporids, worms and cornulitids. Image:StromatoporoidSideDevColumbus.jpg, Side view of a stromatoporoid showing ''laminae'' and ''pillars'';

Columbus Limestone The Columbus Limestone is a mapped bedrock unit consisting primarily of fossiliferous limestone, and it occurs in Ohio, Pennsylvania, and Virginia in the United States, and in Ontario, Canada. Description Depositional environment The depositiona ...

(

) of Ohio. File:Stromatoporoid1 Keyser Formation.jpg, Stromatoporoids in the Devonian

Keyser Formation The Late Silurian to Early Devonian Keyser Formation is a mapped limestone bedrock unit in Pennsylvania, Maryland, Virginia, and West Virginia. Description The Keyser is a nodular limestone overlain by thick- and thin-bedded limestone and lamina ...

, Pennsylvania. File:Densastroma pexisum.jpg, ''Densastroma pexisum'', a stromatoporoid from the

of Saaremaa Island,

Estonia Estonia, formally the Republic of Estonia, is a country by the Baltic Sea in Northern Europe. It is bordered to the north by the Gulf of Finland across from Finland, to the west by the sea across from Sweden, to the south by Latvia, an ...

. File:Stromatoporoid reef, Cairn Formation (Devonian).jpg, Stromatoporoid reef ( Cairn Formation,

Late 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, wher ...

) in Calgary, Alberta,

Canada Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by to ...

References

External links

University of California, Berkeley 2019 museum blog post on StromatoporoideaDigital Atlas of Ancient Life page on Stromatoporoidea
Ordovician invertebrates Devonian animals Late Devonian animals Silurian animals Prehistoric animal classes {{paleo-sponge-stub