Stromatoporoidea

fossil order

Also known as: Conulariida

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July 14, 2026

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Stromatoporoids were an extinct order of colonial marine organisms that existed from the Cambrian to the Cretaceous periods. These organisms formed dense, laminated masses of calcium carbonate, with some species constructing reef-like structures. The term "stromatoporoid" can also refer to a genus of extinct hydrozoans, Stromatopora, which formed thick, concentric layers of calcareous tissue and are found in Paleozoic rocks.12

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Devonian Period
Sediment types
…reefs are largely formed of stromatoporoids. These marine invertebrates suddenly vanished almost entirely by the end of the Frasnian Age, after which reefs were formed locally of cyanobacterian stromatolites. Other areas have reefs formed by mud mounds, and there are spectacular examples in southern Morocco, southern Algeria, and Mauritania. Also…
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…reefs are largely formed of stromatoporoids. These marine invertebrates suddenly vanished almost entirely by the end of the Frasnian Age, after which reefs were formed locally of cyanobacterian stromatolites. Other areas have reefs formed by mud mounds, and there are spectacular examples in southern Morocco, southern Algeria, and Mauritania. Also…
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cnidarian
Evolution
Colonies of Stromatoporoidea, considered to be an order of the class Hydrozoa that extended from the mid-Cambrian Period to the Cretaceous Period (about 145 million to 66 million years ago), produced massive skeletons. Although there were two groups of Paleozoic corals, neither of which has modern descendants,…
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Colonies of Stromatoporoidea, considered to be an order of the class Hydrozoa that extended from the mid-Cambrian Period to the Cretaceous Period (about 145 million to 66 million years ago), produced massive skeletons. Although there were two groups of Paleozoic corals, neither of which has modern descendants,…
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Silurian Period
Pentamerid communities
…developed a continuum of coral-stromatoporoid, Pentamerus, and Stricklandia communities. (Stromatoporoids are large colonial marine organisms similar to hydrozoans.) Clorinda communities were rare in this setting. Stricklandia communities sometimes included smaller, less-robust individuals of calcareous green algae, indicating a slightly deeper-water environment than that occupied by the Pentamerus community. Coral-stromatoporoid…
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…developed a continuum of coral-stromatoporoid, Pentamerus, and Stricklandia communities. (Stromatoporoids are large colonial marine organisms similar to hydrozoans.) Clorinda communities were rare in this setting. Stricklandia communities sometimes included smaller, less-robust individuals of calcareous green algae, indicating a slightly deeper-water environment than that occupied by the Pentamerus community. Coral-stromatoporoid…
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