Sphaerocoeliidae is an extinct family of calcareous sponges, the only family in the monotypic order Sphaerocoeliida. Sphaerocoeliids are one of several unrelated sponge groups described as "sphinctozoans", with a distinctive multi-chambered body structure. Sphaerocoeliids persisted from the Permian to the Cenomanian stage of the Cretaceous, a longer period of time than most other "sphinctozoans". Sphaerocoeliids make up the majority of calcareous "sphinctozoans", as well as a large portion of post-Triassic "sphinctozoan" diversity.[1][2] "Sphinctozoans" and the similar "inozoans" were historically grouped together in the polyphyletic order Pharetronida.[2]
| Sphaerocoeliidae Temporal range:
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Scientific classification 
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| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Porifera |
| Class: | Calcarea |
| Order: | †Sphaerocoeliida Vacelet, 1979 |
| Family: | †Sphaerocoeliidae Steinmann, 1882 |
| Genera | |
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see text. | |
In general form, sphaerocoeliids are cylindrical, as a chain of dome-shaped chambers stacked up on each other. Each layer is pierced by a central osculum (outflow vent), which has the form of a simple hole. Sphaerocoeliids are hypermineralized, with a skeleton of loose calcareous spicules cemented together in calcite walls.[1][2]
Genera
edit- †Barroisia Munier-Chalmas, 1882 [Jurassic[2]–Cretaceous (Aptian–Cenomanian)]
- †Sphaerocoelia Steinmann, 1882 [Permian–Cretaceous (Cenomanian)]
- †Sphinctonella Hurcewicz, 1975 [Jurassic (Oxfordian)]
- †Thalamopora Roemer, 1840 [Jurassic[2]–Cretaceous (Cenomanian)]
- †Tremacystia Hinde, 1884 [Cretaceous (Albian–Cenomanian)]
References
edit- ^ a b Treatise on Invertebrate Paleontology Part E, Revised. Porifera, Volume 3: Classes Demospongea, Hexactinellida, Heteractinida & Calcarea, xxxi + 872 p., 506 fig., 1 table, 2004, available here. ISBN 0-8137-3131-3.
- ^ a b c d e Treatise on Invertebrate Paleontology Part E, Revised. Porifera, Volumes 4 & 5: Hypercalcified Porifera, Paleozoic Stromatoporoidea & Archaeocyatha, liii + 1223 p., 665 figs., 2015, available here. ISBN 978-0-9903621-2-8.