Minchinellidae
Order of sponges
From Wikipedia, the free encyclopedia
Minchinellidae is a family of calcareous sponges, members of the class Calcarea.[1] It is the only family in the monotypic order Lithonida. The families Petrobionidae (genus Petrobiona)[2] and Lepidoleuconidae (genus Lepidoleucon)[3] have also sometimes been placed within Lithonida, though more recently they have been moved to the order Baerida.[4] Thanks to their hypercalcified structure, minchinellids have a fossil record reaching as far back as the Jurassic Period.[3][4]
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| Minchinellidae Temporal range: | |
|---|---|
| |
| Porosphaera globularis fossil from the Cretaceous of Germany | |
Scientific classification  | |
| Kingdom: | Animalia |
| Phylum: | Porifera |
| Class: | Calcarea |
| Order: | Lithonida Vacelet, 1981 |
| Family: | Minchinellidae Dendy & Row, 1913 |
| Genera | |
|
see text. | |
| Synonyms | |
| |
Description
Minchinellids are hypercalcified sponges. They have a robust skeleton of tetractine (four-rayed) calcareous spicules. The tetractine spicules are propeller-shaped, with three curved actines (rays) radiating perpendicular to a straight basal actine. These spicules may be linked by their basal actines or cemented together by calcite. The skeleton is reinforced with layers of loose diapason (tuning fork-shaped) spicules. Minchinellid sponges have a leuconoid canal system.[3][4]
List of genera
- †Bactronella Hinde, 1884 [Jurassic–Miocene, Holocene?][3]
- Minchinella Kirkpatrick, 1908 [Holocene]
- Monoplectroninia Pouliquen & Vacelet, 1970 [Holocene]
- †Muellerithalmia Reitner, 1987 [Upper Jurassic][3]
- Petrostroma Döderlein, 1892 [Cretaceous–Holocene]
- Plectroninia Hinde, 1900 [Jurassic?, Cretaceous–Holocene]
- †Porosphaera Steinmann, 1878 [Cretaceous][3]
- †Porosphaerella Welter, 1911 [Cretaceous][3]
- †Retispinopora Brydone, 1912 [Cretaceous–Paleocene][3]
- †Sagittularia Welter, 1911 [Cretaceous][3]
- Tulearinia Vacelet, 1977 [Holocene]
