Craniidae
| Craniidae Temporal range:
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| Petrocrania scabiosa encrusting the edge of a strophomenide brachiopod; Upper Ordovician of northern Kentucky. | |
Scientific classification 
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| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Brachiopoda |
| Class: | Craniata |
| Order: | Craniida Waagen, 1885 |
| Suborder: | Craniidina Waagen, 1885 |
| Superfamily: | Cranioidea Menke, 1828 |
| Family: | Craniidae Menke, 1828 |
| Genera | |
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See text. | |
| Synonyms | |
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The Craniidae are a
taxa are at present redundant and rarely used.There are three living genera within Craniidae: Neoancistrocrania, Novocrania, and Valdiviathyris.[1] As adults, craniids either live freely on the ocean floor or, more commonly, cement themselves onto a hard object with all or part of the ventral
valve.
Like the burrowing
Evolution
Extinct craniids
Most craniid genera are
Lower Ordovician. In the Lower Ordovician, they were mostly restricted to peri-Gondwanan terranes (modern central Europe) in the South Polar region. By the Middle Ordovician, they had spread northwards to Baltica. In the Late Ordovician, their range expanded eastwards to Avalonia before crossing the Iapetus Ocean to Laurentia.[4]
Craniid diversity and abundance was respectable but still fairly low during the Late Ordovician, and even lower through the rest of the
Upper Permian, and the entire Triassic. They reappear in the Oxfordian stage of the Late Jurassic and briefly regain their Ordovician level of diversity in the Late Cretaceous.[5]
Living craniids
Craniids are remarkable for their slow rate of
adaptations to cooler habitat. Present-day Valdiviathyris are indistinguishable from fossils of the Late Eocene, and the genus cannot even be divided into chronospecies. V. quenstedti can be considered a living fossil and one of the oldest and most long-lived species known to science.[6]
Valdiviathyris and Neoancistrocrania have occasionally been separated into their own family, Valdiviathyrididae, though few authors follow this suggestion.[6] Craniscus has sometimes been cited as a fourth living craniid genus,[3][8] based on "Craniscus japonica", a putative species from waters off Japan. Genetic evidence has clarified this misconception, revealing that "Craniscus japonica" actually represents a misattributed species of Neoancistrocrania.[7]
List of genera
From the Treatise on Invertebrate Paleontology Part H, Revised (unless stated otherwise):[3]
- †Caradoc") – Lower Carboniferous]
- †Ancistrocrania Dall, 1877 = Cranopsis [Upper Cretaceous (Coniacian) – Paleocene (Danian?)]
- †Celidocrania[8] Liu, Xhy, & Xue, 1985 [Middle Ordovician] (possible synonym of Acanthocrania)
- †Crania Retzius, 1781 [Upper Cretaceous (Campanian – Maastrichtian)]
- †Craniscus Dall, 1871 [Upper Jurassic (Oxfordian)][7]
- †Conocrania Smirnova, 1996 [Lower Cretaceous (Berriasian – Valanginian)]
- †Danocrania Rozenkrantz, 1964 [Upper Cretaceous (Maastrichtian) – Paleocene (Danian?)]
- †Deliella[8] Halamski, 2004 [Lower Devonian (Emsian) – Middle Devonian (Givetian)]
- †Isocrania Jäkel, 1902 [Upper Cretaceous (Campanian) – Paleocene (Danian?)]
- †Lower Permian]
- †Mesocrania[8] Smirnova, 1997 [Upper Jurassic (Oxfordian) – Lower Cretaceous (Berriasian)]
- †Nematocrania Grant, 1976 [Lower Permian (Artinskian)]
- Neoancistrocrania Laurin, 1992
- Novocrania[8] Lee and Bruton, 2001 = Neocrania
- †Orthisocrania Rowell, 1963 [Ordovician]
- †Petrocrania Raymond, 1911 [Lower Ordovician (Tremadocian)[4] – Lower Carboniferous]
- †Philhedra Koken, 1889[9] [Ordovician]
- †Pseudocrania McCoy, 1851 [Lower Ordovician ("Arenig")]
- Valdiviathyris Helmcke, 1940[10]
Gallery
-
Petrocrania (small rounded shells) encrusting an Ordovician strophomenide brachiopod -
Pseudocrania sp., from the Ordovician of Estonia -
The Netherlands -
Illustration ofNorth Atlantic
.jpg)
References
- ^ a b Emig, Christian C.; Bitner, Maria Aleksandra; Álvarez, Fernando. "Craniiformea". Brachiopoda Database. Retrieved 7 June 2023.
- ISBN 0-8137-3015-5.
- ^ ISBN 0-8137-3108-9.
- ^ ISSN 0435-4052.
- ISBN 978-0-8137-3136-0.
- ^ ISSN 1477-2000.
- ^ ISBN 978-1-4051-8664-3.
- ^ ISBN 978-0-8137-3136-0.
- ^ Brunton, C.H.C. (1968). "Silicified brachiopods from the Visean of County Fermanagh (II)". Bulletin of the British Museum (Natural History), Geology. 16: 8.
- ^ Emig, Christian C. (2009). "Nummulus brattenburgensis and Crania craniolaris (Brachiopoda, Craniidae)" (PDF). Carnets de Géologie (08). Archived from the original (PDF) on 2016-03-04. Retrieved 2014-08-05.
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