Biology:Orthothecida
From HandWiki
Revision as of 19:49, 19 May 2022 by imported>WikiEditor (change)
Short description: Extinct order of shelled animals
| Orthothecida | |
|---|---|
Scientific classification 
| |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Superphylum: | Lophotrochozoa |
| Class: | †Hyolitha |
| Order: | †Orthothecida Marek, 1966 |
| Families | |
| |
The orthothecids are one of the two hyolith orders.[2]
Marek diagnoses the order thus: Conchs with a flat or concave ventral surface — opercula with large, flat cardinal processes but without clavicles – tightly sigmoidal, sediment-filled intestine – helens absent.
Sometimes the Circothecidae and Tetrathecidae are split out into a separate order 'Circothecida', which is defined by the bottom surface not being flat, the cardinal processes being pronounced, and a circular rim sometimes showing hints of differentiation into clavicles.[3]
Internal taxonomy
Marek [4] gives the following diagnoses:
- Orthothecidae: Flat or concave bottom surface of conical shell. Transverse aperture.
Kouchinsky[5] lists the following taxonomic criteria:
- Circothecidae: circular cross-section; same shape and sculpture on upper and lower surfaces.
- Turcurthecidae: oval or lenticular cross-section; top and bottom identical
- Allathecidae: top side flat or slightly convex; bottom side convex
Elsewhere[6]:243 is stated:
- Tetrathecidae: polyhedral cross-section; shell axially twisted
- Novitatidae: bottom side concave
- Lenatheca: aperture heart-shaped.
Additional genera are not assigned to a family:
- Probactrotheca [7]
- Pedunculotheca [8]
References
- ↑ Malinky, J. M. (2009). "Permian Hyolithida from Australia: The Last of the Hyoliths?". Journal of Paleontology 83: 147–152. doi:10.1666/08-094R.1.
- ↑ Malinky, J.M.; Skovsted, C.B (2004). "Hyoliths and small shelly fossils from the Lower Cambrian of North−East Greenland". Acta Palaeontologica Polonica 49 (4): 551–578.
- ↑ http://palaeontologia.pan.pl/Archive/1994-53-1-2_213-252_52-56.pdf [bare URL PDF]
- ↑ MACHAERIDIANS, CHITONS, and CONCHIFERAN: MOLLUSCS of the MOJCZA LIMESTONE. http://palaeontologia.pan.pl/Archive/1994-53-1-2_213-252_52-56.pdf.
- ↑ Kouchinsky, A. V. (2000). "Skeletal microstructures of hyoliths from the Early Cambrian of Siberia". Alcheringa 24 (2): 65–81. doi:10.1080/03115510008619525.
- ↑ Lipps, Jere H; Signor, Philip W (2013-11-21). Origin and Early Evolution of the Metazoa. ISBN 9781489924278. https://books.google.com/books?id=CQzyBwAAQBAJ&q=Tetrathecidae&pg=PA243.
- ↑ Valent, M. (2012). "Two new orthothecids from the Cambrian of the Barrandian area (Hyolitha, Skryje-Týřovice Basin, Czech Republic)". Bulletin of Geosciences 87 (2): 241–248. doi:10.3140/bull.geosci.1142. https://www.researchgate.net/publication/259192183.
- ↑ Sun, Haijing; Smith, Martin R.; Zeng, Han; Zhao, Fangchen; Li, Guoxiang; Zhu, Maoyan (2018). "Hyoliths with pedicles illuminate the origin of the brachiopod body plan". Proceedings of the Royal Society B: Biological Sciences 285 (1887): 20181780. doi:10.1098/rspb.2018.1780. PMID 30257914.
Wikidata ☰ Q7104939 entry
 |  |
