Meekopinna
| Meekopinna | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Temporal occurrence | ||||||||||||
| Pennsylvania to Guadalupian | ||||||||||||
| 298.9 to 259.9 million years | ||||||||||||
| Locations | ||||||||||||
|
USA, Brazil |
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| Systematics | ||||||||||||
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| Scientific name | ||||||||||||
| Meekopinna | ||||||||||||
| Yancey , 1978 |
Meekopinna is an extinct clam - genus of the family of plug shells (Pinnidae) from the order of Ostreida . The three species of the genus are restricted to the Pennsylvania and Unterperm.
features
The genus Meekopinna is characterized by small, rather elongated and narrow housings. The housing angle is only about 15 °, the length about 10 centimeters. You are only moderately bloated. The lock edge is thickened on both flaps by shell material. The vertebrae are near the anterior end, but not terminal.
The shell is thin. The surface of the housing has closely spaced growth strips. The lines of growth run almost parallel to the ventral margin, then bend to the rear end and are then straight or slightly convex. They then hit the edge of the castle almost vertically.
Similar genera
The three Paleozoic genera Aviculopinna Meek, 1867, Meekopinna Yancey, 1973 and Pteronites M'Coy, 1844 differ from Atrina Gray, 1842 and Pinna Linné, 1768 by the vertebrae, which in the first three genera still clearly differ from the pointed, anterior (lower ) Ends are removed. In addition, the first three types mentioned are significantly narrower with smaller housing angles (around 15 °).
Geographical distribution and stratigraphic range
The genus is far from the Conemaugh group ( Pennsylvanian ) and of the Perm Loray formation (Arcturus Group, Leonardian approx. Kungurian ), the more recent Kaibab formation (also Leonardian), the Tosi formation and Ervay formation ( both Guadalupium ) known in the southern USA. Anelli et al. (2006) also found them in the Piauí Formation (Pennsylvania) of the Parnaíba Basin in Brazil.
Taxonomy
The genus was established in 1973 by Thomas Yancey. The type species is Aviculopinna amaricana Meek, 1867. Hoare and Sturgeon and Hoare et al. (1979) withdrew the genus again and placed it in the synonymy of Pteronites M'Coy in Griffith, 1844. Anelli et al. (2006) reiterate the genre as independent, but emphasize the need for a comprehensive revision. Waller and Stanley (2005) and Lucas et al. (2013) also treat Meekopinna as an independent genus. Three species are added to the genus:
- Genus Meekopinna Yancey, 1973
- † Meekopinna americana Meek, 1867
- † Meekopinna sagitta (Chronic, 1952)
- † Meekopinna subspatulata (Worthen, 1875)
supporting documents
literature
- Thomas E. Yancey: Brachiopods and mollusca of the Lower Permian Arcturus Group, Nevada and Utah, Part 1: brachiopods, scaphopods, rostroconchs, and bivalves. Bulletins of American Paleontology, 74 (303): 257-367, 1978 Online at www.biodiversitylibrary.org (p. 338/9)
Individual evidence
- ↑ a b Luiz E. Anelli, AC Rocha-Campos, Marcello G. Simões: Pennsylvanian Pteriomorphian Bivalves from the Piauí Formation, Parnaíba Basin, Brazil. Journal of Paleontology, 80 (6): 1125-1141, 2006 abstract at JSTOR
- ^ Richard D. Hoare, MT Sturgeon: Pteronites americana (Meek) from the Brush Creek (Conemaugh), southeastern Ohio. The Compass, 49: 61-64, 1972. (not seen)
- ^ Richard D. Hoare, MT Surgeon, EA Kindt: Pennsylvanian marine Bivalvia and Rostroconchia of Ohio. Geological Survey of Ohio Bulletin, 67: 1-77, 1979.
- ^ Thomas R. Waller, George D. Stanley: Middle Triassic Pteriomorphian Bivalvia (Mollusca) from the New Pass Range, West-Central Nevada: Systematics, Biostratigraphy, Paleoecology, and Paleobiogeography. Journal of Paleontology Memoir, 61: 1-64, 2005, JSTOR 4095819
- Jump up ↑ Spencer G. Lucas, James E. Barrick, Karl Krainer, Jörg W. Schneider: The Carboniferous-Permian boundary at Carrizo Arroyo, Central New Mexico, USA. Bulletin - New Mexico Museum of Natural History and Science, 25: 153-170, 2013 PDF
- ^ Hanns Bruno Geinitz: Carbonformation and Dyas in Nebraska. 91 S., Dresden, E. Blochmann 1866 Online at www.biodiversitylibrary.org Plate 2
- ↑ Fielding Bradford Meek: Note by FB Meek to his review of Prof. Genitz in regard to Nebraska fossils. American Journal of Science, 2. series, 44: 282-283, 1867 Online at www.biodiversitylibrary.org (p. 283)
- ^ H. Chronic: Molluscan fauna from the Permian Kaibab Formation, Walnut Canyon, Arizona. Geological Society of America, Bulletin, 63 (2): 95-166, 1952.
- ^ Amos Henry Worthen: Geology and Palaeontology. Geological Survey of Illinois, Volume VI, 531 pp., 1875 Online at www.archive.org (p. 524)