Astrotholus Mah 2023, nov. gen.
Astrotholus nov. gen. Etymology The genus is a combination of astro for star and the Latin tholus for dome, which alludes to the strongly arched, convex shape present in this genus. Diagnosis Body form pentagonal to stellate, arms short, disk large. Disk strongly arched, interradial body wall thin....
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| Format: | Other/Unknown Material |
| Language: | unknown |
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Zenodo
2023
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| Online Access: | https://doi.org/10.5281/zenodo.8090084 http://treatment.plazi.org/id/03C387E86639FFEAFF68E6CC838EFE2C |
| Summary: | Astrotholus nov. gen. Etymology The genus is a combination of astro for star and the Latin tholus for dome, which alludes to the strongly arched, convex shape present in this genus. Diagnosis Body form pentagonal to stellate, arms short, disk large. Disk strongly arched, interradial body wall thin. Actinal surface concave. Abactinal plates imbricate, variably flat to subpaxillate, rounded to elongate in shape. Plates with spinelets, variably thorn like, tips glassine to blunt and strongly club-like or granuliform in shape. These accessories showing association with underlying plates. Abactinal disk plates irregularly arranged on disk and arm radii but present in ordered series interradially between radial disk plates and superomarginals. Marginal plates small, forming crenulate lateral boundary between abactinal and actinal surface. Actinal intermediate plate region in linear rows showing association between inferomarginals and adambulacral plates. Actinal plate surface bare or in some taxa with single to multiple spinelets. Furrow spines webbed, numbering 3 to 6. Type species: Astrotholus mei n. gen, n. sp. Comments This genus accommodates “ Anseropoda ” antarctica and the four new species reported herein, which had fallen under the broad range of the description for “ Anseropoda ” antarctica. The type species, described by Fisher (1940) from Clarence Island was collected from relatively shallow depth (311–426 m) compared to the species reported here which were collected from between 1000 and 4000 m except for Astrotholus phasma n. gen, n. sp. from 339– 494 m. Included Species: Astrotholus antarcticus (Fisher, 1940), Astrotholus infernalis n. gen. n. sp. Astrotholus mei n. gen, n. sp. Astrotholus molginos n. gen. n. sp. Astrotholus phasma n. gen. n. sp. Type species : Astrotholus mei n. sp. Key to the species of Astrotholus n. gen. (0) Surface with strongly convex or subpaxillate abactinal plates with multiple spinelets, each adorned with microspinelets or club-shaped tips. (3) (0’) Surface flat with single ... |
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