Lytvolasma Soshkina 1925
Genus Lytvolasma Soshkina, 1925. Type species: Lytvolasma asymetrica Soshkina, 1925 [sic!]. Diagnosis: Non dissepimented small solitary corals; cardinal fossula deep, key-hole shaped, often bordered by half aulos in counter quadrants; cardinal septum shortened late in ontogeny; counter septum slight...
| Main Authors: | , , |
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| Format: | Other/Unknown Material |
| Language: | unknown |
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Zenodo
2023
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| Subjects: | |
| Online Access: | https://doi.org/10.5281/zenodo.12783839 http://treatment.plazi.org/id/493869167F13FFF3FC91FDF2FDDEF9C8 |
| Summary: | Genus Lytvolasma Soshkina, 1925. Type species: Lytvolasma asymetrica Soshkina, 1925 [sic!]. Diagnosis: Non dissepimented small solitary corals; cardinal fossula deep, key-hole shaped, often bordered by half aulos in counter quadrants; cardinal septum shortened late in ontogeny; counter septum slightly elongated; major septa semi-radial in arrangement; minor septa very short; microstructure of septa trabecular (Fedorowski, 1987a). Remarks: Lytvolasma is a complex genus with unclear relations to several other taxa, as extensively discussed by Fedorowski (1987a). He modified the diagnosis by Hill (1981) who questioned the validity of Lytvolasma and considered it as a possible junior synonym of Bradyphyllum Grabau, 1928. However, due to morphological differences Fedorowski (1987a) considered both genera as valid and did not include the presence of long, slightly curved, thickened septa that are laterally contiguous over much of their length and almost reach the axis from Hill’s diagnosis. However, opposed to Fedorowksi, these characteristics were confirmed by Chwieduk (2013, tab. 3). According to Fedorowski (1987a), intimate relations of the genus exist with further Antiphyllinae, as Lytvolasma specimens were attributed by authors in part to Actinophrentis Ivanovski, 1967, as well as to species of Allotropiophyllum Grabau, 1928 and Bradyphyllum . In addition, the type species of the hapsiphyllinid Parasterophrentis , P. virgata Fomichev, 1953 has to be transferred to Lytvolasma . Opposed, Lytvolasma (?) cf. L. geinitzi (Toula, 1875) described by Flügel (1973) from the Upper Permian of eastern Greenland was included in Tachylasma rhizoides Soshkina, 1925 by Fedorowski (1982). He also excluded Lytvolasma from Northeast China figured by Guo (1980), but opposed, Fedorowski and Bamber (2001) did not rule out the possibility that some of Guo’s specimens might be included. Lytvolasma described from Tibet (Wang and Liu, 1982; Wu, 1975) and Xingjiang (Wang and Yu, 1986) were included in Euryphyllum (Fedorowski, 1982). ... |
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