Taxonomy

English

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Genus HEMIGORDIELLINA Marie in Deleau and Marie, 1961 emend. Vachard in Vachard and Beckary, 1991 Type Species. Glomospira diversa Cushman and Waters, 1930; by original designation. Synonyms. Glomospira (in the senses of the Russian authors, from Lipina, 1949 to Filimonova, 2010); Pseudoglomospira (of the USA and Japan authors; from Groves (1983) to Kobayashi, 2006; even if the same taxon is called Glomospira in Kobayashi, 2006). Remarks. Small glomospiroid porcelaneous tests are here assigned to Hemigordiellina, because “Glomospira” is truly agglutinated and Pseudoglomospira of the authors is microgranular. Many micropaleontologists do not admit this interpretation, and therefore, a new name might be introduced in the nomenclature. We consider that, among the Cornuspiridae, the most primitive genus, Hemigordiellina, give rise to two lineages; either Midiella Pronina, 1988 (which do not attain the planispiral terminal stage) or Hemigordius (the terminal stage of which is planispiral). On the other hand, Midiella differs from Neodiscus by the smaller size and microstructure of the test (see below the analysis of family Neodiscidae), from Hemigordius by the inflated test due to oscillating-sigmoidal coiling, and from Septigordius Gaillot and Vachard, 2007 by the absence of pseudosepta. Occurrence. Pennsylvanian–Permian; cosmopolitan. Vachard (2019) pers. com.

Not documented