Oerstediidae Chernyshev 1993
Family OERSTEDIIDAE Chernyshev, 1993 Morphological circumscription Oerstediina having a two-layered rhynchocoel wall; the cephalic vessels protrude into the rhynchocoel as they pass through cerebral ring; the mid-dorsal vessel does not penetrate the rhynchocoel to form a vascular plug. Clade definit...
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| Format: | Other/Unknown Material |
| Language: | unknown |
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2021
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| Online Access: | https://zenodo.org/record/4519283 https://doi.org/10.5281/zenodo.4519283 |
| Summary: | Family OERSTEDIIDAE Chernyshev, 1993 Morphological circumscription Oerstediina having a two-layered rhynchocoel wall; the cephalic vessels protrude into the rhynchocoel as they pass through cerebral ring; the mid-dorsal vessel does not penetrate the rhynchocoel to form a vascular plug. Clade definition Eumonostiliferans that are more closely related to Oerstedia dorsalis (Abildgaard, 1806) than to Plectonemertes sinensis Gibson, 1990a. See the clade definition for Plectonemertidae for the potential problem stemming from the absence of molecular sequence data for Plectonemertes sinensis. Remarks Thollesson & Norenburg (2003) were the first to recognize the clade Oerstediidae, as treated herein, which in their molecular phylogeny included Antarctonemertes varvarae Chernyshev, 1999; Nemertellina yamaokai Kajihara et al., 2000; Oerstedia polyorbis Iwata, 1954 [two specimens, erroneously identified as Oerstedia venusta Iwata, 1954 and Oerstedia zebra (Chernyshev, 1993), respectively; see Akhmatova et al. (2012) for the corrected identifications]; ‘ Tetrastemma ’ elegans (Girard, 1852); and ‘ Tetrastemma ’ wilsoni Coe, 1943. Thollesson & Norenburg (2003) referred to this clade as Tetrastemmatidae, probably because it included two species of ‘ Tetrastemma ’; furthermore, Gibson (1982a) had placed Nemertellina Friedrich, 1935b in Tetrastemmatidae, and Bürger (1895) had once placed Oerstedia Quatrefages, 1846 in Tetrastemmatidae. In a subsequent study by Strand & Sundberg (2005a), however, Tetrastemma flavidum Ehrenberg, 1828 (type species of Tetrastemmatidae) and Oerstedia dorsalis (Abildgaard, 1806) (type species of Oerstediidae) appeared in different clades, representing the Amphiporina and Oerstediina, respectively, as treated herein. The name Tetrastemmatidae should thus be used to denote a subclade in the Amphiporina, given the species identification of T. flavidum (see Nomenclatural notes below). Listed in Table 3 are species that have been confirmed to constitute Oerstediidae by means of molecular ... |
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