(2833) Proposal to conserve the name <i>Phalacroma</i> ( <i>Dinophysales</i> : <i>Dinophyceae</i> )

(2833) Phalacroma F. Stein, Organism. Infusionsthiere 3(2): 9, 23, 24. Nov 1883, nom. cons. prop. Typus: P. porodictyum Stein (Organism. 1883) described the dinophysoid genus as distinct from Dinophysis Ehrenb. (in Ber. Bekanntm. Verh. Königl. Preuss. Akad. Wiss. Berlin 1839: 157. 1839). Balech Physis 19: 429. 1944) noted that was a later homonym of trilobite Hawle & Corda Abh. Böhm. Ges. Wiss., ser. 5, 5: 159. 1847). In consequence, he proposed replacement name Prodinophysis Balech, and transferred to it 41 species Phalacroma. this followed by Loeblich Taxon 14: 16. 1965; 16: 68. 1967), who another 25 into Prodinophysis. (l.c.) treated dinoflagellates animalcules (“Infusionsthiere”) under provisions zoological nomenclature. The has been used after 1899, so provision for reversal precedence Art. 23.9.1 International Code Zoological Nomenclature (Ride al., Int. Zool. Nomencl., ed. 4: 28. 1999) does not apply. Under ICZN, is “objectively invalid”, equivalent illegitimate ICN, because only senior may be “valid name” (i.e., correct name) (Art. 52.2 ICZN). satisfies “publication” ICZN thus valid publication 45.1 ICN (although would, in any case validly published without provision). status such amended at Shenzhen Congress 54.1 now states part, “Consideration homonymy extend names taxa Code, except stated below […]. (b) A applied an organism covered 32–45) but originally taxon other than alga, fungus, or plant, i.e. if (1) unavailable use usually homonymy, […]”. Consequently, being (“objectively invalid”) substitute would dinoflagellate no earlier it. Abé Publ. Seto Mar. Biol. Lab. 15: 38–77. 1967) Revista Mus. Argent. Ci. Nat., Bernardino Rivadavia Inst. Nac. Invest. Hidrobiol. 2: 79–92. carried out studies on dinoflagellates, they concluded should junior synonym Dinophysis. Consequently (l.c. 1967: 82–85) As result, most authors next 40 years, forgotten more 50 years (except Böhm Biblioth. Phycol. 22: 104, 110, 112, 114. 1976). synonymy numerous tested with advent molecular data. Jensen Daugbjerg J. 45: 1136–1152. 2009) revealed DNA sequence material (l.c.: legend t. 18, fig. 11–14), provides type Phalacroma, distantly related Dinophysis, D. acuta (l.c.). This supported treatment independent genera. 1147) emended description lectotype (Stein, l.c.: 11) epitype (Jensen Daugbjerg, 1141, 3N) porodictyum. These did mention make comment homonymy. Both are currently listed genera Algaebase: https://www.algaebase.org/search/genus/detail/?genus_id=44962 https://www.algaebase.org/search/genus/detail/?genus_id=46078 basis statement ING (https://naturalhistory2.si.edu/botany/ing/) “Prodinophysis nomenclature et 1847 (Trilobita)”. However, entry must predate (Turland al. Regnum Veg. 2018) because, its 54.1(b)(1), legitimate both Codes. generic literature last while common use. Since reinstatement l.c), three new have (Parra-Toriz Nova Hedwigia 99: 85–86. 2014; Esqueda-Lara Hernández-Becerril 105: 301–312. 2017). placed absence considered latter. either referred one time well applicable Pseudophalacroma Jørg. Schmidt, Rep. Danish Oceanogr. Exped. 1908–10, 2, 3, 47. 1923) original nasutum (F. Stein) 4. 1923; ≡ 18. 1–8 nasuta Loebl. 1965 Parke P.S. Dixon 1968); Oxyphysis Kof. Univ. Calif. 28: 205. 1926) O. oxytoxoides (≡ (Kof.) Gómez 47: 404. 2011); Dinofurcula Skogsb. Mem. Comp. Harvard Coll. 51: 201. 1928) ultima Bull. 50: 195. 1907). [Loeblich Stud. Trop. 3: 52. 1966) “provisionally established”. Jørgensen clearly accepted providing Latin diagnosis 47) publishing combination 4), satisfying requirements 36.1 publication.] Other morphologically Metaphalacroma L.S. Tai Arch. Protistenk. 82: 457. 1934) M. skogsbergii Skogsberg, l.c.), Proheteroschisma 460) connectens Skogsb., Latifascia A.R. 38) Heteroschisma 36, rej.) L. inaequale (Kof. Skogsb.) 38). Molecular data might confirm relationship lacking Dinofurcula, Proheteroschisma. available Metaphalacroma, Pseudophalacroma, Oxyphysis. Eukaryot. Microbiol. 59: 189. 2012) demonstrated small subunit ribosomal RNA gene supporting recognition Pseudophalacroma. 2012: 189) also reported individual identified sp. (likely skogsbergii); unpublished (GenBank No. FJ561749 https://www.ncbi.nlm.nih.gov/nuccore/238683611) suggest distant porodictyum, There is, therefore, support consider synonymous By contrast, 2011: 403–404) oxytoxoides, Oxyphysis, very closely consequently proposing Hoppenrath Lewis Geol. Perspect. Dinoflagellates: 199–206. 2013) questioned 205), endorsing close considering monotypic family Oxyphysaceae Sournia Phycologia 23: 350. 1984) longer warranted, nevertheless “transfer […] premature”, going state “significant morphological differences exist between Phalacroma”. accepted, latter earliest group congeneric illeg. Excluding do cluster clade type, total 84 combinations need conserved. conserved made despite previously 14.1) conservation overcomes illegitimacy serves stability 14.2) maintaining widely avoiding all these combinations. On hand, rejection proposal coherent cases homonyms (proposals Nos. 477, Abedinium against Leptophyllus; 493, Dogelodinium Collinella; 497, Gyrodinium Spirodinium; 502, Keppenodinium Hollandella; 503, Heteroschisma; 513, Sphaeripara Lohmannia – Wiersema App. I–VII. 2018–, https://naturalhistory2.si.edu/botany/codes-proposals/ [accessed 19 Jul 2021]), avoids having two organisms same (e.g., bibliographical search entries trilobites dinoflagellate). FG, https://orcid.org/0000-0002-5886-3488 I like thank Prof. John McNeill his constructive comments. Open Access Funding provided Universita del Salento within CRUI-CARE Agreement.