UUID: http://zoobank.org/84e649ca-bbcf-4c7a-a77d-0bc7579ec402
According to the International Code of Zoological Nomenclature (ICZN, 1999), the Principle of Homonymy (Article 52) states that when two or more taxa are distinguished from each other, they must not be denoted by the same name because this would cause confusion. Consequently, in a case of homonymy, only the senior name may be used as valid (Art. 52.2). The ICZN (1999) also indicates that if the rejected junior homonym has no known available and potentially valid synonym, it must be replaced by a new substitute name (Art. 60.3), that is, a replacement name.
Among stony corals of the order Scleractinia, homonyms are not common. This is perhaps why there has been some confusion in coral taxonomy regarding the application of replacement names. These replacement names often refer to species that were previously misidentified in the literature but are, in fact, new species (Hoeksema, Reference Hoeksema1993). An example of a nomen novum concerns the replacement name Fungia curvata Hoeksema, Reference Hoeksema1989 for the extant mushroom coral Fungia elegans Verrill, Reference Verrill1870 (now Cycloseris curvata) from the Indo-Pacific (Hoeksema, Reference Hoeksema1989; Gittenberger et al., Reference Gittenberger, Reijnen and Hoeksema2011), junior homonym of the extinct Fungia elegans Bronn, Reference Bronn1837 (now Stephanophyllia elegans), from the Pliocene of Italy (Bronn, Reference Bronn1837; Michelin, Reference Michelin1841). The fact that both species were originally described in the genus Fungia Lamarck, Reference Lamarck1801 (family Fungiidae) and later were moved to other genera in different families, thus forming new combination names, does not prevent them from being considered homonyms with the junior in need of replacement. Considering the rarity of documented homonyms in the taxonomy of Scleractinia, we here present a unique case involving both homonymy and triple homonymy among extinct species of a genus of deep-water corals.
The genus Flabellum Lesson, Reference Lesson1831 (Cnidaria, Anthozoa, Hexacorallia, Scleractinia, Flabellidae) comprises more than 160 distinctive extinct and recent azooxanthellate, deep-water corals (Cairns, Reference Cairns1995, Reference Cairns1999; Uhen et al., Reference Uhen, Allen, Behboudi, Clapham and Dunne2023; GBIF, 2024; Hoeksema and Cairns, Reference Hoeksema and Cairns2024a). Its name in Latin, meaning “fan,” is derived from the flabellate shape of the corallum. A study of a putative new species of fossil corals from Chile (submitted elsewhere) has revealed previously overlooked or unresolved cases of homonymy within this genus. Three of these cases involve species names of Chilean fossils that were preoccupied by extinct species of this genus from Europe, for which three replacement names are proposed in accordance with the ICZN (1999). In addition, another case of homonymy involves one species from the United States and another one from Europe, for which a replacement name is proposed (Table 1). All cases relate to primary homonymy.
Table 1. Summary of species found in homonymy and their proposed replacement names, with complementary information, including species samples
a Samples.
b Two syntypes figured in the original description (Gabb, Reference Gabb1860).
c Two syntypes (Richards, Reference Richards1968).
d Samples deposited in 1980 (unpublished).
Systematic paleontology
Class Anthozoa Ehrenberg, Reference Ehrenberg1834
Order Scleractinia Bourne, Reference Bourne and Lankester1900
Family Flabellidae Bourne, Reference Bourne1905
Genus Flabellum Lesson, Reference Lesson1831
Type species
Flabellum pavoninum Lesson, Reference Lesson1831.
Flabellum philippii nom. nov.
Reference Philippi1887 Flabellum costatum Philippi, p. 226, pl. 53, fig. 5. nom. preocc. (not Flabellum costatum Michelin, Reference Michelin1846 in Michelin (Reference Michelin1840–1848), p. 271, pl. 61, fig. 10. No synonym was found to be available as a possible replacement name.
Type material
The name-bearing type is the specimen described and illustrated by Philippi (Reference Philippi1887) (Art. 72.5.6).
Etymology
The species is named after the German naturalist Rodulfo Amando Philippi, the author of the original species name.
Remarks
Flabellum costatum Michelin, Reference Michelin1846 was originally described as a fossil coral specimen from the Eocene of “du Jarrier” and “de la Palarea,” France, which was deposited in the collections of Bellardi, Caillaud, Michelin, Perez, and Vandenhecke as noted by Michelin (Reference Michelin1840–1848). The specimen was originally referred to as “Flabellum costatum Bellardi” (Michelin, Reference Michelin1846, p. 271, pl. 61; Milne Edwards and Haime, Reference Milne Edwards and Haime1848, p. 266; Haime, Reference Haime1852, p. 282; Milne Edwards and Haime, Reference Milne Edwards and Haime1857, p. 83), taking the name from Bellardi’s unpublished manuscript notes. According to Michelin (Reference Michelin1846, p. 271), the species “forms an intermediary between F. appendiculatum and F. avicula” and “except for its folds, it also resembles F. cuneatum,” referring to Flabellum appendiculatum (Brongniart, Reference Brongniart1823), Flabellum avicula (Michelotti, Reference Michelotti1838), and Flabellum cuneatum (Goldfuss, Reference Goldfuss1826). Subsequently, Milne Edwards and Haime (Reference Milne Edwards and Haime1848, Reference Milne Edwards and Haime1857) and Haime (Reference Haime1852) recorded “Flabellum costatum Bellardi” from “La Palarea,” which was also found in the Eocene “Subapennine” formation by von Leonhard and Bronn (Reference von Leonhard and Bronn1856). The species has also been recorded in Italy (Piedmont, Alessandria) (Morris, Reference Morris2025).
Outside of Europe, a preserved specimen of this coral was documented in Navidad, central Chile, in the GBIF database (https://www.gbif.org/) by Dr. Stephen D. Cairns (Orrell, Reference Orrell2025). In the species data of this website, Flabellum costatum Philippi, Reference Philippi1887 is qualified as an “Excluded” scientific name. Flabellum costatum Philippi, Reference Philippi1887 was originally described from Miocene Tertiary terrains in Levu (a misspelling of Lebu), south-central Chile. The main characteristics of the species include a coined polyp with a length of 23 mm, a width of 27 mm, and a thickness of 15 mm, which is elliptical in cross section and features slightly ridged ribs on the outside that regularly alternate between larger and smaller ribs with a smooth space between them. In the original description, Philippi did not mention the fate of the type specimens or samples of the species. In later literature, the species was recorded by Tavera (Reference Tavera1942, p. 106) from the Eocene fauna of the Arauco Formation, also in southern Chile. The same author, as Tavera Jerez (Reference Tavera Jerez1979, p. 15, 40, 75, 98, 106, 148, 149), again recorded the species from the Eocene–Miocene terrains of Navidad, although he suggested that these samples could correspond to “Lythomices costellatus Phil.” Subsequently, Flabellum costatum Philippi, Reference Philippi1887 was also recorded in Miocene terrains of Navidad by Frassinetti and Covacevich (Reference Frassinetti and Covacevich1982, p. 108). Covacevich and Frassinetti (unpublished) deposited samples of the species from Punta Alta de Navidad in 1980 at the Museo Nacional de Historia Natural, Santiago, Chile (MNHNCL). More recently, Volosky Medina (Reference Volosky Medina2021, p. 78) synonymized Flabellum costatum Philippi, Reference Philippi1887 with Flabellum costellatus (Philippi, Reference Philippi1887), originally described as Lithomyces costellatus Philippi, Reference Philippi1887 and currently accepted as Flabellum (Flabellum) costellatum (Philippi, Reference Philippi1887). In this context, we do not agree with this synonymy, considering that the descriptions and illustrations of both species are quite distinct (see Philippi, Reference Philippi1887; Volosky Medina, Reference Volosky Medina2021). Thus, we consider Flabellum costatum Philippi, Reference Philippi1887 as a valid taxon.
After establishing that the species described by Michelin, the senior homonym, has been employed as a valid name post-1899 (Art. 23.9.1.1), and confirming that Philippi’s name, the junior homonym, is valid and has been cited in fewer than 25 works (Art. 23.9.1.1), the next step is to ascertain whether they denote distinct entities (thus homonymous) or refer to the same species, with Flabellum costatum Philippi, Reference Philippi1887 as junior synonym. In the original description of this species (in Spanish and in German), the author described this coral on the basis of an incomplete specimen illustrated in calicular and lateral view. The fossil was characterized as cuneiform in shape, elliptical (in cross section), and showing 19 ribs, somewhat keeled, alternating between major and minor in a regular pattern, with smooth spaces between them. The cuneiform shape is consistent with the external appearance described (in French) by Michelin (Reference Michelin1846) for his Flabellum costatum. However, Michelin also described the polyp with an ovate–oblong star, having longitudinal lines, rounded, interrupted, raised on both sides; few and unequal lobes; and edges with appendages. The slightly keeled ribs differentiate Philippi’s species from Michelin’s species, in addition to the fact that the former lacks appendages on the edges. Furthermore, the species were found on different continents.
Flabellum taveri nom. nov.
Reference Tavera Jerez1979 Flabellum solidum Tavera Jerez, p. 15, 54, 75, 98 (description), 108, 139, 144, 147, 165, pl. 21, fig. 86. nom. preocc. (not Flabellum solidum Seguenza, Reference Seguenza1864, p. 484, 557, pl. 10, fig. 6). No synonym was found to be available as a possible replacement name.
Type material
The name-bearing type is the specimen described and illustrated by Tavera Jerez (Reference Tavera Jerez1979) (Art. 72.5.6).
Etymology
The species is named in honor of the pioneering Chilean paleontologist Juan Tavera Jerez.
Remarks
Flabellum solidum Seguenza, Reference Seguenza1864 was originally described as a fossil from Miocene marls of Rometta, Italy, on the basis of an incomplete specimen, well illustrated, deposited in the author’s collection. In the original description, Seguenza (Reference Seguenza1864) noticed some resemblance with Flabellum messanense Seguenza, Reference Seguenza1864, described in the same work, and therefore he did not establish Flabellum solidum without any doubt. However, in a subsequent work, alluding to another Italian species of the genus, Seguenza (Reference Seguenza1875, p. 29) explicitly recognized the species as valid. Thus, although in the World List of Scleractinia of the World Register of Marine Species (WoRMS) database the species is currently listed as a taxon inquirendum (Hoeksema and Cairns, Reference Hoeksema and Cairns2024b), we consider the species as valid.
Flabellum solidum Tavera Jerez, Reference Tavera Jerez1979 was originally described as a fossil from lower Miocene terrains of Navidad, central Chile. The main characteristics of the polyp include a length of 38.5 mm, a maximum diameter of 11 mm, and a thickness of 10 mm, soft and irregularly spaced transverse wrinkles on the surface, a tectura with fine, low-relief crest, along with other finer ones, and about 23 first-order septa plus one interstitial. Although the species has not been subsequently cited, Tavera Jerez (Reference Tavera Jerez1979, p. 54) noted in the original description (in Spanish) that this coral was “frequent and characteristic,” collecting several specimens at different sites along a 35 to 40 km coastline. Considering its presence on a different continent, its “abundance” and the observable characteristics in two well-photographed specimens of the species, we conclude that Flabellum solidum Tavera Jerez, Reference Tavera Jerez1979 is distinct from Flabellum solidum Seguenza, Reference Seguenza1864.
Flabellum rachelis nom. nov.
Reference Gabb1860 Flabellum striatum Gabb and Horn in Gabb, p. 399, pl. 69, figs. 10, 11. nom. preocc. (not Flabellum striatum Keferstein, Reference Keferstein1859, p. 362, pl. 14, fig. 4). No synonym was found to be available as a possible replacement name.
Type material
Syntypes, Academy of Natural Sciences of Philadelphia (ANSP).
Etymology
The species is named in honor of the American marine biologist and conservationist Rachel Carson.
Remarks
Flabellum striatum Keferstein, Reference Keferstein1859 was originally described as a fossil of an extinct species from the upper Oligocene of Crefeld and Neuss, Germany. The main characteristics of the species include a nearly conical polyp with an angle at the tip of 75–80°, elliptical in shape, with an axial ratio of 100:210 and a rough tectura. The septa are organized into six non-uniform systems, with a total of 24 septa (1, 2, 3 cycles) extending to the spiral formed by their thickened edges, in addition to 24 septa of the fourth cycle, which are approximately one-third wider, and a fifth cycle of septa in all chambers that are very fine and narrow. The largest individual from the original description has a calyx length of 12 mm and a height of 13 mm. In his paper, Keferstein (Reference Keferstein1859) did not mention the fate of the type specimens or samples of the species. Shortly after, it was recognized and illustrated by Roemer (Reference Roemer1863, p. 40). De Gruyter (Reference De Gruyter1944) subsequently reported the species from the late Oligocene terrains of the Netherlands. The species has also been recorded in limestones of southwestern France (Chaix et al., Reference Chaix, Cahuzac and Cluzaud1999; Chaix and Cahuzac, Reference Chaix and Cahuzac2001) and clayey–sandy strata of the Langhian (middle Miocene) of Lăpugiu de Sus site (southwest Romania) (Chaix et al., Reference Chaix, Saint Martin, Merle, Saint Martin and Caze2018). Concerning websites, Flabellum striatum Keferstein, Reference Keferstein1859 is currently recognized as valid in the World List of Scleractinia of the WoRMS database (Hoeksema and Cairns, Reference Hoeksema and Cairns2024c), Mineralienatlas - Fossilienatlas database (https://www.mineralienatlas.de), and Paleobiology Database (Uhen et al., Reference Uhen, Allen, Behboudi, Clapham and Dunne2023). In appearance, the species resembles Flabellum thouarsii Milne Edwards and Haime, Reference Milne Edwards and Haime1848 (Keferstein, Reference Keferstein1859).
Flabellum striatum Gabb and Horn in Gabb, Reference Gabb1860 was originally described as a fossil species from the Rotten limestone of the Cretaceous Period in Prairie Bluff, Alabama, USA, using two specimens figured by Gabb and Horn, which are deposited in the ANSP. The species was described as thick wedge-shaped, with acute angles, thin laminae, finely crenate slightly undulating edges, coarsely granulous sides, regular striations, and granules finer toward the edge. After the first description, the species was recorded by Vaughan (Reference Vaughan1900, p. 196), who wrote “The figures given by Gabb are worthless and the description is entirely insufficient for specific identification. The types sent to me from the Academy of Natural Sciences of Philadelphia are only internal casts, and are not sufficient for specific characterization, so the species lapses.” Nevertheless, the species was recognized shortly after by Johnson (Reference Johnson1905) after reviewing the material deposited in the ANSP, later cited by Richards (Reference Richards1968) as cotypes, validating the species. More recently, Groves and Squires (Reference Groves and Squires2018) cited the species and recognized it as a junior homonym of Flabellum striatum Keferstein, Reference Keferstein1859, which was not further resolved. Flabellum striatum Gabb and Horn in Gabb, Reference Gabb1860 is also cited in the GBIF (2023) and WoRMS databases (Hoeksema and Cairns, Reference Hoeksema and Cairns2024d). Considering the various citations, we conclude that this species is not a nomen dubium.
Flabellum pirii nom. nov.
Reference Philippi1887 Flabellum striatum Philippi, p. 226, pl. 53, fig. 6. nom. preocc. (not Flabellum striatum Keferstein, Reference Keferstein1859, pl. 14, fig. 4). No synonym was found to be available as a possible replacement name.
Type material
The name-bearing type is the specimen described and illustrated by Philippi (Reference Philippi1887) (Art. 72.5.6).
Etymology
The species is named after the Ottoman cartographer Piri Reis.
Remarks
Flabellum striatum Philippi, Reference Philippi1887 was originally described from Miocene Tertiary terrains of Levu (a misspelling of Lebu), south-central Chile, without reference to the type material. The main characteristics of the species include a coined polyp that is elliptical in cross section, densely and deeply striated, and slightly rough. It has thin lamellae extending from the center to the circumference, spaced 3 mm apart, and an exterior surface that is also deeply striated and rough. The height is approximately 23 mm, the width is approximately 25 mm, and the thickness is 16 mm. Tavera (Reference Tavera1942, p. 603, 605) recorded this species from the Tertiary of Arauco (Miocene), south-central Chile. Recently, it was also recorded by Volosky Medina (Reference Volosky Medina2021, p. 77), who deposited samples from the Ranquil Formation, south-central Chile, at the Museo de Historia Natural de Concepción (MHNC). Thus, we consider the species as valid.
Taking into account the original descriptions of Flabellum striatum by their authors, the differences observed in the drawings or photographs of the species, and the different continents or subcontinents where they were described (Keferstein, Reference Keferstein1859; Gabb and Horn in Gabb, Reference Gabb1860; Philippi, Reference Philippi1887; Chaix et al., Reference Chaix, Cahuzac and Cluzaud1999; Chaix and Cahuzac, Reference Chaix and Cahuzac2001; Volosky Medina, Reference Volosky Medina2021), we consider the three species named as Flabellum striatum to be distinct from each other. Thus, replacement names are justified.
Acknowledgments
We thank D. Volosky for valuable suggestions. We also thank those who assisted in locating type specimens: A. Martínez-Melo and J. Sessa, both from the ANSP, and I. Araya from the MNHNCL. We also thank the editor and two anonymous reviewers for their valuable comments on the original manuscript.
Competing interests
The authors declare that they have no competing interests.
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