Fungiacyathus deltoidophorus (Felix, 1909)

Baron-Szabo, Rosemarie C., 2008, Dendrophylliina, Caryophylliina, Fungiina, Microsolenina, and Stylinina, Zootaxa 1952, pp. 1-244 : 99-101

Fungiacyathus deltoidophorus (Felix, 1909)

Text-Fig. 20

?1902? Brachycyathus daniensis n. sp.: Wanner, p. 98, pl. 13, figs 10–10b.

*1909 Cycloseris deltoidophora nov. sp.: Felix, p. 4, pl. 1, figs 1–2.

1909 Cycloseris antarctica nov. sp.: Felix, p. 7, pl. 1, figs 3–4.

1909 Cycloseris larseni nov. sp.: Felix, p. 8, pl. 1, figs 5–6.

cf. v1945 Fungiacyathus sp. : Wells, p. 7, pl. 2, figs 7–8.

1949 Cycloseris antarctica Felix : Furque & Camacho, p. 276.

v1994 Fungiacyathus deltoidophorus (Felix, 1909) : Filkorn, p. 29, figs 6–9 (older synonyms cited therein) (topotypes studied).

v1994 Fungiacyathus larseni (Felix, 1909) : Filkorn, p. 34, figs 10–11.

v1994 Fungiacyathus antarcticus (Felix, 1909) : Filkorn, p. 37, fig. 12.

? 1996 Discocyathus daniensis (Wanner, 1902) : Schuster, Appendix list.

2000 Cycloseris antarctica, Felix 1909 : Löser, p. 27.

2000 Cycloseris deltoidophora, Felix 1909 : Löser, p. 27.

2000 Cycloseris larseni, Felix 1909 : Löser, p. 27.

2002 Fungiacyathus antarcticus (Felix, 1909) : Baron-Szabo, p. 98.

2002 Fungiacyathus deltoidophorus (Felix, 1909) : Baron-Szabo, p. 98.

2002 Fungiacyathus larseni (Felix, 1909) : Baron-Szabo, p. 98.

Dimensions. d= 4–26 mm; s=48–96.

Description. Solitary, cupolate, free; base of corallum flat or convex; septa correspond with costae; columella weakly developed.

Text-Fig. 20 Fungiacyathus deltoidophorus (Felix, 1909) , topotype, USNM 93024, Maastrichtian of Antarctic Peninsula, upper surface, oblique, scale bar: 2 mm (from Filkorn 1994, see full reference in Reference list; copyright 1994 by the American Geophysical Union; reproduced by permission of American Geophysical Union).

Remarks. Based on corallite diameter and number of septa, Felix (1909; see also Filkorn 1994) distinguished 3 different species: Fungiacyathus antarcticus (Felix, 1909) , F. deltoidophorus (Felix, 1909) , and F. larseni (Felix, 1909) : d= 4–14 mm and 48 septa in F. deltoidophorus , d = up to 14 mm and 48 septa in F. larseni , and d=up to 26 mm and 48–96 septa in F. antarcticus . The large overlap in the dimensions of the skeletal elements of F. deltoidophorus and F. larseni was previously pointed out by Filkorn (1994, p. 33–34). In addition to the dimensions of skeletal elements, Felix also included characteristics like the development of the bottom (flat or convex) and the length of the costae and relative size difference of the finely granulated central region of the aboral surface. All of these characters are interpreted as environmentally induced, and are therefore non-specific variations. Moreover, the form F. antarcticus appears to correspond to a later ontogenetical stage of F. larseni and F. deltoidophorus . Therefore, the three species are considered synonymous.

In having 48 septa in a corallite of around 8 mm in diameter, the specimen described from the Lower Eocene of Barbados by Wells (1945) fits well into the above proposed model and closely corresponds to the species F. deltoidophorus . However, because Wells’ specimen represents a fragment its assignment is provi- genus Brachycyathus is generally considered a junior synonym of Discocyathus (for generic characteristics see chapter on Discocyathus in this paper), Wanner’s species was transferred to the latter genus (e.g., Schuster 1996). However, in lacking pali before S3 the species B. daniensis differs from the genus Discocyathus , whereas the development of septa (compact septa that seem to be granulated to carinate laterally), the lack of endothecal structures, and the presence of a trabecular columella, supports the idea that the taxon B. daniensis belongs to the genus Fungiacyathus . In addition, Wanner’s species is characterized by 48 septa in corallite diameters ranging between 8–16 mm, thus closely agreeing with the species F. deltoidophorus . However, because of the problematic preservation and the fact that Wanner’s type material is lost and could therefore not be studied, its synonymy with the latter species is provisional.

Type location of species. Maastrichtian of Antarctic Peninsula .

Distribution. Campanian-Maastrichtian of Antarctic Peninsula (Seymour Island and Snow Hill Island),?Paleocene of Egypt, Middle Eocene of Barbados (Upper Scotland Formation).