Fedora nodosa Silén, 1947a
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publication ID |
https://doi.org/ 10.11646/zootaxa.5379.1.1 |
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publication LSID |
lsid:zoobank.org:pub:430102D2-4EAA-41B3-B57F-CC532F929DA3 |
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DOI |
https://doi.org/10.5281/zenodo.10248955 |
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persistent identifier |
https://treatment.plazi.org/id/4B6E902E-FFF0-FFC8-FF46-F94E1D8FF9AA |
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treatment provided by |
Plazi |
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scientific name |
Fedora nodosa Silén, 1947a |
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Fedora nodosa Silén, 1947a View in CoL
( Fig. 50 View FIGURE 50 ; Table 44)
Material examined. Lectotype (designated here) SMNH-Type-8735a ( Fig. 50A, B View FIGURE 50 ; specimen figured in Silén 1947a, pl. 4, fig. 22) North Atlantic , Gulf of Mexico, Fort Pickens, Florida, United States; depth 415 m. Leg. Albatross 1885, Station 2398 . Paralectotypes SMNH-Type-8735b ( Fig. 50C–E View FIGURE 50 ), SMNH-Type-8735c ( Fig. 50F, G View FIGURE 50 ), SMNH-Type-8735d ( Fig. 50H, I View FIGURE 50 ), and SMNH-Type-8735e (not figured), same details as lectotype.
Other species material for comparison: Fedora edwardsi Jullien, 1882 ( Fig. 51 View FIGURE 51 , Table 45), North Atlantic Ocean, Josephine Bank, off Portugal, 38°7'N, 9°18'W, depth 1001 m, leg. Josephine Expedition 1869: SMNH-127677, three colonies ( Fig. 51H, I View FIGURE 51 ); SMNH-128029, five colonies ( Fig. 51E–G View FIGURE 51 ); SMNH-128030, 2 colonies ( Fig. 51A–D View FIGURE 51 ).
Fedora ovum ( Smitt, 1873) ( Fig. 52 View FIGURE 52 , Table 46). Lectotype (designated here) SMNH-Type-1799a ( Fig. 52H, I View FIGURE 52 ), North Atlantic Ocean , off Tennessee Reef, Florida, United States, depth 209 m. Leg. Gulf Stream Explorations 1868–69, L.F. Pourtales 1869 . Paralectotypes SMNH-Type-1799b ( Fig. 52A, B View FIGURE 52 ), SMNH-Type-1799c ( Fig. 52C–E View FIGURE 52 ), SMNH-Type-1799d ( Fig. 52F View FIGURE 52 ), SMNH-Type-1799e ( Fig. 52G View FIGURE 52 ), same details as lectotype. Paralectotype SMNHType-9106, one colony (not figured), off the Pacific Reef , depth 426 m.
Description. Colony ovoidal, 2.44–2.66 mm long by 2.05 mm wide (L/ W 1.29 –1.19, N 2) ( Fig. 50A, C View FIGURE 50 ); apical area occupied by ancestrular complex consisting of six radially arranged autozooids, similar in appearance (including the presence of an adventitious avicularium) and slender than later autozooids (mean L/ W 1.37) ( Fig. 50F, G View FIGURE 50 ); antapical area occupied by polygonal kenozooids and avicularia ( Fig. 50H, I View FIGURE 50 ).
Autozooids arranged in seven alternating whorls of 6–14 zooids each (the highest number of zooids at about colony mid-length), distinct with narrow grooves and a thin rim of smooth calcification when not obliterated by secondary calcification, hexagonal, almost equidimensional (mean L/ W 1.06); a basal pore chamber, rounded triangular, subelliptical or subcircular, 165–230 µm long by 135–180 µm wide, visible distal to each autozooid ( Fig. 50I View FIGURE 50 , some arrowed).
Frontal shield imperforate and coarsely tubercular ( Fig. 50B, D, E View FIGURE 50 ); an elliptical marginal areolar pore, 35–40 µm long by 25–45 µm wide, sometimes visible at the proximal zooidal corner and/or at the lateral corner ( Fig. 50D, E View FIGURE 50 ).
Primary orifice cleithridiate, longer than wide (mean L/ W 1.24), a horseshoe-shaped anter separated from a bowl-shaped sinus by two robust rounded condyles proximomedially directed ( Fig. 50D, E View FIGURE 50 ); oral spines absent also in early ontogeny. Closure plates tubercular as the frontal shield observed sealing the orifice up to the third generation of autozooids ( Fig. 50B, G View FIGURE 50 ). Intramural budding observed in autozooids, visible as a series of concentric orificial rims ( Fig. 50D, E View FIGURE 50 ).
Adventitious avicularia infrequent, present as early as the first generation of autozooids ( Fig. 50G View FIGURE 50 ), single, placed laterally to the orifice at the same level as the condyles ( Fig. 50B View FIGURE 50 ) or more distally ( Fig. 50D View FIGURE 50 ), subcircular (mean L/ W 0.85), rostrum rounded, directed laterally or distolaterally, with complete crossbar ( Fig. 50D View FIGURE 50 ); mandible semicircular ( Fig. 50I View FIGURE 50 ). Interzooidal avicularia occupying the antapical area, similar in shape to adventitious avicularia, located centrally on a rectangular or irregularly polygonal cystid, 320–330 µm long by 285–310 µm wide, with the surface tubercular as the zooidal frontal shield, rostrum directed distally ( Fig. 50H, I View FIGURE 50 ).
Kenozooids also present in the antapical area ( Fig. 50H, I View FIGURE 50 ), rectangular or irregularly polygonal, 250–430 µm long by 175–270 µm wide, tubercular as autoozooids, either without openings or with central 8-shaped or elliptical opening, 100–110 µm long by 70–95 µm wide.
Ovicells not observed, likely absent.
Remarks. Silén’s (1947a) original material of Fedora nodosa consisted of 13 colonies. Unfortunately, only five were available in the type series studied here, including the colony figured by Silén (1947a, pl. 4, fig. 22) and here designated as the lectotype. The information on the type locality and legacy reported on the specimen label is consistent with that in the publication, except for the depth which is slightly deeper (i.e. 415 m versus 340 m).
The striated, chitinous tube observed in two of the colonies ( Fig. 50A, C View FIGURE 50 ) was originally interpreted by Silén (1947a) as a kenozooidal attachment rootlet. However, upon closer examination of its peculiar morphology, exhibiting a narrow base of attachment to the colony (c. 130 µm) that widens towards the outer tip (c. 300 µm), the alternative interpretation of it as the polypide tube of a coronate scyphozoan seems to be equally plausible. While the original interpretation of the tube as a kenozooidal rootlet is supported by its presence in the exact same position in which the bryozoan rhizoid would be expected to emanate as well as by the absence of any other structures that could explain how the colony is actually attached to the substrate, the lack of evident scars from the ‘rootlet’ at its attachment point supports its alternative interpretation as a scyphozoan tube.
Eleven species are currently assigned to Fedora . Seven species are fossil: five are from the Eocene (Lutetian or Priabonian) of Europe ( France, Germany and Italy), one is from the Oligocene (Rupelian) of Mississippi ( USA), and one from the Miocene of Austria. Four species, including F. nodosa , are Recent, all found in North Atlantic waters, except for Fedora platydiscus Gordon & d’Hondt, 1997 , which was described from Mindoro Strait in the Philippines at 92–97 m depth. However, Gordon & d’Hondt (1997) were uncertain about the generic placement of the species given its flat discoidal colony form and the complete absence of avicularia, and forewarned the necessity to introduce a new genus, an action they did not undertake because only a single, infertile specimen was available.
Fedora nodosa is very similar in appearance to the type species of the genus, F. edwardsi (see Fig. 51 View FIGURE 51 ), sharing all diagnostic features of the genus such as the autozooid distobasal pore chamber, the inconstant adventitious avicularia adjacent to the orifice, the cleithridiate shape of the orifice, the tubercular frontal shield, and the absence of ovicells. They can be distinguished based on the colony form, shape of condyles and type of frontal tuberculation. Fedora edwardsi has more cylindrical to pear-shaped colonies, with the highest number of zooids in a whorl usually located in the proximal third of the colony ( Fig. 51A, C View FIGURE 51 ), pointed orificial condyles ( Fig. 51D View FIGURE 51 ), and a finer and more prickly frontal tuberculation ( Fig. 51B, D, I View FIGURE 51 ). The apical area is occupied by the ancestrular complex consisting of four radially arranged autozooids, with opposite pairs similar in size (365–375 × 300–330 µm versus 470–490 × 385–420 µm) ( Fig. 51E, G, H View FIGURE 51 ).
Fedora ovum ( Fig. 52 View FIGURE 52 ) was originally assigned to Myriozoum by Smitt (1873) based on some similarities with Myriapora truncata ( Pallas, 1766) and species of Leieschara , and re-assigned to Fedora by Silén (1947a). In this species, however, autozooids lack a distobasal pore chamber, avicularia with condyles (incomplete crossbars) are numerous and placed along autozooidal boundaries (e.g. Fig. 52A, C, F–H View FIGURE 52 ), the orifice although cleithridiate is cormidial and formed by both the zooid it belongs to and the distal zooid ( Fig. 52B, E View FIGURE 52 ), the frontal is pitted, and large ovicells, occupying the entire length of the frontal shield of the distal zooid, are present ( Fig. 52A, F, H, I View FIGURE 52 ). All these features were observed in the genus Sphaerulobryozoon d’Hondt, 1981 , which appears as a better fit for F. ovum . The new combination Sphaerulobryozoon ovum ( Smitt, 1873) is therefore suggested. Silén (1947a) acknowledged the absence of the distobasal pore chamber in S. ovum n. comb., and justified the re-assignment of the species to Fedora , interpreting the avicularia as special lateral chambers homologous with the distobasal chamber of F. edwardsi and F. nodosa . In his diagnosis of the genus Sphaerulobryozoon , with type species S. pedunculatum from bathyal western Atlantic waters, d’Hondt (1981) described two types of zooids with opercula, i.e. normally functioning autozooids (“autozoécies”) and microzooids (“microzoécies”). The microzooids(e.g. Fig. 52B, E View FIGURE 52 ) are here re-interpreted as interzoooidal avicularia with condyles and semicircular mandibles (see d’Hondt 1981, pl. 7, fig. 3).
The type specimens of Paleogene and Neogene species attributed to Fedora also need to be revised.Unfortunately, in most cases the quality of the illustrations and/or images available from the original publications prevent any meaningful re-interpretation.
No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.