Gephyrotes moissettei, Martino, Emanuela Di & Rosso, Antonietta, 2015

Martino, Emanuela Di & Rosso, Antonietta, 2015, Revision of the bryozoan genus Gephyrotes Norman, 1903 (Cheilostomata, Cribrilinidae) with the description of two new taxa, Zootaxa 3941 (2), pp. 261-283 : 267-270

publication ID

https://doi.org/ 10.11646/zootaxa.3941.2.7

publication LSID

lsid:zoobank.org:pub:9FC33747-4C50-4D56-81D1-69B9930698B7

DOI

https://doi.org/10.5281/zenodo.6101460

persistent identifier

https://treatment.plazi.org/id/D379EF57-FF96-FFE4-FAB5-FD51FE6F30EF

treatment provided by

Plazi

scientific name

Gephyrotes moissettei
status

sp. nov.

Gephyrotes moissettei View in CoL n. sp.

( Figs 13–22 View FIGURES 13 – 17 View FIGURES 18 – 22 , 26; Table 3 View TABLE 3 )

Gephyrotes View in CoL sp. Moissette 1988: 112, pl. 18, figs 8, 11.

Gephyrotes cf. fortunensis Zágoršek 2010: 140 View in CoL View Cited Treatment , pl. 71, figs 1–3.

Material examined. Holotype: PMC.B18.6.9.2006a late Tortonian, Calabria, Italy. Paratype: PMC.B18.6.9.2006b, same details as holotype; FSL 119799 late Tortonian, Fortuna (Murcie, Spain).

Etymology. Named after Dr Pierre Moissette (Université Claude Bernard, Lyon) for his contribution to the knowledge of Miocene bryozoans.

Description. Colony encrusting unilaminar, multiserial ( Figs 13 View FIGURES 13 – 17 , 18 View FIGURES 18 – 22 ). Ancestrula tatiform. Periancestrular zooids similar to later autozooids but smaller ( Fig. 18 View FIGURES 18 – 22 ). Autozooids distinct, with deep interzooidal furrows, arranged quincuncially, oval to irregularly polygonal, almost twice as long as wide (mean L/W = 1.92). Gymnocyst smooth, forming steeply inclined marginal portions of frontal shield ( Fig. 20 View FIGURES 18 – 22 ), usually narrow laterally, more extensive proximally, often hidden in frontal view by adjacent zooids ( Figs 14 View FIGURES 13 – 17 , 18–19, 22 View FIGURES 18 – 22 ). Frontal shield moderately convex, formed by 11–15 costae, more often 13, not including the 2 distalmost pairs participating in the proximal peristomial rim. Costae 30–50 µm broad, separated by 3 large subquadrangular intercostal pores, except for proximalmost pairs in which only 1–2 pores are present. Costal fusion evident, marked by thin slits along entire costal length, enlarged in places, probably corresponding to original position of pelmatidia. Proximal peristomial rim formed by conjunction of two pairs of raised costae, one pair originating from bifurcation of those most proximal to orifice and projecting upwards, the second pair originating lateral to orifice as continuations of avicularian rostra, if present ( Figs 17 View FIGURES 13 – 17 , 19, 22 View FIGURES 18 – 22 ); this collar-like rim with semicircular intercostal lacuna centrally that is smaller than the two elliptical lateral lacunae ( Figs 14–15 View FIGURES 13 – 17 , 22 View FIGURES 18 – 22 ). Primary orifice broader than long, semicircular with straight or slightly concave proximal margin ( Fig. 16 View FIGURES 13 – 17 ); secondary orifice subcircular, bean-shaped in zooids with ooecia. Oral spines absent. Ooecium prominent, subglobular, wider than long, with less-calcified irregularly shaped patches ( Figs 19, 22 View FIGURES 18 – 22 ), becoming deeply immersed in distal zooid in late ontogeny by encroaching secondary calcification ( Fig. 15 View FIGURES 13 – 17 ). Adventitious avicularia large, usually paired, lateral to orifice, proximomedially directed, sickle-shaped, slender if associated with ordinary autozooids ( Fig. 14 View FIGURES 13 – 17 ), squatter if associated with ooecia ( Fig. 15 View FIGURES 13 – 17 ); sometimes absent in autozooids. Pivot bar complete ( Figs 20, 22 View FIGURES 18 – 22 ) but rarely preserved. Small irregularly shaped or tubular hollow structures, interpreted as kenozooids, frequent along zooidal margins, more often placed lateral and distal to orifice ( Figs 14 View FIGURES 13 – 17 , 19 View FIGURES 18 – 22 ). Uniporous mural septula in inner vertical walls ( Fig. 21 View FIGURES 18 – 22 ).

Remarks. Within-colony variability is mostly related to zooid size and shape, with some of the zooids distinctly shorter than average ( Figs 13 View FIGURES 13 – 17 , 18 View FIGURES 18 – 22 ). The lace-like appearance of the frontal shield renders G. moissettei n. sp. similar to G. spectabilis (see below) but readily distinguishable from other species of the genus. Gephyrotes moissettei differs from the other Mediterranean species, G. f o r t u n e n s i s Pouyet, 2000 in having more numerous costae, a less extensive gymnocyst and much larger intercostal pores. Further differences are related to the collarlike peristomial complex, which exhibits three transversally aligned intercostal lacunae, with the central one smaller in G. moissettei but more proximal and larger than the two lateral lacunae in G. fortunensis , as figured by N, Number of colonies and number of zooids measured; SD, standard deviation.

Berning (2006, figs 48–49). As mentioned above, we disagree with the original description of G. fortunensis regarding the presence of distally directed avicularia, oral spines, and an ooecium characterized by a median ridge and two fenestrae. Specimens assigned to Gephyrotes sp. by Moissette (1988, pl. 18, figs 8, 11), catalogue numbers FSL119779 and FSL119849, are here synonymized with G. moissettei , as well as with G. cf. fortunensis , specimen P01606, of Zágoršek (2010). Berning (2006, p. 54) already highlighted the differences between Moissette's specimens and typical G. fortunensis . The ancestrula has not been figured, having been accidentally detached during preparation of the specimen for SEM.

Distribution. Langhian of the Czech Republic; late Tortonian of Calabria, southern Italy, and SE Spain; Messinian of Algeria ( Fig. 1 View FIGURE 1 ).

TABLE 3. Measurements (in Μm) of Gephyrotes moissettei n. sp., holotype, PMC. B 18.6.9.2006 a.

  N (colonies, zooids) Mean SD Range
Zooid length 1, 15 760 68 737–866
Zooid width 1, 15 411 79 364–502
Orifice length 1, 10 126 4 122–130
Orifice width 1, 10 191 19 171–209
Ovicell length 1, 6 267 10 260–274
Ovicell width 1, 6 321 24 304–339
Avicularia length 1, 10 190 9 182–202
Avicularia width 1, 10 83 7 73–89
FSL

Collections de la Faculte des Sciences de Lyon

Kingdom

Animalia

Phylum

Bryozoa

Class

Gymnolaemata

Order

Cheilostomatida

Family

Cribrilinidae

Genus

Gephyrotes

Loc

Gephyrotes moissettei

Martino, Emanuela Di & Rosso, Antonietta 2015
2015
Loc

Gephyrotes cf. fortunensis Zágoršek 2010 : 140

Zagorsek 2010: 140
2010
Loc

Gephyrotes

Moissette 1988: 112
1988
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