Page 3 - Rosso_et_al.2010.Bertorsonidra

Bertorsonidra n. gen. (Bryozoa, Cheilostomata) a new genus for Tremopora prenanti Gautier, 1955
localities, all from Sicily (Fig. 1). Two specimens,
from lower Pleistocene sediments, were found at
Pianometa (central-eastern Sicily) and Case Catarinic-
chia (western Sicily) sections, which are described in
Pedley et al. (2001) and Di Geronimo et al. (1994),
respectively. A further specimen originates from
Plio-Pleistocene layers cropping out in the Barcellona-
Pozzo di Gotto Basin, in north-eastern Sicily (Messina
2003). The few available living specimens come from
two sampling stations in the Egadi Archipelago, off
western Sicily. The material was collected within a
CoNISMa project for the assessement of habitat and
species biodiversity in four Italian Marine Protected
Areas (4AMP) in October 2007.
Measurements (in μm) were taken with a Zeiss
Stereodiscovery V8 system equipped with Axiocam
MRC and Axiovision acquisition system. The cleaned
but uncoated material was examined in low vacuum
conditions with a Tescan Vega 2 LMU Scanning
Electron Microscope (SEM).
Type material is housed at the Muséum national
d’Histoire naturelle, Paris (MNHN), whereas newly
collected specimens of the same species are stored at
the Paleontological Museum of Catania University
(PMC). Further examined material is in the Natural
History Museum, London (BMNH).
Bryozoan systematics follows d’Hondt (2001)
partly revised after the working classification proposed
by D. P. Gordon (pers. comm. 2007) for the eventual
use in the Treatise of Invertebrate Paleontology.
SYSTEMATICS
Suborder ASCOPHORINA Levinsen, 1909 Bertorsonidra prenanti (Gautier, 1955) n. comb.
Infraorder LEPRALIOMORPHA Gordon, 1989
Family ROBERTSONIDRIDAE Rosso, n. fam.
DIAGNOSIS. — As for the genus (see below), but frontal
wall including a pseudoporous or a centrally imperforate ?Zabala 1986: 438. — ?Zabala & Maluquer 1988:
area, besides the row of marginal areolae.
Genus Bertorsonidra Rosso, n. gen.
DIAGNOSIS. — Colony encrusting attached to the
substratum through pillar-like structures emanating
from the basal surface. Autozooids loosely arranged and
ZOOSYSTEMA • 2010 • 32 (3)
20°W 0 20 40°E
35°N Mediterranean Sea
FIG. 1. — Geographical distribution of Bertorsonidra prenanti (Gautier,
1955) n. comb.: Þ, living populations; ¹, fossil populations.
leaving interzooidal spaces. Frontal wall pseudoporous
bordered by marginal pores. Orifice semicircular with
a proximal sinus and lateral condyles. Peristome incon-
spicuous. Spines present, not articulated at the base, two
persisting in ovicellate zooids. Suboral umbo sporadic
but characteristic. Avicularia present, typically single,
lateral-suboral on an inflated cystid. Ovicell prominent
with uncalcified ectooecium and a granular, evenly
pseudoporous entooecium. Interzooidal communication
through uniporous septulae arranged in a band in the
vertical walls.
TYPE SPECIES. — Tremopora prenanti Gautier, 1955 by
present designation.
ETYMOLOGY. — The name is an anagram of Robertsonidra,
a closely related genus.
(Figs 2; 3; 4A)
Tremopora prenanti Gautier, 1955: 236, pl.1, figs 6-8.
Rhamphostomella argentea – Gautier 1962: 160. —
124, fig. 275.
Non Schizoporella argentea Hincks, 1881: 158, pl. 9,
fig. 6a, b.
Non Robertsonidra argentea – Ryland & Hayward 1992:
261, fig. 19b. — Tilbrook 2006: 261, pl. 57E, F.
Hippoporina sp. – Di Geronimo et al. 1994: 102, part.
459