Page 1 - Rosso_et_al.2010.Bertorsonidra

Bertorsonidra n. gen. (Bryozoa, Cheilostomata)
for Tremopora prenanti Gautier, 1955,
a rare species from the Mediterranean

Antonietta ROSSO
Francesco SCIUTO
Alessandro SINAGRA

Università degli Studi di Catania, Dipartimento di Scienze Geologiche,
Sezione di Oceanologia e Paleoecologia,
Corso Italia, 57, I-95129 Catania (Italy)
rosso@unict.it
fsciuto@unict.it

Rosso A., Sciuto F. & Sinagra A. 2010. — Bertorsonidra n. gen. (Bryozoa, Cheilostomata)
for Tremopora prenanti Gautier, 1955, a rare species from the Mediterranean. Zoosystema
32 (3) : 457-467.

KEY WORDS ABSTRACT
Bryozoa, The genus Bertorsonidra n. gen. is here proposed for Tremopora prenanti Gautier,
1955, a cheilostome bryozoan species from the Mediterranean area. The new
Cheilostomata, description and first SEM illustration is mostly based on living material col-
Recent, lected from infralittoral (17-19 m) bottoms off W Sicily and fossil specimens
from lower Pleistocene, and possibly Pliocene, associations from three different
Pliocene-Pleistocene, localities in Sicily. The genus and species are characterized by a pseudoporous
ecological distribution, lepraliomorph frontal shield bordered by marginal areolae, with a prominent
functional morphology, suboral umbo; a subcircular primary orifice with a shallow large sinus flanked
by condyles, usually protected by oral spines; a prominent ovicell with an
new family, entirely exposed calcified entooecium sculptured by tubercles and pseudopores;
new genus. a lateral suboral, hooked avicularium; and basal calcified pillar-like prominences
for adhering to the substratum. The affinities of the genus with Robertsonidra
Osburn, 1952, characterized by a frontal shield only perforated by peripheral
areolae, are discussed. The erection of the new family Robertsonidridae n. fam.
within the Lepraliomorpha is suggested for accommodating both Robertsonidra
and Bertorsonidra n. gen. Information is given about ecological requirements
of the species, persisting during time, and its morphological adaptation for
colonising algal substrata, which Bertorsonidra prenanti n. comb. shares with some
species of the genus Robertsonidra and other ones belonging to systematically
unrelated genera.

ZOOSYSTEMA • 2010 • 32 (3) © Publications Scientifiques du Muséum national d’Histoire naturelle, Paris. www.zoosystema.com 457