Ceriopora heteropora d'Orbigny, 1850,
Cretaceous, Cenomanian, Le Mans, Sarthe, France
?Syntype material: MNHN R61539, d'Orbigny Collection
colony erect, comprising slender cylindrical branches
expanding in width distally and becoming club-shaped
autozooids fixed- or free-walled; in one ?syntype (R61539a),
free-walled within a narrow zone proximal of the growing
tip, then fixed-walled and lacking a frontal wall but
with short collar-like peristomes; in the second ?syntype
(R61539b), fixed-walled (except where abraded) and with
pseudoporous frontal walls.
kenozooids numerous, fixed- or free-walled in R61539a
polygonal, closed by slightly depressed terminal diaphragms,
and surrounding the apertures of the autozooids, in R61539b
fixed-walled, somewhat elongate and interspersed among
gonozooid in R61539a fixed-walled, lobate, with finger-like
distal extensions extending between the autozooids and
filling space otherwise occupied by kenozooids, frontal
wall sunken beneath level of autozooids; R61539b lacks
Gregory (1899, p. 408) selected the type species of Clausa from among the nine species listed in this genus by d'Orbigny (1853, pp. 893-898). Material of C. heteropora in the d'Orbigny Collection comprises more than one species and none of it matches well enough with his figures to be confident that it corresponds with the species he described in 1850 and which became the type of his 1853 genus Clausa. The putative syntype numbered R61539a, which was refigured by Walter et al. (1975, pl. 10, fig. 10) is the better match of the two species depicted here and may provisionally serve as a basis for understanding the genus. This specimen is similar to a specimen from Uzbekistan figured by Voigt (1967, pl. 32, fig. 5) as Clausa heteropora, whereas the other 'syntype' resembles Clinopora.
Clausa is the type genus of d'Orbigny's family Clausidae.
Gregory, J.W. 1899. Catalogue of the Fossil Bryozoa in the Department of Geology, British Museum (Natural History). The Cretaceous Bryozoa. Volume 1. BM (NH), London, 457 pp.
Orbigny, A. d' 1850. Prodrome de Paléontologie Stratigraphique Universelle des Animaux Mollusques et Rayonnés faisant suite au cours élémentaire de Paléontologie. Tome 1. Masson, Paris.
Orbigny, A. d' 1851-1854. Paléontologie Française, Terrains Crétacé, 5, Bryozoaires. Masson, Paris, 1192 pp, pls 600-800.
Voigt, E. 1967. Oberkreide-Bryozoen aus den asiatischen Gebieten der UdSSR. Mitteilungen aus dem Geologisch-Staatinstitut der Universität Hamburg, 36: 5-95.
Walter, B., Arnaud-Vanneau, A., Arnaud, H., Busnardo, R. and Ferry, S. 1975. Les Bryozoaires Barrémo-Aptiens du sud-est de la France. Gisements et paléoécologie, biostratigraphie. Geobios 8: 83-117.