Lepraliellidae

Belongs within: Cheilostomata.

Lepraliellidae is a family of bryozoans (including both erect and encrusting forms) with relatively smooth frontals and an avicularium set in the proximal ring of the orifice (Gordon 1993).

Lacy Lepraliellidae

Published 10 May 2010

Lepraliellidae are a family of bryozoans (small colonial animals sometimes known as ‘lace animals’ or ‘moss animals’ due to the appearance of the colonies) found around the world with the highest diversity in warmer waters. Different species may grow as encrusting forms or as upright branching colonies and even lunulitiform varieties have been recorded from the Eocene of Australia (Schmidt & Bone 2002).

Distinction of the various types of bryozoan requires close microscopic examination of the individual zooids (the units of the colony). Lepraliellidae belong to one of the more successful branches of the bryozoans, the Cheilostomata, which have each individual animal in a separate calcified box-shaped chamber. Within the Cheilostomata, they belong to the Ascophora which have an entirely calcified frontal wall on each chamber. Characters used in distinguishing Lepraliellidae from other ascophorans include umbonuloid growth of the relatively smooth frontal wall (i. e. primary calcification of the wall is internal rather than external), widely open ovicells (embryo brooding chambers) and a small spine-encircled ancestrula (the first zooid of a new colony to develop from a metamorphosed larva). In most species, an avicularium is present on the lower edge of the main opening of each feeding zooid though this feature is absent in Kladapheles gammadeka (Gordon 1993).

Lepraliellids of the genus Celleporaria include some of the largest of all bryozoan colonies, with individual heads up to a foot in height and nearly a metre in diameter, that may form predominantly bryozoan reefs (Hageman et al. 2003). Branches of upright Celleporaria colonies have a characteristic nodular appearance and are generally thick but hollow as they originally grow around an organic substrate such as a sponge that later dies off after being overgrown. Some species of Celleporaria are significant fouling agents on the bottoms of boats, and have been spread around the world by shipping.

Systematics of Lepraliellidae

<==Lepraliellidae
    |--Lepraliella granulata Canu & Bassler 1929THG01
    |--FrurionellaJB12
    |--Drepanophora Harmer 1957THG01
    |    |--*D. incisor (Thornely 1905) [=Rhynchozoon incisor]THG01
    |    |--D. corrugata (Thornely 1905)THG01
    |    |--D. gutta Tilbrook, Hayward & Gordon 2001THG01
    |    |--D. indica Hayward 1988THG01
    |    |--D. longiuscula Harmer 1957THG01
    |    |--D. tuberculata (Osburn 1914) [=Rhynchozoon tuberculatum]THG01
    |    `--D. verrucosa Winston & Heimberg 1986THG01
    `--Celleporaria Lamouroux 1826 [Celleporaridae]THG01
         |--*C. cristata (Lamark 1816) [=Cellepora cristata]THG01
         |--C. aperta (Hincks 1882)THG01
         |--C. columnaris (Busk 1881)THG01
         |--C. granulosa (Canu & Bassler 1920)T93
         |--C. inaudita Tilbrook, Hayward & Gordon 2001THG01
         |--C. mauritiana Hayward 1988THG01
         |--C. palmataPP05
         |--C. pilaefera (Canu & Bassler 1929) [=Holoporella pilaefera]THG01
         `--C. vagans (Busk 1881) [=Cellepora vagans]THG01

*Type species of generic name indicated

References

Gordon, D. P. 1993. Bryozoan frontal shields: studies on umbonulomorphs and impacts on classification. Zoologica Scripta 22 (2): 203–221.

Hageman, S. J., J. Lukasik, B. McGowran & Y. Bone. 2003. Paleoenvironmental significance of Celleporaria (Bryozoa) from modern and Tertiary cool-water carbonates of southern Australia. Palaios 18 (6): 510–527.

[JB12] Johnson, M. E., & B. G. Baarli. 2012. Development of intertidal biotas through Phanerozoic time. In: Talent, J. A. (ed.) Earth and Life: Global biodiversity, extinction intervals and biogeographic perturbations through time pp. 63–128. Springer.

[PP05] Pushkin, V. I., & L. E. Popov. 2005. Two enigmatic bryozoans from the Middle Ordovician of the East Baltic. Palaeontology 48 (5): 1065–1074.

Schmidt, R., & Y. Bone. 2002. Eocene bryozoan assemblages of the St Vincent Basin, South Australia. In: Wyse Jackson, P. N., C. J. Buttler & M. E. Spencer Jones (eds) Bryozoan Studies 2001 pp. 293–298. A. A. Balkema.

[T93] Taylor, P. D. 1993. Bryozoa. In: Benton, M. J. (ed.) The Fossil Record 2 pp. 465–489. Chapman & Hall: London.

[THG01] Tilbrook, K. J., P. J. Hayward & D. P. Gordon. 2001. Cheilostomatous Bryozoa from Vanuatu. Zoological Journal of the Linnean Society 131: 35–109.