Host preferences in Late Ordovician (Sandbian) epibenthic bryozoans: example from the Zahořany Formation of Prague Basin


Authors: Kácha P, Šarič R

Published in: Bulletin of Geosciences, volume 84, issue 1; pages: 169 - 178; Received 20 August 2007; Accepted in revised form 4 February 2009; Online 23 March 2009

Keywords: host preferences, epibiontic bryozoans, Late Ordovician, taphonomy,

full text (PDF, 4.14 MB)

Export to RIS



Detailed analysis of the ecologic position of Late Ordovician epibenthic bryozoans within fossil associations from the upper part of the Zahořany Formation have revealed a statistically significant host preference. The most common hosts were found to be cephalopod shells and conulariid exoskeletons, less commonly disarticulated trilobite exoskeletons and brachiopod shells were utilized. Among the trilobite remains, the bryozoans prefered to settle on the central part of cephala in the medium-sized trilobites Dalmanitina socialis. However only one pygidium of more the 450 studied pygidia of the latter species was colonized by epibenthic bryozoans. No preferred area for attachment of bryozoans on brachiopod shells was found. The relation between fluctuating input of clastic material into the mostly siltstone sequence and the occurrence of the epibentic bryozoans is discussed. The changes in the faunal associations of the Zahořany Formation are also documented.


Baird, G.C., Brett, C.E. & Frey, R.C. 1989. “Hitchhiking” epizoans on orthoconic cephalopods: preliminary review of the evidence and its implications. Senckenbergiana lethaea 69(5/6), 439-465.

Barrande, J. 1846. Notice préliminaire sur le systeme silurien et les trilobites de Boheme. 97 pp. C.L. Hirschfeld, Leipzig.

Barrande, J. 1852. Systeme silurien du centre de la Boheme. Iere Partie: Recherches paléontologiques. Vol. I, Crustaces: Trilobites. 935 pp., 51 pls. Prague & Paris.

Barrande, J. 1887. Echinodermes. Études locales et comparatives. 356 pp., 30 pls. Ouvrage posthume de feu Joachim Barrande publié par le Doct. W. Waagen, Prague.

Brandt, D.S. 1996. Epizoans on Flexicalymene (Trilobita) and implications for trilobite paleoecology. Journal of Paleontology 70(3), 442-449.

Budil, P. & Bruthansová, J. 2005. Moulting in Ordovician dalmanitoid and acastoid trilobites of the Prague Basin. Preliminary observation. Geologica Acta 3(4), 373-383.

Budil, P. & Šarič, R. 1995. Cemented epibionts on the exoskeleton of the odontopleurid trilobite Selenopeltis vultuosa tenyl Šnajdr, 1984. Věstník Českého geologického ústavu 70(2), 29-31.

Emmrich, H.F. 1839. De Trilobitis. Dissertatio petrefactologica quam consensu et auctoritate amplissimi philosorum ordinis. 56 pp. Nietackianis, Berolini.

Galle, A.&Parsley, R. 2005. Epibiont relationships on hyolithids demonstrated by Ordovician trepostomes (Bryozoa) and Devonian tabulates (Anthozoa). Bulletin of Geosciences 80(2), 125-138.

Hawle, I. & Corda, A.J.C. 1847. Prodrom einer Monographie der böhmischen Trilobiten. Abhandlungen der Königlichen Böhmischen Gesellschaft der Wissenschaften 5. 176 pp. J.G. Calve, Prague.

Horný, R. & Bastl, F. 1970. Type specimens of fossils in the National Museum, Prague. Vol. I. Trilobita. 354 pp. Museum of Natural History, Prague.

Kácha, P. & Šarič, R. 1995. Bryozoans attached to exuvia of the Ordovician trilobite Dalmanitina (D.) proaeva. Věstník Českého geologického ústavu 70(4), 43-46.

Kloc, G.J. 1993. Epibionts on Selenopeltinae (Odontopleurida) Trilobites, 103. Geological Society of America Abstracts with Programs 25A.

Kukal, Z. 1960. Petrografický výzkum vrstev chlustinských barrandienského ordoviku. Sborník Státního geoogického ústavu Československé republiky, Oddíl geologický 26(1), 359-391.

Kulich, J. 1984. Trepostomatous bryozoans from the Ordovician, Silurian and Devonian of the Barrandian basin. Journal of the Czech Geological Society 29(3), 225-233.

McNamara, K.J. 1978. Symbiosis between gastropods and bryozoans in the Late Ordovician of Cumbria, England. Lethaia 11, 25-40.View article

Mikuláš, R. 1997. Proudem orientované hlavové štíty trilobita Dalmanitina proaeva (Emmr.) na lokalitě Loděnice - vinice (zahořanské souvrství, ordovik Barrandienu). Zprávy o geologických výzkumech v roce 1997, 102-103.

Mikuláš, R. 1998. Ordovician of the Barrandian area: Reconstruction of the sedimentary basin, its benthic communities and ichno assemblages. Journal of the Czech Geological Society 44(3), 147-159.

Mikuláš, R. 1999. Joint occurrences of body- and trace-fossil communities (Ordovician, Barrandian area, Czech Republic). Journal of the Czech Geological Society 44, 69-78.

Počta, F. 1894. Systeme silurien du centre de la Boheme par Joachim Barrande. Iere Partie: Recherches Paleontologiques. Vol. VIII, Tome I, Bryozoaires, Hydrozoares et partie des Anthozoaires. 230 pp. Prague.

Počta, F. 1902. Systeme silurien du centre de la Boheme par Joachim Barrande. Iere Partie: Recherches Paleontologiques. Vol. VIII, Tome II, Anthozoaires et Alcyonaires. 347 pp. Prague.

Prokop, R.J. & Petr, V. 1999. Echinoderms in the Bohemian Ordovician. Journal of the Czech Geological Society 44, 63-68.

Prantl, F. & Přibyl, A. 1949. Studie o trilobitech nadčeledi Odontopleuracea nov. superfam. Rozpravy Státního geologického ústavu Republiky eeskoslovenské 12, 1-221.

Richards, R.P. 1972. Autecology of Richmondian brachiopods (Late Ordovician of Indiana and Ohio). Journal of Paleontology 46(3), 386-405.

Taylor, P.D. & Wilson, M.A. 2003. Palaeoecology and evolution of marine hard substrate communities. Earth Science Reviews 62, 1-103.View article

Tetreault, D.K. 1992. Paleoecologic implications of epibionts on the Silurian lichid trilobite Arctinurus, 289. Fifth North American Paleontological Convention, Abstracts and Program, Paleontological Society Special Publication 6.