Abstract
back to Publications Guilbault, J.-P., Krautter, M., Conway, K.W., & Barrie, J.V. (2006): Modern foraminifera attached to hexactinellid sponge meshwork on the west Canadian shelf: comparison with Jurassic counterparts from Europe.
Modern foraminifera attached to hexactinellid sponge meshwork on the west Canadian shelf: comparison with Jurassic counterparts from Europe
Abstract: A foraminiferal fauna from siliceous sponge remains, collected in modern sponge bioherms on the continental shelf off British Columbia, Canada, are compared with assemblages reported from Late Jurassic sponge reefs in central and southern Europe. Forty arenaceous and 53 calcareous taxa were found either loose in, attached to, trapped in or engulfing parts of the meshwork. Specimens found loose belong to the same species as present in the surrounding mud or nearby on the shelf. Most commonly attached, trapped or engulfing genera are Crithionina, Gaudryina, Karreriella, Placopsilina, cf. Tritaxis, Trochammina, em>Islandiella, Lobatula and Ramulina. Two new taxa are described and illustrated: Placopsilina spongiphila n. sp. and Ramulina siphonifera n. sp. The main genera attached or closely associated with Jurassic reefal sponges are Vinelloidea, Thurammina, Tolypammina, Tritaxis, Subbdelloidina, and Bullopora. Comparison of Recent and the Jurassic sponge reef foraminiferal assemblages indicate that there are no taxa in common at the species and few at the genus level. However, foraminifera from both the Recent and Jurassic seem to have interacted with the sponge meshwork in a way that taxa are attached to, trapped in, laced-in, and to a certain extent engulf the meshwork. Many ecological niches seem to have remained essentially unchanged since the Jurassic in the dead sponge meshwork environment with new taxa substituting themselves into niche spaces to replace taxa which went extinct.