Reducing taxonomic noise in problematic fossils: revision of the incertae sedis genus Allonema based on shape analysis


Authors: Jarochowska E, Hierl F, Vinn O, Munnecke A

Published in: Bulletin of Geosciences, volume 91, issue 1; pages: 97 - 110; Received 22 September 2015; Accepted in revised form 22 December 2015; Online 12 February 2016

Keywords: Wetheredella, sclerobionts, pseudobryozoans, microproblematica, encrusters, Baltica, Devonian,

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List of lengths and widths of complete, undamaged Allonema vesicles as measured from SEM photographs.



Organisms of unknown biological affinity are widespread in Paleozoic ecosystems and play key ecological roles. Recognition of these roles relies on consistent identification and sound taxonomy, yet many microproblematica lack complex morphological features that could be the basis for qualitative taxonomic diagnoses. Allonema is an incertae sedis calcareous sclerobiont widespread in Paleozoic carbonates. At least seven species of Allonema have been proposed, but their diagnoses based on size ranges overlap. In this work, dimensions of 590 individuals from the Silurian of Estonia and Sweden have been measured. Regression analysis of the dimensions revealed two groups, overlapping in size ranges, but differing significantly in proportions. These groups could be matched with previously described A. botellus and A. moniliforme, but both showed a wider range of sizes than previously reported. Another previously described species, A. minimum, fell within the range of dimensions of A. moniliforme and is proposed to be its junior synonym. Differences in proportions revealed in the study do not seem to be dependent on sedimentary environment or local growth conditions such as competition for space, and thus may represent consistent interspecific variability. Although the affinity of Allonema remains unknown, this quantitative approach to its taxonomy reduces unnecessary species in the genus. The success of this approach may encourage its application to other microproblematica populating the fossil record.


BEŁKA, Z. 1981. The alleged algal genus Aphralysia is a foraminifer. Neues Jahrbuch für Geologie und Paläontologie, Monatshefte 5, 257-266.View article

BERKYOVÁ, S. & MUNNECKE, A. 2010. “Calcispheres” as source of lime mud and peloids - evidence from the Devonian of the Prague Basin, Czech Republic. Bulletin of Geosciences 85, 585-602.View article

BRETT, C.E., SMRECAK, T., HUBBARD, K.P. & WALKER, S. 2012. Marine sclerobiofacies: encrusting and endolithic communities on shells through time and space, 129-157. In TALENT, J. (ed.) International Year of Planet Earth, Earth and Life. Springer Netherlands, Amsterdam.View article

CALNER, M. 1999. Stratigraphy, facies development, and depositional dynamics of the Late Wenlock Fröjel Formation, Gotland, Sweden. GFF 121, 13-24.View article

CALNER, M. & JEPPSSON, L. 2003. Carbonate platform evolution and conodont stratigraphy during the middle Silurian Mulde Event, Gotland, Sweden. Geological Magazine 140, 173-203.View article

COLBATH, G.K. & GRENFELL, H.R. 1995. Review of biological affinities of Paleozoic acid-resistant, organic-walled eukaryotic algal microfossils (including “acritarchs”). Review of Palaeobotany and Palynology 86, 287-314.View article

CONDRA, G.E. & ELIAS, M.K. 1944. Carboniferous and Permian ctenostomatous bryozoa. Geological Society of America Bulletin 55, 517-568.View article

DZIK, J. 1975. The origin and early phylogeny of the cheilostomatous bryozoa. Acta Palaeontologica Polonica 20, 395-423.

ELIAS, M.K. 1950. Paleozoic Ptychocladia and related Foraminifera. Journal of Paleontology 24, 287-306.

ELICKI, O. 1999. Palaeoecological significance of calcimicrobial communities during ramp evolution: An example from the Lower Cambrian of Germany. Facies 41, 27-39.View article

FLÜGEL, E. 2004. Cyanobacteria and Calcimicrobes, 408-412. In FLÜGEL, E. Microfacies of carbonate rocks. Analysis, interpretation and application. Springer, Berlin.

FRISCH, K., MUNNECKE, A., SCHULBERT, C. & ZHANG, Y. 2013. Tubes or cell sheet? A 3-D reconstruction of Halysis Hoeg, 1932, from the Upper Ordovician of South China. Facies 59, 113-132.View article

GŁUCHOWSKI, E. 2005. Epibionts on upper Eifelian crinoid columnals from the Holy Cross Mountains, Poland. Acta Palaeontologica Polonica 50, 315-328.

GRADZIŃSKI, M., TYSZKA, J., UCHMAN, A. & JACH, R. 2004. Large microbial-foraminiferal oncoids from condensed Lower-Middle Jurassic deposits: a case study from the Tatra Mountains, Poland. Palaeogeography, Palaeoclimatology, Palaeoecology 213, 133-151.View article

HIERL, F. 2014. Karbonatische Mikrofossilien aus den Svarvare-Schichten (Silur, Gotland) und ihre Bedeutung für die Rekonstruktion der Ablagerungsbedingungen. 29 pp. Bachelors thesis, Friedrich-Alexander Universität Erlangen-Nürnberg, Erlangen, Germany.

JAKUBOWICZ, M., BEŁKA, Z. & BERKOWSKI, B. 2014. Frutexites encrustations on rugose corals (Middle Devonian, southern Morocco): complex growth of microbial microstromatolites. Facies 60, 631-650.View article

JAROCHOWSKA, E. & MUNNECKE, A. 2014. The Paleozoic problematica Wetheredella and Allonema are two aspects of the same organism. Facies 60, 651-662.View article

JAROCHOWSKA, E., TONAROVÁ, P., MUNNECKE, A., FERROVÁ, L., SKLENÁŘ, J. & VODRÁŽKOVÁ, S. 2013. An acid-free method of microfossil extraction from clay-rich lithologies using the surfactant Rewoquat. Palaeontologia Electronica 16(3),, 1-16.View article

JEPPSSON, L., ERIKSSON, M.E. & CALNER, M. 2006. A latest Llandovery to latest Ludlow high-resolution biostratigraphy based on the Silurian of Gotland - a summary. GFF 128, 109-114.View article

KIEPURA, M. 1965. Devonian bryozoans of the Holy Cross Mountains, Poland. Acta Palaeontologica Polonica 10, 11-48.

LAUFELD, S. 1974. Reference localities for palaeontology and geology in the Silurian of Gotland. Sveriges Geologiska Undersökning, ser. C 705, 1-172.

LEGENDRE, P. & LEGENDRE, L. 1998. Developments in Environmental Modelling. Numerical ecology. 852 pp. Elsevier, Amsterdam.

MALINKY, J.M., WILSON, M.A., HOLMER, L.E. & LARDEUX, H. 2004. Tube-Shaped Incertae Sedis, 214-222. In WEBBY, B.D., PARIS, F., DROSER, M.L. & PERCIVAL, I.G. (eds) The Great Ordovician Biodiversification Event. Columbia University Press, New York.View article

MÄNNIK, P. 2014. The Silurian System in Estonia, 123-128. In BAUERT, H., HINTS, O., MEIDLA, T. & MÄNNIK, P. (eds) 4th Annual Meeting of IGCP 591 The Early to Middle Paleozoic Revolution, Estonia 10-19 June 2014. Abstracts and Field Guide. University of Tartu, Tartu.

MUNNECKE, A., SAMTLEBEN, C. & BICKERT, T. 2003. The Ireviken Event in the lower Silurian of Gotland, Sweden - relation to similar Palaeozoic and Proterozoic events. Palaeogeography, Palaeoclimatology, Palaeoecology 195, 99-124.View article

MUNNECKE, A., SAMTLEBEN, C., SERVAIS, T. & VACHARD, D. 1999. SEM-observation of calcareous micro- and nannofossils incertae sedis from the Silurian of Gotland, Sweden: Preliminary results. Geobios 32, 307-314.View article

MUNNECKE, A., SERVAIS, T. & VACHARD, D. 2000. A new family of calcareous microfossils from the Silurian of Gotland, Sweden. Palaeontology 43, 1153-1172.View article

NESTOR, V. 1984. Zonal distribution of chitinozoans in the Wenlocki Jaani Stage of Estonia and the problem of its upper boundary, 119-127. In MÄNNIL, R.M. & MENS, K.A. (eds) Stratigraphy of early Paleozoic sediments of the East Baltic. Valgus, Tallinn.

NOSE, M., SCHMID, D.U. & LEINFELDER, R.R. 2006. Significance of microbialites, calcimicrobes, and calcareous algae in reefal framework formation from the Silurian of Gotland, Sweden. Sedimentary Geology 192, 243-265.View article

OLEMPSKA, E. & RAKOWICZ, Ł. 2014. Affinities of Palaeozoic encrusting ascodictyid “pseudobryozoans”. Journal of Systematic Palaeontology 12, 983-999.View article

PAGE, A., WILBY, P.R., MELLISH, C.J.T., WILLIAMS, M. & ZALASIEWICZ, J.A. 2008. Dawsonia Nicholson: linguliform brachiopods, crustacean tail-pieces and a problematicum rather than graptolite ovarian vesicles. Earth and Environmental Science Transactions of the Royal Society of Edinburgh 99, 251-266.View article

PARIS, F. & NOLVAK, J. 1999. Biological interpretation and paleobiodiversity of a cryptic fossil group: The “chitinozoan animal”. Geobios 32, 315-324.View article

PRATT, B.R. 1984. Epiphyton and Renalcis; diagenetic microfossils from calcification of coccoid blue-green algae. Journal of Sedimentary Research 54, 948-971.

R CORE TEAM 2015. R: A language and environment for statistical computing. R Foundation for Statistical Computing, Vienna.

RAUKAS, A. & TEEDUMÄE, A. 1997. Geology and Mineral Resources of Estonia. 436 pp. Estonian Academy Publishers, Tallinn.

RIDING, R. 1991. Calcified Cyanobacteria, 55-87. In RIDING, R. (ed.) Calcareous Algae and Stromatolites. Springer, Berlin.View article

RIDING, R. & SOJA, C.M. 1993. Silurian calcareous algae, cyanobacteria, and microproblematica from the Alexander Terrane, Alaska. Journal of Paleontology 67, 710-728.View article

SIMONSEN, A.H. & CUFFEY, R.J. 1980. The University of Kansas Paleontological Contributions. Fenestrate, pinnate, and ctenostome bryozoans and asociated barnacle borings in the Wreford Megacyclothem (Lower Permian) of Kansas, Oklahoma, and Nebraska. 38 pp. The Paleontological Institute, The University of Kansas.

SPJELDNAES, N. 1984. Epifauna as a tool in autecological analysis of Silurian brachiopods. Special Papers in Palaeontology 32, 225-235.

SZULCZEWSKI, M. 1995. Depositional evolution of the Holly Cross Mts. (Poland) in the Devonian and Carboniferous - a review. Geological Quarterly 39, 471-488.

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

ULRICH, E.O. & BASSLER, R.S. 1904. A revision of the Paleozoic Bryozoa, Part I: On genera and species of Ctenostomata. Smithsonian Miscellaneous Collections 45, 256-294.

VACHARD, D., HAUSER, M., MARTINI, R., ZANINETTI, L., MATTER, A. & PETERS, T. 2001. New algae and problematica of algal affinity from the Permian of the Aseelah Unit of the Batain Plain (East Oman). Geobios 34, 375-404.View article

VINE, G.R. 1884. IX. - Notes on species of Ascodictyon and Rhopalonaria from the Wenlock Shales. Annals and Magazine of Natural History 14, 77-89.View article

VINE, G.R. 1887. Notes on the classifications of cyclostomatous Polyzoa; old and new. Proceedings of the Yorkshire Geological and Polytechnic Society 9, 346-362.View article

VINN, O. & WILSON, M.A. 2013. Silurian cornulitids of Estonia (Baltica). Carnets de Géologie 357-368.View article

VINN, O. & ZATOŃ, M. 2012. Phenetic phylogenetics of tentaculitoids - extinct, problematic calcareous tube-forming organisms. GFF 134, 145-156.View article

WARTON, D.I., DUURSMA, R.A., FALSTER, D.S. & TASKINEN, S. 2012. Smatr 3 - an R package for estimation and inference about allometric lines. Methods in Ecology and Evolution 3, 257-259.View article

WESTFALL, P.H. & YOUNG, S.S. 1993. Resampling-based multiple testing: Examples and methods for p-value adjustment. 360 pp. John Wiley & Sons, New York.

WHITEAVES, J.F. 1891. The Fossils of the Devonian Rocks of the Mackenzie River Basin. Contributions to Canadian Paleontology 1, 197-253.

WILSON, M.A. & TAYLOR, P.D. 2001. ”Pseudobryozoans” and the problem of encruster diversity in the Paleozoic. PaleoBios 21, 134-135.

WILSON, M.A. & TAYLOR, P.D. 2014. The morphology and affinities of Allonema and Ascodictyon, two abundant Palaeozoic encrusters commonly misattributed to the ctenostome bryozoans. Studi Trentini di Scienze Naturali 94, 259-266.

WOOD, A. 1948. “Sphaerocodium,” a misinterpreted fossil from the Wenlock limestone. Proceedings of the Geologists’ Association 59(1), 9-22, IN2-IN5.View article