16 research outputs found
Trace fossil associations in the Swedish Mickwitzia sandstone (Lower Cambrian): Did trilobites really hunt for worms?
Cambrian Hyolitha of Siberian, Baltican and Avalonian aspect in east Laurentian North America: taxonomy and palaeobiogeography
Unravelling Phanerozoic evolution of radial to rosette trace fossils
Feeding trace fossils, produced by either deposit or detritus feeders and showing radial to rosetted morphology, are all included in the same architectural category. These radial to rosette ichnofossils are widely recorded worldwide throughout the Phanerozoic and have attracted the attention of numerous ichnologists for decades. Construction of a database summarizing occurrences of radial to rosette trace fossils through the Phanerozoic shows that representatives of this category occurred for the first time during the Fortunian, which accounts for the appearance of at least 12% of the total number of ichnogenera in this category. Overall, 32% of all known rosette ichnogenera resulted from the Cambrian Explosion. A second ichnodiversity increase took place (20%) during the Ordovician. Subsequent to the Great Ordovician Biodiversification Event, this architectural category shows minor fluctuations in ichnodiversity resulting in a long-term plateau. The apparent decline in ichnodiversity by the end of the Cenozoic could reflect a taphonomic artefact resulting from the difficulties of identifying cumulative trace fossils in highly bioturbated modern sediments. Our data set indicates that several radial to rosette ichnogenera (e.g. Arenituba, Dactylophycus, Gyrophyllites, Phoebichnus, Volkichnium) occurred first in shallow-marine settings and then migrated to either deeper-water or marginal-marine environments, while others (e.g. Asterichnus, Cladichnus, Dactyloidites) apparently first occurred in deep-sea environments and then migrated to shallower waters.Fil: Muñoz, Diego Fernando. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - CĂłrdoba. Centro de Investigaciones en Ciencias de la Tierra. Universidad Nacional de CĂłrdoba. Facultad de Ciencias Exactas FĂsicas y Naturales. Centro de Investigaciones en Ciencias de la Tierra; ArgentinaFil: Mangano, Maria Gabriela. University of Saskatchewan; CanadĂĄ. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; ArgentinaFil: Buatois, Luis Alberto. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; Argentina. University of Saskatchewan; Canad