Late Cambrian to early Ordovician trilobites, the family Olenidae, were tolerant of oxygen-poor, sulfur-rich sea floor conditions, and a case is made that they were chemoautotrophic symbionts. Olenids were uniquely adapted to this habitat in the Lower Paleozoic, which was widespread in the Late Cambrian over Scandinavia. This life habit explains distinctive aspects of olenid morphology: wide th...

The geological evolution of the Proto-Tethys Ocean remains vague. Tianshuihai Terrane (TSHT), a subterrane West Kunlun, distributed to south during Early Palaeozoic, records abundant information on Ocean. In this study, we reported SHRIMP and LA-ICP-MS zircon U–Pb ages, whole-rock major trace element composition data, Sr-Nd-Hf isotopes suite monzogranites monzonitic-syenitic enclaves in Zankan ...

Evidence of the morphological evolution of metazoans has been preserved, in varying degrees of completeness, in the fossil record of the last 600 million years. Although extinction has been incessant at lower taxonomic levels, genomic comparisons among surviving members of higher taxa suggest that much of the developmental systems that pattern their bodyplans has been conserved from early in th...

Agić, H. 2015. Palaeobiology and diversification of Proterozoic-Cambrian photosynthetic eukaryotes. Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology 1308. 47 pp. Uppsala: Acta Universitatis Upsaliensis. ISBN 978-91-554-9389-9. One of the most important events in the history of life is the evolution of the complex, eukaryotic cell. The eukaryote...

Neoproterozoic and Palaeozoic rocks of the Mérida Massif (SW Iberia) have been grouped into tectonostratigraphic units. Each unit is separated from rest ones by either crustal-scale thrusts and/or extensional detachments. The lowermost (Magdalena Gneisses; lower plate) has continental crust affinity, below a mafic-ultramafic ensemble, referred to as Ophiolite (suture zone). Serie Negra Group co...

Kullingia is considered a key taxon in demonstrating the presence of terminal Proterozoic–early Cambrian chondrophorine hydrozoans. However, Kullingia concentrica from the Lower Cambrian of northern Sweden possesses several features that show that it is not a body fossil but that it was formed by current or wave-induced rotation of an anchored tubular organism, possibly a sabelliditid. A scratc...

A multi-proxy provenance study of Late Carboniferous to Middle Jurassic sandstones from the eastern Sverdrup Basin was undertaken employing optical petrography and heavy mineral analysis, chemical analysis apatite, garnet rutile grains, as well detrital zircon U–Pb geochronology Hf isotope analysis. strata on southern basin margin are inferred being predominantly reworked Silurian Devonian with...

The Alto Quixaba pegmatite, Seridó region, northeastern Brazil, is a 60 degrees/80 degrees SW-trending subvertical dike discordantly intruded into biotite schists of the Upper Neoproterozoic Seridó Formation. It has three distinct mineralogical and textural zones, besides a replacement body that cuts the pegmatite at its central portion and in which occur, among other gem minerals, colored elba...

What are they? Ediacarans are a highly distinctive assemblage of fossil organisms, apparently all marine. Most typical are frondose, discoidal and segmented forms. Their overall taxonomic diversity is modest, but there is considerable disparity and they include one rather bizarre group with prominent three-fold body symmetry. A striking feature of many forms is their modular construction and th...