Stromatolites have been widely reported from the Archean and Paleoproterozoic successions worldwide, they could represent one of oldest life forms on Earth. Of these, a group small stromatolites occur as microdigitate low-relief columns, are also conspicuous in field. However, biogenicity these (MDSs) has long disputed due to abundance radial-fibrous texture lack convincing microfossils. New ex...

The Ruyang (Mesoproterozoic; Pt2) and Luoyu (Neoproterozoic; Pt3) groups in the southern North China Platform are dominated by peritidal siliciclastic rocks and contain abundant microbially induced sedimentary structures (MISS), including multidirected and mat-protected ripple marks, mat chips, mat-smoothed ripple marks, various sand cracks, and irregular growth ridges. These MISS can be groupe...

Unravelling the timing of the metazoan radiation is crucial for elucidating the macroevolutionary processes associated with the Cambrian explosion. Because estimates of metazoan divergence times derived from molecular clocks range from quite shallow (Ediacaran) to very deep (Mesoproterozoic), it has been difficult to ascertain whether there is concordance or quite dramatic discordance between t...

The Mesoproterozoic Eon [1,600-1,000 million years ago (Ma)] is emerging as a key interval in Earth history, with a unique geochemical history that might have influenced the course of biological evolution on Earth. Indeed, although this time interval is rather poorly understood, recent chromium isotope results suggest that atmospheric oxygen levels were <0.1% of present levels, sufficiently low...

The Precambrian rocks in western Ethiopia consist of highand low-grade terranes intruded by granitoids with a wide compositional spectrum. The formation ages of these granitoid rocks are, so far, poorly understood. Single-grain zircon Pb/Pb evaporation and conventional U/Pb dating conducted on four granitoids places time constraints on their emplacement and tectonothermal events. Three granitoi...

The early evolutionary history of the chloroplast lineage remains an open question. It is widely accepted that the endosymbiosis that established the chloroplast lineage in eukaryotes can be traced back to a single event, in which a cyanobacterium was incorporated into a protistan host. It is still unclear, however, which Cyanobacteria are most closely related to the chloroplast, when the plast...

A new chroococcalean cyanobacterium is described from approximately 1-billion-year-old non-marine deposits of the Torridonian Group of Scotland and the Nonesuch Formation of Michigan, USA. Individual cells of the new microfossil, Eohalothece lacustrina gen. et sp. nov., are associated with benthic microbial biofilms, but the majority of samples are recovered in palynological preparations in the...