This study presents a paleobiological investigation and systematic taxonomy of early Cambrian calcified cyanobacteria in 10 shallow marine carbonate sections – both reefal and non-reefal – from South China. Our findings provide robust support for the view that cyanobacterial calcification was widespread in shallow marine environments and associated facies during the early Cambrian, defining a major cyanobacterial calcification episode (CCE). 

By combining incubation experiments, microscopy, biomolecular analyses, and spectroscopy to assess the biomacromolecular composition of cyst walls, we show that Selenopemphix and Multispinula represent two distinct cyst-based genera, with different preservation potentials. We emend their diagnoses and describe two new Multispinula species, M. varispinosa sp. nov. and M. robusta sp. nov., in addition to M. quanta. 

In the Marmolance succession (SE Spain), in limestones intercalating marls with planktonic foraminifera, we documented Langhian Nummulites species as well as Serravallian lepidocyclinids and Risananeiza. Papazzoni et al. questioned our results, arguing that the larger benthic foraminifera (LBF) must be reworked. However, the quantitatively defined LBF assemblages are spatially and temporally segregated, which can only be due to in situ accumulation across different facies belts of the carbonate ramp.

Today’s sea-ice-covered Arctic Ocean hosts only one species of calcifying planktonic foraminifera, unlike warmer oceans with diverse communities. Fossils show that other species once inhabited the Arctic, but their identities and environmental significance remain uncertain. Using detailed microscopy and hundreds of shell measurements, we resolve these fossil species and establish a new taxonomic framework providing the foundation for improved reconstructions of Quaternary Arctic climate history.

We developed an automated method that uses artificial intelligence to identify marine microscopic organisms called foraminifera, which serve as bioindicators of ocean health. By combining a low-cost imaging system with computer vision, our approach can quickly and accurately recognize both living and dead specimens. This makes environmental monitoring faster, more consistent, and more accessible for studying how coastal ecosystems respond to pollution and climate change.

Based on type specimens, we reassess the larger benthic foraminifera Miogypsinella borodinensis, type of the genus, and Miogypsinoides lateralis. We show that two Miogypsinella species were widespread across the Indo-Pacific in the Chattian–Aquitanian, while another lived in the eastern Pacific. The latest Aquitanian Indonesian Seaway restriction and widespread deeper-water deposition on SE Asia carbonate platforms likely caused the extinction of the studied Indo-Pacific taxa.

We studied how genetic material from foraminifera in Hong Kong mangroves and mudflats varies through seasons and how this affects records of past sea levels. Over 2 years, communities in mangroves were relatively stable, allowing accurate estimates of elevation relative to the sea. The mudflat–mangrove transitional zone changed with season, causing biased estimates. Mangroves are therefore more accurate than mudflats for tracking past sea-level change.