in the upper Mattaia Formation, Kessyusa Group in the Olenek Uplift, NE of the Siberian Platform. The Mattaia Formation characterizes an upper shoreface to inner-shelf depositional setting and provides important faunal ties and correlation with carbonate-dominated and aliminosiliciclastic open-shelf areas. A section of the upper Mattaia Formation at Boroulakh, Olenek River is suggested here as a model for the Global Boundary Stratotype Section and Point for the base of the Cambrian Stage 2. This level contains the lowermost occurrence of the cosmopolitan fossil helcionelloid mollusc Aldanella attleborensis. Section global markers near the base of the stage include a positive excursion of δ13C values reaching +5.4‰, a U- Pb zircon date of 529.7 ± 0.3 Ma, massive appearance of diverse small skeletal fossils (including Watsonella crosbyi), a sudden increase in diversity and abundance of trace fossils, as well as a conspicuous increase in depth and intensity of bioturbation. Coincidently, it is this level that has always been regarded as the lower Tommotian boundary on the Olenek Uplift.

Gribaldo, S., Brochier-Armanet, C., 2020. Evolutionary relationships between Archaea and eukaryotes. Nature Ecology &Evolution 4, 20-21.

https://doi.org/10.1038/s41559-019-1073-1 A phylogenomic re-analysis of sequence data strongly supports the emergence of eukaryotes from within the archaeal radiation and underlines the importance of using the most accurate approaches to reconstruct ancient divergences in the tree of life.

Griffiths, W., Wang, Y., 2020. Lipidomics: Current and Emerging Techniques New Developments in Mass Spectrometry. Royal Society of Chemistry, p. 288.

https://doi.org/10.1039/9781788013109 Lipidomics is one of the emerging 'omics' techniques with growing importance in bioscience. Discussing interesting standard and non-standard techniques relevant to the measurement and analysis of lipids by mass spectrometry, this book will provide a guide to the possibilities of the techniques. It will introduce the reader to exciting new methods that allow isomer differentiation, improve sensitivity, allow spatial location and go beyond annotation of simply matching a mass to a database entry. The book is written and edited by the some of the world leaders in the field of lipid mass spectrometry and will have international appeal in industry and academia for analytical chemists, biochemists and biotechnologists. Furthermore, it will provide a useful resource for anyone interested in lipid structure characterization particularly for graduates and postgraduates who require a starting point for their projects. Chapter 1: Lipidomics Basics. W. J. Griffiths, E. Yutuc, D. Davies, A. Dickson, R. Angelini, D. El Assad, G. Frache and Y. Wang. Pages 1 - 24 Lipidomics can be regarded as the quantitative profiling of the entire lipid composition of a defined system, be that a cell, tissue, biofluid or intact organism. Lipidomics is a descendent of what was previously known as 'metabolite profiling' and is a relative of the related 'omic' disciplines of genomics, transcriptomics and proteomics. Lipidomics can be regarded as a sub-division of metabolomics. In this chapter we will discuss the current methodologies popular in lipidomics, highlighting gas-chromatography mass spectrometry (GC-MS), liquid-chromatography MS (LC-MS) and direct- infusion, also known as 'shotgun' MS (DI -MS). We will also introduce newer methods including low-flow-rate-LC MS, ion mobility MS (IM-MS) and MS imaging (MSI), described in detail in later chapters. Chemical derivatisation is not a new idea to lipidomics; however, its use goes in and out of vogue, hence we also introduce some of its benefits and disadvantages here and in a later chapter. Chapter 2. Multivariate Statistics in Lipidomics. Julian L. Griffin, Sonia Liggi and Zoe Hall. Pages 25 - 48 In lipidomics the aim is to measure the concentration of every lipid above the limit of detection in a biofluid or tissue extract. By its very nature this produces large multivariate datasets where standard univariate statistical