Martin David Brasier FGS, FLS (12 April 1947 – 16 December 2014) was an English palaeobiologist and astrobiologist known for his conceptual analysis of microfossils and evolution in the Precambrian and Cambrian.

He was Professor of Palaeobiology at the University of Oxford[1] and Emeritus Fellow of St Edmund Hall.

His research critically examined the context and character of the early fossil record, making use of field mapping, logging, optical petrography, stable isotope geochemistry, confocal microscopy, NanoSims microprobes, and lasers for high resolution 3D scanning and laser Raman spectroscopy.

[2][3] His contributions include the Brasier–Schopf debate on critical testing of questionable 3460 Ma Apex chert 'microfossils' at NASA; work on the earliest well-preserved fossils of cells (biology) (3430 Ma Strelley Pool); the pumice hypothesis for the origins of life; mapping the earliest life on land (1000 Ma Torridonian); and the palaeoecology, development and evolution of Ediacaran to early Cambrian organisms.

[5] His sequel, called Secret Chambers, goes in search of the symbiotic origins of the eukaryote chloroplast, tracing its evolution through the last two billion years, exploring the ideas of Robert Hooke, Elso Barghoorn, Tom Cavalier-Smith and Lynn Margulis, and delving into the interval that Brasier dubbed 'the Boring Billion'.