Microbially induced sedimentary structures (MISS) are primary
sedimentary structures formed by the interaction of
microbes with sediment and physical agents of erosion, deposition, and transportation. The structures commonly form when
microbial mats (which may comprise
bacteria,
fungi,
protozoans,
archaea or
algae) are preserved in the sedimentary geological record. There are 17 main types of macroscopic and microscopic MISS. Of those, wrinkle structures and microbial mat chips are the most abundant in the fossil record. Other MISS include sinoidal structures, polygonal oscillation cracks, multidirected ripple marks, erosional remnants and pockets, or gas domes.