Bacteria may play big role in forming fossils

Bacteria can build a biofilm that preserves a tissue's structure

Paleontologists were stunned when fossils appearing to belong to the soft-tissued embryos of marine creatures were unearthed in Chinese sediments a decade ago (SN: 2/7/98, p. 84).

BACTERIA ON EMBRYO Bacteria played an active role in making this this modern sea urchin embryo into a fossil (inset shows an unfossilized embryo).