How were dinosaur footprints preserved?
ANJANA KHATWA ANSWERS:
Imagine walking across a muddy field in a pair of wellies, your feet squelching with each step you take. If the depressions left behind were quickly filled in with sand or small pebbles, your footprints could become ‘trace fossils’ (indirect evidence of your existence, rather than preserved remains).
This is what happened to some dinosaur footprints left on the muddy surfaces of lagoons and swamps. Each layer of sediment deposited on the footprint compressed to become layers of sedimentary rock, preserving this moment of contact forever. Known as ichnites, dinosaur footprints are found in two forms: as shallow depressions on a rock surface (see image) or as footprint-shaped blocks known as casts.
These extraordinary fossils reveal themselves
