Researchers have discovered microscopic sea animal Saccorhytus.
This is the earliest known ancestor of humans along with a vast range of other species.
The exquisitely well preserved fossilised traces of this 540-million-year-old creature were discovered by researchers.
This balloon-like sea is the earliest known step on the evolutionary path that led to fish and eventually to humans.
Saccorhytus is the most primitive example of deuterostomes.
This is a category of animals which are common ancestors of a broad range of species, including vertebrates (backboned animals).
It was about a millimetre and its body was symmetrical.
This is a characteristic inherited by many of its evolutionary descendants, including humans.
It was also covered with a thin, relatively flexible skin and muscles which concludes that it moved by contracting its muscles and got around by wriggling.
It is estimated to have lived between grains of sand on the sea bed.
It had large mouth, relative to the rest of its body indicating that it probably ate by engulfing food particles, or even other creatures.
Its body also had conical structures which might have allowed the water swallowed by it to escape. It also indicates these conical structures might have been an early version of gills.
