Tadpole Shrimps (Lepidurus apus viridis) have a lineage that dates back more than 300 million years 

The species has an life cycle that can include blowing around in dust for years until they can colonise in temporary puddles.

Parks Victoria Area Chief Ranger Zoe Wilkinson said this discovery in Biodiversity Month was a timely reminder of the many strange and more secretive creatures that exist across Victoria.

Ms Wilkinson said she and The Friends of Arapiles community group were surprised when they climbed to the top of rock outcrops at the park after heavy rains to find the shrimp swimming in a puddle.

“I knew they were something special. They seemed like living fossils and really ancient looking, like the little extinct marine trilobites,” said Ms Wilkinson.

“These animals have an unusual lifecycle. They start life as an extremely hardy egg that can dry out completely and then blow around in the dust and rest in the soil for years.

“When the timing of spring rains is just right, the eggs hatch and the shrimp start swimming around in shallow puddles.”

Ms Wilkinson said the shrimp look like miniature horseshoe crabs with a big shield on their back, but only grow to about 40 millimetres long.

Tadpole Shrimp are never found in deeper creeks, streams or ponds where fish and larger predatory insects live as any that do hatch probably get snapped up pretty quickly.

“Our parks are special places and with the good winter rains, nature is very busy this spring,” Ms Wilkinson said.

“Although it is easy to overlook the smaller things, I encourage everyone to take the lead from children: Stop, crouch down and take a moment to look around.

“You’ll be amazed to discover the activity going on in the miniature world within our parks.”