When the first diminutive dinosaurs emerged on land, the common tadpole shrimp was already swimming around the Earth’s wetland pools. And it looked very much like the one that recently hatched in an aquarium in Scotland.
The Triops cancriformis represents a new colony of what’s believed to be the oldest animal species to continuously survive on Earth. Scientists thought the shrimps only existed in a single pond in Hampshire, England, until 2004, when a second colony was discovered in Caerlaverock, Scotland.
Researchers from the University of Glasgow had a hunch that the second colony may have come from dormant eggs reawoken after heavy rains, so they set out to search for more sleeping colonies. They collected mud from other pools, dried it out and placed it in aquariums. (Mother tadpole shrimp lay hundreds of eggs that sit dormant in dry mud until enough water returns.) When a research student went back to check the heat level two weeks later, she found a prehistoric friend. Theoretically, one may be all that’s needed to start a new colony: the shrimp have both male and female reproductive organs.