Fossils of a female crustacean — the oldest known example of a female animal with eggs — suggest that parental care is almost as ancient as animals themselves.

Jean-Bernard Caron at the Royal Ontario Museum in Toronto, Canada, and Jean Vannier of Claude Bernard University Lyon in France report the discovery of 5 well-preserved, 508-million-year-old fossils of the extinct crustacean Waptia fieldensis, with remnants of embryos visible. The specimens showed that Waptia carried broods of around 24 large eggs, each measuring up to 2.5 millimetres across, in a crevice between the body and the shell. The shell may have helped parental care to evolve by providing a safe environment to incubate eggs.

The findings suggest that parental care appeared less than 50 million years after the evolution of animals.

Curr. Biol. (2015)