125-million-year-old fossil reveals 'pregnant' shellfish

An international team of scientists led by Dr.

Graciela Delvene of the Geological and Mining Institute of Spain (CSIC) has uncovered the oldest known evidence of maternal care in shellfish, revealing that some freshwater species were protecting and incubating their young more than 125 million years ago.

Published today in Scientific Reports, the new research found fossilized soft tissues preserved inside ancient shells.

This is a remarkable discovery because such tissues normally decay soon after an animal dies.

Among these tissues were microscopic embryos and larvae preserved within the gills. ...