‘Impossible’ Hybrid Suggests Non-Darwinian Change July 28, 2020 | David F. Coppedge Animals may be more capable of sharing genetic information than coming up with it de novo. What is a sturdlefish? It’s a cross between a sturgeon and a paddlefish. But this is no silly riddle for middle schoolers. It’s a reality that biologists thought was impossible: two species of fish from different continents that interbred and produced live offspring, even though their “common ancestor” supposedly lived 184 million years ago.