SCIENCE BRIEFING
Times Staff and Wire Reports
The fossilized remains of two pregnant fish indicate that sex as we know it took place as much as 30 million years earlier than previously thought, researchers said Thursday in the journal Nature.
Scientists studying 380-million-year-old fossils of the armored placoderm fish had thought the fish laid their eggs before fertilization. Then they realized the pelvis of male placoderms had a fin not seen on the female fish, and surmised it was probably used to grip its mate during fertilization, much as sharks do.