Washington: A new research has found that the males of some ancient fish species called "dinosaurs of the sea" had penetrative sex and gave birth to live young, just like today's sharks.
An international team, which carried out the research, has claimed that it demonstrates that some fish species as far back as 380 million years ago engaged in penetrative sex and gave birth to live young, the Nature journal reported.
These findings, involving the identification of claspers in a fossil of a male Incisoscutum, exceed the oldest known date for vertebrates by approximately 200 million years. The Incisoscutum is an extinct species of placoderm, a primitive, shark-like armoured fish. Placoderms were dominant creatures of the Earths oceans for around 70 million years, until their extinction about 360 million years ago.
Lead researcher Kate Trinajstic of Curtin University of Technology said their discovery shed light on the evolution of vertebrates on Earth, including our own species.
"This discovery provides a link in the chain of evolution that scientists have been uncovering for over a century. It is the first time that we have been able to determine the sex of the fossil fish we study.
"We now know that nearly all the fish we have collected are female, with only a few males represented. This suggests that males and females lived separately for most of the time and only came together to reproduce."