A prehistoric fish which roamed the seas almost 400 million years ago has been unveiled by scientists as the “oldest mother ever discovered”.
The fossilised placoderm - a now extinct, armoured fish - was discovered in Western Australia complete with a perfectly preserved embryo and umbilical cord.
Dr John Long, Head of Sciences at Museum Victoria, points out the umbilical cord on the fossil
Scientists have hailed the discovery as not only the earliest example of an animal giving birth to live young, but also the oldest evidence of vetebrates having "sex that was fun".
The 10in fossil, dug up at the Gogo rock formation, east of the remote town of Fitzroy Crossing, has been named Materpiscis Attenboroughi - 'Attenborough's mother fish' - after the naturalist Sir David Attenborough.
Thought to be at least 380 million years old, the find pushes back the record for a live birth by 200 million years.
"It dawned on me after studying the specimen that this was the earliest evidence of vertebrates having sex by copulation - not just spawning in water, but sex that was fun."
An Antarctic fur seal has been observed trying to have sex with a king penguin.
The South African-based scientists who witnessed the incident say it is the most unusual case of mammal mating behaviour yet known.
The incident, which lasted for 45 minutes and was caught on camera, is reported in the Journal of Ethology.
Why the seal attempted to have sex with the penguin is unclear. But the scientists who photographed the event speculate that it was the behaviour of a frustrated, sexually inexperienced young male seal.
The penguin flapped its flippers and attempted to stand and escape - but to no avail.
The seal then alternated between resting on the penguin, and thrusting its pelvis, trying to insert itself, unsuccessfully.
After 45 minutes the seal gave up, swam into the water and then completely ignored the bird it had just assaulted, the scientists report.
The penguin did not appear to have been injured by the seal, the scientists report.