Fish beat birds and bees to sex, science says

Never mind the birds and bees: a new article published in Nature reports that the first creatures on Earth to have sex were … fish.

The first known embryos of any type of animal were recently discovered within an extinct class of armoured fish known as Placodermi. A 365-million-year-old fossil of the species, part of the collection at the Natural History Museum in London, features a five-centimetre-long embryo inside.

Scientists have thought that external reproduction was the first method of producing young, so the discovery of internal reproduction from such an early period has shaken up earlier theories. (Any relevance to the fact that this particular fossil was discovered in western Australia, in a rock formation known as the Gogo formation?)

“Sex was far more common in these primitive prehistoric animals,” said museum palaeontologist Zerina Johanson. “We used to think that external fertilisation was the earliest form of reproduction but copulation appears to be  the main way they reproduced, demonstrating that ‘sex’ started a lot sooner than we thought.”