Old, older, penis
2002-09-15 17:56
Leicester - Sex was first recognised in the fossil records more than 500 million years ago and the oldest known penis is about 100 million years old, a conference heard on Friday.
It belongs to an ostracod, an early crustacean related to crabs, shrimps and water fleas, and was found in a fossil sample unearthed in Brazil.
"To my knowledge it is the oldest penis. I don't know of any older," Professor David Siveter, of the University of Leicester, told the British Association science conference.
Dinosaurs were around 100 million years ago but the only known dinosaur fossils are of bones, not soft tissue.
In fact the ostracod fossil had not one penis but two.
Siveter, an expert in palaeontology, believes ostracods are very sexy animals because they have the second longest sperm in the animal kingdom. A one millimetre ostracod can produce a single sperm 10 millimetres long.
"An ostracod has the longest sperm to body ratio of any animal known to man, so clearly it has to have special equipment to deal with the sperm. It doesn't have one penis, it has two. We found the two penises in a 100 million year old fossil," he said.
By studying gender and sexuality and how far it goes back in the fossil record, Siveter said scientists can learn more about how animal reproduction evolved and behavioural traits.
In a separate presentation, Professor Scott Sampson of the University of Utah Museum of Natural History in the United States said that dinosaurs probably used their enormous horns, pikes, plates and crests to attract the opposite sex, in a similar way that peacocks use their colourful array of feathers.
Some of the appendages were used as weapons but Sampson said others were simply not strong enough to be useful against an enemy and like deer or antelope they used the horns to impress potential mates.
"I think the evidence is quite strong that dinosaurs did too," he said.