13 October,2010 05:06 PM IST | | Agencies
New research from the Gogo Formation of Western Australia suggests that fish were the first to have intimate sex by copulation.
Well-preserved fossils of extinct armoured fish belonging to in the early Devonian Period around 400 to 410 million years ago suggest that the activity of sex wasn't just "spawning in water, but sex that was fun", according to project leader John Long.
"Jaws might not have first evolved for feeding, as widely presupposed, but to facilitate copulatory mating," Discovery News quoted Long as saying.
"In many sharks the jaws are used to hold on to pectoral fins of females so copulation can take place," he added.
"Our finds show that these extinct armored fishes, the placoderms, had intimate copulation with males inserting claspers (a structure that is part of the pelvic fin) inside the female to deposit sperm," Long said.
The find is important because "it means that an advanced form of reproduction involving copulation and live-bearing was more widespread than previously thought."
Long explained that that limbs and genitals developed via the same developmental pathways, so fossils showing the oldest evidence of pelvic fins (the placoderms) also showing the oldest expression of sexual organs (claspers) might not be such a coincidence.
Long and his team announced the determinations today at the Society of Vertebrate Paleontology''s 70th Anniversary Meeting in Pittsburgh.
