Skip to main content

New species shows sex is older than we thought

Media release

Curtin University of Technology researchers have lead a team recognised for finding one of the most interesting new species in the past year.

The discovery, a fossil of a fish showing the earliest evidence of giving birth to live young, has changed the way scientists look at the evolution of various species of fish. It has also indicated that sex in vertebrates started much sooner than was previously thought.

Doctor Kate Trinajstic and her team have been recognised by the International Institute for Species Exploration (IISE) for their discovery of this new species of fish, Materpiscis attenboroughi, named after famous naturalist David Attenborough.

The IISE has named the Materpiscis one of the top ten most notable new species discovered in the past year.

For Dr Trinajstic, the discovery highlights the Earth’s amazing diversity of life both now and in past times.

“For someone in my field there is no better feeling than knowing that you have definitely discovered a new species that no one else knew existed,” she said.

The mother fish, discovered with a developed embryo inside of her, is a significant find.

“This find could be considered one of Australia’s most important fossil finds because it represents the world’s oldest vertebrate mother,” Dr Trinajstic said.

“Besides being significant in itself, finding the mother fish was a ‘Rosetta Stone’ that we have been able to use to reinterpret other fossils.

“It has also spurred the team on to search for other evidence of live birth in the fossil record. Another embryo was discovered in a different fish, Incisoscutum ritchiei, which was originally thought to have been that fish’s last meal.”

This find is also significant for science, as it can tell researchers a great deal about the behaviour of different species of fish.

“You cannot have internal fertilisation without evolving complex sexual behaviours and also having major changes in physiology and endocrinology,” Doctor Trinajstic said.

It also shows that it is not only humans that can be involved in some interesting foreplay.

“These groups were the first fish to have jaws. There may be a connection in having jaws and this type of mating, because in modern sharks the males hold the female in position by biting onto her fins.

“This shows us that sex in vertebrates started much sooner in the Earth’s history than we thought.”

This research was the result of collaboration between Curtin University of Technology, The University of Western Australia, Australian National University and the Museum of Victoria.

Dr Trinajstic belongs to Curtin’s new Centre for WA Organic and Isotope Geochemistry directed by Prof. Kliti Grice in the Department of Applied Chemistry, which will move to the new $115 million Resources and Chemistry Precinct on the University’s Bentley Campus from late 2009.