The fossilized remains of two pregnant fish indicate that sex as we know it — fertilization of eggs inside a female — took place as much as 30 million years earlier than previously thought, researchers said on Thursday.
Scientists from Australia and Britain studying 380 million-year-old fossils of the armored placoderm fish, or Incisoscutum richiei, said they were initially confused when they realized that the two fish were carrying embryos. They originally thought the fish laid their eggs before fertilization.
“Once we found embryos in this group, we knew they had internal fertilization. But how the hell are they doing it?” said John Long, the head of sciences at the Museum Victoria in Melbourne who wrote a paper on the discovery that appeared in Thursday’s issue of the journal Nature.
The answer came when the scientists re-examined the pelvis of the male placoderm, armed with the new information about fertilization.
After looking at specimens at the Natural History Museum in London and the Museum Victoria, they realized the pelvis had a fin not seen on the female fish and surmised it was likely used to grip its mate during fertilization, much as sharks do.
“These fish have an extra large bone that attaches to the pelvic bone,” he said. “It had been overlooked and hadn’t been identified. So in a nutshell, we have reinterpreted the structure of the pelvic bone in these placoderms to show they had a method for copulation.”
Zerina Johanson, a paleontologist at the Natural History Museum who also took part in the study along with the University of Western Australia’s Kate Trinajstic, said findings of internal fertilization showed that “sex started a lot sooner than we thought.”
“We expected these early fish would show a more primitive type of reproduction, where sperm and eggs combine in the water and embryos develop outside fish,” Johanson said in a statement.
Per Ahlberg, a professor of evolutionary organismal biology at Uppsala University in Sweden who did not take part in the study, said the discovery “may prove to have far-reaching implications for our understanding of early vertebrate evolution.”
“Every once in a while, a discovery comes along that puts our biological understanding of some extinct group of organism on much firmer footing,” Ahlberg wrote in Nature. “Long and colleagues present such a discovery.”
Long first became enamored with the reproductive skills of this ancient fish last year, when his team identified the first placoderm containing embryos at the Gogo dig site in Western Australia.
The 380 million year old fossils were hailed as one of the most important discoveries in Australia and the fossil represents the world’s oldest known vertebrate mother. The site, which Long has worked since 1986, is believed to have once been the home of an ancient tropical reef that would have rivaled the Great Barrier Reef.
A fire caused by a burst gas pipe yesterday spread to several homes and sent a fireball soaring into the sky outside Malaysia’s largest city, injuring more than 100 people. The towering inferno near a gas station in Putra Heights outside Kuala Lumpur was visible for kilometers and lasted for several hours. It happened during a public holiday as Muslims, who are the majority in Malaysia, celebrate the second day of Eid al-Fitr. National oil company Petronas said the fire started at one of its gas pipelines at 8:10am and the affected pipeline was later isolated. Disaster management officials said shutting the
US Vice President J.D. Vance on Friday accused Denmark of not having done enough to protect Greenland, when he visited the strategically placed and resource-rich Danish territory coveted by US President Donald Trump. Vance made his comment during a trip to the Pituffik Space Base in northwestern Greenland, a visit viewed by Copenhagen and Nuuk as a provocation. “Our message to Denmark is very simple: You have not done a good job by the people of Greenland,” Vance told a news conference. “You have under-invested in the people of Greenland, and you have under-invested in the security architecture of this
Japan unveiled a plan on Thursday to evacuate around 120,000 residents and tourists from its southern islets near Taiwan within six days in the event of an “emergency”. The plan was put together as “the security situation surrounding our nation grows severe” and with an “emergency” in mind, the government’s crisis management office said. Exactly what that emergency might be was left unspecified in the plan but it envisages the evacuation of around 120,000 people in five Japanese islets close to Taiwan. China claims Taiwan as part of its territory and has stepped up military pressure in recent years, including
UNREST: The authorities in Turkey arrested 13 Turkish journalists in five days, deported a BBC correspondent and on Thursday arrested a reporter from Sweden Waving flags and chanting slogans, many hundreds of thousands of anti-government demonstrators on Saturday rallied in Istanbul, Turkey, in defence of democracy after the arrest of Istanbul Mayor Ekrem Imamoglu which sparked Turkey’s worst street unrest in more than a decade. Under a cloudless blue sky, vast crowds gathered in Maltepe on the Asian side of Turkey’s biggest city on the eve of the Eid al-Fitr celebration which started yesterday, marking the end of Ramadan. Ozgur Ozel, chairman of the main opposition Republican People’s Party (CHP), which organized the rally, said there were 2.2 million people in the crowd, but