Fish Fossil Catch from China Includes Oldest Teeth Ever

This illustration provided by Heming Zhang in September 2022 depicts Xiushanosteus mirabilis, one of the fossil fish, more than 400 million years old, which were found by researchers in southern China, announced in a series of studies published in the journal Nature on Wednesday, Sept. 28, 2022. (Heming Zhang via AP)
This illustration provided by Heming Zhang in September 2022 depicts Xiushanosteus mirabilis, one of the fossil fish, more than 400 million years old, which were found by researchers in southern China, announced in a series of studies published in the journal Nature on Wednesday, Sept. 28, 2022. (Heming Zhang via AP)
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Fish Fossil Catch from China Includes Oldest Teeth Ever

This illustration provided by Heming Zhang in September 2022 depicts Xiushanosteus mirabilis, one of the fossil fish, more than 400 million years old, which were found by researchers in southern China, announced in a series of studies published in the journal Nature on Wednesday, Sept. 28, 2022. (Heming Zhang via AP)
This illustration provided by Heming Zhang in September 2022 depicts Xiushanosteus mirabilis, one of the fossil fish, more than 400 million years old, which were found by researchers in southern China, announced in a series of studies published in the journal Nature on Wednesday, Sept. 28, 2022. (Heming Zhang via AP)

A big catch of fish fossils in southern China includes the oldest teeth ever found — and may help scientists learn how our aquatic ancestors got their bite.

The finds offer new clues about a key period of evolution that’s been hard to flesh out because until now scientists haven't found many fossils from that era. In a series of four studies, published Wednesday in the journal Nature, researchers detail some of their finds, from ancient teeth to never-before-seen species.

The fossils date back to the Silurian period, an important era for life on earth from 443 million years ago to 419 million years ago. Scientists believe our backboned ancestors, who were still swimming around on a watery planet, may have started evolving teeth and jaws around this time.

This let the fish hunt for prey instead of "grubbing around" as bottom feeders, filtering out food from the muck. It also sparked a series of other changes in their anatomy, including different kinds of fins, said Philip Donoghue, a University of Bristol paleontologist and an author on one of the studies.

"It’s just at this interface between the Old World and the New World," Donoghue said.

But in the past, scientists haven’t found many fossils to show this shift, said Matt Friedman, a University of Michigan paleontologist who was not involved in the research. They’ve been relying on fragments from the time — a chunk of spine here, a bit of scale there.

The fossils from China are expected to fill in some of those gaps as researchers around the world pore over them.

A field team discovered the fossil trove in 2019, Min Zhu, a paleontologist at the Chinese Academy of Sciences who led the research, said in an email. On a rainy day, after a frustrating trip that hadn't revealed any fossils, researchers explored a pile of rocks near a roadside cliff. When they split one rock open, they found fossilized fish heads looking back at them.

After hauling more rocks back to the lab for examination, the research team wound up with a huge range of fossils that were in great condition for their age.

The most common species in the bunch is a little boomerang-shaped fish that likely used its jaws to scoop up worms, said Per Erik Ahlberg of Sweden’s Uppsala University, an author on one of the studies.

Another fossil shows a sharklike creature with bony armor on its front — an unusual combination. A well-preserved jawless fish offers clues to how ancient fins evolved into arms and legs. While fossil heads for these fish are commonly found, this fossil included the whole body, Donoghue said.

And then there are the teeth. The researchers found bones called tooth whorls with multiple teeth growing on them. The fossils are 14 million years older than any other teeth found from any species — and provide the earliest solid evidence of jaws to date, Zhu said.

Alice Clement, an evolutionary biologist at Australia’s Flinders University who was not involved with the research, said the fossil find is "remarkable" and could rewrite our understanding of this period.

The wide range of fossils suggests there were plenty of toothy creatures swimming around at this time, Clement said in an email, even though it's the next evolutionary era that is considered the "Age of Fishes."



China Heatwaves Boost Ice Factory Sales

A worker uses tongs to move ice blocks inside a refrigerated store at the Feichao Ice Factory in Hangzhou. Heatwaves across China have caused demand for ice to soar  - AFP
A worker uses tongs to move ice blocks inside a refrigerated store at the Feichao Ice Factory in Hangzhou. Heatwaves across China have caused demand for ice to soar - AFP
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China Heatwaves Boost Ice Factory Sales

A worker uses tongs to move ice blocks inside a refrigerated store at the Feichao Ice Factory in Hangzhou. Heatwaves across China have caused demand for ice to soar  - AFP
A worker uses tongs to move ice blocks inside a refrigerated store at the Feichao Ice Factory in Hangzhou. Heatwaves across China have caused demand for ice to soar - AFP

In a high-ceilinged room on the outskirts of eastern China's Hangzhou, workers use tongs to slide large blocks of frosty white ice along a metal track into a refrigerated truck.

Sales have picked up in recent weeks, boosted by heatwaves sweeping the whole country as summer sets in, the owner of Feichao ice factory, Sun Chao, told AFP.

Globally, heatwaves are becoming more frequent and intense because of climate change, experts say, and China is no exception -- 2024 was the country's hottest on record, and this year is also set to be a scorcher.

Last week, authorities warned of heat-related health risks across large swathes of eastern China, including Zhejiang province where Hangzhou is located.

"In the spring, autumn, and winter, a higher temperature of two to three degrees doesn't have a big impact on our sales," Sun said.

"But in the summer, when temperatures are slightly higher, it has a big impact."

Feichao is a relatively small facility that sells ice to markets, produce transporters, and event organizers.

As the mercury soared past 40 degrees Celsius (104 degrees Fahrenheit) in multiple cities across China recently, ice from businesses like Sun's was used to cool down huge outdoor venues.

In neighbouring Jiangsu province, organisers of a football match attended by over 60,000 people placed more than 10,000 large blocks of ice around the stadium, according to the state-owned Global Times.

As AFP watched lorries being loaded with Feichao's ice on Wednesday, an employee from a nearby seafood shop came on foot to purchase two ice blocks -- each selling for around $3.50 -- hauling them off in a large plastic bag.

"In May and June, I can sell around 100 tonnes a day. In July, that number grows, and I can sell around 300 to 400 tonnes," Sun told AFP.

China has endured a string of extreme summers in recent years.

In June, authorities issued heat warnings in Beijing as temperatures in the capital rose to nearly 40 degrees Celsius, while state media said 102 weather stations across the country logged their hottest-ever June day.

The same month, six people were killed and more than 80,000 evacuated due to floods in southern Guizhou province.

China is the world's biggest emitter of the greenhouse gases that scientists generally agree are driving climate change and making extreme weather more intense and frequent.

It is also a global leader in renewable energy, adding capacity at a faster rate than any other country.