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What an historical Maya metropolis excavation taught scientists concerning the origins of reef fishes


This article was initially featured on Hakai Magazine, a web based publication about science and society in coastal ecosystems. Read extra tales like this at hakaimagazine.com.

Sixty-nine million years in the past, an asteroid practically 10 kilometers vast slammed into what’s now the Yucatan Peninsula in Mexico. The influence lit huge stretches of the planet on hearth. Soot and mud choked the Earth. As the world burned, temperatures within the ocean plummeted, and creatures that when dominated, together with ammonites, plesiosaurs, and mosasaurs, died out—together with 80 % of the opposite animal species on the planet.

In the void, new life flourished.

Within three million years, new fish species had been thriving on a reef of coral-like algae and enormous tuberous clams simply 500 kilometers from the asteroid’s crater. One day, one in every of these fish—with an elongated snout and a fragile, slender physique—died. It sank to the sandy seafloor the place, together with different animals, the imprint of its skeleton was compressed into limestone.

The ocean receded and, within the seventh century, Maya builders developing temples within the metropolis state of Palenque started quarrying fossil-studded rocks from the now-dry seabed. The petrified creatures got here to tell Maya beliefs a couple of earlier world destroyed by fires and floods. One slab imprinted with fish was introduced into the palace, the place it was painted and adorned with plaster. Palenque’s residents used different fossils, together with megalodon tooth and stingray spines, as chopping instruments or buried them with the dead.

But the skeleton of the long-snouted fish remained buried within the quarry.

When Palenque, like many Maya metropolis states, collapsed within the tenth century, its temples and their fossils had been deserted and swallowed by the forest. They lay forgotten till Spanish colonists started learning the positioning within the 1800s. But it wasn’t till the 2000s that researchers examined the impressions within the limestone extra intently.

The fish fossils present in Palenque had been from species that had by no means been seen earlier than. “It was similar to a film script,” says marine biologist David Bellwood at James Cook University in Australia, who was introduced in to assist establish the fossilized fishes. “We discovered them on the lids of tombs.”

But the extra surprising discovery got here after paleontologists traced the limestone again to the quarry from which it was initially unearthed.

There, after millennia buried in stone, the long-snouted fish lastly noticed gentle—and upended our understanding of fish evolution.

Researchers recognized the fish as a flutemouth, a species whose descendants dwell on fashionable coral reefs. Dozens of different fossils pulled from the quarry included two different households of reef fishes: damselfish and grouper.

Bellwood and his colleagues present in a new study that these fossils signify the earliest identified examples of reef fishes discovered wherever on Earth. Today, we consider grouper, flutemouth, and damselfish as coral reef fishes. But these teams really emerged in a world earlier than fashionable coral, which wouldn’t arrive on the scene for one more 29 million years.

Before this discovery, the oldest proof of reef fishes was from about 50 million years in the past: fossils pulled from what’s now Monte Bolca in northern Italy. Based on the range represented in these Italian fossils, some scientists suspected that reef fishes possible emerged earlier—nearer in time to the asteroid influence. But no fossils from that interval had ever been discovered. The specimens from the Palenque quarry, which date from between 65 and 63 million years in the past, assist fill in that hole.

Although grouper, flutemouth, and damselfish are the one present households represented within the Palenque fossils, Bellwood thinks most different reef fishes possible advanced across the identical time. The examine additionally means that reef fishes emerged within the western Atlantic Ocean, reasonably than the traditional Tethys Ocean, close to present-day Italy, as scientists had thought.

“These fossil deposits are actually necessary for understanding the historical past of coral reef fish,” says David Wainwright, an evolutionary biologist on the University of California, Davis, who was not concerned within the analysis. Wainwright notes that this examine possible isn’t the ultimate phrase on the origins of reef fishes. “We in all probability will ultimately discover one other fossil that’s even older,” he says—perhaps even one from earlier than the asteroid hit.

Bellwood, for his half, is worked up about what should lie hidden within the Palenque quarries. Future excavations might yield much more fossils that additional unravel the historical past of coral reef ecosystems. “Theoretically, there might be all types of fossils in there,” he says. “It might simply be a magical little location.”

This article first appeared in Hakai Magazine, and is republished right here with permission.



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