Even millions of years ago, Australia was a paradise for spiders.
In the arid heart of the continent, scientists have discovered exquisitely preserved fossils of fascinatingly large spiders that roamed and hunted in what was once lush rainforest.
It’s not just a fossilized spider. This is his fourth spider fossil ever discovered in Australia, and the world’s first fossil of a large spider belonging to the spider family. A new species that lived during the Miocene epoch, 11 million to 16 million years ago, has been officially named. Megamonodontium maculuskie.
“Only four spider fossils have ever been discovered across the continent, making it difficult for scientists to understand the evolutionary history of spiders. That’s why this discovery is so important, “It reveals new information about the extinction and fills a gap in spider fossils,” said palaeontologist Matthew McCurry from the University of New South Wales and the Australian Museum.
“This fossil’s closest living relatives now live in humid forests from Singapore to Papua New Guinea. This is because this group once lived in similar environments on mainland Australia, but later in Australia. This suggests that it became extinct as the area became arid.
The spider was discovered among a rich assemblage of Miocene fossils discovered in a grassy region of New South Wales known as McGrath Flats.
This assemblage is so exceptional that it has been classified as a Lagerstätte, a sedimentary fossil bed in which soft tissues are sometimes preserved.
Some fossils from McGrath Flat even show intracellular structures.
The types of rocks found in the fossil beds make the entire assemblage even more surprising. game site, exceptional fossils are rarely discovered. Because the preservation was so detailed, the researchers were able to identify every detail of the spider’s body and were able to confidently determine that the spider was closely related to modern spiders. monodontium – However, the size is 5 times larger.
It’s not super huge, so monodontium Although typically quite small, it is still the second largest spider fossil ever discovered in the world. Megamonodontium maculuskieThe body size of is 23.31 millimeters, or just under 1 inch. If you spread your legs apart, it might fit in the palm of your hand.
The ancient beast’s enormous size makes the detailed preservation of its physical features even more impressive.
“Scanning electron microscopy allowed us to study the details of the spider’s palps, legs, claws and setae on its body,” said Michael, a virologist at the University of Canberra who scanned the fossil using stacked micrographs. Frese explains.
“Setae are hair-like structures that have a variety of functions. They can sense chemicals and vibrations, protect the spider from attackers, and even make sounds.”
And the discovery may give clues about how Australia has changed over time as the landscape has dried dramatically.not here monodontium or Megamonodontium This suggests that aridification during and after the Miocene was responsible for the local extinction of some spider lineages.
We might even learn something about why there are so few trapdoor spiders in the fossil record.
“This is not only the largest spider fossil ever found in Australia, but also the first fossil of an arachnid found anywhere in the world,” says Queensland Museum arachnologist Robert Raven.
“Currently, there are about 300 species of long-billed spiders, but they don’t seem to turn into fossils very often. This is because they spend a lot of time in their burrows and are not in an environment suitable for fossilization. It will be considered” . ”
This study Zoological journal of the Linnean Society.