
Like the Maulcenia animal, this is an example when he lived his life, more than 500 million years ago. Credit: Nick Straussfield
A new analysis of a highly secure gosh, who lives half a billion years ago, suggests that Arachinds – spiders and their close relatives are roaming the sea, which challenged the large -scale belief that their ordinary ancestors had conquered the earth after their conquest.
The spiders and the scorpions have been for about 400 400 million years, which has little change. The closely associated with the Artrophods has been group as arachinds, they have dominated the ground as the most successful group of arthropoden hunters. Based on their fantasy records, Arachinds looks exclusively residing and diverse on the ground.
In a research headed by Nicholas Strasfield at the University of Arizona and appeared in Existing organismsResearchers from the United States and the United Kingdom conducted a detailed analysis of the fossilized properties of the brain and central nervous system called Molsenia Simmterica.
Until now, it was believed that a native member of a particular group of arthropids, called Chelserates, lived during Cambrien (between 540 to 485 million years ago), and included the ancestors of today’s Harshoshow crabs.
Surprisingly, researchers found that nerve arrangements in Mulcensiana’s brain are not organized like horse tract crabs, as can be expected, but instead they are organized as they are in modern spiders and their relatives.
“It is still being strongly debated where and when Arachinds appeared for the first time, and how their ancestors were cheated,” said Straussfield, a Regent Professor Straussfield in the Nuro Science Department.
Mulcenia apparently resembles some other early Chelstrates from the lower and mid -Cambrian, in which her body consisted of two parts: a wide round “carpess” in the front and a strong, which eliminates a wide, tail -like structure.
Some scientists have cited the organization of a carpase, followed by a scorpion body plan like a segment trunk. But no one claimed that Mulcenia was more foreign than the basal challenge, for example, the ancestors of the horse’s groove shrimp were even more ancient.

Modern imaging techniques allowed the research team to identify the key physical properties in the remnants of the mausoleum of Maulcenia. Credit: Nick Straussfield
Straussfield and his colleagues have to identify the status of Mulcenia as a rashland, its focused brain and nervous system. As in the spiders and other present -day erachinds, the back of the body of Mulcenia (called Prosoma) contains a radling pattern of segments, which controls the movement of five pairs of classes.
In addition to these arachandic features, Maulcenia also revealed an unmarried brain in which the small nerves were extended to a pairs of “paws”, which reminds the fungus of the spiders and other arachinds.
But the decisive feature that shows the atchinded identity is the unique organization of the Mollynide brain, which is the opposite of current crustsian, insects and centuries, and even horse drainage crabs, such as the front -to -back arrangements found in jeans limelis.
“It is as if the Lemolis type brain is seen in Cambrian Jovashim, or the brains of the native and present -day Christians and pests have been turned backwards, which we see in modern spiders,” he said.
According to Frank Herath, co -author of Kings College London, the search for the latter can be an important evolutionary development, as the study of the current spider’s brain shows that these fronts provide shortcuts from neuronal control centers to basic circuits, which are integrated with spider (or spider).
This arrangement potentially hunted, pursuing fast and spiders, hunted hunting, the Web -Web -web -web spinning.
“This is a big step in evolution, which seems to be special to Arachinds,” said Heath. “Until now, in Molisana, we have identified brain domains that are in line with living generations, with which we can predict basic genetic makeup that is common in all arthrrops.”
Straussfield added, “The Arachinide Brain is unlike any other brain on the planet, and it shows that its organization has something to take into control of computational speed and motor action.”

The comparison of the brain of the horse drain (left), the mausenia fossil (center) and a modern spider (right) brains shows the amazing results of this study: the organization of the three mental regions (green, magneta and blue) of Mulcenia is turned upside down when it is in a hug. Credit: Nick Straussfield
According to Strasfeld, the first creature on Earth was probably an evolutionary branch of Milli pad -like arthropids and perhaps some native, insect -like creatures, Christians.
“We can imagine that a maulacenia -like archetype has also been adapted to a life of life, which makes the early insects and mills make their daily diet.”
“When you are pursued by a spider, being able to fly, you have a serious benefit.” “Still, despite their air movements, millions of people have been trapped in magnificent nets of silk by insects.”
For this study, Straussfield spent time at the Museum of Comparative Zoology at Harvard University, where the sample of Mulcenia has been drawn, which has taken several images under different directions of light, light and polarization light.
To reject the possibility that the alliance between the brains and spiders of Mulcenia was the result of a parallel evolution-in other words, instead of getting from the shared lineage, the coincidentally, David Andrew, who is a former graduate triple in the Strasfield Laboratory, is now related to a Pennsylonian trap. Artrophys, both endless and living.
The results kept Maulcenia as the sister of modern Erachinds, and gave more weight on the idea that the lineage of Molisana has given birth to the cloud, which today includes spiders, scorpions, sunflowers, sirkina and whip scorpions.
Unfortunately, arteropads, such as Mulcenia, are not saved in a way that allows them to analyze their nervous system. But if they shared the same unique brain, the authors suggested that their children would have established to divert the tissues that today calculate the various branches of the trees of life.
More information:
Arachinide brain’s Cambrien original, Existing organisms (2025) DOI: 10.1016/j.cub.2025.06.063. www.cell.com/current-biology/f… 0960-9822 (25) 00822-x
Provided by the University of Arizona
Reference: Fosylized nervous system for spiders and relatives indicates (2025, 22 July) on July 22, 2025, https://phys.org/news/2025-07-fossilized-nervous-cean-spiders.html.
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