The forests of the Late Carboniferous Period (about 300-320 million years ago) were home to a wide variety of arachnids. In addition to the familiar spiders, harvestmen, and scorpions, there were other strange kinds of spider-like animals. new paper this month, paleontology journal a pair of paleontologists explained. douglas sarachne echinopod a large spider-like arachnid with highly spiny legs (presumably to deter predators) from the world-famous Mason Creek fossil site in Illinois, USA.
“douglas sarachne echinopod “It comes from Illinois' famous Mason Creek and is approximately 308 million years old,” said Dr. Paul Selden, a paleontologist at the University of Kansas and the Natural History Museum in London.
“This compact arachnid, about 1.5 cm long, has surprisingly strong, spiny legs, and is completely unlike any other known arachnid, living or extinct.”
“Coal measurements are an important source of information about fossil arachnids and represent the first time in Earth's history that most living groups of arachnids arose together. However, the fauna remains quite different from what it is today. It was different.”
Dr Jason Dunlop, a paleontologist at the Berlin Museum of Nature, said: 'Spiders are a fairly rare group, only known from primitive lineages at the time, and they are similar to a variety of long-extinct arachnids and these. They shared a shared ecosystem.”
“douglas sarachne echinopod is a particularly striking example of one of these extinct forms. ”
“Although this fossil's highly spiny legs are reminiscent of modern harvesters, its body structure is quite different from harvesters and other known arachnid groups.”
douglas sarachne echinopod The researchers discovered that it does not belong to any known order of Araneidae.
“Unfortunately, we can't see details such as the mouth parts, so it's difficult to say exactly which group of arachnids are our closest relatives,” Dr Selden said.
“It may belong to a broader group that includes spiders, whip spiders and whip scorpions.”
“Whatever their evolutionary similarities, these spiny arachnids likely come from a time when arachnids were experimenting with different body plans.”
“Some of these later became extinct, probably shortly after the Mason Creek era, during the so-called 'Carboniferous rainforest collapse,' when coal forests began to fragment and disappear. Or perhaps these strange arachnids are hanging on until the mass extinction at the end of the Permian?”
Specimen douglas sarachne echinopod It was discovered in clay and ironstone concretions by Bob Macek in the 1980s.
Macek introduced a common method of cracking stones by leaving them outdoors in water over the winter, allowing frost to penetrate the natural cracks in the stones along the fossil-containing surface.
A sharp hammer blow split the stone along a plane, exposing the fossil.
Around 1990, David Douglas acquired a specimen from Bob, at which point it became part of the David and Sandra Douglas Collection and was displayed in the Douglas Family Museum of Prehistoric Life.
In 2023, when it became clear that the specimen was a new species, David Douglas donated it to the Field Museum of Natural History for study.
“Genus name douglas sarachne We recognize the Douglas family,” Dr. Dunlop said.
“after that, echinopods “Refers to the animal's unique and distinctive spiny legs.”
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Paul A. Selden and Jason A. Dunlop. A remarkable spiny arachnid from Mason Creek Lagerstätte, Pennsylvania, Illinois. paleontology journal, published online on May 17, 2024. Doi: 10.1017/jpa.2024.13
Source: www.sci.news
