The ancestor of the scorpion and the spider turned out to be a "big-eyed cute" person.

Discover the oldest known chelipods

500 million years ago, in a sea of Burgess, Canada, only the size of a thumb Morrison worm, quietly waiting, once there are small larvae, worms swimming by, it will wait for the opportunity to move, with pliers quickly grasp, into the mouth ...

Morrison was discovered in canada's Burgess Shale a century ago by American paleontologist Charles Woccott, but only exoskeletons were found at the time, limiting scientists' further study of it.

A century later, Cedric Aria, a French postdoctoral fellow from The Zhu Maoyan's research group at the Nanjing Institute of Geology and Paleontology of the Chinese Academy of Sciences, in collaboration with his counterparts at the Royal Museum of Ontario in Canada, took a specimen from the new fossil site of the Burgess Shale, "Marble Valley", to study Morrison's worm in depth, and this time they had a surprising new discovery.

The new species of Morrisonia discovered this time has a body length of about 2.5 cm. Although only the size of a thumb, its specimen preserves more precise information.

Aria et al. found that Morrisonia developed a pair of small pincer-like appendages called "claws" in front of its mouth. It has large, oval eyes, long walking limbs, and a "multifunctional" head with multiple pairs of appendages that perform sensory, gripping, crushing, and chewing functions, respectively. This pair of typical appendages allows it and arthropods such as scorpions and spiders to kill, pinch and chop prey.

The discovery advanced the origin of crayons to 500 million years ago, about 30 million years earlier than previously confirmed dates of origin.

They are "relatives" with scorpions and spiders

The new species of Morrison insect discovered by the researchers this time belongs to the arthropod phylum, commonly known as arthropods. A typical arthropod can be divided into three parts: head, thorax, and abdomen, or the head and chest are healed into cephalothorax, or the chest and abdomen are healed as trunks, and each body segment has a pair of appendages. Well-known shrimp, crabs, mosquitoes, flies, butterflies, spiders, centipedes and extinct trilobites are arthropods.

The living arthropods are mainly divided into two categories: one is the claws represented by scorpions, spiders, tick mites, horseshoe, etc.; The other group is composed of polypods (represented by centipedes, horses, etc.), crustaceans (represented by shrimp, crabs, etc.) and hexapods (represented by insects).

About 540 million years ago, there was a "Cambrian explosion" of life on Earth, and the vast majority of arthropod taxa have originated or even radiated, but it has not been clear whether cheetus has originated in the Cambrian.

Prior to this, although some Cambrian arthropods had obvious chelating-like features, the most typical "claws" of cerules had not been confirmed in Cambrian fossils.

Helps to learn more about the "Cambrian Explosion"

Morrison's insect has well-developed walking feet and is a predator that lives on the seabed. Their similar morphology to that of modern crayons suggests that crayons most likely originated earlier in the Cambrian period and quickly occupied the benthic niches where other arthropods were less involved.

Aria said: "The discovery of new species of Morrisonia further indicates that biological explosions during the Cambrian period saw the emergence of many complex species in the modern sense, which we tend to think of in early studies as closer to simple species. ”

At present, crayons are a huge group of arthropods with more than 115,000 species, and figuring out their origins will continue to improve people's understanding of the origin and evolution of animals on Earth, especially the magical "Cambrian explosion".

At the same time, this new discovery further demonstrates the scientific importance of the Cambrian fossil pool. Cambrian fossil repositories such as the Burgess Shale in Canada and the Chengjiang Biota in China have preserved the rapidly diversifying animal body shapes and earliest marine animal communities in the Cambrian Explosion.

Zhao Fangchen, a team member and researcher at the Nanjing Institute of Geology and Paleontology of the Chinese Academy of Sciences, said: "These fossils fully show the morphological characteristics of animals' soft bodies, including appendages, eyes, digestive tract and even nerve tissue. The discovery of new species of Morrisonia corroborates the central importance of the Cambrian fossil bank, which provides the earliest community samples for studying the diversity of rapid biological development in the Cambrian explosion. ”