jake4480, 
The 5 to 10 millimeter long official first ancestor of scorpions, spiders, and horseshoe crabs from hundreds of millions of years ago was just described, named Setapedites abundantis, and is undergoing further study https://phys.org/news/2024-05-discovery-ancestors-scorpions-spiders-horseshoe.html
#science #history #arthropods #paleontology #scorpions #spiders #HorseshoeCrabs #evolution #biology #fossil #fossils