Fossil of Pincer-Wielding Crawler Reveals Origins of Spiders, Scorpions and Others The Trilobites column over at the New York Times has a interesting story about the origin of chelicerates - spiders, scorpions, mites, horseshoe crabs, and others. Chelicerates are a diverse group of arthropods that consists of more than 120,000 known species. Member of this group are classified by having a pair of appendages called chelicerae. These appendages are adapted for various purposes like snatching prey, injecting venom, and even spinning silk.

Fossil of Pincer-Wielding Crawler Reveals Origins of Spiders, Scorpions and Others #fossils #paleontology #WheelerShale #Utah #arthropods #chelicerates #Cambrian

1/5 Try that speaking 3x fast! #chelicerates #HorseshoeCrab #linocut

Arachnid evolution redefined: Whole-genome duplications and multiple land colonizations A recent paper provides an updated perspective on the evolutionary history of chelicerates—a diverse and ecologically significant group of arthropods that includes spiders, scorpions, mites, and horse...

#Arachnid #evolution redefined: Whole-#genome duplications and multiple land #colonizations.

#chelicerates #phylogenomics

phys.org/news/2025-02...

A reconstruction of Pentecopterus decorahensis by Patrick Lynch. These large sea scorpions lived during the Ordovician, ~450 mya!

A black and white illustration of large Eurypterid. via Ernst Haeckel from “Artforms in Nature” c. 1899

Eurypterids are a group of animals that are sometimes called “sea scorpions”. They were chelicerates, like scorpions and spiders, but they were aquatic.

They were predators, and lasted from at least the mid-Ordovician to the end Permian (~ 460–250). (2/?)

#paleontology #invertebrates #chelicerates