Stylinida

Stylinida is an extinct order of decapod crustaceans that lived from the Jurassic period to the Cretaceous period. These marine animals were characterized by their elongated, slender bodies and the presence of long, slender appendages, particularly their chelipeds (claws). The name "Stylinida" derives from the Greek word "stylos," meaning pillar or column, referring to their distinctive body shape.

Fossil evidence suggests that stylinidans inhabited shallow to moderately deep marine environments. They were likely scavengers or detritivores, feeding on organic matter found on the seafloor. Their elongated claws may have been used for probing soft sediments to uncover food or for defense against predators. The exact phylogenetic placement of Stylinida within Decapoda has been a subject of debate among paleontologists, with some suggesting a relationship to the infraorder Astacidea (lobsters and crayfish) or Axiidea. However, their unique morphology sets them apart.

Notable genera within Stylinida include Stylinella and Stylinopsis. The fossil record of Stylinida is relatively sparse, and many aspects of their biology and behavior remain speculative due to the limited number of specimens and the preservation state of the fossils. The extinction of Stylinida at the end of the Cretaceous period may have been linked to broader environmental changes and the extinction event that marked the end of the Mesozoic Era. Their disappearance highlights the dynamic nature of marine ecosystems and the evolutionary turnover of life forms over geological time.