Chelicerates By Tony Tedesco, Noah Roberts, Lucas Tekle Characteristics and Behaviors Abstrac/Summary ● One of the most diverse groups of animals ● All have an exoskeleton ● They have evolved from eurypterids and arachnids ● They all came from marine animals ● Some of live in the water some live on land ● They are omnivores Introductory Information ● Chelicerates are sea spiders and horseshoe crabs scorpions, mites, spiders ● Belong to the Arachnida ● They often live under logs, stones, leaves, mold, and other sorts of vegetation ● However some live in saltwater as well as freshwater ● There are 1300 species of sea spiders ● They have six pairs of appendages ● It has 2 different body segments ● Were originally predators, but has diversified to use all the major feeding strategies: predation, herbivory, scavenging, and eating decaying organic matter ● The appendages or chelicerae are usually modified into fangs or pincers ● They constantly patrol large areas ● They move at right angles ● It sucks the liquid out of the prey as food ● Has an Exoskeleton ● They can hear, but they can't distinguish between noises because they can't sense frequencies (they only hear noise). ● Some participate in parental care ● They also have some very unique mating rituals ● They can be deadly to insects, but the great majority are are harmless to vertebrates ● Air breathing chelicerates use internal but usually indirect fertilization ● Most lay eggs that hatch as what look like miniature adults Environment and Evolution ● They live in several environments depending on the species ● These include: beneath stone and logs, in leaf mold, and in vegetation ● There are a few that live in freshwater and the sea ● They are known to have evolved from a common ancestor of eurypterids or arachnids ● Some of the chelicerates have evolved to live in aquatic environments such as sea spiders, horseshoe crabs, and water mites. ● Most of the species complete development with four pairs of legs, but some some have five or six pairs Ecological Analysis ● Chelicerates include species such as insects and fishes. ● Examples of them are scorpions, mites, spiders, and horseshoe crabs. ● They all came from marine animals during the Late Ordovician period. ● An estimated amount of 77,000 air breathing chelicerates have been identified, however, there are 500,000 species that are yet to be discovered. ● There may be 130,000 undescribed species of spiders Acknowledgements/References Conclusion To conclude, Chelicerates are a distinct animal since they are on the older end of the evolutionary scale. Chelicerates come in a variety of shapes and sizes, and each one is distinct from the others. They devour both animals and plants. They can also survive in practically any environment and under the most adverse conditions. This is why they are unique and one of the world's oldest animals. https://www.sciencedirect.com/topics/agricultural -and-biological-sciences/chelicerata https://www.thoughtco.com/ https://www.sciencedirect.com/science/article/pii/ S0960982218306729 https://www.britannica.com/animal/Chelicerata https://www.thoughtco.com/cheliceratesarthropods-129497 https://kids.kiddle.co/Chelicerata#:~:text=Althoug h%20well%20behind%20the%20insects,species %20of%20mites%20and%20ticks.