Tag Archives: arachnida

Order Opiliones: Harvestmen Harvestmen, often known as “daddy longlegs,” are common throughout the world and comprise about 5000 species. They are easily distinguished from spiders: their abdomen and cephalothorax are rounded and broadly joined, without the constriction of a pedicel; their abdomen shows external segmentation; and they have only two …

Order Scorpiones: Scorpions Scorpions are perhaps the most ancient of terrestrial arthropods and comprise about 1400 species worldwide. Although scorpions are more common in tropical and subtropical regions, some occur in temperate zones. Scorpions are generally secretive, hiding in burrows or under objects by day and feeding at night. They …

Arachnids (Gr. arachne¯, spider) exhibit enormous anatomical variation. In addition to spiders, the group includes scorpions, pseudoscorpions, whip scorpions, ticks, mites, daddy longlegs (harvestmen), and others. There are many differences among these taxa with respect to form and appendages. They are mostly free-living and are most common in warm, dry …