Tracheal-respiration
Guides
Myriapoda
myriapods
Myriapoda is a subphylum of terrestrial arthropods comprising approximately 13,000–16,000 described species across four extant classes: Chilopoda (centipedes), Diplopoda (millipedes), Pauropoda, and Symphyla. All myriapods are obligate terrestrial, characterized by elongated bodies with numerous segments bearing legs. The group represents one of the earliest arthropod lineages to colonize land, with fossil evidence dating to the Late Silurian–Early Devonian boundary. Myriapods exhibit diverse ecological roles: centipedes are primarily nocturnal predators using venomous forcipules, while millipedes, pauropods, and symphylans function predominantly as detritivores in soil and leaf litter ecosystems.
Opiliones
harvestmen, harvesters, daddy longlegs, granddaddy longlegs, shepherd spiders
Opiliones is an ancient order of arachnids comprising over 6,650 described species, with estimates suggesting more than 10,000 extant species worldwide. The order includes five suborders: Cyphophthalmi, Eupnoi, Dyspnoi, Laniatores, and Tetrophthalmi. Fossil evidence from 410 million-year-old Devonian deposits demonstrates that harvestmen have remained morphologically conservative since their early evolution. Despite superficial resemblance to spiders, Opiliones represent a distinct arachnid lineage with unique anatomical and behavioral characteristics.
arachnidharvestmandaddy-longlegsancient-lineageomnivorenocturnalgregariouscave-dwellingpaternal-carechemical-defenseautotomymodel-organismconservation-concernvenomlesstracheal-respirationdirect-copulationshort-range-endemictroglobiteaposematiccrypsismimicrythanatosisviscoelastic-adhesiveanurophagyvertebrate-predator