Araneae

Spider spinnerets are abdominal appendages that control silk deployment. Garwood et al. distinguish true spiders from the Carboniferous Idmonarachne fossil, whose preserved underside lacks spinnerets; its spider-like appearance alone does not make it a member of Araneae.

Extensive target-gene and taxon sampling provides a reproducible topology and revised classification for sampled spiders. It does not establish the fossil first appearance, exact crown age or a direct ancestor of Araneae.

The 315–0 Ma Araneae display is an oldest-known-fossil-to-living navigation envelope and does not date spider origination or crown divergence.

Wheeler et al. use extensive target-gene sampling to revise relationships among living spiders, while Garwood et al. distinguish the Carboniferous Idmonarachne from true spiders by its preserved appendages; the combined classification remains a sampled and revisable hypothesis.

The spider fossil review records Carboniferous and younger occurrences, and Wheeler et al. sample living lineages broadly for target-gene phylogeny; these fossil localities and sampled species do not form a complete geographic distribution of Araneae.

The cited spider phylogeny and fossil-origin studies test relationships and preserved anatomy rather than diet, habitat use, locomotor performance, body size or ecological guild; those fields remain unassigned for Araneae here.