Trochanteriidae
Flat Rock Spider Identification in Australia
A family-level guide to extremely flattened Hemicloea-type ground spiders that shelter beneath bark or rock and are easily confused with huntsmans and newly separated trachycosmids.
Usually low risk“Flat rock spider” is a practical field label here for a possible Australian Trochanteriidae, especially Hemicloea, not one species. Modern research moved most Australian genera formerly called trochanteriids into Trachycosmidae, leaving an important taxonomic boundary that older guides miss. A clear photograph may support a flat-spider group; exact family, genus or species can require expert anatomy.
Quick identification
- Body and legs compressed strongly from top to bottom
- Usually brown, grey or charcoal and shaped to enter very narrow crevices
- Commonly discovered under close-fitting bark, rock, timber or another slab
- No permanent prey-catching web; may run rapidly when shelter is lifted
- Family-level match only unless current taxonomic characters can be checked
What to check next
Compare Hemicloea-type Trochanteriidae with Trachycosmidae, Selenopidae and flattened huntsmans. The common name, shelter and silhouette do not by themselves settle the modern family.
When to seek medical help
No useful Australian species- or family-level clinical bite series was found. Avoid handling. Wash a suspected bite, use a cold pack for local pain and seek medical advice if symptoms are severe or persist; call 000 for breathing difficulty, collapse or another serious reaction.
Where it is usually seen
Narrow spaces beneath bark, rocks, logs, slabs and other close-fitting cover in woodland, dry country, gardens and built environments across Australia.