| Asaphida Temporal range:
| |
|---|---|
| |
| Asaphus lepidurus | |
Scientific classification 
| |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Arthropoda |
| Class: | †Trilobita |
| Subclass: | †Librostoma |
| Order: | †Asaphida Fortey & Chatterton, 1988 |
| Superfamilies | |
Asaphida is a large, morphologically diverse order of trilobites found in marine strata dated from the Middle Cambrian until their extinction during the Silurian. Asaphida contains six superfamilies (Anomocaroidea, Asaphoidea, Cyclopygoidea, Dikelocephaloidea, Remopleuridoidea and Trinucleioidea), but no suborders. Asaphids comprise some 20% of described fossil trilobites.
In 2020, the superfamily Trinucleioidea was proposed to be raised to an order (Trinucleida) and removed from Asaphida.[1]
- ^ Bignon, Arnaud; Waisfeld, Beatriz G.; Vaccari, N. Emilio; Chatterton, Brian D. E. (2020-07-02). "Reassessment of the Order Trinucleida (Trilobita)". Journal of Systematic Palaeontology. 18 (13): 1061–1077. Bibcode:2020JSPal..18.1061B. doi:10.1080/14772019.2020.1720324. ISSN 1477-2019. S2CID 212995185.