Olenellidae

Superregnum: Eukaryota
Cladus: Unikonta
Cladus: Opisthokonta
Cladus: Holozoa
Regnum: Animalia
Subregnum: Eumetazoa
Cladus: Bilateria
Cladus: Nephrozoa
Cladus: Protostomia
Cladus: Ecdysozoa
Cladus: Panarthropoda
Phylum: Arthropoda
Subphylum: †Trilobitomorpha
Classis: †Trilobita
Ordo: †Redlichiida
Subordo: †Olenellina
Superfamilia: Olenelloidea

Familia: Olenellidae
Subfamiliae: Biceratopsinae – Bristoliinae – Gabriellinae – Mesonacinae – Olenellinae – Laudoniinae – Wanneriinae

Overview of genera: Arcuolenellus – Biceratops – Bolbolenellus – Bristolia – Eopeachella – Fremontella – Fritzolenellus – Gabriellus – Lochmanolenellus – Mummaspis – Nephrolenellus – Olenellus – Paedeumias – Peachella – Teresellus
Name

† Olenellidae Walcott, 1890

Type genus: † Olenellus Hall, 1861
References
Primary references

Walcott, C.D. 1890. Descriptive notes of new genera and species from the Lower Cambrian or Olenellus zone of North America. Proceedings of the United States National Museum 12: 33–46. BHL Reference page.

Additional references

Gapp, I.W. & Lieberman, B.S. 2014. New olenelloid trilobites from the Northwest Territories, Canada. Zootaxa 3866(4): 479–498. DOI: 10.11646/zootaxa.3866.4.2 Reference page.

Links

Olenellidae – Taxon details on Fossilworks.

Olenellidae is an extinct family of redlichiid trilobite arthropods. Olenellids lived during the late Lower Cambrian (Botomian/Toyonian) in the so-called Olenellus-zone in the former paleocontinent of Laurentia[1] plus parts of what became the Famatinian orogen in what is now Argentina.[2] This family can be distinguished from most other Olenellina by the partial merger of the frontal (L3) and middle pair (L2) of lateral lobes of the central area of the cephalon, that is called glabella, creating two isolated slits.[1]
Key to the subfamilies
1 The angle in the back rim of the cephalon is less than 15°. Genal spines are reaching back no further than the 6th thorax segment. Spine on the 15th thorax segment almost as wide as the axis.[1]
→ Olenellinae
- The angle in the back rim of the cephalon is more than 25°. Genal spines are reaching back at least to the 8th thorax segment. spine on the 15th thorax segment less than half as wide as the axis.[1]
→ Mesonacinae
References

Lieberman, B.S. (1999). "Systematic Revision of the Olenelloidea (Trilobita, Cambrian)" (PDF). Bulletin of the Peabody Museum of Natural History. 45.
Dalla Salda, Luis H.; Dalziel, Ian W.D.; Cingolani, Carlos A.; Varela, Ricardo (1992). "Did the Taconic Appalachians continue into southern South America?". Geology. 20 (12): 1059–1062. doi:10.1130/0091-7613(1992)020<1059:dttaci>2.3.co;2.