Redlichiida Trilobites

Redlichiida Trilobites and Geological Time Members of trilobite Order Redlichiida (pronouced Red-li-chee-da) are the oldest trilobites known from the fossil record. The Redlichiids appear in the Cambrian Epoch 2 and disappear from the fossil record prior to the Furongian at the end of the Cambrian. The order is believed to contain the progenitors of members of Order Corynexochida, and Order Ptychopariida.

A number of morphological features in the Redlichiids are considered by definition to be the characteristics of the earliest and most primitive trilobites. These include: 1) numerous thoracic segments having spinose tips; 2) large and semicircular cephalon; 3) large crescent-shaped holochroal eyes; 4) and a diminutive (micropygous) pygidium having one to a few segments.

Order Redlichiida is divided into two suborders, Olenellina and Redlichiina. Of the two, the Olenellina are considered to be the earliest trilobites. Primarily due to their lack of facial sutures, some scientists have argued unsuccessfully for their separation from Trilobita. In all likelihood, Olenellina is most closely related to the last arthropod common ancestor of the trilobites. Read more about Redlichiid Trilobites.

Trilobite Order Redlichiida

Suborder Olenellina
- Superfamily Olenelloidea
- Superfamily Judomioidea
- Superfamily Nevadioidea
- Superfamily Fallotaspidoidea
Suborder Redlichiina
- Superfamily Emuelloidea
- Superfamily Redlichioidea
- Superfamily Paradoxidoidea

Also see: Redlichida Trilobites Classification

Redlichiid Trilobite Fossils

Nevadia weeksi	Olenellus fowleri	Olenellus chiefensis	Olenellus gilberti
Lower Cambrian Suborder Olenellina, Superfamily Fallotaspidoidea, Family Nevadiidae Campito Formation, Esmeralda County, Nevada	Lower Cambrian Suborder Olenina, Family Olenellidae Pioche Shale Formation, Nevada	Lower Cambrian Suborder Olenellina Family Olenellidae Pioche Shale Formation, Nevada	Lower Cambrian Suborder Olenellina Family Olenellidae Pioche Shale Formation, Nevada

Nephrolenellus geniculatus	Olenellus terminatus	Mesonacis fremonti	Olenellus thompsoni
Lower Cambrian Suborder Olenellina, Family Olenellidae Pioche Shale Formation, Nevada	Lower Cambrian Suborder Olenellina, Family Olenellidae Carrara Formation, Nopah Range, California	Early Cambrian Family Olenellidae Latham Shale Formation, Marble Mountains California	Early Cambrian Family Olenellidae Kinzer Formation Pennsylvania

Fallotaspis typical	Acadoaradoxides nobilis	Olenellus chiefensis	Balcoracania dailyi
Early Cambrian Suborder Olenellina Family Fallotaspidae Zagora, Morocco	Early Cambrian Suborder Redlichiina Family Paradoxididae Mecissi, Morocco	Lower Cambrian Suborder Olenellina Family Olenellidae Pioche Shale Formation, Nevada	Lower Cambrian Suborder Redlichiina Family Emuellidae Emu Bay Shale, Kangaroo Island, South Australia

Mesonacis eagerensis	Eofallotaspis	Yiliangellina sp	Archaeaspis macropleuron
Early Cambrian Suborder Olenellina Subfamily Mesonacinae Eager Formation, Cranbrook, British Columbia	Early Cambrian Suborder Olenellina Subfamily Fallotaspidinae Campito Formation, Nevada Oldest American Trilobite	Early Cambrian Suborder Redlichiina Superfamily Redlichioidea Family Gigantopygidae Wulongqing Formation, China	Lower Cambrian Suborder Redlichiina Superfamily Fallotaspidoidea Family Archaeaspididae Inyo-White Mountains, California

Esmeraldina sp	Eoredlichia intermedia	Eoredlichia intermedia with Legs Preserved	Eoredlichia intermedia with Antennae
Lower Cambrian Suborder Olenellina Superfamily Olenelloidea Family Holmiidae Esmeraldina County, Nevada	Early Cambrian Suborder Redlichiina Superfamily Redlichioidea Family Redlichiidae Chengjiang Maotianshan Shales, China	Early Cambrian Suborder Redlichiina Superfamily Redlichioidea Family Redlichiidae Chengjiang Maotianshan Shales, China	Early Cambrian Suborder Redlichiina Superfamily Redlichioidea Family Redlichiidae Chengjiang Maotianshan Shales, China

Bristolia insolens	Bristolia mohavensis
Lower Cambrian Suborder Olenellina Superfamily Olenelloidea Family Olenellidae Latham Shale, California	Lower Cambrian Suborder Olenellina Superfamily Olenelloidea Family Olenellidae Pioche Shale, Nevada