Redlichiina

Taxobox
name = "Redlichiina"
fossil_range = Cambrian


image_width = 240px
image_caption = "Redlichia takooensis" , a member of the trilobite suborder Redlichiina.
Lower Cambrian Emu Shale
Kangaroo Island, South Australia
(© Dave Simpson)
regnum = Animalia
phylum = Arthropoda
classis = Trilobita
ordo = Redlichiida
subordo = Redlichiina
subdivision_ranks = Superfamilies
subdivision =
* Superfamily Emuelloidea
* Superfamily Redlichioidea
** Abadiellidae
** Chengkouaspidae
** Dolerolenidae
** Gigantopygidae
** Kuechowiidae
** Mayiellidae
** Menneraspididae
** Metadoxididae
** Redlichiidae
** Redlichiidae
*** "Redlichia takooensis"
** Saukiandidae
** Yinitidae
* Superfamily Paradoxidoidea
** Centropleuridae
** Paradoxididae
*** "Paradoxides"
** Xystriduridae

Redlichiina is a suborder of the order Redlichiida of Trilobites. The suborder contains three superfamilies: Emuelloidea, Redlichioidea and Paradoxidoidea. These trilobites are some of the oldest trilobites known. They originated at the beginning of the Cambrian era and disappeared (possibly by evolving into members of the Ptychopariida order) at the end of the middle Cambrian.

Physiology

(See the Trilobite article for a definition of morphological terms)

Cephalon: Opisthoparian facial sutures. Early forms tend to have tapering, conical glabella with furrows extending far backwards while later forms with glabella expanding forwards to inflated frontal lobe. The hypostome is conterminant (e.g., Redlichia) or natant (e.g., Dolerolenus). The rostral plate is narrower than in suborder Olenellina, bound by rostral and connective sutures.

Thorax: Fulcrate or non-fulcrate, typically with many segments (60+ in an Emmuelid). The axis is infrequently spine-bearing.

Pygidium: Typically small, but can be larger and with many segments.

References