cranidium मीनिंग इन हिंदी

Exigua is only known from the central part of the headshield or cranidium, so free cheeks ( or librigenae ), thorax and pygidium are unknown.
Its major characteristics are a wide cranidium, heavy eye ridges, longitudinal striae on the pre-glabellar area, and a small pygidium with few segments.
During molting in trilobites like " Paradoxides ", the rostrum is used to anchor the front part of the trilobite as the cranidium separates from the librigena.
This is known in " Triarthrus ", and in the Phacopidae, but in that family are the facial sutures not functional, as can be concluded from the fact that free cheeks are not found separated from the cranidium.
Cephalon : Cranidium subquadrate, glabella cylindrical, slightly contracted at S3, three pairs of glabellar furrows, preglabellar field short or absent, eye ridge wide, long, directed slightly postero-laterally, palpebral lobe cresentic, posterior area of fixigena with fulcrum, free cheeks ( or librigenae ) with long spines; hypostome conterminant, attached to a narrow rostral plate.