Ptychopariida

Hypermecaspis inermis

Order Ptychopariida / Suborder Olenina / Family Hypermecaspididae

Tremadocian (Early Ordovician)Argentina

Hypermecaspis inermis — photo 1 — Photo 1 · Holotype CPBA 4377 (Argentina; Harrington et al., Restoration (Harrington et al., 1957) (Argentina; Harrington et al., 1957) 1957) Literature specimen (Argentina; Harrington et al., 1957)

Hypermecaspis inermis — photo 2 — Photo 2 · Holotype CPBA 4377 (Argentina; Harrington et al., Restoration (Harrington et al., 1957) (Argentina; Harrington et al., 1957) 1957) Literature specimen (Argentina; Harrington et al., 1957)

Hypermecaspis inermis — photo 3 — Photo 3 · Holotype CPBA 4377 (Argentina; Harrington et al., Restoration (Harrington et al., 1957) (Argentina; Harrington et al., 1957) 1957) Literature specimen (Argentina; Harrington et al., 1957)

Hypermecaspis inermis — photo 4 — Photo 4 · Holotype CPBA 4377 (Argentina; Harrington et al., Restoration (Harrington et al., 1957) (Argentina; Harrington et al., 1957) 1957) Literature specimen (Argentina; Harrington et al., 1957)

Classification

Order Ptychopariida / Suborder Olenina / Family Hypermecaspididae

Genus

Hypermecaspis Harrington & Leanza, 1957

Genus author

Harrington H. J. & Leanza A. F.

Genus etymology

hyper-, Greek, excessive, elevated, beyond, above, outside; mec-, Greek, length, height; aspis, Greek, shield

Species

H. inermis Harrington & Leanza, 1957

Species author

Harrington H. J. & Leanza A. F.

Species etymology

inermis, unarmed, spineless

Age

Tremadocian (Early Ordovician)

Distribution

Argentina

Diagnosis

Cephalon subtrapezoidal to semi-elliptical, transversely wide; glabella slightly narrowing forward with truncate front and 5 pairs of lateral glabellar furrows; occipital ring trilobate; preglabellar field extremely narrow; palpebral lobes medium-long; librigenae wide, with flat borders, widest at the genal angles, which are rounded and slightly protruding forward. Thorax of 19 segments; axis subequal in width to pleurae; pleural fulcra very close to the axis, pleural furrows deep and long, pleural spines short and pointed. Pygidium elliptical; axis rather short, with a postaxial ridge and 5 or 6 axial rings; pleural region with 5 or 6 pleural ribs, pleural furrows distinct, interpleural furrows faint; border wide, without a border furrow.

Remarks

This species is the type species of the genus Hypermecaspis.