Asaphida

Symphysurus palpebrosus

Order Asaphida / Superfamily Cyclopygoidea / Family Nileidae

Middle OrdovicianSweden, Norway

Symphysurus palpebrosus — photo 1 — Photo 1 · Lectotype Ar 17066 (Sweden; Fortey 1986) Restoration (Harrington et al., 1959) Literature specimen (Sweden; Fortey Hypostome specimen, the lower figure without terrace lines 1986) (Sweden; Fortey 1986)

Symphysurus palpebrosus — photo 2 — Photo 2 · Lectotype Ar 17066 (Sweden; Fortey 1986) Restoration (Harrington et al., 1959) Literature specimen (Sweden; Fortey Hypostome specimen, the lower figure without terrace lines 1986) (Sweden; Fortey 1986)

Symphysurus palpebrosus — photo 3 — Photo 3 · Lectotype Ar 17066 (Sweden; Fortey 1986) Restoration (Harrington et al., 1959) Literature specimen (Sweden; Fortey Hypostome specimen, the lower figure without terrace lines 1986) (Sweden; Fortey 1986)

Symphysurus palpebrosus — photo 4 — Photo 4 · Lectotype Ar 17066 (Sweden; Fortey 1986) Restoration (Harrington et al., 1959) Literature specimen (Sweden; Fortey Hypostome specimen, the lower figure without terrace lines 1986) (Sweden; Fortey 1986)

Classification

Order Asaphida / Superfamily Cyclopygoidea / Family Nileidae

Genus

Symphysurus Goldfuss, 1843

Genus author

Goldfuss A.

Genus etymology

ymphy-, Greek, glued together

Species

S. palpebrosus (Dalman, 1827)

Species author

Dalman J. W.

Species etymology

palpebr-, Latin, eye, eyelid; -osus, an adjectival suffix meaning "full of"

Age

Middle Ordovician

Distribution

Sweden, Norway

Synonyms

Asaphus palpebrosus; Nileuspalpebrosus

Diagnosis

Cephalon and pygidium subequal, both semicircular. Glabella large, strongly convex, slightly widening anteriorly, surface densely covered with concentric terrace lines, median node at the middle; glabellar and occipital furrows effaced; dorsal furrows deep; palpebral lobes large; librigenae small with rounded genal angles. Thorax of 8 segments; axis slightly narrower than pleurae; pleural spines absent. Pygidial axis short-conical; pleural region smooth; pygidial border absent.

Remarks

This species is the type species of the genus Symphysurus.