Ptychopariida

Triarthrus novoaustralis

Order Ptychopariida / Suborder Olenina / Family Olenidae

Katian (Late Ordovician)Australia

Triarthrus novoaustralis — photo 1 — Photo 1 · Restoration (Smith et al. 2024) Holotype MMF 47648B (Australia; Smith et al. 2024) Paratypes (Australia; Smith et al. 2024)

Triarthrus novoaustralis — photo 2 — Photo 2 · Restoration (Smith et al. 2024) Holotype MMF 47648B (Australia; Smith et al. 2024) Paratypes (Australia; Smith et al. 2024)

Triarthrus novoaustralis — photo 3 — Photo 3 · Restoration (Smith et al. 2024) Holotype MMF 47648B (Australia; Smith et al. 2024) Paratypes (Australia; Smith et al. 2024)

Classification

Order Ptychopariida / Suborder Olenina / Family Olenidae

Genus

Triarthrus Green, 1832

Genus author

Green J.

Genus etymology

tri-, three; arthr-, Greek, joint

Species

T. novoaustralis Smith, Schoon, Hart, Bicknell, Smith P. M., Schoon I., Hart L. J., Bicknell R. D. C.,

Species author

Hopkins & Zhen, 2024 Hopkins M. J. & Zhen Yongyi

Species etymology

novo-, Latin, new; australis, Latin, southern. Referring to the species occurring in New South Wales, Australia

Age

Katian (Late Ordovician)

Distribution

Australia

Diagnosis

Dorsal shield with tubercles of varying size. Cephalon subsemicircular; anterior border straight; glabella subrectangular with four pairs of glabellar furrows, the anterior two pairs deep; anterior glabellar lobe with a narrow median longitudinal furrow; preglabellar field short; occipital ring of uniform width with a small occipital spine; occipital furrow narrow; palpebral lobes small, in the anterior part opposite the glabella; librigenae narrow with short genal spines. Thorax of 15 segments; axis slightly wider than pleurae, each segment with an axial spine; pleural furrows deep, pleural spines short. Pygidium small; axis with 4 rings plus a terminal piece; pleural and interpleural furrows distinct; border absent.