Triglypta jiyuanensis Liao & Huang sp. nov.

urn:lsid:zoobank.org:pub: 5FAACDA1-59A9-4DDE-AB7B-8CE71A74B5FB

(Figs 2, 3)

Material. Holotype, NIGP203506, a complete individual. Paratypes, NIGP203503–203505, 203507–203508.

Etymology. After the Jiyuan City, from where the specimens were collected.

Diagnosis. Carapace round to oval, with a small larval valve; dorsal to middle area of the carapace ornamented with sparse micro-punctae; linear arrangements of punctae and radial lirae present at the middle to anterior part of the carapace.

Type locality and horizon. Maao Formation near the Anyao Village, Jiyuan City; lowermost Upper Jurassic (Oxfordian).

Description. Carapace round to oval in outline, moderate in size (L= 4.2–6.1 mm, 5.1 mm in average; H= 2.9–4.6 mm, 3.8 mm in average; H/L=0.65–0.80, 0.73 in average; Fig. 2); larval valve small; umbo in medial and marginal position (Fig. 2); dorsal margin very short and slightly arched; growth bands fine and densely distributed, 22–28 in number (24 in average; Fig. 2); growth bands ornamented with micro punctae (2–5 μm in diameter; Fig. 3); punctae sparse distributed at the upper to middle part of the carapace (Fig. 3A, B); punctae gather together to form linear arrangements at the middle to anterior part (Fig. 3C–H); linear arrangements extremely prominent at the anterior part (Fig. 3E, G, H); each linear arrangement formed by two rows of punctae (Fig. 3D, F, G); radial lirae present between linear arrangements (Fig. 3D, F, G); linear arrangements and radial lirae not prominent at the posterior part of the carapace.