Louwoichthys pusillus, Xu, 2021

Xu, Guang-Hui, 2021, A new stem-neopterygian fish from the Middle Triassic (Anisian) of Yunnan, China, with a reassessment of the relationships of early neopterygian clades, Zoological Journal of the Linnean Society 191, pp. 375-394 : 377-378

LOUWOICHTHYS PUSILLUS SP. NOV.

( FIGS 1–10)

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Etymology: The epithet is the Latin word pusillus , very little or petty, referring to the small size of the fish body.

Holotype: IVPP V 20421 , a nearly complete, laterally compressed specimen from Luoping.

Referred material: IVPP V 20422 –20425, 22943, 22944, 22946, 22947, 22956–22958 from Luoping, and IVPP V 20597 and 25558 from Luxi, Yunnan.

Locality and horizon: Luoping and Luxi, Yunnan, China; Second (Upper) Member of Guanling Formation, Pelsonian (~244 Mya), Anisian, Middle Triassic ( Zhang et al., 2009; Huang et al., 2013).

Diagnosis: A small-sized louwoichthyid distinguished from other genera of this family by the following features: skull roofing bones tending to be fused into a single plate; most cranial bones (except small regions of frontal, maxilla and preopercle) with smooth surface (*); ratio of frontal/parietal length being 2.5 (*); anterior infraorbital portion of maxilla relatively dorsoventrally short; two pairs of branchiostegal rays; eight or nine principal dorsal rays; seven or eight principal anal rays; 18–20 principal caudal rays; scales with smooth surface; and pterygial formula of D19/ P10–11, A16–18, C28–29/T31–32 (*).

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