Species New to Science: Miaojiaaspis

Subclass Galeaspida Tarlo, 1967

Order Eugaleaspiformes (Liu, 1965) Liu, 1980

Family Tujiaaspidae fam. nov.

Type genus Tujiaaspis Gai et al., 2022.

Referred genus Miaojiaaspis gen. nov.

Differential diagnosis Tujiaaspidae differs from other families of Eugaleaspiformes in the short medial dorsal canal, and the branching ends of the lateral transverse canal.

Remarks Our phylogenetic analysis shows that M. dichotomus and T. vividus form a monophyletic clade supported by two synapomorphies.

Genus Miaojiaaspis gen. nov.

Type species Miaojiaaspis dichotomus sp. nov.

Etymology From Miaojia, Pinyin for the Miao People, a minority ethnic group in China, which is one of the two main autonomous minority ethnic groups in Xiushan County, Chongqing, and aspis (Gr.), shield.

Differential diagnosis M. dichotomus differs from T. vividus in a more subtriangular headshield, no highly developed subordinate branches of sensory canals and a shorter median dorsal opening.

Miaojiaaspis dichotomus sp. nov.

Holotype An incomplete headshield with the trunk articulated, CIGMR V0125a, b (Figs. 2–3).

Referred specimens 8 complete headshields, CIGMR V0126–V0129, IVPP V28714–V28717 (Fig. 4).

Etymology From dichotomus (Latin), referring to the dichotomous ends of the lateral transverse canals.

Diagnosis Small-sized eugaleaspiform fish with a subtriangular headshield. Spine-shaped cornual and inner cornual processes caudo-laterally or caudally oriented. Longitudinal oval-like median dorsal opening. Pineal opening positioned behind the posterior margin of the orbits. Funnel-shaped supraorbital canals. Short medial dorsal canal.