A taxonomical revision of ’Dongfangaspis qujingensis’from the Lower Devonian of Qujing, Yunnan Province

摘要: The affinity of ‘Dongfangaspis qujingensis’, initially assigned to Dongfangaspis but later to Laxaspis, has long been controversial. However, the taxonomical revision raises a new problem of junior homonym since the type species of Laxaspis is L. qujingensis. Here, we describe some new materials of ‘Dongfangaspis qujingensis’ and Damaspis vartus from the Xishancun Formation (early Lochkovian, Early Devonian) in Qujing, Yunnan Province. ‘Dongfangaspis qujingensis’ strikingly resembles Damaspis vartus in the slightly longer headshield, bifurcated ends of the lateral transverse canals, unconnected V-shaped posterior supraorbital canals, and at least seven pairs of lateral transverse canals issuing from the lateral dorsal canal. These similarities indicate that ‘D. qujingensis’ is more suggestive of Damaspis than
Dongfangaspis and Laxaspis. Therefore, we propose to remove ‘Dongfangaspis qujingensis’ from Laxaspis to Damaspis. The new specimens of Damaspis vartus reveal five long lateral transverse
canals on the right side, corroborating that the asymmetric sensory canal system in the holotype is
the intraspecific variation.