The most ancient roach (Blattodea): a new genus and species from the earliest Late Carboniferous (Namurian) of China, with a discussion of the phylomorphogeny of early blattids

Abstract

The most ancient known roach, Qilianiblatta namurensis gen. et sp. nov. from the earliest Pennsylvanian (Namurian B/C) Qilianshan entomofauna, is described from material excavated in the Qilianshan Mountains of north-western China. The new genus is characterized by a mosaic of plesiomorphic and apomorphic features typical of various Euramerican and Angaran Late Palaeozoic blattid genera. Despite a limited time gap between the age of Q. namurensis and that of the previously known oldest blattids (archimylacrids of Westphalian A age, 1–2 Ma younger), the pattern of main veins and cross venation of Q. namurensis appears in some regards more advanced. This is particularly apparent in the only weakly expressed primary dichotomy of main veins and the relatively modern aspect of the cross venation. The new taxon raises questions regarding the polyphyletic origin of the ‘phyloblattoid' groundplan, namely once in the Euramerican biotic province at the end of the Westphalian and stemming from archimylacrids, and earlier in the Cathaysian (–Angaran?) biotic province from forms like Qilianiblatta. Forewings of Q. namurensis are clearly protective wings (tegmina) and probably were not involved directly in the production of lift during flight. These wings are considerably advanced relative to the earliest diversification of the winged insects and the general groundplan for hexapodan wings. It is possible that winged blattids appeared as early as the Devonian. http://zoobank.org/urn:lsid:zoobank.org:pub:85EE542A-5A05-4790-9F67-ABE3FE85FF83