First subioblattid roachoid (Insecta: Holopandictyoptera) from the Middle Triassic of Monte San Giorgio (Switzerland)

Abstract

Abstract A fossil attributed to the roachoid family of Subioblattidae, characterized by elongated ellipsoidal forewings and sigmoidal stem of radial vein, is described as Samaroblattella valmarensis sp. nov. The fossil displays a simple subcosta posterior, a long, narrow area posterior to cubitus posterior, with specific wing traits aligning it with Samaroblattella. It differs from Samaroblattella kenderlykensis in the pattern of forewing coloration. The morphology of the hind leg resembles that of the extant jumping cockroach Saltoblattella montistabularis, suggesting a possible jumping behavior, indicative of convergent evolution in Eoblattodea. The elongate ovipositor of this Subioblattidae differs significantly from the reduced ones of the crown group Dictyoptera. Subioblattidae were likely laying their eggs in sediment or plant tissues and did not have hardened ootheca as those in extant lineages. This discovery extends the temporal and geographical range of Samaroblattella, marking it the oldest known representative of the genus and establishing a connection between species from South Africa and Kazakhstan.

Keywords

• Dictyoptera
• Jumping behaviour
• Oviposition
• Middle Triassic
• Monte San Giorgio