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The earliest termite of the extant genus Mastotermes, is herein recorded in the Jurassic/Cretaceous (J/K) transitional beds of Chernovskie Kopi in Transbaikalian Russia along with Santonitermes of an uncertain family. These records represent the earliest eusocial organisms. No termites have ever been recorded among the hundreds of thousands of fossil insects in the Jurassic/Cretaceous boundary Beds of China and Mongolia or in prior time periods. Both genera indicate that the early termites survived for an extremely long period of time. The present find both provides evidence of the greatest ghost range (60 Mya) of any winged stem cockroach family and indicates that the origin of termites and evolution of eusociality occurred later than the Middle Jurassic.

There is little fossil evidence for cave arthropods. Small size, disfunctional wings, extremely long antenna, dense minute setation, palidity and reduced eyes are typical adaptations to life in caves shown by the cockroach Mulleriblattina bowangi gen. et sp. n., found together with epigeic Crenocticola svadba sp. n., both from Myanmar amber and belonging to the cavernicolous cockroach family Nocticolidae. These lineages of earliest still living cavernicoles suggest large, numerous caverns, lava tubes or caves within the source area. They provide the first unequivocal evidence for the Mesozoic origin of any living troglomorphic organism, and explain the "long branches" in DNA analyses. Phylogenetic trees show little hierarchical structure and place Latindiinae and Myrmecoblatta within the explosively radiating Nocticolidae. Biogeography indicates a common cosmopolitan Early Cretaceous ancestor except for 8 (of 49) species of true Nocticolidae, which diverged during the Late Cretaceous breakup of Gondwana. A review of all troglofauna documents no other unequivocal pre-Cenozoic cave biotas (including vertebrates). Stable environments and small populations result in a short-time (˂3 Ma) origination of bizarre forms and long term extinctions (˃30 Ma). Unlabelled Image • All cave organisms including vertebrates reveal Cenozoic origin. • Why all cave fauna of the Mesozoic went extinct becomes now a big enigma. • Exceptions are herein described cockroaches from Myanmar amber. [ABSTRACT FROM AUTHOR]