First record of the pseudoscorpion tribe Tyrannochthoniini Chamberlin, 1962 from mid-Cretaceous Burmese amber of northern Myanmar (Pseudoscorpiones: Chthoniidae: Chthoniinae)

The pseudoscorpion tribe Tyrannochthoniini (Pseudoscorpiones: Chthoniidae) is one of the oldest and most specious groups within this arachnid order and is found in almost all tropical and subtropical habitats. Although molecular dating analyses suggest a Paleozoic origin for this tribe, the only known fossil records of Tyrannochthoniini until now are from the Miocene (ca. 16 Ma), indicating a significant gap in the fossil record. Here we provide the earliest record of Tyrannochthoniini in mid-Cretaceous (lowermost Cenomanian: ca. 99 Ma) Burmese amber from northern Myanmar, with the description of a new genus (Burmeochthonius) and two new species (Burmeochthonius kachinae and Burmeochthonius muelleri), extending the known fossil record of this tribe by ca. 75 Ma, from the Miocene to the Cretaceous. We also provide a discussion on the evolution and biogeography of this widespread pseudoscorpion lineage in the tropics. The occurrence of a tropical, extant pseudoscorpion tribe in Burmese amber and the similarities between these fossils and the modern fauna suggests that the paleoclimate and perhaps also paleoenvironments of Cretaceous Burmese forests did not differ much from the forests of Myanmar today. •First fossil record of the pseudoscorpion tribe Tyrannochthoniini.•Crown-group age of Tyrannochthoniini extended by ca. 75 Ma.•Tyrannochthoniini exhibit morphological and ecological stasis.