Abstract

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 fauna, 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 (Cenomanian: ca. 99 Ma) Burmese amber from northern Myanmar, with the description of one new genus and two new species, 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 record 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.