Abstract: The family Scytodidae is known for its unique spitting predatory mechanism, but its fossil record is extremely scarce, with reliable Mesozoic records previously lacking. Based on two male specimens preserved in Kachin amber, we report the first unequivocal Cretaceous record of this family — †Stedotuber gen. nov., with two new species, †S. longitibialis sp. nov. and †S. brevitibialis sp. nov. Maximum parsimony analysis of morphological characters recovers the new genus within the subfamily Scyloxinae, forming a sister-group relationship with the extant genus Stedocys. Tip-dating analyses estimate the crown age of Scytodidae at the Late Jurassic (~150.32 Ma), the crown age of Scyloxinae in the Early Cretaceous (~136.71 Ma), and the split between †Stedotuber gen. nov. and Stedocys in the late Early Cretaceous (~123.68 Ma), all substantially older than previous estimates for comparable nodes based on Cenozoic fossils or molecular clocks alone. Combined with paleogeographic models, our results favour a scenario in which early scyloxine lineages became isolated on the northward-drifting Burma Terrane, consistent with its proposed role as a “biotic ferry” for Gondwanan-derived lineages.

Key words: Burma Terrane, Gondwana, phylogeny, Scyloxinae, tip-dating