J Syst Evol

• Research Article •     Next Articles

Spitting spiders (Araneae: Scytodidae) from Cretaceous Kachin amber reveal deep divergence times and Burma Terrane-linked biogeography

Yanmeng Hou1, 2, Paul A. Selden1, 4, 5, Feng Zhang2, 3, Xiangbo Guo2, 3*, and Dong Ren1*   

  1. 1 College of Life Sciences, Capital Normal University, 105 Xisanhuanbeilu, Haidian District, Beijing 100048, China
    2 Key Laboratory of Zoological Systematics and Application, College of Life Sciences, Hebei University, Baoding 071002, China
    3 Hebei Basic Science Center for Biotic Interaction, Hebei University, Baoding 071002, China
    4 Department of Geology, University of Kansas, Lawrence, KS, United States
    5 Natural History Museum, London, United Kingdom
    *Authors for correspondence. Xiangbo Guo. E-mail: xiangboguo@126.com; Dong Ren. E-mail: rendong@mail.cnu.edu.cn
    Yanmeng Hou: https://orcid.org/0000-0003-0059-3419
    Paul A. Selden: https://orcid.org/0000-0001-7454-4260
    Feng Zhang: https://orcid.org/0000-0002-3347-1031
    Xiangbo Guo: https://orcid.org/0000-0002-7074-8642
    Dong Ren: https://orcid.org/0000-0001-8660-0901
  • Received:2026-07-12 Accepted:2026-08-28
  • Supported by:
    This research is supported by the National Natural Science Foundation of China (No. 32300364).

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.