Sharma, P. P. & Gavish-Regev, E. The evolutionary biology of Chelicerata. Annu. Rev. Entomol. 70, 143–163 (2025).
Google Scholar
Legg, D. A., Sutton, M. D. & Edgecombe, G. D. Arthropod fossil data increase congruence of morphological and molecular phylogenies. Nat. Commun. 4, 2485 (2013).
Google Scholar
Garwood, R. J. & Dunlop, J. Three-dimensional reconstruction and the phylogeny of extinct chelicerate orders. PeerJ 2, e641 (2014).
Google Scholar
Aria, C. The origin and early evolution of arthropods. Biol. Rev. 97, 1786–1809 (2022).
Google Scholar
Nolan, E., Santibáñez-López, D. C. E. & Sharma, P. P. Developmental gene expression as a phylogenetic data class: support for the monophyly of Arachnopulmonata. Dev. Genes Evol. 230, 137–153 (2020).
Google Scholar
Dunlop, J. A. New ideas about the euchelicerate stem-lineage. Acta Zool. Bulg. 1 (Suppl.), 9–23 (2006).
Aria, C. & Caron, J. B. A middle Cambrian arthropod with chelicerae and proto-book gills. Nature 573, 586–589 (2019).
Google Scholar
Legg, D. A. Sanctacaris uncata: the oldest chelicerate (Arthropoda). Naturwissenschaften 101, 1065–1073 (2014).
Google Scholar
Cotton, T. J. & Braddy, S. J. The phylogeny of arachnomorph arthropods and the origin of the Chelicerata. Earth Environ. Sci. Trans. R. Soc. Edinb. 94, 169–193 (2003).
Google Scholar
Boxshall, G. A. The evolution of arthropod limbs. Biol. Rev. 79, 253–300 (2004).
Google Scholar
Sharma, P. P., Schwager, E. E., Extavour, C. G. & Giribet, G. Evolution of the chelicera: a dachshund domain is retained in the deutocerebral appendage of Opiliones (Arthropoda, Chelicerata). Evol. Dev. 14, 522–533 (2012).
Google Scholar
Haug, J. T., Waloszek, D., Maas, A., Liu, Y. & Haug, C. Functional morphology, ontogeny and evolution of mantis shrimp-like predators in the Cambrian. Palaeontology 55, 369–399 (2012).
Google Scholar
Liu, Y., Haug, J. T., Haug, C., Briggs, D. E. & Hou, X. A 520 million-year-old chelicerate larva. Nat. Commun. 5, 4440 (2014).
Google Scholar
Chen, J., Waloszek, D. & Maas, A. A new ‘great-appendage’ arthropod from the Lower Cambrian of China and homology of chelicerate chelicerae and raptorial antero-ventral appendages. Lethaia 37, 3–20 (2004).
Google Scholar
Tanaka, G., Hou, X., Ma, X., Edgecombe, G. D. & Strausfeld, N. J. Chelicerate neural ground pattern in a Cambrian great appendage arthropod. Nature 502, 364–367 (2013).
Google Scholar
Lerosey-Aubril, R. & Ortega-Hernández, J. A chelicera-bearing arthropod reveals the Cambrian origin of chelicerates. Nature 652, 931–937 (2026).
Google Scholar
Boudreaux, H. B. Significance of Intersegmental Tendon System in Arthropod Phylogeny and a Monophyletic Classification of Arthropoda (Van Nostrand Reinhold, 1979).
Ortega-Hernández, J., Lerosey-Aubril, R., Losso, S. R. & Weaver, J. Neuroanatomy in a middle Cambrian mollisoniid and the ancestral nervous system organization of chelicerates. Nat. Commun. 13, 410 (2022).
Google Scholar
Rota-Stabelli, O., Daley, A. C. & Pisani, D. Molecular timetrees reveal a Cambrian colonization of land and a new scenario for ecdysozoan evolution. Curr. Biol. 23, 392–398 (2013).
Google Scholar
Lozano-Fernandez, J. et al. A molecular palaeobiological exploration of arthropod terrestrialization. Phil. Trans. R. Soc. Lond. B 371, 20150133 (2016).
Google Scholar
Lozano-Fernandez, J. et al. A Cambrian–Ordovician terrestrialization of arachnids. Front. Genet. 11, 182 (2020).
Google Scholar
Liu, Y. et al. Exites in Cambrian arthropods and homology of arthropod limb branches. Nat. Commun. 12, 4619 (2021).
Google Scholar
Jago, J. B., García-Bellido, D. C. & Gehling, J. G. An early Cambrian chelicerate from the Emu Bay Shale, South Australia. Palaeontology 59, 549–562 (2016).
Google Scholar
Liu, C. et al. Cambrian euarthropod Urokodia aequalis sheds light on the origin of Artiopoda body plan. iScience 27, 110443 (2024).
Google Scholar
Hou, X. et al. The Cambrian Fossils of Chengjiang, China: The Flowering of Early Animal Life 2nd edn (John Wiley & Sons, 2017).
O’Flynn, R. J. et al. The early Cambrian Kylinxia zhangi and evolution of the arthropod head. Curr. Biol. 33, 4006–4013 (2023).
Google Scholar
Liu, Y. et al. Three-dimensionally preserved minute larva of a great-appendage arthropod from the early Cambrian Chengjiang biota. Proc. Natl Acad. Sci. USA 113, 5542–5546 (2016).
Google Scholar
Zhang, X. et al. Ventral organization of Jianfengia multisegmentalis Hou, and its implications for the head segmentation of megacheirans. Palaeontology 65, e12624 (2022).
Google Scholar
Schmidt, M. et al. Unveiling the ventral morphology of a rare early Cambrian great appendage arthropod from the Chengjiang biota of China. BMC Biol. 22, 96 (2024).
Google Scholar
Lamsdell, J. C. Revised systematics of Palaeozoic ‘horseshoe crabs’ and the myth of monophyletic Xiphosura. Zool. J. Linn. Soc. 167, 1–27 (2013).
Google Scholar
Budd, G. E. Head structure in upper stem-group euarthropods. Palaeontology 51, 561–573 (2008).
Google Scholar
Ortega-Hernández, J. Homology of head sclerites in Burgess Shale euarthropods. Curr. Biol. 25, 1625–1631 (2015).
Google Scholar
Budd, G. E. The origin and evolution of the euarthropod labrum. Arthropod Struct. Dev. 62, 101048 (2021).
Google Scholar
Liu, Y., Ortega-Hernández, J., Zhai, D. & Hou, X. A reduced labrum in a Cambrian great-appendage euarthropod. Curr. Biol. 30, 3057–3061 (2020).
Google Scholar
Dunlop, J. A. & Lamsdell, J. C. Segmentation and tagmosis in Chelicerata. Arthropod Struct. Dev. 46, 395–418 (2017).
Google Scholar
Lustri, L., Gueriau, P. & Daley, A. C. Lower Ordovician synziphosurine reveals early euchelicerate diversity and evolution. Nat. Commun. 15, 3808 (2024).
Google Scholar
Lustri, L., Antcliffe, J. B., Gueriau, P. & Daley, A. C. New specimens of Bunaia woodwardi Clarke, 1919 (Euchelicerata): a new member of Offacolidae providing insight supporting the Arachnomorpha. R. Soc. Open Sci. 11, 240499 (2024).
Google Scholar
Lerosey-Aubril, R., Zhu, X. & Ortega-Hernández, J. The Vicissicaudata revisited – insights from a new aglaspidid arthropod with caudal appendages from the Furongian of China. Sci. Rep. 7, 11117 (2017).
Google Scholar
Lerosey-Aubril, R. & Ortega-Hernández, J. Appendicular anatomy of the artiopod Emeraldella brutoni from the middle Cambrian (Drumian) of western Utah. PeerJ 7, e7945 (2019).
Google Scholar
Liu, Y. et al. Supplementary datasets (tiffstacks and phylogeny-related files) for “Urokodia illuminates the origin of chelicerae and book gills of Chelicerata” [Data set]. Zenodo https://doi.org/10.5281/zenodo.20156157 (2026).
Potin, G. J. M. & Daley, A. C. The significance of Anomalocaris and other Radiodonta for understanding paleoecology and evolution during the Cambrian explosion. Front. Earth Sci. 11, 1160285 (2023).
Google Scholar
Zeng, H., Zhao, F. & Zhu, M. Innovatiocaris, a complete radiodont from the early Cambrian Chengjiang Lagerstätte and its implications for the phylogeny of Radiodonta. J. Geol. Soc. 180, 164 (2022).
Zeng, H., Zhao, F., Niu, K., Zhu, M. & Huang, D. An early Cambrian euarthropod with radiodont-like raptorial appendages. Nature 588, 101–105 (2020).
Google Scholar
Bicknell, R. D., Klinkhamer, A. J., Flavel, R. J., Wroe, S. & Paterson, J. R. A 3D anatomical atlas of appendage musculature in the chelicerate arthropod Limulus polyphemus. PLoS ONE 13, e0191400 (2018).
Google Scholar
Angelini, D. R., Kikuchi, M. & Jockusch, E. L. Genetic patterning in the adult capitate antenna of the beetle Tribolium castaneum. Dev. Biol. 327, 240–251 (2009).
Google Scholar
Farley, R. D. Book gill development in embryos and first and second instars of the horseshoe crab Limulus polyphemus L. (Chelicerata, Xiphosura). Arthropod Struct. Dev. 39, 369–381 (2010).
Google Scholar
Bolton, S. J. & Sharma, P. P. Reconciling morphology with phylogenomics in Chelicerata (Arthropoda). Zool. J. Linn. Soc. 206, zlag017 (2026).
Google Scholar
Bolton, S. J., Friedrich, M. & Sharma, P. P. Mollisonia is probably not an arachnid. Curr. Biol. 36, R126–R127 (2026).
Google Scholar
Goloboff, P. A. & Morales, M. E. TNT version 1.6, with a graphical interface for MacOS and Linux, including new routines in parallel. Cladistics 39, 144–153 (2023).
Google Scholar
Huelsenbeck, J. P. & Ronquist, F. MRBAYES: Bayesian inference of phylogenetic trees. Bioinformatics 17, 754–755 (2001).
Ronquist, F. et al. MrBayes 3.2: efficient Bayesian phylogenetic inference and model choice across a large model space. Syst. Biol. 61, 539–542 (2012).
Google Scholar
Lewis, P. O. A likelihood approach to estimating phylogeny from discrete morphological character data. Syst. Biol. 50, 913–925 (2001).
Google Scholar
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