Urokodia aequalis was recovered on the upper chelicerate stem in the cited morphology matrix; navigation placement does not assert direct ancestry.
claim:taxon:urokodia:taxonomyUrokodia
Micro-CT reconstructions expose pincer-like short great appendages, overlapping exite flaps and a seven-segmented head used in a stem-chelicerate test.
Represented range519–518 Ma
Content packagetrilobites-chelicerates
PBDBtxn:19096
Evidence boundary
Automated checks cover structure, identifiers, translations and links only; maintainer and external expert review are not complete.
Claim ledger
The profile is limited to Chengjiang material from Yunnan and does not establish a global Urokodia distribution.
claim:taxon:urokodia:biogeographyAppendage form permits bounded feeding and locomotor hypotheses, but diet, performance and habitual behaviour are not preserved.
claim:taxon:urokodia:ecologyMicro-CT reveals pincer-like short great appendages, overlapping exite flaps and a seven-segmented head interpretation.
claim:taxon:urokodia:morphologyThe 519–518 Ma envelope is a Chengjiang sample interval, not a stem-chelicerate origin date or global species duration.
claim:taxon:urokodia:fossil-rangeKnown limits
- A missing branch or fossil occurrence does not imply biological absence. Internal nodes are not calibrated divergence estimates.
References
- Urokodia sheds light on the origin of chelicerae and book gills of ChelicerataLiu, Y. et al. · 2026 · DOI 10.1038/s41586-026-10713-2
- Open Tree of Life web servicesOpenTreeOfLife Project
- The Paleobiology Database application programming interfacePeters, S.E.; McClennen, M. · 2016 · DOI 10.1017/pab.2015.39
- Denormalized occurrence and taxon tables of the Paleobiology DatabaseThe Paleobiology Database Community; Kocsis, Á.T. · 2026 · DOI 10.5281/zenodo.21620933