Qianodus duplicis is represented by twenty-three isolated tooth whorls and was recovered as a stem chondrichthyan; it is not an articulated crown shark.
claim:taxon:qianodus:taxonomyQianodus duplicis
A late Aeronian stem chondrichthyan known from twenty-three isolated tooth whorls rather than an articulated body or jaw.
Represented range439–439 Ma
Content packagechondrichthyes
PBDBtxn:503113
Evidence boundary
Automated checks cover structure, identifiers, translations and links only; maintainer and external expert review are not complete.
Claim ledger
The Qianodus tooth whorls come from the late Aeronian Rongxi Formation at Leijiatun, Guizhou, China; this single sample does not establish a global distribution.
claim:taxon:qianodus:biogeographyThe whorls document tooth development and histology, but diet, prey, locomotion, body size and habitat preference cannot be recovered from the isolated elements.
claim:taxon:qianodus:ecologyQianodus whorls preserve non-shedding teeth added lingually in offset rows, with histology examined from named specimens including IVPP V26641.
claim:taxon:qianodus:morphologyThe displayed approximately 439 Ma point is the late Aeronian Rongxi Formation sample and is not a global Chondrichthyes first appearance.
claim:taxon:qianodus:fossil-rangeKnown limits
- A missing branch or fossil occurrence does not imply biological absence. Internal nodes are not calibrated divergence estimates.
References
- The oldest gnathostome teethAndreev, P.S.; Sansom, I.J.; Li, Q.; Zhao, W.; Wang, J.; Wang, C.-C.; Peng, L.; Jia, L.; Qiao, T.; Zhu, M. · 2022 · DOI 10.1038/s41586-022-05166-2
- 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