The oldest articulated bony fish from the early Silurian period
Article Date: 04 March 2026
Article URL: https://www.nature.com/articles/s41586-026-10125-2
Article Image: https://www.nature.com/articles/s41586-026-10125-2/figures/4
Summary
Researchers describe a new early Silurian osteichthyan, Eosteus chongqingensis gen. et sp. nov., represented by an articulated specimen (holotype IVPP V30022). Using microscopy, RTI, SEM and CT-based analyses, the team documents well-preserved cranial and dermal features, fin spines, scales and dentition. Phylogenetic analyses (parsimony and Bayesian) place this taxon among early bony fishes, reshaping timing and character evolution in the origin of Osteichthyes. All data and supplementary materials are archived (IVPP; Figshare; ZooBank registration) and are available to other researchers.
Key Points
- New species: Eosteus chongqingensis gen. et sp. nov. is reported from the early Silurian and represents the oldest articulated bony fish described to date.
- Exceptional preservation: the holotype preserves cranial bones, fin spines, scales and teeth, allowing detailed anatomical description.
- Analytical approach: authors combined SEM, RTI, photography stacks and phylogenetic analyses (parsimony and Bayesian) plus morphospace and evolutionary-rate studies.
- Phylogenetic implications: the fossil bears a mosaic of characters that refines the placement of early osteichthyans and pushes aspects of bony-fish character assembly deeper into the Silurian.
- Open data and archiving: specimens are held at IVPP (Chinese Academy of Sciences); datasets, matrices and supplementary material are deposited on Figshare and in the Supplementary Information; nomenclature registered at ZooBank.
Content summary
The paper presents the holotype and negative counterpart of Eosteus chongqingensis, with photographic plates and illustrative drawings (Extended Data Figs. 1–2) and SEM images highlighting scales, fin elements and cranial details (Extended Data Fig. 4). The authors assembled a character matrix and ran multiple phylogenetic protocols, producing consensus trees shown in the Extended Data (Fig. 5). Comparative figures contrast skull-roof and cheek complex anatomy across early osteichthyans and stem gnathostomes (Extended Data Figs. 6–7). Restorations and 3D reconstructions are provided (Extended Data Fig. 8).
Supplementary materials include nexus data for phylogenetic and morphospace analyses, rates of morphological evolution, detailed photos and RTI stacks, and line drawings of specimen halves. The study credits extensive fieldwork and lab support, lists funding sources (National Science Foundation of China, international research programmes) and provides full author affiliations and contributions. No competing interests were declared.
Context and relevance
Finding an articulated osteichthyan from the early Silurian has broad implications for the timing and pattern of jawed-vertebrate evolution. The specimen supplies direct anatomical evidence for when key bony-fish features — cranial architecture, scale types and fin organisation — were assembled. This can affect molecular-clock interpretations, calibrations for timetrees of gnathostomes and our understanding of early vertebrate disparity and rates of morphological change.
For researchers in vertebrate palaeontology, evolutionary biology and comparative anatomy, the study supplies new characters and an open dataset to revisit early osteichthyan relationships. For a general science audience, it sharpens the story of how modern vertebrate body plans began to emerge after the Silurian.
Why should I read this?
Short answer: because it’s a proper fossil that actually fills a hole in the story of how bony fishes appeared. If you care about when jaws, scales and early fish skulls came together, this paper gives fresh bones, solid data and openly shared files — all without the usual guesswork. Plus, the figures and 3D reconstructions make the anatomy easy to eyeball even if you’re not a specialist.
Author style
Punchy: the team backs a big claim with multiple imaging methods, explicit phylogenetic tests and open data. If you follow vertebrate origins, this is one of those papers worth reading in full — it’s not just another fossil note; it changes the timing and detail of early osteichthyan character assembly.