Eosteus

Eosteus; Temporal range:
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Clade:	Osteichthyes
Genus:	†Eosteus
Species:	†E. chongqingensis
Binomial name
	†Eosteus chongqingensis; Zhu et al., 2026

Eosteus is an extinct monotypic genus of basal bony fish that lived in what is now China during the Telychian stage of the Llandovery epoch.

Description

Eosteus chongqingensis was fusiform in overall body appearance. It possessed caudal fulcra and a single dorsal fin, features characteristic of actinopterygians. It also had pectoral, dorsal, and anal fin spines, serial dorsal plates, and an absence of lepidotrichia, features shared with stem group chondrichthyans.¹

References

Zhu, You-An; Chen, Yang; Li, Qiang; Zhao, Wen-Jin; Zhou, Zheng-Da; Jia, Lian-Tao; Yu, Yi-Lun; Yu, Han-Xin; Wei, Guang-Biao; Ahlberg, Per E.; Lu, Jing; Zhu, Min (5 March 2026). "The oldest articulated bony fish from the early Silurian period". Nature. 651 (8104): 128–134. doi:10.1038/s41586-026-10125-2. ISSN 0028-0836. Retrieved 11 April 2026 – via Nature Publishing Group.

[1] Zhu, You-An; Chen, Yang; Li, Qiang; Zhao, Wen-Jin; Zhou, Zheng-Da; Jia, Lian-Tao; Yu, Yi-Lun; Yu, Han-Xin; Wei, Guang-Biao; Ahlberg, Per E.; Lu, Jing; Zhu, Min (5 March 2026). "The oldest articulated bony fish from the early Silurian period". Nature. 651 (8104): 128–134. doi:10.1038/s41586-026-10125-2. ISSN 0028-0836. Retrieved 11 April 2026 – via Nature Publishing Group.

1