March 2026: publication Acta Palaeontologica Polonica
Early Paleocene siluroid catfish from Bolivia and its evolutionary and paleogeographic importance
The discovery of three bones in the Paleocene assemblage at Tiupampa (Cochabamba-Potosí Basin, Bolivia), all exhibiting the same distinctive morphology, has enabled us to propose the presence of Yuskaichthys, an extinct genus of catfish previously known only from the Eocene deposits at Maíz Gordo in Argentina.
More specifically, the presence of the genus is proposed on the basis of three parieto-supraoccipitals. The morphological features, notably the bifid posterior margin of the supraoccipital process, closely resemble those described for Yuskaichthys. Furthermore, these catfish share a longitudinal groove running the entire length of the supraoccipital process.
The presence of Yuskaichthys at Tiupampa and Maíz Gordo is consistent with the Palaeogene palaeobiogeography of the regional river systems of the Andean foreland basin. This discovery also supports an early diversification of modern catfish lineages (families), including extinct genera with a long history of existence.
References
Caron E., Mayrinck D., Cespedes R., Otero O. 2026 – Early Paleocene siluroid catfish from Bolivia and its evolutionary and paleogeographic importance – Acta Palaeontologica Polonica 71 (1): 109–118 – http://doi.org/10.4202/app.01300.2025