Hidden for 70 million years, a tiny fossil fish is rewriting freshwater evolution

Researchers in Alberta uncovered a fossil fish that rewrites the evolutionary history of otophysans, which today dominate freshwater ecosystems. The new species, Acronichthys maccognoi, shows early adaptations for its unusual hearing system. Evidence suggests otophysans moved from oceans to rivers more than once, leaving scientists puzzled about their ancient global journeys.

source https://www.sciencedaily.com/releases/2025/10/251004092907.htm