Ancient mammal ancestor reveals early roots of mammalian hearing
CT scans and 3D simulations of the 250‑million‑year‑old cynodont Thrinaxodon liorhinus indicate ear structures capable of tympanic (ear‑based) hearing emerged earlier than previously thought, suggesting the mammalian middle ear began evolving before dinosaurs; the model estimates a hearing range of about 38–1,243 Hz with peak sensitivity near 1,000 Hz at ~28 dB, aiding prey detection and predator avoidance.