Overview
- The study describing Austronaga minuta was published Wednesday in Science Advances after analysis of a fossil found in Luoping, China, that is now curated in Beijing.
- Researchers used UV imaging and mass spectrometry to identify a sac-like single stomach, a red liver with traces of haemoglobin, and a long simple tube interpreted as intestines.
- The 60-centimetre specimen shows advanced swimming anatomy — a long tail for propulsion, enlarged fin-like front limbs for steering and reduced hind limbs — indicating strong aquatic adaptation in this archosaur relative.
- Internal anatomy suggests early archosaur-line reptiles had simple, single-chamber stomachs and short guts suited to a fish-eating diet, implying the two-part stomach of birds and crocodiles evolved later.
- The find offers a rare window into soft-tissue preservation in the Triassic and researchers say further study using chemical imaging will test how widespread these early marine adaptations were and what they reveal about post‑extinction reptile diversification.