245-Million-Year-Old Reptile Fossil Preserves Internal Organs

Scientists in China have discovered an exceptionally well-preserved fossil of a marine reptile that lived 245 million years ago, complete with its stomach, liver and intestines.

The specimen belongs to Austronaga minuta, a Triassic reptile that lived about 15 million years before the first dinosaurs appeared. Around 60 cm long, it had a small head, a narrow snout lined with fang-like teeth, a long neck and flippers adapted to life in shallow seas.

According to the authors of a study published in Science Advances, the find contains the oldest well-preserved reptile digestive tract known to science.

The fossil shows that Austronaga had a simple, single-chambered stomach, unlike the two-chambered organs found in birds, crocodiles and some dinosaurs. Researchers believe the more complex arrangement evolved later in this lineage.

Its liver was also preserved behind the stomach and retained a reddish color from iron-rich hemoglobin residues.

Fish scales found in the intestines revealed the animal’s last meal. The discovery offers a rare insight into reptile anatomy and evolution following the largest mass extinction in Earth’s history.

(Reuters, lud)