Scientists Peek Inside a 245-Million-Year-Old Marine Reptile

Paleontologists in China have discovered a fossil of the marine reptile Austronaga minuta, dating back about 245 million years. The find is unique for its preservation of internal organs: a single-chambered stomach, traces of hemoglobin in the liver, and a simple intestine. The reptile is linked to early archosaurs, ancestors of dinosaurs, challenging previous notions about their adaptation to water.

Paleontologists in China have discovered a fossil of a marine reptile about 245 million years old, named Austronaga minuta. The find is unique in preserving not only a nearly complete skeleton about 60 centimeters long but also some internal organs, allowing for the first time a study of the internal anatomy of an ancient Triassic marine reptile. The animal had an unusually long neck and tail, front limbs transformed into flipper-like structures, and reduced hind legs. An international team of researchers from China, Europe, and the United States, including Dr. Stephan Spiekman from the State Museum of Natural History Stuttgart, notes a high level of early adaptation to an aquatic lifestyle. Genetically, the reptile is linked to early archosaurs, ancestors of dinosaurs and crocodiles, challenging previous assumptions about their limited ability to conquer the ocean. Using ultraviolet photography and mass spectrometry, scientists led by Dr. Wei Wang from Beijing discovered a large single-chambered stomach, traces of hemoglobin in the liver, and a simple intestine. This indicates that the complex two-chambered stomach structure in archosaurs developed later. The fossil is housed in Beijing.