Lagosuchus (Lagosuchus talampayensis) is a genus of small archosaur that lived approximately 230 million years ago. It belongs to a group known as the "ruling reptiles" or archosaurs, which include crocodiles, dinosaurs, and birds. The first fossils of Lagosuchus were discovered in the early 1960s in the Talampaya National Park of Argentina, providing important insights into the early stages of archosaur evolution.

Lagosuchus had a compact and agile body, reaching lengths of about 1 to 1.5 meters. It possessed a long neck and tail, with relatively short limbs. Lagosuchus had a slender skull with sharp teeth adapted for capturing and consuming small prey. Its limb structure suggests a bipedal stance, enabling it to move swiftly on land. Although it shares some characteristics with later dinosaurs, Lagosuchus is not classified as a dinosaur.

Lagosuchus lived in the diverse ecosystems of the Triassic period, which were inhabited by various reptiles and early dinosaurs. It likely occupied a niche as a small, carnivorous predator, feeding on insects, small vertebrates, and other invertebrates. The bipedal locomotion and agile body of Lagosuchus would have allowed it to efficiently navigate its environment in pursuit of prey. However, due to the scarcity of fossil evidence, further research is needed to fully understand its ecological role.