Huayracursor: The Oldest Known Ancestor of Giant Long-Necked Sauropods Discovered in the Andes

In a Nature paper published March 2026, Argentine paleontologists have unveiled Huayracursor kellyae, the earliest and most primitive sauropodomorph ever found in the Andes and the oldest confirmed ancestor of the colossal long-necked dinosaurs that would later dominate the Jurᴀssic.

The partial skeleton, recovered from the 230-million-year-old Chañares Formation in La Rioja Province, northwestern Argentina, includes a well-preserved skull, neck vertebrae, and limb bones. At just 2.5 metres long and weighing under 100 kg, this small, bipedal herbivore already possessed the elongated neck vertebrae, robust shoulder girdle, and columnar limb proportions that foreshadowed the 30-tonne giants of the Jurᴀssic.

Phylogenetic analysis places Huayracursor at the very base of Sauropodomorpha, pushing the origin of the entire sauropod lineage back by at least 10 million years in Gondwana. Its discovery in the Andes demonstrates that the evolutionary roots of the largest land animals in Earth’s history began in southern South America during the Triᴀssic, not in the northern continents as many models once ᴀssumed.

“This tiny dinosaur is the great-great-grandfather of every Brachiosaurus and Argentinosaurus that ever lived,” said lead author Ricardo Martínez. “It shows that the sauropod body plan began evolving right here in the Andes 230 million years ago.”

The find also reveals that early sauropodomorphs were already experimenting with longer necks and more efficient feeding strategies while living alongside the first dinosaurs. After decades of searching, the Andes have finally delivered the missing link that explains how the most successful group of giant herbivores on the planet first appeared.

Huayracursor — named after the Quechua word for “wind runner” — proves that the story of the long-necked тιтans began not in the Jurᴀssic, but deep in the Triᴀssic shadows of the Andes.