Titanosaurs Nested Far South of Equator, Fossil Eggshells Reveal

Paleontologists working in Patagonia, Argentina, have uncovered fossilized eggshells that push the known range of dinosaur nesting deeper into the southern hemisphere than previously documented.

Titanosaur hatchlings emerging from a nest in the Cretaceous of Patagonia, Argentina. Image credit: Masato Hattori.

“Few discoveries have yielded fossil evidence of non-avian dinosaurs nesting at high paleolatitudes,” lead author Dr. Kohei Tanaka from the University of Tsukuba and colleagues wrote in their paper.

“Such paleoenvironments probably posed nesting challenges because of low seasonal temperatures and prolonged periods of reduced sunlight, where dinosaurs probably would have adopted various reproductive strategies for egg incubation.”

“Among non-avian dinosaurs, nesting in northern polar paleoenvironments is evidenced by hadrosaur and theropod eggshells recovered from a Late Cretaceous site in Siberia representing approximately 70-75 degrees north paleolatitude, as well as theropod perinatal bones and small hadrosaur tracks and perinatal bones from Upper Cretaceous deposits of Alaska.”