Lambeosaurinae

Lambeosaurinae is a subfamily of hadrosaurid dinosaurs, commonly known as crested duck-billed dinosaurs. They lived during the Late Cretaceous period, roughly 83 to 66 million years ago, with fossils found in North America and Asia. A hallmark of lambeosaurines is their elaborately hollow cranial crests, which varied in shape from long, tubular tubes to ornate fan-like structures. These crests, formed by modified nasal passages, are interpreted as tools for vocalization and visual display and help distinguish lambeosaurines from the closely related hadrosaurines, which typically have solid crests or none at all.

Notable genera within Lambeosaurinae include Lambeosaurus, Corythosaurus, Parasaurolophus, Hypacrosaurus, Tsintaosaurus, and Olorotitan. The diversity of crest morphologies among these genera reflects substantial variation in skull anatomy and probable differences in behavior and ecology. Lambeosaurines occupied a range of habitats and are often found in association with other hadrosaurids, suggesting complex communities and potential social behavior.

Taxonomically, Lambeosaurinae is one of the two major subfamilies within Hadrosauridae, the other being Hadrosaurinae. Phylogenetic analyses place lambeosaurines as a distinct lineage that diversified in the Late Cretaceous before their extinction at the end of the period, coinciding with the broader Cretaceous–Paleogene boundary event. Their distinctive crests remain a defining feature in the study of hadrosaurid evolution and paleobiology.