abstract:Macronaria is a clade of sauropod dinosaurs from the Middle Jurassic (Bathonian) to Late Cretaceous Periods of what are now North America, South America, Europe, Asia, Africa and Australia. The name means 'large nostrils' (from Greek makros 'big' + Latin nares 'nostrils'), in reference to the large nasal openings high on the head that probably supported fleshy resonating chambers.