Definite evidence of Late Cretaceous sauropods in North America was first discovered in 1922, when Charles Whitney Gilmore described … See more

Around the end of the Early Jurassic, sauropods, a clade of large, long-necked dinosaurs, established themselves as the "dominant group" of large herbivores in land-based environments, possibly following a … See more

The North American sauropod hiatus began during the Cenomanian, the first age of the Late Cretaceous. Several sauropods are known from the upper Albian or lower Cenomanian of North America. The brachiosaurid… See more

The cause of the sauropod hiatus has been a subject of debate. Lucas and Hunt proposed two hypotheses: a lack of properly preserved remains or a genuine extinction followed by re-population from South Ame… See more

Whatever the cause of the sauropod hiatus, sauropods do not reappear in the North American fossil record until near the end of the Cretaceous. Various specimens have been claimed to represent Campanian records of s… See more