Most fossil vertebrates of Jurassic age from Arizona are derived from the Glen Canyon Group on the southern Colorado Plateau in the northeastern part of the state. Glen Canyon Group strata of Jurassic age in Arizona that yield fossils include the upper Dinosaur Canyon and the Whitmore Point members of the Moenave Formation, the Kayenta Formation, and the Navajo Sandstone. All of these units yie...

BACKGROUND Many extant male animals exhibit exaggerated body parts for display, defense or offence in sexual selection, such as male birds of paradise showing off colorful and elegant feathers and male moose and reindeers bearing large structured antlers. For insects, male rhinoceros and stag beetles have huge horn-like structure for fighting and competition and some male Leptopanorpa scorpionf...

Upper Triassic rocks in northwestern Argentina preserve the most complete record of dinosaurs before their rise to dominance in the Early Jurassic. Here, we describe a previously unidentified basal theropod, reassess its contemporary Eoraptor as a basal sauropodomorph, divide the faunal record of the Ischigualasto Formation with biozones, and bracket the formation with (40)Ar/(39)Ar ages. Some ...

Stable isotope compositions of a late Jurassic ammonite shell: a record of seasonal surface water temperatures in the southern hemisphere? C. Lécuyer and H. Bucher Laboratory “Paléoenvironnements & Paléobiosphère”, UMR CNRS 5125 , Bâtiment “Geode”, Université Claude Bernard Lyon I et Institut Universitaire de France, 27–43 Boulevard du 11 Novembre 1918, 69622 Villeurbanne, France Paläontologisc...