Bird-Like Anatomy, Posture, and Behavior Revealed by an Early Jurassic Theropod Dinosaur Resting Trace

BACKGROUND: Fossil tracks made by non-avian theropod dinosaurs commonly reflect the habitual bipedal stance retained in living birds. Only rarely-captured behaviors, such as crouching, might create impressions made by the hands. Such tracks provide valuable information concerning the often poorly understood functional morphology of the early theropod forelimb. METHODOLOGY/PRINCIPAL FINDINGS: Here we describe a well-preserved theropod trackway in a Lower Jurassic ( approximately 198 million-year-old) lacustrine beach sandstone in the Whitmore Point Member of the Moenave Formation in southwestern Utah. The trackway consists of prints of typical morphology, intermittent tail drags and, unusually, traces made by the animal resting on the substrate in a posture very similar to modern birds. The resting trace includes symmetrical pes impressions and well-defined impressions made by both hands, the tail, and the ischial callosity. CONCLUSIONS/SIGNIFICANCE: The manus impressions corroborate that early theropods, like later birds, held their palms facing medially, in contrast to manus prints previously attributed to theropods that have forward-pointing digits. Both the symmetrical resting posture and the medially-facing palms therefore evolved by the Early Jurassic, much earlier in the theropod lineage than previously recognized, and may characterize all theropods

Meteospace, a New Instrument for Solar Survey at the Calern Observatory

International audienceHigh cadence observations of solar activity (active regions, flares, filaments) in the Hα line were performed at Meudon and Haute Provence Observatories from 1956 to 2004. More than 7 million images were recorded, mainly on 35 mm films. After a review of the scientific interest of solar surveys at high temporal resolution and the historical background, we describe the new instrument which will operate automatically in 2020 at the Calern station of the Côte d’Azur observatory (1270 m). It will replace the former heliographs with improved cadence, seeing and time coverage. We summarize the capabilities of the optical design and present new scientific perspectives in terms of flare onset and Moreton wave detection