Ancient shell shows days were half-hour shorter 70 million years ago

(American Geophysical Union) Earth turned faster at the end of the time of the dinosaurs than it does today, rotating 372 times a year, compared to the current 365, according to a new study of fossil mollusk shells from the late Cretaceous in AGU's journal Paleoceanography and Paleoclimatology. The new measurement informs models of how the Moon formed and how close to Earth it has been over the 4.5-billion-year history of the Earth-Moon gravitational dance.