title: Comet impact theory faces repeat analysis.
authors.forename: Rex
authors.initials: R
authors.lastname: Dalton
mesh_terms: D044822:Biodiversity; D002681:China; D019015:Geologic Sediments / Q000737:chemistry; D019110:Meteoroids; D008954:Models, Biological; D015203:Reproducibility of Results; D013997:Time Factors; D014481:United States; D018557:United States National Aeronautics and Space Administration