title: Bolide impact triggered the Late Triassic extinction event in equatorial Panthalassa.
abstract: Extinctions within major pelagic groups (e.g., radiolarians and conodonts) occurred in a stepwise fashion during the last 15 Myr of the Triassic. Although a marked decline in the diversity of pelagic faunas began at the end of the middle Norian, the cause of the middle Norian extinction is uncertain. Here we show a possible link between the end-middle Norian radiolarian extinction and a bolide impact. Two palaeoenvironmental events occurred during the initial phase of the radiolarian extinction interval: (1) a post-impact shutdown of primary and biogenic silica production within a time span of 10(4)-10(5) yr, and (2) a sustained reduction in the sinking flux of radiolarian silica for ~0.3 Myr after the impact. The catastrophic collapse of the pelagic ecosystem at this time was probably the dominant factor responsible for the end-middle Norian conodont extinction.
authors.affiliation: Department of Earth and Environmental Sciences, Kumamoto University, 2-39-1 Kurokami, Kumamoto 860-8555, Japan.
authors.forename: Tetsuji
authors.initials: T
authors.lastname: Onoue
authors.affiliation: Japan Agency for Marine-Earth Science and Technology (JAMSTEC), 2-15 Natsushima-cho, Yokosuka 237-0061, Japan.
authors.forename: Honami
authors.initials: H
authors.lastname: Sato
authors.affiliation: Department of Earth and Environmental Sciences, Kumamoto University, 2-39-1 Kurokami, Kumamoto 860-8555, Japan.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Yamashita
authors.affiliation: Centre for Advanced Marine Core Research, Kochi University, B200 Monobe, Nankoku 783-8502, Japan.
authors.forename: Minoru
authors.initials: M
authors.lastname: Ikehara
authors.affiliation: Japan Agency for Marine-Earth Science and Technology (JAMSTEC), 2-15 Natsushima-cho, Yokosuka 237-0061, Japan.|Department of Systems Innovation, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan.
authors.forename: Kazutaka
authors.initials: K
authors.lastname: Yasukawa
authors.affiliation: Japan Agency for Marine-Earth Science and Technology (JAMSTEC), 2-15 Natsushima-cho, Yokosuka 237-0061, Japan.|Frontier Research Centre for Energy and Resources (FRCER), School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan.
authors.forename: Koichiro
authors.initials: K
authors.lastname: Fujinaga
authors.affiliation: Japan Agency for Marine-Earth Science and Technology (JAMSTEC), 2-15 Natsushima-cho, Yokosuka 237-0061, Japan.|Department of Systems Innovation, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan.|Frontier Research Centre for Energy and Resources (FRCER), School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan.
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Kato
authors.affiliation: Department of Geology, Niigata University, Igarashi 2-no-cho 8050, Niigata 950-2181, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Matsuoka