Ascent of Dinosaurs Linked to an Iridium Anomaly at the Triassic-Jurassic Boundary

Articles:

Title:: Ascent of Dinosaurs Linked to an Iridium Anomaly at the Triassic-Jurassic Boundary
Author(s):: Olsen, Paul E.
Kent, Dennis V.
Montanari, Alessandro
Rainforth, Emma C.
Huber, Heinz
Fowell, Sarah J.
Sues, Hans-Dieter
Koeberl, Christian
Szajna, Michael J.
Hartline, Brian W.
Date:: 2002
Type:: Articles
Department:: Lamont-Doherty Earth Observatory
Volume:: 296
Permanent URL:: http://hdl.handle.net/10022/AC:P:11963
Book/Journal Title:: Science
Abstract:: Analysis of tetrapod footprints and skeletal material from more than 70 localities in eastern North America shows that large theropod dinosaurs appeared less than 10,000 years after the Triassic-Jurassic boundary and less than 30,000 years after the last Triassic taxa, synchronous with a terrestrial mass extinction. This extraordinary turnover is associated with an iridium anomaly (up to 285 parts per trillion, with an average maximum of 141 parts per trillion) and a fern spore spike, suggesting that a bolide impact was the cause. Eastern North American dinosaurian diversity reached a stable maximum less than 100,000 years after the boundary, marking the establishment of dinosaur-dominated communities that prevailed for the next 135 million years.
Subject(s):: Paleontology
DOI:: 10.1126/science.1065522