Publication Date:
2002-05-23
Description:
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.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Olsen, P E -- Kent, D V -- Sues, H-D -- Koeberl, C -- Huber, H -- Montanari, A -- Rainforth, E C -- Fowell, S J -- Szajna, M J -- Hartline, B W -- New York, N.Y. -- Science. 2002 May 17;296(5571):1305-7.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY 10964, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/12016313" target="_blank"〉PubMed〈/a〉
Keywords:
Animals
;
Biological Evolution
;
*Dinosaurs
;
*Ecosystem
;
Ferns
;
*Fossils
;
Geologic Sediments/chemistry
;
Iridium/*analysis
;
Meteoroids
;
Minor Planets
;
North America
;
Spores
;
Time
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
