• journal_title：Geology
• Contributor：P. H. Ostrom ; S. A. Macko ; M. H. Engel ; D. A. Russell
• Publisher：Geological Society of America
• Date：1993-
• Format：text/html
• Language：en
• Identifier：10.1130/0091-7613(1993)021<0491:AOTSOC>2.3.CO;2
• journal_abbrev：Geology
• issn：0091-7613
• volume：21
• issue：6
• firstpage：491

New δ¹⁵N data suggest the retention of an indigenous signal in ancient high molecular weight organic material. These data open the possibility of obtaining new paleoecological information, based on isotopic analyses, on ancient, well-preserved fossil communities. Stable carbon and nitrogen isotope analyses were performed on high molecular weight organic material isolated from 22 taxa of Late Cretaceous vertebrates (Judith River Formation, Alberta,Canada). The majority of δ¹³C and δ¹⁵N values (-27‰ to -23‰ and 4‰ to 12‰, for δ¹³C and δ¹⁵N, respectively) are similar to those reported for modern consumers. An assessment of trophic levels based on δ¹⁵N is consistent with previous interpretations of food web structure derived from paleoecological interpretations. Among terrestrial consumers, carnivorous theropods (tyrannosaurids and dromaeosaurids) have high δ¹⁵N values (6.6‰ ±0.4‰ and 7.9‰, respectively) relative to those of the dominant megaherbivore (hadrosaurids, 4.7‰ ±0.5‰). Within aquatic environments, the values of δ¹⁵N of the bowfin Amia (11.6‰) and plesiosaur (11.0‰),distinguish the piscivorous tendencies of these organisms from those of tower trophic level consumers such as the benthic feeding sturgeon Acipenser and the turtle Aspideretes (δ¹⁵N = 5.1‰ and 4.5‰, respectively). The correlation in trophic position between δ¹⁵N values and paleoecological evidence is unlikely to be coincidental.