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GEOREF RECORD

Comparison of thermoregulation of four ornithischian dinosaurs and a varanid lizard from the Cretaceous Two Medicine Formation; evidence from oxygen isotopes

Reese E. Barrick, William J. Showers and Alfred G. Fischer
Comparison of thermoregulation of four ornithischian dinosaurs and a varanid lizard from the Cretaceous Two Medicine Formation; evidence from oxygen isotopes (in Skeletal records of ecologic change, Douglas S. Jones (editor))
Palaios (August 1996) 11 (4): 295-305

Abstract

The delta (super 18) O values of vertebrate bone phosphate are dependent upon the delta (super 18) O values of their body water and the temperature of bone deposition. This allows the measurement of the temperature fluctuation during bone deposition for individual skeletal elements within any individual. delta (super 18) O results for bones from a varanid lizard and four Late Cretaceous ornithischian dinosaurs (Orodromeus makelai, Hypacrosaurus stebingeri, Montanaceratops sp., and a juvenile Achelousaurus horneri) from the Campanian Two Medicine Formation in Montana are compared. Results from the varanid indicate that bone deposition occurred over a range of 10-15 degrees C, as expected for an ectotherm. Results from the dinosaurs indicate that bone deposition occurred over a range 2-7 degrees C within the body core and 3-8 degrees C in the extremities. The intrabone and interbone pattern of values suggests that these dinosaurs were primarily homeotherms with all but Orodromeus exhibiting regional heterothermy. Homeothermy over the size range of the individual dinosaurs suggests that they had metabolic rates elevated above those of modern ectotherms and the range of isotopic variability suggests intermediate endothermy.


ISSN: 0883-1351
Serial Title: Palaios
Serial Volume: 11
Serial Issue: 4
Title: Comparison of thermoregulation of four ornithischian dinosaurs and a varanid lizard from the Cretaceous Two Medicine Formation; evidence from oxygen isotopes
Title: Skeletal records of ecologic change
Author(s): Barrick, Reese E.Showers, William J.Fischer, Alfred G.
Author(s): Jones, Douglas S.editor
Affiliation: North Carolina State University, Department of Marine, Earth and Atmospheric Sciences, Raleigh, NC, United States
Affiliation: University of Florida, Florida Museum of Natural History, Gainesville, FL, United States
Pages: 295-305
Published: 199608
Text Language: English
Publisher: Society of Economic Paleontologists and Mineralogists, Tulsa, OK, United States
References: 37
Accession Number: 1999-027790
Categories: Vertebrate paleontology
Document Type: Serial
Bibliographic Level: Analytic
Illustration Description: illus.
N47°30'00" - N48°08'60", W113°01'00" - W111°25'00"
N48°19'00" - N49°00'00", W114°04'60" - W112°10'60"
Secondary Affiliation: University of Southern California, USA, United States
Country of Publication: United States
Secondary Affiliation: GeoRef, Copyright 2017, American Geosciences Institute. Reference includes data supplied by SEPM (Society for Sedimentary Geology), Tulsa, OK, United States
Update Code: 199910
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