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Re: Cold-blooded vs. warm-blooded
Re: current thoughts about whether dinosaurs were warm- or
Each year I run a graduate seminar on dinosaur thermophysiology. I've
just pasted in the relevant sections of introduction and the reading
list, which should be FAIRLY up to date. Hope this helps! My
interpretation of the most recent work is that dinosaurs were probably
unlike any extant group in terms of metabolism. Furthermore, it's
possible (if not likely) that dinosaurs did not all share the same
Over the past 20 years there have been three major ongoing debates in
the dinosaur literature: avian relationships, causes of dinosaur
extinction, and dinosaur thermoregulation. Up until the 1960s dinosaurs
were generally assumed to have had an ectothermic, reptile-like
metabolism. In the 1960s and 1970s Loris Russell, John Ostrom and
Armand de Ricql?s presented arguments for a degree of endothermy in
dinosaurs, and these arguments were championed and popularised by the
paleontological maverick Bob Bakker (pronounced "Bokker"). In the
absence of a time machine evidence for dinosaur thermal physiology is
restricted to the fossil record and analogies to extant animals. But
there are many lines of evidence, including comparative anatomy, the
ecological and evolutionary success of dinosaurs, bone histology,
predator/prey ratios, fossil distributions, relationships to living
groups (notably the birds), oxygen isotope composition in fossil bone
(e.g. Barrick et al. 1997), and most recently, preserved internal soft
Be aware when you're reading these papers that you may not always get
the full story. For example, in his review of "The dinosaur heresies"
Reid (1987) says: "Bakker could have written an objective account of
the relevant evidence and arguments, and used it to give a balanced
assessment of what can currently be surmised; but, instead, he has
written a one-sided study, in which everything appears to support his
conclusions, and contrary evidence or arguments are either dismissed or
Basic reading list
Barrick, R.E., M.K. Stoskopf and W.J. Showers (1997) Oxygen isotopes
in dinosaur bone. In: J.O. Farlow and M.K. Brett-Surman (eds.) The
complete dinosaur. Indiana University Press, Bloomington, pp. 474-490
Benton, M.J. (1991) Polar dinosaurs and ancient climates. TREE 6: 28-30
Chiappe, L.M. (1995) The first 85 million years of avian evolution.
Nature 378: 349-355
Chinsamy, A., and P. Dodson (1995) Inside a dinosaur bone. Amer. Sci.
Farlow, J.O. (1990) Dinosaur energetics and thermal biology. In:
D.B. Weishampel, P. Dodson and H. Osm?lska (eds.) The Dinosauria.
University of California Press, Berkeley, California, pp. 43-55
Farlow, J.O., P. Dodson, and A. Chinsamy (1995) Dinosaur biology.
Ann. Rev. Ecol. Syst. 26: 445-471
Fischman, J. (1995) Were dinos cold-blooded after all? The nose knows.
Science 270: 735-736
Hicks, J.W., and C.G. Farmer (1998) Lung ventilation and gas exchange
in theropod dinosaurs. Science 281:45-46 and following letters on pp.
Morell, V. (1994) Warm-blooded dino debate blows hot and cold.
Science 265: 188
Morell, V. (1996) A cold, hard look at dinosaurs. Discover 17(12):
Paladino, F.V., J.R. Spotila and P. Dodson (1997) A blueprint for
giants: modelling the physiology of large dinosaurs. In: J.O. Farlow
and M.K. Brett-Surman (eds.) The complete dinosaur. Indiana University
Press, Bloomington, pp. 491-504
Reid, R.E.H. (1997) Dinosaurian physiology: the case for "intermediate"
dinosaurs. In: J.O. Farlow and M.K. Brett-Surman (eds.) The complete
dinosaur. Indiana University Press, Bloomington, pp. 449-473
Ruben, J. (1991) Reptilian physiology and the flight capacity of
Archaeopteryx. Evolution 45: 1-17
Ruben, J.A., W.J. Hillenius, N.R. Geist, A. Leitch, T.D. Jones, P.J.
Currie, J.R. Horner, and G. Espe III (1996) The metabolic status of
some late Cretaceous dinosaurs. Science 273: 1204-1207
Ruben, J., A. Leitch, W. Hillenius, N. Geist and T. Jones (1997)
New insights into the metabolic physiology of dinosaurs. In: J.O.
Farlow and M.K. Brett-Surman (eds.) The complete dinosaur. Indiana
University Press, Bloomington, pp. 505-518
Ruben, J.A., C. Dal Sasso, N.R. Geist, W.J. Hillenius, T.D. Jones
and M. Signore (1999) Pulmonary function and metabolic physiology of
theropod dinosaurs. Science 283: 514-516
Shipman, P. (1997) Birds do it...did dinosaurs? New Scientist
Spotila, J.R., M.P. O'Connor, P. Dodson, and F.V. Paladino (1991)
Hot and cold running dinosaurs: body size, metabolism and migration.
Modern Geology 16: 203-227