Fast walking tachyaerobic dinosaurs

[GSP1954@aol.com]

Pontzer et al. in PLoS One used estimated sustained walking speeds derived 
from hip height to show that the dinosaurs probably needed the high aerobic 
capacity characteristic of tachyaerobic mammals and birds. I did much the 
same thing using large samples of dinosaur trackway based speed estimates. 
Archaic fossil reptile trackways record the very slow mean speeds 
characteristic of bradyaerobic animals with limited sustainable aeroboc 
exercise 
performance. We humans can easily and usually do walk at speeds well above 
those of 
oras and crocs. Both bipedal and quadrupedal dinosaurs of all sizes tended 
to walk at the high speeds that exceed the reptilian sustainable maximum and 
matches those of birds and mammals. The high aerobic capacity probably 
required that the resting energy state be tachymetabolic, producing 
tachyenergetic endothermy. The calculations are in Dinosaurs of the Air (2002); 
Modern 
Geology (1998) 23: 179-217; 405-408 in D. Thurston and K. Fujita (eds), 1992 
Proceedings International Conference on Arctic Margins (1994); with G. Leahy 
(1994) The Paleontological Society Special Publication 7: 177-198; and will 
be in the upcoming Complete Dinosaur. 

GSPaul 

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