P1:AR:the difference between endo- & ecto- --- method: put bones under microscope
Dinosaur bone = the bone of today birds and mammals: dense weave & haversian canal
Texture of bone & canal---skeleton grow quickly---high metabolic rate---endo-
P2: evidence---under fire
TO: physical exertion√endothermy×---experiment
P3:O: exercise shape bone microstructure,not thermal physiology
P4: bone strained and stressed---form a tiny stress fracture---remodeling: active√metabolic rate×body temperature× endothermy×