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Dinosaur speeds, sauropod hearts



Someone asked if there was progressive increase in dinosaur speeds 
through the Mesozoic (sorry, I forget who that was... and message is now 
deleted).
        One diagram published by RT Bakker (1987, fig. 7) does appear to 
show progressive increases in median "cruising" speeds for bipedal 
dinosaurs, from Triassic through Jurassic and into Cretaceous.  However, 
I've pointed out elsewhere (1992) that data underlying Bakker's diagram 
are less than convincing and open to different interpretation.

        Presumably the principal 'pool' of blood in sauropods was 
contained in major veins leading into the rear of the heart itself.  This 
is the case throughout vertebrates; these veins hold much of the body's 
total supply of blood, representing an "emergency pack" that can be 
shunted off to any destination at an instant's notice.

        Bakker, RT. 1987.  The Return of the Dancing Dinosaurs.  In: SJ
Czerkas & EC Olson (eds), Dinosaurs Past & Present, vol. 1: 38-69.  Univ 
of Washington Press, Seattle.
        Thulborn, T.  1992.  The Demise of the Dancing Dinosaurs?  The 
Beagle, vol. 9, part 1: 29-34.