[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]
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.