Ponderous tales

[pwillis@ozemail.com.au (Paul Willis)]

On the subject of sauropod tails as (or as not) cooling devices. The
argument that a flattened tail would be optimal for heat transfer has been
well made. But to take the argument from the opposite direction; the
optimal shape for heat retention (or more correctly, to minimise heat
transfer) is a sphere, and sauropods certainly are not spherical. A similar
argument has been put (but in the reverse) for why modern ectotherms such
as snakes can take on an extremely attenuated form while endotherms of the
same size can not (they would suffer too much heat loss). So surely the
argument is that sauropods, as the most attenuated forms of dinosaur and,
coincidentally the largest, could afford such large size/attenuated form
only if they had a heat surplus and dumping heat was a priority in their
lives. A heat dump does not have to be the most efficient type of heat
dumper in order to be used, particularly if the structure being used to
dump heat (the neck and tail) are also used for other purposes (to improve
reach, defence, balance or what ever). There would be no point in having a
flattened tail the length of a tennis court that was the most efficient
heat dumper ever if it was useless for defence and the first Allosaurus it
meets bites it off.

Cheers, Paul

pwillis@ozemail.com.au