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re:GSP & dinosaur growth
Greg Paul said:(just the parts I wondered about)
Let us turn to Ruben's 1995 claim that Troodon grew no more rapidly
than Alligator, which is based on misleading manipulation of the data
(his idea of comparing growth in full grown dinosaurs to still growing
reptiles not only distorts the comparison, but is impractical because
we do not now at what % of final size most dinosaurs become fecund).
The theropod may have grown to 50-70 kg in 3-5 years assuming bone
rings were annuli (faster growth is suggested if the deep set rings
were multi-annular, as they are in some mammals).
Ruben neglected to note that Reid 1987, 1990 has used bone rings to
estimate that A) the ornithopod Rhabdodon grew faster than crocs (to
~300 kg in 10-15 years), and B) a sauropod died at a mass of about 8
tonnes at age 28-29.
Assertions that fully terrestrial reptiles can somehow manage to grow
as fast as a number of dinosaurs seem to constitute further examples
of unsubstantiated, untestable, speculative arm waving. The inability
of juvenile land reptiles to grow fast may be another reason why only
mammals and dinos with high metabolic rates grow gigantic on land
(Ruben is correct that sharp declines in metabolic rates upon
cessation of growth are improbable).
How do the growth patterns of Troodon you site compare with J Horner
and Mary wass-her-face's study (ALL my dino refs are packed, sorry) of
Maiasaur growth patterns. As far as I know, this is the only reliable
growth study as samples exist for all ages, which is not seen yet in
Do you support the idea that dinosaurs seem to have a high metabolism
in their young-and-growing phase, and then seem to slow down their
metabolism as they reach full size, shown by Horner and wassherface by
growth rings and pockets in the bone sampled from an entire selection
of ages of Maiasaur?
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