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Re: Dinosaur Hunters to Head to Patagonia * Working On The Porsche Of Its Time * Small pseudo-lizards * Dinosaur Junior Found
The reference to Porsche in a dinosaur story succesfully caught my
attention, but the article is interesting for a very different reason....
From: Roger Smith <firstname.lastname@example.org>
To: email@example.com <firstname.lastname@example.org>
Date: Tuesday, 6 January 2004 6:34
Subject: Dinosaur Hunters to Head to Patagonia * Working On The Porsche Of
Its Time * Small pseudo-lizards * Dinosaur Junior Found
>Welcome to this edition of DINOSAURNEWS.
>** Working On The 'Porsche Of Its Time'
>Using all of the information available, palaeontologists must confront the
>fossil world reality that the classification of a new fossil species is
>subjective and varies among taxonomists
Part of the article refered to reads:
Because the Rauisuchian fossil record is generally sparse, Novak instead
dove into the
dinosaurian fossil record in attempts to quantify the
amount of skeletal difference historically
regarded as valid to erect a new species within the same
genera. She analyzed 28 genera
containing 68 species from both the saurischian
(lizard-hipped) and ornithischian
(bird-hipped) orders. Using the fact that the skeleton
of a dinosaur generally contains
approximately 338 different bones, she catalogued the
number of differences as well as
where the differences were found on the skeleton.
Calculations indicated that, on average,
two species of dinosaur that are members of the same
genera varied from each other by just
2.2 percent. Translation of the percentage into an
actual number results in an average of just
three skeletal differences out of the total 338 bones in
the body. Amazingly, 58 percent of
these differences occurred in the skull alone.
"This is a lot less variation than I'd expected," said
Novak, whose advisor is Josh Smith,
Ph.D., Washington University assistant professor of
earth and planetary sciences. "As a
concept, this is not statistically perfect. But I think
it's something taxonomists can consider if
they are in doubt over classifying something. It's a
kind of benchmark with historical validity."
Novak was able to determine, using her Archosaurian
Morphospecies Concept, that the
Ghost Ranch Postosuchus was indeed the same species,
Postosuchus kirkpatricki, as the
two specimens from Texas.
Looks like Stephanie Novak is building the 'genericometer' that George is
after. Very interesting.
Does anyone know of the citations for Novak's work? Is she on this list (or
is Josh still on it?). I'd be keen to hear more about this work.