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RE: Princeton Field Guide



My partial reply to Mike Taylor, partly quoting the below and falsely 
attributed to Mike (my apologies, I read my email backwards, recent to older, 
and it gets a bit cobbled when the mail is a day old due to my work schedule), 
should cover much of what I would say, and when this book arrives in my hands, 
I will certainly have more to say, but for now, because this book invokes the 
inevitable, ineffable, and unkillable argument, I will ask nonetheless:

  Greg, Mike, anyone:

  What is a genus?

Cheers,

Jaime A. Headden
The Bite Stuff (site v2)
http://qilong.wordpress.com/

"Innocent, unbiased observation is a myth." --- P.B. Medawar (1969)


"Ever since man first left his cave and met a stranger with a
different language and a new way of looking at things, the human race
has had a dream: to kill him, so we don't have to learn his language or
his new way of looking at things." --- Zapp Brannigan (Beast With a Billion 
Backs)





----------------------------------------
> Date: Thu, 30 Sep 2010 16:13:58 -0400
> From: GSP1954@aol.com
> To: dinosaur@usc.edu; vrtpaleo@usc.edu
> Subject: Princeton Field Guide
>
> Now that the field guide is out and about some comments.
>
> The book is a POPULAR work entirely in the style of a field guide for birds
> or mammals. So it does not include specimen numbers, diagnoses or the like
> and I don’t want to hear about it. It was enough to get the project done as
> it is what with all the illustrations. The anatomical descriptions are of
> the informal nature seen in field guides. A technical book with specimen
> numbers, diagnoses and the like would be a very different, more massive and 
> bar
> ely sellable work, and require far too much work. Even a version of PDW
> expanded to all dinosaurs would be massive and unsellable in the trade 
> market. (As
> it was Don Glut’s encyclopedias made doing the book vastly easier than it
> otherwise would have been.)
>
> While doing the skeletal restorations I found that in order to avoid doing
> chimeras I had to separate overlumped taxa which contributed to more
> revision of species and genera than I expected. Overall I was shocked with the
> pathetic state of dinosaur taxonomy, which is a scandal that is going largely
> ignored (Paul Upchurch and I were talking about the problem at the conference
> in Salas Spain is Sept, which was very pleasant affair including the dinners
> at 10 PM, the last in a private smokehouse; Jim Farlow was especially
> pleased with the abandoned church on the ridge overlooking the spectacular 
> valley
> as the moon rose where a Good, Bad Ugly scene was shot). Long standing,
> major dinosaur taxa such as Allosaurus, Diplodocus, Stegosaurus, Ornithomimus,
> Struthiomimus, Ornithomimus, Troodon are based on air, and are in desperate
> need of revision. And don’t get me started with what is going on about all
> the stuff being tossed into Mamenchisaurus and Omeisaurus. I put in an
> abstract for an SVP talk but they reject me every year these days (more on 
> that
> later). There are some interesting problems that have me scratching my head,
> such as the Triceratops/Torosaurus thing. I made some suggestions but we will
> have to see what the stratigraphic work indicates (as per the upcoming SVP
> presentation).
>
> Concerning the latter, I tried to avoid the simplistic tendency to assign a
> species to a formation when it is now known to be from a particular level
> of a formation. For example there were a series of faunas in the Morrison
> that took ~8 million years to be deposited, with A. fragilis, D. longus and
> probably S. stenops are known only from the lower sections, and B. altithorax
> from the middle (the skull from the lower Morrison is probably a different
> taxon). The Carnegie skeleton always placed in D. altus is almost certainly
> not that taxon since it is considerably in lower in the Morrison than the
> incomplete type. There were series of species in the Dinosaur Park Formation.
> The AMNH S. altus skeleton from Dinosaur Park is almost certainly not altus
> since it is probably younger than the type from the Oldman.
>
> There are a few properly handled dinosaur genera that include a normal,
> large number of species such as Psittacosaurus, Apatosaurus (some species not
> yet named), Diplodocus (ditto). But dinopaleo has gotten into the bad habit
> of usually making almost every species into its own genus. This is illogical
> considering that many modern bird and mammals contain large numbers of
> species – Varanus (now formally includes Megalania), Panthera, Felis, Canis,
> Vulpes, Cervus, Tragelaphus, Cephalophus, Ovis, Gazella, Macropus, 
> Balaenoptera,
> Buteo, Falco, Anas. It is also notable that Cenozoic fossil mammal genera
> often include multiple species, in many cases extending back in time from
> current time (For example extinct species in Canis, Panthera, Varanus). Is
> there something special about dinosaurs in which even in the best documented
> faunas almost every species is a genus even when the differences between these
> taxa in a clade are limited to display structures? I see that ceratopsid
> genera are now actually being defined entirely on differences in their cranial
> adornments – that’s a mind blowing development – when these are of course
> specific level in nature. In an SVP abstract it is stated that ceratopsians
> were evolving lots of genera when the degree of variation they are refering
> to is actually the minor specific grade. Many in dinopaleo seem to have
> forgotten that the most prolific level of evolution is SPECIATION, not 
> GENUATION,
> with evolution churning out the minor variants we call species in far
> greater numbers than the larger divergences that are gathered into a genus.
> Matters have gotten out way of out hand, and when finishing the book I could 
> not
> use all the pseudogenera because people would presume I actually accepted
> them (as in “even Greg Paul agrees that Agujaceratops and Corythosaurus are
> real genera). Someone needs to call out the taxonomic madness instead of
> facilitating it (the usual names are of course noted).
>
> There are also a number of cases in which what are clearly juveniles
> (perhaps with some sexual variation thrown in) are being assigned their own 
> genus
> distinct from their adults, this is especially true of some oviraptors and
> pachycephalosaurs. There was no way I was going to keep these as separate
> taxa.
>
> It cannot be overemphasized how the nested classification system is
> virtually useless for a popular field guide, it providing no graded structure 
> that
> the public can latch onto. Monophyletic clade only classification is a slap
> at the public already skeptical about scientists whom they see as elitists
> who don’t care all that much with communicating with ordinary folks. In any
> case the phylogenetic classifications disagree with one another so much that
> I threw up my hands and cobbled what I could together (an SVP abstract on
> how difficult it is to place heterodontosaurs relative to other ornithischians
> addresses this problem). In some areas the phylogeny reflects my particular
> views, in others I have no agenda and arbitrarily used one among the
> recently published arrangements that is available for the group.
>
> Despite my desire to do a skeleton for every dinosaur that it can be done
> for, a number of skeletal restorations proved unfeasible at this time. For
> example photographs of the skeleton of Jinzhousaurus are available, but as I
> was working on it unresolvable issues with interpreting some elements forced
> me to abandon the effort until better images or the description come out. I
> was reluctant to do a direct side view life restoration unless the skeleton
> was pretty well documented.
>
> The book would have not occurred without Ian Paulsen complaining on the
> list about the absence of a high quality field guide in early 07 and providing
> contacts so a round of applause for him.
>
> My talk on the book at the Carnegie Museum is 2 PM Sunday (when there are
> no dinosaur talks at the meeting).
>
> I’ve got something fairly big and rather shocking coming out in one of the
> major science journals in mid Oct so stay tuned.
>
> GSPaul
>