Re: Science is CHANGING

["David Marjanovic" <david.marjanovic@gmx.at>]

----- Original Message -----
From: "Ken Kinman" <kinman@hotmail.com>

>       Mike Keesey's dinosauricon is great, very detailed and useful for
> professional and serious amateur dinosaurologists, but it is a
> "cladification" (Ernst Mayr's term, not mine) and not a true
classification
> in the minds of much of the rest of the world.

True.
The names on the nodes and stems are, however.

> In my opinion, both cladifications and
> classifications serve a purpose, and they will eventually converge into
one
> [...]
> We need *both* cladograms and
> classifications to answer different questions and meet the extremely
varied
> needs of all scientists.

I'd like to just naïvely ask why. :-)

>      Case in point----SNOWFL96@aol.com wrote:
> >Hi, does anybody know where the camarasaurids fit ...  Were they a sister
> >group to the brachiosaurids?
> >
> Mike Keesey answered: _Camarasaurus_ is outside _Titanosauriformes_ (which
> could be defined as Clade(_Brachiosaurus_ + _Titanosaurus_)), but inside
> _Macronaria_ (Clade(_Saltasaurus_ <-- _Diplodocus_)).  It may form a clade
> with other basal macronarians, such as _Aragosaurus_ and _Lourinhasaurus_,
> which could be called _Camarasauridae_.
>
>      EGAD, is that the kind of answer Snowfl96 was looking for?  Don't
know
> for sure,

This may be a complicated form of the answer, but HP T. Mike Keesey just
said that maybe there is no (non-redundant) Camarasauridae in the first
place.

For more visually oriented people:

Neosauropoda
|--Diplodocimorpha (stem)
|
`--Macronaria (stem)
     |--?*Haplocanthosaurus*
     |
     `--Camarasauromorpha (node)
           |--*Camarasaurus*
           |
           `--Titanosauriformes (node)
                 |--Brachiosauridae
                 `--Titanosauria

(empty lines added for better presentation only, though one could actually
use suchlike to represent morphological and/or temporal distance in
cladograms)

> but I think my more traditional classification answers this
> question more clearly (without all the details and strictly cladistic
> "legalese"-like technicalities).

The clearest expression I can think of is the following reduced cladogram:

--+--Diplodocimorpha
    |
    `--+--*Camarasaurus*
         |
         `--+--Brachiosauridae
              `--Titanosauria

and this _answers the question_ IMHO: *Camarasaurus* and whatever its
closest relatives are is in the sister group to (Brachiosauridae +
Titanosauria), not Brachiosauridae alone (as thought for decades). :-)

> neosauropod

eusauropod

> families listed in the order that they may have
> split off cladistically:
>
> 6C  Euhelopodidae
>   D  Diplodocidae
>   E  Camarasauridae
>   F  Brachiosauridae
>   G  Titanosauridae (incl. saltasaurs)

Where are *Cetiosaurus*, *Jobaria*, *Patagosaurus*?

> Although just my first preliminary stab at classifying this group (plesia
to
> be added later), it shows camarasaurs as sister group to a
> Brachiosauridae-Titanosauridae clade.

Not a very strong objection, but one has to learn first that a sequence of
letters or numbers represents a Hennigian comb in your system, rather than
(as I would think at first glance) a polytomy. A cladogram is much easier to
interpret at first glance IMHO.

> I should note that the placement of
> Euhelopodidae is controversial, and if it is actually sister group to
> Titanosauridae (to the exclusion of Brachiosaurids and Camarasaurids), I
> will simply move Euhelopodidae down:

Wilson & Sereno have moved *Euhelopus* _alone_ into the position you show,
but not *Omeisaurus*, *Mamenchisaurus*, *Shunosaurus* etc.. If you use
Euhelopodidae for *Euhelopus* alone, that makes the impression that you use
a stem-based definition for it :-P

> 6C  Diplodocidae
>   D  Camarasauridae
>   E  Brachiosauridae
>   F  Euhelopodidae
>   G  Titanosauridae

(Rather irrelevant here -- the papers on *Sauroposeidon* show that the
pneumatic characters used to justify the new position of *Euhelopus* occur
in several other sauropod groups as well, so I wouldn't support that
position.)