[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

Re: Bad as opposed to BADD



In a message dated 96-10-29 03:01:30 EST, znc14@ttacs1.ttu.edu (Jonathan R.
Wagner) writes:

> As I have pointed out to Senor Olshevsky in the past, there is
> already a fantastically concise and accurate cladistic taxon already
> defined for an group of animals which sit about in trees randomly
> shooting off the non-avian dinosaur lineages, and that name is
> Dinosauria (sensu cladistica Owen. I apologize to all, the year
> escapes me, and for this I should be flogged...).  Dinosauria is
> currently and probably insufficently (Holtz, semi-pers. com.),
> defined as most recent common ancestor of _Triceratops_ and birds,
> and thus these "dinobirds" George keeps mentioning are for the most
> part properly termed dinosaurs.
>         "That which begets dinosaur is dinosaur." 

As I have repeatedly mentioned on this list and every time this question
comes up, OF COURSE DINO-BIRDS ARE DINOSAURS. Like a few other list members,
Senor Wagner has a penchant for not reading my postings completely, and/or
not understanding them, before firing off hasty and sometimes ill-considered
replies.

Padian & Holtz's (or is it Holtz & Padian's?) node-based definition of the
clade Dinosauria as the common ancestor of _Triceratops_ and birds and all
its descendants is quite precise, and I use the completely equivalent
definition of Dinosauria as the common ancestor of _Iguanodon_ and
_Megalosaurus_ and all its descendants in _Dinosaur Folios_ and _Mesozoic
Meanderings_. All but the very earliest dino-birds would certainly fall into
this clade. Note that "dino-bird" is an >informal< term with >no taxonomic
standing<.

The closing quotation above, "That which begets dinosaur is dinosaur," is
false. According to the Padian-Holtz definition, the common ancestor of
Dinosauria is a dinosaur--but its parent species, which "begat" that
dinosaur, is >not<, since it is not one of its descendants. What Senor Wagner
should have said is, "Dinosaurs only beget more dinosaurs," or something like
that.

The Owen date Senor Wagner is hunting for is 1842.