Message 2001-06-0129: Re: Crown groups mainstream?

Sun, 24 Jun 2001 12:13:01 +0200

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Date: Sun, 24 Jun 2001 12:13:01 +0200
From: David Marjanovic <>
To: PhyloCode mailing list <>
Subject: Re: Crown groups mainstream?

> So friggin' what if
> multis are not member of Mammalia? They can still be mammals. So
> may anything grouped in Mammaliaformes, which is the stem
> opposing the cynodonts.

(Rather irrelevant here, but Cynodontia is a node that includes mammals; I
haven't figured out whether Mammaliaformes is a node or a stem, but -formes
is usually applied to nodes.)
People will, for obvious reasons, continue to refer to Mammalia, and nothing
else, as mammals. No problem for PT, though.

>   Pterosaurs are irrelevant to Archosauria -- they cannot
> comprise the definition of a crown-group, as they are extinct.


> As well, Dave Peters quite clearly espouses and convinces the
> relationship of pterosaurs as basal to archosaurs, as
> archosauriforms closer to lizards than crocs (lepidosauriforms),
> as members of Archosauromorpha, and which becomes a senior
> subjective synonym of Ornithodira by content.

Prolacertiforms, not lizards:

Sauria (node)
  |--Lepidosauromorpha (stem)
  |     |--maybe ichthyosaurs and/or plesiosaurs, who knows
  |     `--Lepidosauriformes (node)
  |           |--Sphenodontia (or is it -ida?)
  |           `--Lepidosauria (lizards including snakes)
  `--Archosauromorpha (stem)
             `--*--Prolacertiformes (a misnomer)
                  |     `--Pterosauria if Peters is right
                  `--Archosauriformes = non-crown A.sauria (node)
                        |== various basal groups (*Proterosuchus*...)
                        `-- crown Archosauria (node)
                               |--Crurotarsi (stem, includes crocs)
                               `--**--Pterosauria traditionally
                                     `--Dinosauriformes (node)
                                           |== a few basal species
                                           `--Dinosauria (node)

* Ornithodira if Peters is right
** Ornithodira if he's wrong
Ornithodira = (*Pterodactylus antiquus* + *Passer domesticus*)

Ornithodira is always, no matter what happens (save synonymy), composed of
Pterosauromorpha (*P. a.* > *P. d.*) and Dinosauromorpha (*P. d.* > *P.

The name Prolacertiformes (I don't know its definition, if it has one) is
based on the superficially lizard-like *Prolacerta* which was thought to be
the oldest lizard when it was discovered. Turned out to be wrong.


Feedback to <> is welcome!