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Re: ?Microraptor? gui/pauli

An initial warning about species diagnoses: there are _supposed to be_
differences between species and genera, and the subjective choise here is to
denote how many of these denote individual variation within a subjectively
recognized fossil species, a "genus" itself and the complex of species allocated
to it, and collections of genera. Any number of features legitimately define
species, and no one has successfully defended arguments countering the idea that
a certain number of characters or percentiles of matching genome basepairs
define a species or genus. That said, let me get on:

Daniel Selvidge () wrote:

<M. gui was said by its describers to be assigned to the genus Microraptor due

2. Extremely short manual phalanx III-2
3. Manual III-3<III-1 in length
4. Small ventrally skewed distal articulation on
manual III-3

However, Microraptor zhaoianus possess features  very
unlike M. gui and vise versa.  These include:

1. Sternum composed of a single large flat bone in M.
gui, instead of two unfused sternal plates in M.

  Warning, fusion between elements, which is what Xu et al proposed for *M.
gui,* can be a consideration of age, rather than specific variation; two
dissimilarly-sized but otherwise morphologically identical sterna are known for
*Ingenia* (GI 100/30 (type), and GI 100/33) which suggest along with other
ontogenetic studies that the sterna should fuse with age; the type of *M. gui*
is the largest specimen of *Microraptor* known to date, of any species, and it
is likely this size variation has led to the fusion of the sterna in *M. gui*,
whereas referred material to *M. zhaoianus* implies that species was at a
relatively younger stage of development.

<2. Strongly back turned pubic bones in M. gui along
with long Sinornithosaur-like pubic boot, but that of
M. zhaoianus appears to be much straighter and has a
shorter hook-like pubic boot>

  The pubis of *M. zhaoianus* is not preserved in any specimen in side view, so
this is hard to denote, whereas it is currently undescribed and unfigured in
cranial/caudal view in *M. gui.*

<3. Bowed tibia in specimens of M. gui>

  Considered a likely autapomorphy of *M. gui.*

<4. Tuberosity on the radius of M. gui

M. gui shares these same distinct characteristics with Cryptovolans pauli, which
I believe to be the same
species as M. gui.  However, should these creatures be assigned to the genus
Microraptor or their own genus (?possibly Cryptovolans?) due to their few but
very distinct differences?>

  If *Cryptovolans* cannot be distinguished from a suite comprising *M.
zhaoianus* and *M. gui*, as well as itself, there are two generally applicable
options that most researchers face: 1) separate all species as unique "genera"
that form a suite of morphological variation, or 2) subsume them all into the
earliest available genus (or even species) and treat all features as variations
of a "primordial" quality of the genus. A third option proposes that after
tallying up features, and this being proposed onlist by at least two that I can
remember, Mickey Mortimer and myself, subsume *M. gui* with *C. pauli.* This was
also Stephen Czerkas' reaction to the generation of the species of *M. gui.* The
problem here is dating, as *M. gui* (January, 2003) was to some degree
technically named after *C. pauli* (April, 2002), though others have questioned
the validity or credibility of the diagnostic value of Czerkas' publication, it
would be a permanent record for descriptive purpose as satisfies the ICZN, and
would thus be valid. This would make either *M. gui* a synonym of *C. pauli,*
and force it to become a member of *Microraptor* [forming *M. pauli*] as the
distinguishing features of all material are not considered by the majority of
researchers to look at this to adequately formulate multiple genera; or it would
make all three species needing unique generic names. This should be avoided, for
the sake of excessive nomenclature, given the general agreement that all species
appear to form a unique and unified complex of species undergoing individual


  Jaime A. Headden

  Little steps are often the hardest to take. We are too used to making leaps in
the face of adversity, that a simple skip is so hard to do.  We should all learn
to walk soft, walk small, see the world around us rather than zoom by it.

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