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David's Statements [Extended Version]



David Marjanovic (David.Marjanovic@gmx.at) wrote:

<Archaeopterygidae is to mean A. and Unenlagia ?= Megaraptor ?=
Unquillosaurus (possible synonymies after the Dinosauricon);
analyses by HP Mickey Mortimer put U., at least, in the
Dromaeosaurinae.>

  No autapomorphies listed which should include *Unenlagia* as
more closely related to Archaeopteryx than to dromaeosaurs or
birds. *Archaeopteryx* itself is a difficult taxon to diagnose
based on the disparity in taxa which may be included, for the
Aktein-Verein specimen and Eichstätt specimens are considered
either separate species, or separate genera. There may be as
many as two genera and three species, or one species only. It's
not like a statistical study has been performed with charts and
absolute comparison of elements in all specimens. 

<The main paper begins with "When Archaeopteryx was discovered,
birds were thought to have lots of autapomorphies, many of which
were recognised in Archaeopteryx. But for the past 20 years or
so, former bird autapomorphies have been 'sliding down the
cladogram', so it has now become very difficult to diagnose a
bird.">

  This is not necessarily true: extraordinary forelimb length
outstrips the hindlimbs; though as Mickey Mortimer has said, the
radius in *Microvenator* is nearly equal the humerus length, the
manus is not nearly so long and would have been less than 80%
the hindlimb length as posited from reconstruction of the extant
phylogenetic bracket (dromaeosaurs, oviraptorosaurs,
*Archaeopteryx*). The metatarsus is not pinched proximally, so
the breadth of the third metatarsal either equals or exceeds
that of the second and thirds, altered only in enatiornithines
or birds whose metatarsus becomes a cannon bone. 
 
<opisthopubic pelvis | is orthopubic in A. and Patagonykus,
opisthopubic in dromaeosaurs [and secondarily orthopubic in U.,
if HP Mickey Mortimer is right) => probably prone to
convergence>

  The condition of opisthopuby in dinosaurs has not been
quantified wholly, but may be plesiomorphic in birds, as most
maniraptorans seem to be either mesopubic or opisthopubic. You
use the term "orthopubic" for the "strait pubes" but this may
not be exact enough, and I prefer the term "mesopubic" to denote
a transition between a pro and opisthopubic condition. In fact,
based on this, one can then posit that oviraptorosaurs are
secondarily propubic, or that the condition of the pubes
proximally (strait up and down) occurring in tyrannosaurs, makes
this a functional character relating to mass distribution by
bringing the pubes between the knees neutrally, and may then
have respiratory capabilities, then becomes convergent. The
pelvis in *Unenlagia,* *Rahonavis,* and *Sinornithosaurus* are
remarkably similar to one another, in the form of the ilium,
ischia, and pubes, though the first two share the J-shaped
lateral aspect of the pubes (hook-like pubic boot, shaft strait
towards the distal end and not recurved). The condition of the
pelvis in primitive birds, *Archaeopteryx* and dromaeosaurids
are closer in the shape and form of the ilium, and form of the
pubes as they invert caudally. I don't feel the case has been
settled on the orientation of the pubes in the ürvogel, and can
posit both a vertical and everted orientation with equal
impunity.

<loss of coronoid (III) | "In fact, this feature has a very
spotty distribution - Archaeopteryx and ornithomimids lack a
distinct coronoid, Oviraptor has a tiny one, while Dromaeosaurus
and Velociraptor (Currie, 1995) still have two (fused coronoids
II and III), which is considered highly plesiomorphic.">

  This is confusing, because the nature of the coronoid in
oviraptorids has only been once mentioned in an abstract, and
this has been restricted to a skull that forms a new genus (not
*Oviraptor philoceratops*). I can't see how then all
oviraptorids have lost this, when the condition has now become
ambiguous, and the fusion of the coronoid to the surangular has
been doubted from its inception, and receives a nose-thumbing
from Currie et al., 1994, on the basis of a smooth, narrow
surangular in caenagnathids, suggestive that no extra element
has been added to the region. The same may be true of
ornithomimids, but then, I have mostly *Gallimimus* to work
from, and Osmólska, Roniewicz, and Barsbold, 1982 state that
this genus most certainly had a coronoid, illustrated as
situating low on the jaw and posterior to the ascending process
of the prearticular. Now, perhaps someone in Sacramento can look
at the skulls of *Gallimimus* at the Russian Dinosaur Exhibit
and see if they can discern the condition from the casts there.
 
<"A commonly cited bird apomorphy in Archaeopteryx is the
reverted hallux; all preserved feet are crushed, the joint
surface between metatarsals I and II is destroyed [in e. g. the
London specimen and not prepared in the Berlin one], thus to
what extent the halluces were reverted is still a matter of
debate. In any case, Archaeopteryx was incapable of perching,
because the halluces were too short and situated too high on the
foot. >

  This is actually the case in most primitive birds, and even
among extant birds. But please note: perching, and perching with
use of the hallux, are not the same thing, and length of the
hallux does not presume perching. Galliforms, anseriforms, and
procellariiforms, for instance, as well as gaviiforms, perch
without using the hallux.

<Both characters not present in Microraptor... only we don't
know to what extent its halluces were reverted either.>
Caudipteryx dongi (Normile, 2000), on the other hand, seems to
have a reverted hallux as long as the other toes <I have
meanwhile found, but not yet copied, the original Vertebrata
PalAsiatica paper; it wasn't that long>>

  Neither species of *Caudipteryx* possesses an elongated
hallux; I'm not sure where this comes from, frankly, unless it's
the Normile paper. Quality photographs of the pes in all recent
specimens (not the *C. zoui* type and paratype) show the hallux
to be a low but short element.

< - its description will fuel lots of additional debates <for
which I am waiting>. A single bird synapomorphy, according to
Elzanowski & Wellnhofer (1996), has been left to Archaeopteryx:
the triradiate palatines. I think that it is most parsimonious
to explain this feature by convergence <ô surprise>, though I
have no idea why this should have occurred.">

  Unless this is a strict phylogenetic condition related to the
mechanics of the jaw in an edentulous form for which some
propaliny is known, as in oviraptorids and birds; essentially,
the increased space allows a reduction of the moment arm in the
palatal muscles that articulate with the median surface of the
lower jaw, or the dorsal adductor region. This has both a
mechanical and phylogenetic plausibility.
 
<Birds down to Alvarezsauridae have prokinesis (Chiappe, Norell
& Clark, 1998); confuciusornithids have akinetic skulls (Hou et
al., 1999), which is probably secondary because the jugals don't
have ascending processes.>

  Did Mickey point this out? They most certainly do have
ascending jugals and descending postorbitals (postorbital bar).

[cladogram snipped out] 

<"Cladistic implications Archaeopteryx has no bird
synapomorphies, and is probably nothing more than a glorified
small flying near-dromaeosaur, '[a]nd in spite of the fact that
dromaeosaurids are often proclaimed to be the most birdlike of
the theropods <...>, they lack many of the theropod-avian
synapomorphies found in other theropod families, and have too
many specialisations to be plausible avian ancestors' (Currie,
1995, page 587).>
  Curious, but which cladistic analysis has _ever_ suggested
*Archaeopteryx* was nothing but a "glorified near-dromaeosaur,"
but less non avian? The cladistic definition (and preferred
non-cladistic usage) has Aves as including *Archaeopteryx.*
Anyway, Currie's comments were about dromaeosaurids, and placing
*Archaeopteryx* near them and then saying this suggests
*Archaeopteryx* is therefore not a bird is very strange?

<Considering this along with the 'theropod-avian synapomorphies'
listed above <below> produces a cladogram <...> which differs
from all others in the following features: oviraptorosaurs are
the closest relatives of birds, with which they form the taxon
Maniraptora (conventionally defined as Neornithes >
Ornithomimus, in Sereno [1998] defined as Oviraptor +
Neornithes>

  It should be understood that Sereno's definition is not as
widely accepted and should not be used in the sense of priority.
Understand that Sereno's definition comes from placing
tyrannosaurids closer to birds than are ornithomimids, and this
is just plain ridiculous (personal opinion). With tyrannosaurids
outside of the original definition by having ornithomimids being
the stem, we get dromaeosaurids, oviraptorids, "dinobirds," and
birds, and possibly troodontids, as being maniraptorans. This is
the conventional, traditional, and defined content. And as
Padian and Holtz, 1997 and Padian et al., 1999, suggest, should
be used.

<at present, these definitions do not change the contents of
Maniraptora).>

  See above, because they most certainly do.

<Maniraptora and Arctometatarsalia form Maniraptoriformes, which
has been defined as Ornithomimus + Neornithes. The taxon with
the definition Deinonychus + Neornithes has recently been named
Eumaniraptora. Its name implies that it was meant to be a part
of Maniraptora, whereas now it is vice versa -- the irony of
cladistic definitions. I propose to name the taxon which
includes Archaeopteryx and dromaeosaurids Archaeopterygiformes,
which is among the oldest available names, and to define it as
Archaeopteryx > Neornithes. Sereno (1998) has defined
Archaeopteryx this way - that is why I consider it useless to
define genera.>

  Annoying, yes, this will probably stand as the eponymous
Archaeopterygidae, but your usage has no priority, Sereno's does
(unfortunately). Precisely why do you not like defining genera?
Chris Brochu (1998) has not only defined the genus *Crocodylus*,
but several of its species and groups of species, one of which
is called Globidonta, and this does not reflect a "subgenus" or
"superspecies" but a group of unique taxonomic entities (UTE's).

<But what about birds themselves? A commonly used definition is
Aves: Archaeopteryx + Neornithes (e. g. Sereno 1998)>

  Actually, this is Chiappe, 1997, then reaffirmed by Padian,
Hutchinson, and Holtz, 1999.

<and Avialae: Neornithes > Velociraptor. In this case, Aves is
<in terms of content> a senior synonym of Eumaniraptora and
Avialae one of Paraves ( = Neornithes > Oviraptor [Sereno,
1998]), and, whether Aves or Avialae is called 'birds',
Tyrannosaurus is a bird. >

  Yeah, only if you take Sereno's definitions _and_ others'
together. By priority classification, one doesn't get
definitions up the yin-yang to one's own liking. One works in
the system. Aves and Avialae have strict definitions, and so
does Paraves, and in Sereno's recent organization, tyrannosaurs
are members of a group called "Aves;" calling them birds is like
saying "Aves" is defined as "birds."

  So apparently, when Ken chimed in and said that this is how
cladistics can get confusing, what has occurred is Sereno has
redefined based on a bunch of cladograms _tested separately_ and
with such novel and unique positions that these should have been
rigorously scrutinized, not have had taxa named on them.
Ornithomimoidea and Tyrannoraptora are so ? ugh.

  Priority definitions are:
  Maniraptoriformes == { Neornithes + Ornithomimus } (Holtz,
1996, emended from Holtz, 1994 confused this with Maniraptora,
which had an established definition (Gauthier, 1986) which could
be held up)
  Arctometatarsalia == { Ornithomimus > Neornithes } (Holtz,
1996, established by Holtz, 1994, and included Bullatosauria, by
extension, but also has priority over Ornithomimoidea Sereno,
1999 by content, as by definition Alvarezsauridae would then be
closer to Ornithomimus than to birds)
  Ornithomimosauria == { (Pelecanimimus + Ornithomimus) } (I
don't believe this taxon has been strictly defined: Sereno's
[horribly restrictive] usage for Ornithomimidae is {
Pelecanimimus + Ornithomimus } and by the phylogeny of Osmólska
and Barsbold, 1994 and Perez-Moreno et al., 1994, this would
correspond to Ornithomimosauria, which has priority by taxonomic
foundation, and the definition shifts to Ornithomimosauria)
  Maniraptora == { Neornithes > Ornithomimus } (Gauthier, 1986
defined this roughly, emended by Holtz (1994) into a strict
definition)
  Paraves == { Neornithes > Oviraptor } (Gauthier, 1986,
intended as a stem, though Sereno (1998) defines it as a node;
to include dromaeosaurids and birds, but not oviraptorosaurs and
other maniraptorans, explicitly; thus the definition above has
by content and usage originally priority (Padian, Hutchinson,
and Holtz, 1999))
  Eumaniraptora == { Deinonychus + Neornithes } (Padian,
Hutchinson, and Holtz, 1999, originally to oppose so-called
"dinobirds" that would be paravians, but more basal (the
original included taxa, Deinonychosauria and Avialae, do not
include explicit generic specifiers, and it is suggestible to
use such, but the specifiers [I really do prefer Jon Wagner's
term "anchor," if not just because it has an _oomph_ that the
dry "specifier" does not] are reflect this distinction, whether
or not Troodon and Deinonychus are each other's closest taxa))
  Deinonychosauria == either { Deinonychus > Neornithes } or {
Deinonychus + Troodon } (Colbert and Russell, 1969, originally
to demonstrate the raptorial similarities of the two forms,
though not many recent phylogenies support troodont-dromaeosaur
monophyly, so the first definition was provided to preserve the
taxon as a useful stem opposing birds within Maniraptora;
however, I feel the term should be kept as originally defined {
Troodon + Deinonychus } and a new taxon [maybe] to be used for
the first definition (like "Taxon 45, Stem 23" or something))
  Avialae == either { Neornithes > Deinonychus } or
{Archaeopteryx + Aves (crown birds) } (Gauthier, 1986,
originally to define Aves as a crown-group, rather than
including Archaeopteryx, which would follow classic usage; as
discussed _ad nauseum_ on this list, classic usage is derived
from a non-evolutionary perspective, and Archaeopteryx is best
used to include the concept "bird" as being relative to "Aves"
(see below); while the first definition contains the same
knowledge as Gauthier's usage, the original usage was not
explicit, and could be given made more strict, and so now can
include other taxa between Archaeopteryx and dromaeosaurids,
such as "dinobirds")
  Aves == {the ultimate hodgepodge} ? no, I mean { Archaeopteryx
+ Neornithes } (Gauthier, 1986, as stated above, intended this
as the crown group, but traditional usage includes tons of other
types of "birds;" the term is broader than intended, but perhaps
more applicable, as provided by Chiappe, 1997 (an explicit
definition) and Padian, Hutchinson, and Holtz, 1999 (a reason
why))
  Metornithes == { Mononykus + Neornithes } (Perle, Chiappe, and
Norell, 1993, which by all phylogenies except Sereno's and
Martin's, are closer to birds anyway, and the redefining by
Sereno for the placement of alvarezsaurs is based on strict
ornithomimosaur synapomorphies rather than both ornithomimosaur
and neornithine synapomorphies for an unambiguous polarity to
see which clades with which)

<Now the question is whether we accept animals lime
Tyrannosaurus or Ornithomimus as birds or whether we allow the
definitions to change <we can do the latter when PhyloCode is
enacted>.>

  Unless you prefer Sereno's definitions, and feel that the most
recent definition will be the one used, this will happen. But
explicitly defining taxa by non-mobile stems and nodes (that
don't include troodontids and tyrannosaurids, for instance) you
get clarity. Find the most likely position for these "jumping"
taxa, as Holtz puts it, and we might get some resolution. And
alvarezsaurians, too, for that matter, which still look like
birds?.

<In the latter case I propose to define Avialae as Neornithes >
Oviraptor, Ornithomimus, Velociraptor and other well-known
non-avian theropods>

  Been done, see above, you're just adding additional exclusive
specifiers, but this doesn't resolve the definition.

<How would a tetanuran have swum? Undulating the tail, which
many have suggested, was impossible - the distal half was
stiffened - and would have been ineffective, because dinosaur
tails were always pointed at the end instead of flattened like
in crocodiles. Using their legs would have been ineffective,
too, because they weren't able to sprawl and their toes were not
webbed. There was only one other possibility - using the arms,
which already bore wing feathers.>

  Any fool animal can swim unless it bears a direct ecological
or biological penalty. Elephants can swim, and I think camels
could too, but their ecology is a lot different. This was
discussed a while back, swimming camels. Just because an animal
does not have webbed toes does not mean it couldn't kick its
feet: the surface area of the volar surface of the foot to mass
of dogs is less than that of humans, but dogs do readily jump in
and can chase prey (birding dogs, technically a learned behavior
of acquiring a food item). And so can cats, most prominently
jaguars, which have been known to go after capybara and tapirs
in the water, and tigers after pigs.

<Dromaeosaurids became secondarily "flightless". <We know this
from somewhere, don't we?>>

  No, we assume this from the phylogenetic hypothesis of
feathered/filamented animals and the presence of so-called
"flight-related features" in maniraptoriforms.

<? their hands for grasping only,>

  No ability to grasp with the pollex (thumb) that does not
oppose the second digit, and a possibly semi-mobile third
metacarpal.

<Surely somewhere in the reader's head there is lurking the idea
that Protoavis might fit this picture <...>. Protoavis is a
problem because of its poor preservation, and it is probably a
chimera, but it is very difficult to explain which part comes
from which animal. For instance, the "hand" looks much like an
herrerasaur foot - but only the first three digits: "metacarpal
IV" bears no phalanges, and no similar bone occurs in any known
herrerasaur, as is the case with the "quill knobs" on
"metacarpals II and III". There is no explanation for the
(though unfused) furcula and the keeled sternum. Additionally,
the chimera argument doesn't really work - if only a single bone
attributed to Protoavis is avian, then there was a Triassic bird
(Chatterjee, 1997).>

  Huh, and then, of course, there's that idea that much of the
material looks like it could come from a megalancosaurid ? but
don't take my word for this, take Renesto's (1999). I hope, of
course, to get down to Texas Tech to see if Sankar will let me
view the material, some of it is actually quite fascinating from
the scant photos and various illustrations I've seen?.

<"Oviraptorosaurs must also have originated at that time, but
the fossil record keeps silent. <Not entirely true, see below.>
They seem to have changed their diet from fish to freshwater
snails, which were abundant in Mongolia and Liáoníng/China, and
(like many birds later) from underwater flying to wading
(Chirostenotes is often said to have had wading adaptations). A
diet of mainly freshwater snails is probably the best
explanation for their odd skulls as well for the protruding
premaxillary teeth of Caudipteryx which might have been used in
pulling snails out of mud.>

  What mechanical or ecological (or biological) evidence does
one suppose oviraptorosaurs ate snails? Or even *Caudipteryx*?
Or even fish, for that matter?. Barsbold (1977), and Barsbold,
Maryanska, and Osmólska (1990) suggest an entirely different
mechanical proposition (clams) - these are heavily developed
crushing jaws, and one only needs to suck to eat a snail (sorry
if this sounds vulgar, but I can't think of another way to state
it). Ugh, I can't wait until SVP this year?.

<Still true. :-( Is it likely that a mobile scapula-coracoid
joint can evolve twice (or be a misinterpretation)?>

  What evolutionary scenarios do you conceive of that could
account for a mobile scapulo-coracoid joint? Apply this to the
fossil record, and examine your findings. No preconceived ideas
about which forms will make the likeliest canidates for testing:
be frugal.

<Guide to the cladogram (shortened)
"Ornithodira: endothermy,>

  Assuming pterosaurs are more closely related to birds than to
lizards?. Or that they're endothermic?.

<insectivory,>

  Presumptive of the lack of hard evidence. A conical tooth can
be used for more than taking on the über-insects of the era.
Many pterosaurs in fact appear to have fishing adaptations, and
some (e.g., *Eudimorphodon,* dsungaripterids) were much more
specialized and some could have been carnivorous. Not much
variety has been attached to pterosaur diet, though Bakker has
certainly suggested broader ecologies than most have applied.
Furthermore, the "lagosuchid" dinosauriforms have homodont,
ziphodont jaws that appear to be carnivorous rather than insect
eating.

< Neotetanurae: fused distal carpal 1 + 2 semilunate to permit
the swivel wrist motion, 'terrible claws' ?convergently or
?primitively in Ornitholestes,>

  The pes is not complete enough to offer any concept of a
second "raptorial" claw. This appears to be restricted to
Maniraptora (if troodontids and *Megaraptor* are maniraptorans).

<Carnosauria: nearly triangular antorbital fenestra,>

  Pardon? Triangular antorbital fenestra is a very infrequent
aspect of the hole in the head, and is directly influenced by
the presence of the antorbital diverticulum (Witmer, 1993, 1995,
1997), thus may have no phylogenetic significant. The size may
also be difficult to use, but the size of the fossa may not.
Spinosauroids appear to be the only taxon one can reasonably
apply this feature to, phylogenetically.

<some features of hand, lower jaw, skull and pelvis according to
Paul (1998); includes Allosauridae, Ornitholestidae, probably
Sinraptoridae and Carcharodontosauridae. <Any comments???>>

  A lot of the pectoral features (including the forelimbs) are
also seen in coelurosaurs, to many degrees, and are avetheropod
features; *Ornitholestes* is more likely a coelurosaur on the
basis of several pelvic, hindlimb, and cranial features. It may
even be closer to birds than is *Compsognathus,* with a
ventrally concave posterior blade of the ilium, triangular
obturator process, slender and bowed femur, and tapered fibula.
Paul (1988a,b) does suggest the affinities of *Ornitholestes* to
allosaurs, but there is a general dissagreement, and one can
search the debate on the list in the archives. I'm too lazy to
do it right now, it's already getting late. : )

< Maniraptoriformes: ?.

Maniraptora:  ? cervical, dorsal, sacral, and proximal caudal
vertebrae pneumatised,>

  A crash course in pneumatized vertebrae is not in my head to
do right now, but only two taxa have such extensive
pneumatization: the node defining ? == { Erlikosaurus +
Oviraptor } and birds in the strict sense. All other taxa lack a
fully pneumatic sacrum, *Caudipteryx* lacks pneumatization of
the caudals and most of the dorsals, dromaeosaurids lack
pneumatized caudals and dorsals, and ornithomimids have just a
few more pneumatic dorsals. Tyrannosaurids appear to resemble
dromaeosaurids more in the extensivity of pneumatopores in their
vertebrae.

<ornithoid eggshell (Varricchio et al., 1997)>

  Pfffh ? except oviraptorids, which have ratite eggshell.

<Oviraptorosauria: loss of maxillary and dentary teeth, skull
boxlike and adapted to crush ?freshwater snails;>

  This of course does not include caenagnathids who have more
slicer-type jaws, or caudipterids [ugh, I _hate_ that name]
which have pinscer-type jaws?.

<includes Oviraptoridae, Caenagnathidae, Microvenator,
Caudipteryx and probably Protarchaeopteryx (still not completely
prepared).>

  And won't be. It's not like the animal is preserved
Gobi-style, you can't just prep it out in that fashion; its
squished flat like most Liaoning fossils.

<'Dryptosaurus etc.' = Dryptosaurus + Deltadromeus. Holtz (1996)
refers to this group as Dryptosauridae, but that term has
already been used for Dryptosaurus + Diplotomodon.>

  That's right, therefore it can't _possibly_  include another
taxon, especially one as crappy as Diplotomodon [I also dislike
tooth taxa, including *Troodon*?]?.

<Dryptosauria is suggested as and alternative name for the
group.>

  Redundant, useless, Dryptosauridae has never been defined, so
a "replacement name" is useless in any sense.

<Kakuru, a tibia and a toe phalanx from the Early Cretaceous of
Australia, could be an alvarezsaurid, because it resembles the
respective parts of Avimimus which are thought to be mononykine
(if Avimimus is indeed a chimera <obviously not>).>

  Who thinks *Avimimus* is mononykine? Mickey Mortimer puts it
around Pygostylia, Kurzanov as a bird _sensu lato_, other
authors around oviraptorosaurs.

<A probable Early Cretaceous caenagnathid is known from
Victoria/Australia, and there is a possible oviraptorid sacrum
and ilium from the same time of Brazil (33), which I guess to be
possibly alvarezsaurid (for biogeographical reasons).">

  But ignoring the morphological condition of the elements.
There are few other groups it resembles besides oviraptorosaurs
and dromaeosaurids, which at least suggests the jaw fragment is
maniraptoran.
 
---------

  Anyway, I'm done, and my previous comments handle the
"Conclusions" section enough.


=====
Jaime A. Headden

  Aaaaaaaaaaaaaaaaaaaahhhhhhhhhhhhhhhhhhr-gen-ti-na
  Where the Wind Comes Sweeping Down the Pampas!!!!

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