Re: Martin 2004 critique

[Phil Bigelow <bigelowp@juno.com>]

Nice job Mickey!  Does _Acta Zoologica Sinica_ have a "Criticism-Reply"
section?  You could submit your critique.

One can accept as opinion those parts of Martin's paper where he clearly
states it is only his opinion.  However, the bazillion factual errors
that you uncovered suggest that his manuscript wasn't peer reviewed. 
Standard operating procedure is for the reviewers to point out factual
errors to the journal's editor.  The editor than rejects the manuscript
until all the errors are corrected.

Maybe I'm a bit naive, but I doubt that most journal editors would cut
Martin any slack just because he holds a minority viewpoint.  So, either
_AZS_ has no review process at all or its reviewers just rubber stamp
submitted manuscripts.  (?)

Please note that this is *not* an attack on Martin.  Still, it is clear
that something in the system failed.

<pb>
--

On Sun, 15 May 2005 03:18:16 -0700 Mickey Mortimer
<Mickey_Mortimer111@msn.com> writes:
> Here's something I wrote on Spring Break while stuck away from my 
> refs, and
> decided to post...
> 
> Tim Williams wrote-
> 
> >Martin, L.D. (2004). A basal archosaurian origin for birds. Acta
> >Zoologica Sinica 50(6): 978-990.
> 
> It's been a while since I've had the pleasure of critiquing an ABSRD 
> paper.
> This one is similar to the others- bringing up the same old 
> criticisms yet
> ignoring most recent papers, including those which have been written 
> to
> specifically address them.
> 
> "For nearly two decades, Deinonychus stood almost alone as a 
> dinosaurian
> proxy for a bird ancestor, but in recent years, smaller and more 
> birdlike
> theropods were discovered in the Early Cretaceous Confuciusornis 
> fauna from
> Liaoning, China."
> Almost alone? Does Martin not know of all the well-preserved 
> deinonychosaurs
> described prior to 1998? Sinornithoides, Saurornithoides, Troodon,
> Unenlagia, Velociraptor, Saurornitholestes, Dromaeosaurus, 
> Adasaurus, etc..
> Or the well-preserved oviraptorosaurs- Avimimus, Chirostenotes,
> Microvenator, Oviraptor, Rinchenia, "Ingenia", Conchoraptor.
> 
> "The femoral head [of Archaeopteryx] turns forwards rather than 
> extending
> perpendicular to the shaft."
> No it didn't (Hutchinson, 2001).
> 
> "The pelvis has an incompletely open acetabulum, and there is no
> characteristic dinosaurian supra-acetabular shelf."
> There actually IS a supracetabular shelf in Archaeopteryx (Paul, 
> 2002),
> unlike most other maniraptorans.
> 
> The above characters result "in a somewhat sprawling position for 
> the femur
> that is corrected at the knee joint, resulting in a functionally 
> vertical
> leg." No more so than other dinosaurs. Most non-avetheropods have 
> the
> femoral head orientation Martin claims for Archaeopteryx.
> 
> "Archaeopteryx lacks basic features of both modern bird and 
> dinosaur
> postures: and it is difficult to argue that it shared their peculiar 
> backs
> while running, or that the common ancestor of birds and dinosaurs 
> had
> already achieved such a running posture. In fact, confinement of 
> the
> articular surface to the front of the acetabulum results in a 
> vertical
> back."
> Martin earlier noted that modern birds have antitrochanters which 
> produce
> their slight outward femoral projection, unlike Archaeopteryx. This 
> is
> presumably the "basic feature of modern bird postures" Archaeopteryx 
> lacks.
> However, the dinosaur-bird dichotomy in pelvic structure Martin 
> advocates
> isn't real. There are representatives of every combination of 
> acetabulum
> closure, supracetabular shelves and antitrochanters.
> Acetabulum partially closed, supracetabular shelf, no 
> antitrochanter-
> Archaeopteryx.
> Acetabulum partially closed, supracetabular shelf, antitrochanter-
> Unenlagia.
> Acetabulum partially closed, no supracetabular shelf, 
> antitrochanter- most
> birds.
> Acetabulum partially closed, no supracetabular shelf, no 
> antitrochanter-
> Sinornithosaurus.
> Acetabulum open, supracetabular shelf, no antitrochanter- most
> non-coelurosaurian theropods, Stokesosaurus, Archaeornithomimus,
> Microvenator.
> Acetabulum open, supracetabular shelf, antitrochanter- 
> Shenzhousaurus,
> ornithomimids, Patagonykus, Shuvuuia, Mononykus, Neimongosaurus,
> Erliansaurus.
> Acetabulum open, no supracetabular shelf, antitrochanter- 
> Tyrannosaurus,
> Segnosaurus, Avimimus, Oviraptoridae, Troodontidae, Microraptor.
> Acetabulum open, no supracetabular shelf, no antitrochanter- 
> Gorgosaurus.
> Even if Martin's dichotomy were true, it would not suggest the 
> dinosaur-bird
> common ancestor lacked a horizontal back. If the topology is 
> (D(A,B)), and D
> and B have a horizontal back, while A lacks one, it's just as 
> parsimonious
> to assume A reversed the trait as it is to assume it developed in 
> parallel
> in D and B. Paul's demonstration of a supracetabular shelf in 
> Archaeopteryx
> disproves Martin's claim the only acetabular articular surface was 
> anterior,
> so there is no evidence Archaeopteryx stood vertically anyway.
> 
> Interestingly, Martin brings up WAIR, but says it "seems better 
> fitted for
> modern birds with their peculiar leg positioning than 
> Archaeopteryx..." Why
> this should be is never explained and not obvious.
> 
> Did you know that Maniraptora was the "last dinosaurian clade to 
> develop
> (i.e. a crown group)"? I certainly didn't... Martin clearly knows 
> his
> dinosaurs and phylogenetic terminology.
> 
> Martin's first major qualm with BAD is the temporal paradox. He 
> notes that
> the fact Maniraptora is deeply nested in Theropoda leads to "an
> inconsistancy in time of origin for Protoavis, a supposed Late 
> Triassic
> bird; and a similar problem exists for possible Early Jurassic 
> "bird"
> tracks."
> "Embedding birds in the maniraptoran crown group coupled with a 
> Late
> Jurassic age for Archaeopteryx creates a similar problem. Not only 
> is
> Archaeopteryx older than any credible maniraptoran fossil, but 
> maniraptoran
> diversification must be even older"
> "Such discrete evolutionary bursts, if genuine, are more 
> theoretically
> important than the question of avian origins and should be tested 
> with
> evidence outside the bird/dinosaur controversy."
> So just when undeniable maniraptorans are being found just a few 
> stages
> after Archaeopteryx (if not before, if the Daohugou is Middle 
> Jurassic),
> Martin's embraced Protoavis and controversial tracks as being avian 
> in order
> to push birds even further back. A shame Protoavis is thought to be 
> avian by
> so few people (one could bring up Eshanosaurus as an Early Jurassic
> maniraptoran with at least the same amount of confidence), and that 
> the
> ichnological evidence is as ambiguous as the Middle Jurassic 
> maniraptoran
> dental records Martin finds uncredible.
> As described below, in order to not hinder Martin's theory of bird 
> origins,
> Protoavis would actually have to cause longer ghost lineages. 
> Nesting birds
> within Maniraptora is only 'problematic' if Archaeopteryx is itself 
> nested.
> If Archaeopteryx is sister to other maniraptorans (with birds closer 
> to
> Archaeopteryx, as Martin might believe; or with birds closer to 
> other
> maniraptorans, as Paul believes), the temporal problem is solved. Of 
> course,
> both enigmosaurs and deinonychosaurs are known from undeniable 
> specimens a
> mere 10 Ma after Archaeopteryx, not to mention the earlier 
> fragmentary
> specimens. So the temporal paradox is weak to begin with.
> Finally, the very studies Martin advocates HAVE been done, by Brochu 
> and
> Norell (2001). They concluded deriving birds from any 
> non-dinosaurian
> archosaur involved far more temporal inconsistancy and that the 
> fossil
> record actually fits BAD rather well compared to other accepted 
> tetrapod
> phylogenies.
> 
> Martin's next section is titled "anatomical barracades". Instead of 
> bringing
> them up again, what Martin really needs to do is address Makovicky 
> and Dyke
> (2001)- Naive falsification and the origin of birds. For all these
> barracades are are more instances of naive falsification. Birds and
> dinosaurs are supposedly different in some characters, and those 
> states
> couldn't possibly have evolved from each other, so they must have a 
> common
> ancestor before either trait evolved in each line.
> 
> First he brings up the tooth implantation issue, which was addressed 
> by
> Currie and Zhao (1994). Martin says "... once one implantation 
> pattern has
> been achieved, it is hard to understand why it would be lost and 
> replaced by
> another." Regardless of how hard this may be, some deinonychosaurs 
> have the
> dinosaurian pattern, so evolution of this trait would have to 
> happen, even
> in Martin's phylogeny.
> "The teeth in birds or crocodiles are bordered lingually by an 
> extension of
> the tooth-bearing bone (premaxilla; maxilla or dentary), while 
> dinosaur
> teeth are bordered by hypertrophied attachment bone 
> (superpleurodonty:
> Martin and Stewart, 1999). This suggests that the common ancestor of 
> birds
> and dinosaurs did not have socketted(sic) teeth."
> I assume Martin is talking about interdental plates when he mentions
> "hypertrophied attachment bone." The supposedly lost interdental 
> plates of
> most deinonychosaurs seem to be merely fused (and sometimes 
> reduced)
> instead. Crocodiles seem to be similar, from the reports of fused
> interdental plates in various sphenosuchians. I wouldn't be 
> surprised if
> birds took the same evolutionary pathway, though we have no well 
> described
> intermediates between Archaeopteryx's unfused plates and 
> Hesperornis'
> 'absent' plates at the moment. The sequence from Archaeopteryx to
> Bambiraptor (with only some plates fused) to dromaeosaurids provides 
> a
> method to break Martin's barracade and show that birds needn't have 
> branched
> off so basally. See my comments on the term 'superpleurodonty' 
> below.
> "... although dromaeosaurs were originally reported to lack 
> interdental
> plates, a signature trait of dinosaurian tooth implantation. Their 
> tooth
> replacement has also been claimed to be birdlike (Currie, 1987). If 
> they
> had, or had had, the avian/crocodilian implantation and replacement 
> pattern,
> we might argue instead that they are not dinosaurs."
> Currie's 1987 paper was on Troodon, not dromaeosaurs. Archaeopteryx 
> has
> interdental plates, which doesn't make sense in Martin's scheme. 
> Maybe we
> should argue that instead it is not a bird? ;) Bambiraptor and
> Sinornithosaurus also have obvious unfused interdental plates. But 
> these are
> birds in Martin's view. I suppose ornithomimosaurs and 
> alvarezsaurids are
> birds too, since they lack obvious interdental plates?
> 
> Next, Martin discusses the semilunate and digital identity issues. 
> He claims
> dromaeosaurs have only two carpals, and says the dromaeosaur 
> semilunate is
> equivalent to avian distal carpal III! No, distal carpal III in 
> dromaeosaurs
> is fused to the base of metacarpal III, just like in the birds 
> Martin
> mentions (Gishlick, 2002). You might think Martin is renaming the 
> distal
> carpals to correspond to his thinking birds have digits II-III-IV. 
> However,
> he says distal carpal III is fused to metacarpal III in Jeholornis 
> and
> Confuciusornis, which is true of the standard distal carpal III, and 
> not the
> semilunate. And just because the ulnare is missing in many 
> maniraptorans
> doesn't mean it was absent (known in Caudipteryx, Heyuannia,
> Sinornithosaurus and Microraptor, for instance). Because 
> Archaeopteryx and
> other Mesozoic birds have more than two carpals, Martin claims 
> dromaeosaurs
> are more likely to be derived from birds than vice versa. But even 
> if
> derived dromaeosaurs did have such a reduced carpus (physically 
> implausible
> as it may be), that could just be an apomorphy of the clade after it 
> split
> from the line leading to birds, inside Theropoda (since 
> non-maniraptoran
> theropods also all have four carpals or more, except maybe 
> mononykines). So
> Martin's barracade is only relevent to a phylogeny where birds 
> evolved from
> dromaeosaurids, which no one supports.
> Martin brings up digital homology, assuming digital identity and 
> analgen
> identity are equivalent, without even a mention of frameshifts.
> 
> Martin then goes on about the astragalar ascending process and 
> pretibial
> bone, spending quite a lot of time trying to show Archaeopteryx had 
> a
> pretibial bone. He ignores Shenzhouraptor (= Jeholornis), which 
> clearly
> shows an ascending process (that was noted and illustrated by the 
> authors to
> help prove BAD), despite having referenced the taxon only two pages 
> prior.
> Rahonavis would also help here, though one must wonder if Martin 
> thinks it's
> a maniraptoran or a sauriurine, or both. He says, "We can speculate 
> the
> common ancestor of birds and dinosaurs lacked an ascending process 
> of the
> ankle, and that bipedality was achieved independantly." Um, what 
> about the
> ascending processes of non-avian maniraptorans? Don't they throw a 
> wrench
> into Martin's hypothesis?
> 
> The short postacetabular process of birds is said to be more 
> primitive than
> dinosaurs, which was "already elongated in the coelurosaurian 
> dinosaur
> Coelophysis from the Triassic." Coelurosaurian Coelophysis? Martin 
> sure is
> up to date on dinosaurs... In any case, one might bring up the 
> large
> postacetabular processes of most oviraptorosaurs and dromaeosaurs, 
> as well
> as ornithuromorphs, which yet again mean the barracade was broken 
> through
> somehow regardless of what birds are. Perhaps Martin thinks that
> postacetabular processes can only grow, and not shrink, but how he 
> could
> defend such a view is beyond me.
> 
> Finally, Martin thinks the apparently absent external mandibular 
> fenestra of
> Archaeopteryx is symplesiomorphic with pre-archosaurian reptiles, 
> thus
> providing more evidence birds are outside the crocodile-dinosaur 
> clade. The
> presence of mandibular fenestrae in oviraptorosaurs and 
> deinonychosaurs is
> said to be convergent with dinosaurs+crocs. Jixiangornis, 
> Omnivoropteryx,
> confuciusornithids, Vescornis and the Spanish enantiornithine 
> nestling all
> have mandibular fenestrae too. Thus the distribution is not so 
> simple, and
> cannot be used to place birds so basally. Of course, even if birds
> universally lacked mandibular fenestrae, their absence in 
> compsognathids
> proves the state can evolve from one where fenestrae are present.
> 
> Martin ends the section with the kind of flawed logic Makovicky and 
> Dyke
> argued so firmly against. Just because dinosaurs and birds 
> (supposedly) show
> different character states, their common ancestor had to lack the 
> states,
> since they can't evolve from each other. Martin knows how states 
> must/did
> evolve. A pretibial bone can't evolve from an ascending process, so 
> both
> have to evolve from a tarsal arrangement without a proximally 
> extended
> component. Etc.. In addition, Martin constrains states to evolve in 
> only one
> direction. Mandibular fenestrae can't close, sterna can't become
> cartilaginous, femoral heads can't angle anteriorly, sickle claws 
> can't
> reduce. It's all just assumed, and is so often contradicted by 
> exceptions in
> each case.
> Figure 2 is *gasp* an ABSRD cladogram of bird origins. It has the 
> following
> topology-
> |--petrolacosaurs
> `--+--prolacertids
> `--+--+--Longisquama, etc.
> | `--+--maniraptorans
> | `--birds
> `--+--crocodilians
> `--+--thecodonts
> `--+--Ornithischia
> `--Coelophysis
> Notice Martin's basically advocating non-archosaurian birds. Of 
> course,
> birds are by definition archosaurs, but in this scheme birds are 
> placed
> outside the normal concept of Archosauria (including thecodonts, 
> crocodiles
> and dinosaurs), and are descended from protorosaurs like Cosesaurus 
> ands
> avecephalans (all normally outside Archosauria). It's nice to see 
> Martin
> agreeing with current phylogenetic thinking that avicephalans and 
> Cosesaurus
> are outside the Crocodylia+Dinosauria clade. However, he still 
> places them
> as archosauromorphs higher than prolacertiformes, because of their 
> supposed
> antorbital fenestrae. When more characters are analyzed (e.g. in 
> Senter,
> 2004), they fall outside Sauria. Note the precise placement of 
> Sauria in
> Martin's cladogram is unknown since he doesn't include lepidosaurs.
> Also interesting is Martin placing thecodonts as avemetatarsalians, 
> because
> of their 'superpleurodont' teeth. His use of this term doesn't make 
> sense.
> Dinosaurs are not pleurodont- their teeth are not fused to the 
> dentigerous
> bones and they are in distinct sockets. In any case, Martin 
> previously said
> that "dinosaurs retain the primitive pattern of tooth replacement", 
> and
> indeed taxa as basal as Mesosuchus and Captorhinus share it. So 
> this
> character can't support placing birds outside traditional 
> Archosauria.
> Anyone know what kind of tooth replacement sphenosuchians have?
> Finally, Martin uses the elongated postacetabular process as a 
> character to
> unite ornithischians and Coelophysis, but this character is not 
> present in
> basal saurischians (Eoraptor, herrerasaurids) or sauropodomorphs. 
> The
> elongation developed convergently in theropods and ornithischians. 
> Martin
> could have used one of the many actual dinosaurian synapomorphies 
> which are
> known (no postfrontal, cervical epipophyses, perforate acetabulum, 
> prominent
> anterior trochanter, etc.), but maybe their presence in basal birds
> discouraged him.
> 
> Martin finds "such a wide distribution of feathers or hairy 
> coverings" (as
> seen in coelurosaurs and pterosaurs) improbable. I don't see what's 
> so
> improbable about one more clade (in addition to mammals and
> coelurosaurs/birds) having filamentous integument. Martin is 
> noncommittal in
> regards to non-bird filamentous integument though.
> 
> "Protarchaeopteryx has typically avian teeth and there is no reason 
> to doubt
> that it is avian." I suppose if maniraptorans are birds in Martin's 
> mind,
> that's true enough.
> The long primaries of Caudipteryx are said to "so greatly reduce 
> the
> usefulness of the hand for grasping that it must imply derivation 
> from an
> arboreal flyer/glider." Someone hasn't read Gishlick (2001) I see.
> "An arboreal stage is further supported by a reflexed hallux on the 
> foot in
> all of these forms." Someone hasn't read Middleton's work either.
> "The most recent cladistic analyses of oviraptorosaurian 
> relationships (Lu
> et al., 2002; Maryanska et al., 2002) show oviraptorosaur(sic) as 
> flightless
> birds more derived than Archaeopteryx." Convenient how he picks out 
> the two
> oddball analyses, eh? What about all the versions of the Theropod 
> Working
> Group's analysis? Holtz's? Sereno's? Rauhut's?
> There are a lot of unsupported assumptions about microraptorians. 
> The
> hindwings were "clearly a gliding adaptation". "In order for the 
> femur to
> function, they must be able to extend laterally." The "animal could 
> barely
> walk, let alone run." This is also supposedly supported by the small 
> toes
> and reversed hallux. I doubt the toes are any more reduced than
> ornithomimosaurs and troodontids, and the hallux is not reversed.
> 
> Figure 3 includes a portion of the TWG phylogeny, to show how 
> primaries
> imply a volant ancestor for oviraptorosaurs and eumaniraptorans. 
> This would
> suggest Martin agrees oviraptorosaurs are outside Eumaniraptora, but 
> see
> below.
> 
> Martin claims Sereno (1991) called Scleromochlus a dinosauromorph, 
> but he
> did not. He says that only "birds, some pterosaurs, and certain 
> basal
> archosaurs" have scapulae parallel to the vertebral column. Rather
> inconvenient for him the 'basal archosaurs' he uses as bird 
> ancestors aren't
> included in that list. Longisquama has the primitive oblique 
> position
> similar to most dinosaurs, drepanosaurids have scapulae 
> perpendicular to the
> dorsal column, and Cosesaurus lacks a scapular blade altogether. 
> Cosesaurus
> is claimed to have a furcula, contra Sanz and Lopez-Martinez (1984) 
> and
> Peters (2000). Megalancosaurus is said to as well, which I don't 
> recall
> being reported anywhere else. Martin now correctly believes 
> Longisquama
> lacks a mandibular fenestra, and says it has thecodont dentition, 
> including
> teeth with constricted bases. Other avian characters are listed, but 
> are of
> course, also found in non-maniraptoran theropods- accessory 
> antorbital
> fenestrae (also in averostrans), pointed snout (coelurosaurs), 
> elongate
> postorbital (how is this birdlike?), strap-like scapula
> (ceratosaurs+tetanurines), furcula (theropods), elongated 
> penultimate
> phalanges (theropods) and feathers (coelurosaurs).
> 
> Martin says "although we might expect flight feathers to have 
> originated
> from scales along the edge of supporting structures", the fact 
> primary
> feathers originate from the middle finger of birds and the middle of 
> the
> back in Longisquama "would only make sense if they were derived from
> overlapping scales." I don't follow this logic. Besides the 
> non-sequitur,
> there are a couple of additional problems. Martin's Triassic bird 
> Protoavis
> has more quill knobs on its third metacarpal than its second, so 
> might
> suggest basal birds developed primaries on the outer edges. Also, 
> because
> maniraptorans had arched non-pronated hands, their 'outer edge' IS
> metacarpal II. Martin goes on to ignore all the developmental data 
> showing
> feathers did not evolve from scales and are only homologous at a 
> very basic
> level. He speculates Longisquama "may have expanded its ribs much as 
> in the
> prolacertian rib gliders." Which gliders he's talking about is 
> uncertain, as
> I would expect him to include drepanosaurids in his 'Longisquama, 
> etc.'
> group, which is closer to dinosaurs than prolacertids in his scheme. 
> Does
> Martin think drepanosaurids are prolacertiformes which developed 
> their
> birdlike characters convergently? In any case, Martin also ignores 
> the
> criticisms of Reisz, Sues and Senter which show most of the 
> feather-like
> aspects of parafeathers are illusions (sheath, rachis, barbs). He
> furthermore claims that Confuciusornis' retrices have their odd 
> morphology
> because the sheath stays fused to the barbs and rachis. I doubt 
> this
> arrangement would work, and find it more probable the barb ridges 
> simply
> aren't separated early in ontogeny (which I think is how modern 
> birds with
> similar feathers develop).
> 
> Figure 4 includes terribly inaccurate reconstructions of 
> Longisquama's skull
> and furcula. The furcula looks like it was just altered from 
> Archaeopteryx
> or Bambiraptor, instead of the more U-shaped structure in 
> Longisquama with
> its pointed distal tips. The cranial reconstruction assumes a 
> posterior
> section of the skull was broken off, which is contradicted by the 
> cervical
> vertebrae extending to the preserved posterior edge. The 
> frontoparietal
> crest is nowhere to be seen. The naso-fronto-lacrimal area has been
> redesigned to look theropodan. The ventral mandibular edge has been 
> changed
> to expand beneath the orbit. The Archaeopteryx is inaccurate too, of 
> course,
> with no ventral squamosal or postorbital processes.
> 
> Martin's conclusion has much praise for Paul's work, but 
> misrepresents it as
> being equivalent to his own. Neoflightless maniraptorans are not a
> compromise between BAD and ABSRD, since Paul still thinks 
> maniraptorans and
> birds are dinosaurs, while Martin thinks neither are. Martin claims 
> Paul's
> placement of various maniraptorans closer to birds than 
> Archaeopteryx solves
> the problem of "numerous anatomical anomalies indicating that these 
> special
> dinosaurs are too derived to be the ancestors of birds." Yet Paul 
> has
> maniraptorans ancestral to birds in the same way Gauthier and 
> almost
> everyone else does. He only differs in the order of pre-pygostylian
> offshoots (Archaeopteryx more basal, oviraptorosaurs more derived, 
> etc.).
> Another interesting fact- "The monophyly of the Dinosauria has 
> always been
> difficult to support." Apparently Martin hasn't read any of the 
> relevent
> literature since the mid 1980's.
> Martin still believes in the Sauriurae-Ornithurae split. He notes 
> that
> ornithurines "all have rod-like quadratojugals", while "sauriurines 
> all have
> reduced L-shaped quadratojugals." Another symplesiomorphy used to 
> support
> Sauriurae?! Who would have guessed? I suppose that makes 
> Cosesaurus,
> Protoavis and Shuvuuia ornithurines. It will be interesting to see 
> what the
> quadratojugal of the 'basal ornithurine' Yanornis looks like.
> Martin discusses maniraptorans in the sauriurine section (they do 
> have
> L-shaped quadratojugals...), but says they "may form a more 
> exclusive clade
> united by the mandibular fenestra and fan-like tail feathers 
> terminating on
> an elongate tail." He then says Confuciusornis may be related to
> oviraptorosaurs, while Jeholornis "seems closer to dromaeosaurs". So 
> one is
> left confused as to exactly how Martin thinks maniraptorans relate 
> to birds.
> Are maniraptorans sister to Ornithurae+Sauriurae, sister to other 
> Sauriurae,
> polyphyletic within Sauriurae? He supports each of these hypotheses
> somewhere in this paper.
> 
> One has to wonder if Martin has thought through the consequences of
> embracing Protoavis as a bird (the following comments assume 
> Chatterjee's
> identifications are correct). The acetabulum is completely open and 
> the
> femoral head medially projected, which would not be expected in a 
> Triassic
> bird if Archaeopteryx's supposed "somewhat sprawling posture" is 
> primitive.
> It also has an astragalar ascending process, large postacetabular 
> process
> and external mandibular fenestra. This would support these as
> symplesiomorphies of birds, contra Martin's hypothesis. Manual digit 
> III
> (digit IV according to Martin) lacks elongate penultimate phalanges, 
> unlike
> digit IV of Longisquama; the clavicles are unfused and there are no
> accessory antorbital fenestrae, both less birdlike than Longisquama. 
> Of
> course, this all assumes Protoavis is actually helping the temporal 
> paradox
> by being a bird more basal than maniraptorans, sauriurines and 
> ornithurines.
> The first five characters listed above could support Protoavis as a
> maniraptoran in Martin's scheme. Sauriurine characters seem to be 
> absent
> (based on Hou et al., 1996), while some 'ornithurine' characters are 
> seen
> instead (e.g. rod-like quadratojugal; slender furcula; concave facet 
> for
> scapula on coracoid; procoracoid process; large sternal keel placed
> anteriorly). Other 'ornithurine' characters are absent though (e.g. 
> elongate
> sternum; coracoid sulci on sternum; distally fused metatarsus; 
> tarsal cap).
> So Protoavis either helps the temporal paradox but disproves most of 
> Martin'
> s proofs that birds branched off prior to theropods; or it makes 
> the
> temporal paradox worse by requiring ghost lineages of 65 Ma for 
> sauriurines
> and 80 Ma for ornithurines, and makes Martin's phylogeny less 
> credible by
> either having dinosaurian/maniraptoran characters in a basal 
> ornithurine or
> ornithurine characters in a maniraptoran. The number of additional 
> ghost
> lineages that would be needed if it is maniraptoran is uncertain 
> pending
> precisely how Martin thinks they relate to (other) sauriurines.
> 
> In conclusion, Martin uses the standard BAND debating tactics 
> without
> addressing the meta-issues raised by BAD supporters, doesn't 
> realize
> implications for his points which argue against them, shows an 
> ignorance of
> dinosaur knowledge, misrepresents anatomy and misunderstands 
> phylogeny
> reconstruction and character distribution, and uses several 
> non-sequiturs.
> On the plus side, we finally get an explicit BAND hypothesis, 
> although now
> the exact relationships and membership of the maniraptorans is 
> unclear.
> 
> Mickey Mortimer
> Undergraduate, Earth and Space Sciences
> University of Washington
> The Theropod Database - 
> http://students.washington.edu/eoraptor/Home.html
> 
>