Vindex, I'd like to comment on two points, if I may.

You said..."Point 1: Essentially, that there are no transitionals.
This argument is burdened with explaining why there are specimens which display the intermediary anatomy which is predicted by evolutionary biology, of which Archaeopteryx is but one of many. The plain fact remains that according to creationism, there should be no such taxa in the first place."


You're assuming that God didn't make these creatures. I know of no such claim held by Christians to the opposite.
'Transitional is itself a cop-out word. It suggests something is in transition... moving from one form to another, in this case from dinosaurs to birds... Archaeopteryx is but one of many dead-ends... even evolutionaries say this. You then assume that there is an actual ancestor for birds to be found. Also, you say that this is 'predicted' by evolutionary biology, only in so far as it ignores other 'transitionals', such as the echidna, and the platypus... which are not harked on about being pointers between mammals and reptiles, because they fall out of the scope of supposed evolutionary path-ways.

Another 'path-way' is presented by scientists to say that some apes come from men! "John Gribbin and Jeremy Chefas in their article "Descent of Man - of Ascent of Ape?"... (http://www.science-frontiers.com/sf018/sf018p05.htm). Thus having a 'transitional' doesn't even imply that species moved the one way!

You said "Point 2: No phyletic progression from early theropods to Avialae, merely chronologically listed or clade based approach to naming dinosaurs.
To be sure, there is not anagenetic or phyletic progression--the derivation of birds is an example of cladogenesis. However, while the list I presented is by default chronological (after all, evolution proceeds over time and cladograms are mapped with time as the x-axis), that list is based on the quantifiable morphologic change in these taxa, which steadily approaches the avian condition. It is not a clade-based approach, though had I chosen to list clades, it would have been just as valid as clades themselves are delimited on anatomical grounds."

I missed this list. Any list you present could be said to be 'chronological'. Archaeopteryx itself has undergone moving on the lines of evolution. It was once hailed as a direct link between birds and reptiles, now it is in a cul-de-sac.

Let us address your first point, that Archaeopteryx may have just been designed by God to look like it was an anatomical intermediate between Theropoda and Aves. This is a most curious argument that creationists make. It is in fact nothing more than special pleading--here we have a specimen which precisely fits the bill for transitional in the evolutionary sense, and yet, instead of accepting the clear-cut and parsimonious conclusion, you insist that no, it was just made by God to look that way. If the latter option is correct, one can only conclude that God is doing one hell of a job to trick man into thinking his creation evolved.

You furthermore claim that Archaeopteryx is not transitional because it is not the phyletic progenitor of anything. If evolution were merely anagenetic, this would be a problem. As it were, the derivation of birds is a sterling example of cladogenesis, and Archaeopteryx is the sister clade of all other Avialae. It is not the species but its character state which is the most basal known for birds, and which is therefore considered ancestral. To claim that the outgroup status of Archaeopterygiformes somehow precludes its being transitional, is, frankly, indicative of a misunderstanding as to how cladogenesis works.

Your last point, is twofold: that any list is chronological, and that Archaeopteryx was once considered the phyletic progenitor of birds. Both need to be addressed. To former, the answer is actually quite obvious. 'Of course' any list of taxa is going to be chronological...any phylogenetic map must be graphed against time as the x-axis. Now, if one were merely to gather up a group of dinosaurs, starting with medial Jurassic forms and proceeding to the early-medial Cretaceous, and say, voila, here are transitionals, that would be a specious presentation. However, my list (which you can find in earlier posts in this thread--I think pg. 4) is not merely a hodgepodge of dinosaurs assembled by increasing age. It is a list comprised of quantifiable morphologic change over time, which steadily approached and then elaborated on, the avian bauplan. Such a list, grounded in anatomy, cannot merely be waved away. It requires explanation.

Lastly, I find it stunning that you claim Archaeopteryx was once considered the direct ancestor of birds. The first two individuals to extensively review the osteology of the urvogel, Sir Richard Owen and Thomas Henry Huxley both made no such claim. Huxley considered Archaeopteryx an enigmatic side-branch of avian evolution, and Owen of course rejected its status as anything but a bird--albeit strange. A similar treatment runs throughout the work of Seeley, Baur, etc. So, I am at a loss to find where your claim originates.

Vindex Urvogel

If I may interject: I'm convinved that what is confusing Montalban is the root of the word transitional. I think he may be looking at transition, which implies a movement from one state to another, and then jumping to the conclusion that a transitional fossil is actually on the road to a known ancestor to a known descendent -- a logical conclusion, if he hadn't repeatedly been told this is not what the word means.

I think you have become ensnared by a logical fallacy. The final line here about how creationism must necessarily preclude “such taxa” is true only after your incredulous assumption of “intermediary anatomy” becomes established fact, a notion that not even the entire evolutionist world is ready to accept. Fossils can only suggest evolutionary relationships (e.g., your narrow list of chronological dinosauria) but, in the end, are unable to confirm those relationships.

T.S. Kemp in Fossils and Evolution sees the problem as being with either the fossil record or with the whole idea that evolution is gradual. He says, “the observed fossil pattern is invariably not compatible with a gradualistic evolutionary process.” The only evolutionist answer to this dilemma is to continue to advance one or both of two ad hoc hypotheses: 1) undiscovered fossil forms, or 2) unknown mechanisms of evolution, neither of which has been shown to be true or untrue.

But how is all of this superimposed on our conversation here? How will it ultimately be shown that the submission of mere taxonomical lists can by no means satisfactorily prove a theory of gradualistic evolution? I think it will happen when we begin to narrow our observation of the metaphysical world, viz., cease the study of “relatives” and “families” of animals and take up the study of the evolution of anatomical structures peculiar to a derived group. For instance, in this particular study, we may want to ask what distinct anatomical features make a bird a bird, then begin to work backwards through extant fossil data to qualify and quantify the arrival of those features.

Can you agree that if you were able, through the fossil record, to convincingly build a case that demonstrated first, the non-existence of, then the gradual development of, and finally, the full arrival of a furculum and a large, deep sternum (two vital avian traits) in your list of related dinosaurs, that you would have an actual, first-hand snapshot of gradualistic evolution? I’m sure you can see how such a discovery would serve to pull the scientific world together, begin to galvanize your theories, and start to make believers out of skeptics.

Ok, so here it is – the question. Can you do it? From the fossil record, can you show me and others the gradual development of the furculum and the large, deep sternum in dinosaurs that would be essential for eventual flight?

I think that first a discussion of Kemp's quote, and the matter of punctuated equilibrium is in order. Let us review the basic argument. According to some, the fossil record fails to support gradualistic morphologic change over time, and this assertion was largely at the heart of "punctuated equilibrium." The concept was first implied by Mayr, and later Stanley (1975, 1981, 1982), Gould & Eldredge (1977), Eldredge (1984, 1985), Eldredge & Stanley (1984) and Gould (1980, 1982) modified Mayr's work and promoted a model of evolutionary change in which any given lineage exhibited morphologic stasis over time, followed by rapid ontogenetic changes and diversification. Most vociferously championed by Gould, this viewpoint practically rejected the adaptive power of natural selection, but most egregiously of all, Gould presented it as revolutionary--a breathtaking new development hitherto unthinkable. Like any scientific postulate, tests explicitly geared to uphold or refute this concept of punctuated equilibrium have been carried out, and ironically, none have been more damning thereto, than quantitative analysis of morphologic change in fossil taxa. Considering that Gould and his colleagues claimed the fossil record as their staunchest support, this is most curious. If we give the Gouldian argument the benefit of the doubt, and exclude invertebrates (in which there are literally scores of gradualistic changes over time), and restrict our argument solely to the vertebrates, we can isolate a host of studies which have utterly failed to corroborate Gould's ideas. The most thorough and significant, are those of Paul Gingerich. His 1977, 1980 and 1982 reviews of Cenozoic megafauna entirely failed to demonstrate the sort of punctuational nature of evolutionary change that Gould et al would have predicted. Instead, Gingerich found a persistent trend towards gradual morphologic change over time. The same has been found in multiple studies of Cenozoic mammals, including: Hurzeler (1962), Chaline & Laurin (1986), Fahlbusch (1983), Harris & White (1979), MacFadden (1985), Cronin et al (1981), Maglio (1973) and last but not least Krishtalka & Stucky (1985). Furthermore, similar results have been observed in studies of freshwater teleosts from Miocene deposits of Nevada (Bell et al 1985). The natural question, then, is how does the presentation of punctuated equilibrium advanced by Gould et al, and subsequently parroted by creationists stand up to scrutiny of the fossil record? It doesn't at all. The salient lesson of these studies herein cited is that it is attention to morphology, and not taxonomic detail, which reveals the true nature of evolutionary change over time. How do you account for the significant amount of data refuting the punctuational argument that you have advanced?

As a side note, it must further be stressed that this entire argument forces a false dichotomy on evolution: it is either punctuational, or entirely gradualistic. Yet reality does not conform to this limited view. Indeed, G. G. Simpsons terms: bradyteyly, horoteyly, and tachyteyly are by far superior in expressing the plastic nature of rate of change amongst taxa (Simpson 1944, Carroll 1988).

Here are the appropriate references:

Stanley, S. M. 1975. A theory of evolution above the species level. Proceedings of the National Academy of Sciences 72: 646-650.

Stanley, S. M. 1981. The New Evolutionary Timetable: Fossils, Genes, and the Origins of Species. Basic Books, New York.

Stanley, S. M. 1982. Macroevolution adn the fossil record. Evolution 36: 460-473.

Gould, S. J. & Eldredge, N. 1977. Punctuated equilibria: the tempo and mode of evolution reconsidered. Paleobiology 3: 115-151.

Eldredge, N. 1984. Simpson's Inverse: Bradyteyly and the phenomenon of living fossils. In N. Eldredge and S. M. Stanley (eds), Models in Paleobiology: 82-115.

Eldredge, N. 1985. Time Frames. Simon & Schuster, New York.

Eldredge, N. & Stanley, S. M. 1984. Living Fossils. Springer-Verlag, Berlin, Heidelberg, New York, Tokyo.

Gould, S. J. 1980. The evolutionary biology of contstraint. Daedalus 109: 39-52.

Gould, S. J. 1982. The maning of punctuated equilibrium and its role in validating a hierarchical approach to macroevolution. In R. Milkman (ed.), Perspectives on Evolution: 83-104.

Gingerich, P. 1977. Patterns of evolution in the mammalian fossil record. In A. Hallam (ed.), Patterns of Evolution as Illustrated by the Fossil Record: 469-500.

Gingerich, P. 1980. Evolutionary patterns in early Cenozoic mammals. Annual Review of Earth and Planetary Sciences 8: 407-424.

Gingerich, P. 1982. Time resolution in mammalian evolution: Sampling, lineages, and faunal turnover. Third North American Paleontological Convention, Proceedings 1: 205-210.

Hurzeler, J. 1962. Kann die biologische Evolution. Summarized in Carroll, Vertebrate Paleontology & Evolution: 572-573.

Chaline, J. & Laurin, B. 1986. Phyletic gradualism in a European Plio-Pleistocene Mimonys lineage (Arvicolidae, Rodentia). Paleobiology 12: 203-216.

Fahlbusch, V. 1983. Makroevolution. Paleontographica 57: 213-230.

Harris, J. & White, T. D. 1979. The evolution of Plio-Pleistocene African Suidae. Tansaction sof the MAerican Philosphical Society 69" 1-128.

MacFadden, B. J. 1985. Patterns of phylogeny and rates of evolution in fossil horses: Hipparions from the Miocene and Pliocene of North America. Paleobiology 11: 245-257.

Cronin et al. 1981. Tempo and mode in hominid evolution. Nature 292: 113-122.

Maglio, V. J. 1973. Origin and evolution of the Elephantidae. Transactions of the American Philosophical Society, New Series 63: 1-149.

Krishtalka, L. & Stucky, R. K. 1985. Revision of the Wind River Faunas. Early Eocene of Central Wyoming. Part 7. Revision of Diacodexis (Mammalia, Artiodactylia). Annals of the Carnegie Museum 54: 413-486.

Bell et al. 1985. Patterns of temproal change in single morpholocial characters of a Miocene stickleback fish. Paleobiology 11: 258-271.

Carroll, R. L. 1988. Vertebrate Paleontology and Evolution. Freeman & Co., New York.

Simpson, G. G. 1944. Temp and Mode in Evolution. Columbia University Press, New York.


Vindex Urvogel

First and foremost, I find it sublimely ironic that you should be urging attention to morphology, which is something I have been doing from the get-go. The irony is made all the more sublime considering that your previous arguments for punctuated equilibrium being a disproof for gradualistic evolution, are entirely contigent upon attention to taxonomic convention, and 'not' anatomy. This aside, let us address your challenge: provide evidence from the fossil record of the gradual development of the furcula and carinate sternum in dinosaurs. Excellent, and not at all hard. Let us look at the phylogenetic map of Theropoda, and isolate the taxa where these characters appear, their initial morphology, and their subsequent ontogenetic variation over time, leading first to the par-avian and then the bona fide avian condition.

Furculae first appear in the Allosauroidea, being present in Allosaurus fragilis itself. In Allosauroidea the furcula is shallow and incipient. The presence of furcula in Allosauroidea indicates that it may be a synapomorphy of Neotetanurae itself, which pushes the origin of the structure back to the terminal Triassic at earliest and early Jurassic at latest.

The earliest appearance of a furcula in Coelurosauria--the containing clade for Maniraptora and thus of more phylogenetic relevance than Allosauroidea--is in Scipionyx samniticus, from the Aptian. The furcula is rather more robust in this basal coelurosaur than in its larger allosauroid cousins, although it is still not as hypertrophied as later maniraptoran furculae. Further derivation of furculae in the coelurosaurian lineage includes their presence in Tyrannosauroidea, the sister clade of Maniraptora. Tyrannosauroids displaying furculae include Gorgosaurus libratus in which the furcula is nearly as robust as that of velociraptorines, and Daspletosaurus torosus, in which the furcula is more gracile and may indicate a character reversal to the earlier furcula morphology observed in basal coelurosaurs.

The most par-avian of furculae, appear within Maniraptora. They are present in Sinornithosaurus millenni, in which the furcula is as robust as that of Archaeopteryx, in Ingenia yanshini where indeed the furcula exhibits a 'greater' degree of hypertrophy than that seen in the urvogel, in Oviraptor spp., in which the furcula is equally robust as that seen in Ingenia, and finally, robust furculae are known from multiple velociraptorine specimens.

Thus traced, we have gradualistic variation following the derivation of the furcula, in which it progresses from the basal state, to the par-avian, to the avian. You must find a way to explain away the clearly preserved furculae of multiple theropod lineages, to refute these data.

Now let us turn to sterna. Ossified sterna lacking carinas first appear amongst the basal Neotetanurae and Allosauroidea, particularly in Xuanhanosaurus qilixiaensis and Sinraptor spp. In these taxa the sterna are fairly small, and lack derived sternocostal articulations. Nevertheless, as early as Sinraptor spp. we see an incipient carina of the sternum, hinting at the hypertrophy of this element in Coelurosauria.

Sterna are persistent elements of the pectoral girdle throughout Coelurosauria, and are seen in both Tyrannosauroidea (namely Gorgosaurus libratus), in basal form, and in Maniraptoriformes and Maniraptora in increasingly par-avian morphology. The sterna of oviraptors are largely ossified and no longer cartilaginous, and display an incipient carina. Indeed, the oviraptorosaur sterna are more robust than those of the urvogel and are no smaller than those seen in archaic avian lineages, such as the confuciusornithids. The same holds true for the sterna of velociraptorines, which are indeed larger than those of oviraptorosaurs (and they dwarf those of Archaeopteryx). Perhaps most daming is the fact that Rahonavis and the Alvarezsaurs, possess sterna which are more strongly carinate than the earliest Avialae.

And here we are again, a nice, gradualistic change in character state for the sternum. To refute these data one must somehow account for the presence of sterna in these dinosaurs, and moreover, why they should appear to grow increasingly avian in form, over time. The same holds true with the case of the furculae.

Last but not least, you make a statement about quantifying the characters which make a bird, a bird, and then working backwards as it were to isolate taxa which were and were not, birds. I fully concur, and eagerly await your list of autapomorphies of birds.

And finally, references. For the discussion of the furculae I really must refer the reader to Fig. 10.10 in Paul (2002), but a full list of the most important work on dinosaurian furculae includes the following, whose full citations I will have to provide in another post subsequent to this:

Barsbold 1983, Chure & Madsen 1996, Norell et al 1997, 1998, Ji 1998, Makovickyu & Currie 1998, Sasso & Signore 1998, Xu, Tang & Wang 1999, Xu, Tang & Wu 1999, Burnham et al 2000, Downs 2000.

The references for the data on dinosaur sterna:

Burnham & Zhou 1999, Xu, Wang & Wu 1999, Perle et al 1993, Currie & Zhao 1993, Paul 1988, Paul 2002.


Vindex Urvogel

Citations, continued:

Barsbold, R. 1983. Carnivorous dinosaurs from the Cretaceous of Mongolia. Joint Soviet-Mongolian Paleontological Expedition Transactions 19: 1-117.

Chure, D. J. & Madsen, J. H. 1996. On the presence of furculae in some non-maniraptoran theropods. Journal of Paleontology 15: 573-577.

Norell et al. 1997. A velociraptor wishbone. Nature 389: 447.

Norell et al. 1998. Theropod bird link reconsidered--a reply. Nature 391: 754.

Ji, S. 1998. New pterosaurs from northeastern China and the geological age problem of Confuciusornis. Journal of Vertebrate Paleontology 18: 54A

Makovicky, P. J. & Currie, P. J. 1998. The presence of a furcula in tyrannosaurid theropods, and its phylogenetic and functional implications. Journal of Vertebrate Paleontology 18: 143-149.

Sasso, C. D. & Signore, M. 1998. Exceptional soft tissue preservation in a theropod dinosaur from Italy. Nature 392: 383-387.

Xu, X., Tang Z., and Wang, X. 1999. A therizinosauroid dinosaur with integumentary structures from China. Nature 399: 350-354.

Xu, X., Wang, X., and Wu, X. 1999. A dromaeosaurid dinosaur with a filamentous integument from the Yixian Formation of China. Nature 410: 200-203.

Burnham et al. 2000. Remarkable new birdlike dinosaur from the Upper Cretaceous of Montana. Univeristy of Kansas Paleontological Contributions 12: 1-14.

Downs, A. 2000. Coelophysis bauri and Syntarsus rhodesiensis compared, with commonts on the preparation and preservation of fossils from the Ghost Ranch Coelophysis quarry. New Mexico Museum of Natural History and Science Bulletin 17: 33-38.

Paul, G. S. 2002. Dinosaurs of the Air: The Evolution and Loss of Flight in Dinosaurs and Birds. Johns Hopkins University Press, Baltimore.

Paul, G. S. 1988. Predatory Dinosaurs of the World. Simon & Schuster, New York.

Burnham, D. A. & Zhou, Z. 1999. Comparing the furcula in birds and dinosaurs. Journal of Vertebrate Paleontology 19: 34A

Perle et al. 1993. Flightless bird from the Cretaceous of Mongolia. Nature 362: 623-626.

Currie, P. J. & Zhao, X. J. 1993. A new carnosaurs from the Jurassic of Xinjiang, People's Republic of China. Canadian Journal of Earth Sciences 30: 2037-2081.

That should clear up the matter of references for the data on dinosaur furculae/sterna.


Vindex Urvogel

I have not even begun to research your claims here and am readily identifying gaps and reverse evolution and temporal discontinuity. Why do you solidly claim a "nice gradualistic change in character state" for these features? Here is just one contradiction from your post several days ago (after some research, other conflicts with regard to gradualism will be shown):

The lack of a robust, carinate sternum, ossified uncinate processes, a basal sternocostal morphology, the incipient nature of the acrocoracoid and acromion process, and lack of a triosseal canal system indicating that the supracoracoideus and pectoralis major were still fairly generalized comparative to Pygostylia, suggests that Archaeopteryx was not a skilled aerialist

Gaps? Reverse evolution? Temporal discontinuity?

What gaps? And moreover, I suggested one instance of character reversal, in the pectoral girdle of some Allosauroidea. Temporal discontinuity...that is even better...where?

As for your quote, yes, that refers to Archaeopteryx lithographica, and the fact that the most par-avian of Maniraptora had more derived pectoral architecture either underscores their phylogenetic affinities, or, argues for their being more derived than the urvogel, and neoflightless. You have not identified any internal inconsistency in my post, and your mere off-handed response will not adequately fill in for hard data. The simple fact of the matter is that Theropoda have furculae, and sterna, and in some, they are indeed as robust or more so, than those of Avialae proper. You have yet to demonsrate how they do not, or how there is not gradual morphologic change in these features leading to the avian condition.

Vindex Urvogel

You have already started with assumptions. 1) “Shallow and incipient” are your words hinting at an infant state of the furculum. How will you definitively show me and others that the Allosaurus fragilis furculum was really a “robust-furculum-in-progress?” 2) Was or was not the furculum of Allosaurus fragilis a development of Neotetanurae and how will you prove your answer by the fossil record? Also, you will recall I originally asked for “the non-existence of, then the gradual development of, and finally, the full arrival of a furculum.” What then is the ancestor of Allosaurus fragilis wherein the furculum is not present, and how does the fossil record connect the two?

Exactly what line do you intend on developing the avian furculum through? Have we now shifted to Coelurosauria and Scipionyx samniticus? If so, we are left with a major gap or are you counting on the “incipient” furculum found in a “cousin” Allosaurus fragilis to address this problem? I am not sure you should be allowed to do this. What if we were dealing with kiwis and emus, both of the order Struthioniformes, where, say, kiwis were progenitors of true flight but emus were a bifurcation? Should I not insist that you stay with kiwis and demonstrate the gradual development of avian features through its lineage alone? I see your change in direction as a problem.

Aside from that however, you are still faced with a gap. How will you move Allosaurus fragilis along in the fossil record to Scipionyx samniticus and convincingly present the gradual development of the furculum from “incipient” to “rather more robust?” And, in a temporal sense, will this be a lateral movement or a forward movement?

Gaps, parallel evolution, and reverse evolution, suggesting temporal discontinuity, all plague your paragraph. Why has our train of thought jumped tracks over to Tyrannosauroidea, unless it is to include a few instances of a near robust furculum in antecedents of Sinornithosaurus millenni and Archaeopteryx? Again, I do not know that you should be allowed to do this. Why are you not able to trace a single line of fossil data from Coelurosauria to Avialae without introducing offshoots and parallel branches within clades and families? And please offer a full explanation of why the “gracile” furculum in Daspletosaurus torosus apparently throws the evolutionary movement into regression, yet you do not view it as problematic. If you are counting on Daspletosaurus to fill a slot in your continuum, then you are presented with a temporal inconsistency.

But parallel and reverse evolution aside, you are still faced with gaps. Here, your argument has taken us from Scipionyx samniticus and thrown us into a “sister clade of Maniraptora” where we must more or less come to some vague agreement with you that the fossil record bears out a smooth, gradualistic development of the furculum from “rather more robust” in Scipionyx samniticus to exactly who knows what in Tyrannosauroidea - Gracile? Robust? Remember my clear initial request: can you present “the non-existence of, then the gradual development of, and finally, the full arrival of a furculum [for flight]” in these creatures? Here, I must insist that you gradually move us from Scipionyx samniticus all the way through Tyrannosauroidea and use the fossil record to do so, otherwise, one might assume you do not have a clear roadmap to follow.

After trudging through a related clade, we suddenly arrive at Maniraptora where “robust” furcula exist in number. Are we to think that the avian lineage came through the related clade or do we need to insist that you lay out clear fossils from Scipionyx samniticus to Sinornithosaurus millenni? If passing through the related clade is acceptable procedure, are we then to believe that you arrived at Sinornithosaurus millenni, who has a furculum “as robust as that of Archaeopteryx,” after the “gracile” furculum of Daspletosaurus torosus?

Here is the question: Can you or can you not provide a fossil record which plainly and unmistakably establishes the non-existence of, then the gradual development of, and finally, the full arrival of an avian furculum in dinosaurs? If you are unable to do this as you claimed you could, and instead, you begin arguing from a gradualistic clade-to-clade or family-to-family approach, we will have no choice but to suspect that, whether intentionally or by default, you espouse punctuated equilibrium. To be sure, your argument here smacks of punctuated equilibrium already.

A final note. Creationism and punctuated equilibrium are not bedfellows. Somehow or other, I feel, you have been led to believe that creationists adopted that theory after having applauded Gould’s admission of serious gaps in the fossil record. Nothing could be further from the truth. Creationists and Gould remained antagonists until his demise. Though some splinter group of creationists may hold to the theory of punctuated equilibrium, I do not nor does any creationist I personally know.

I do not intend to address the sternum or any more anatomical features until I am satisfied with answers to my questions or until we both agree that the fossil record is too scanty at present to prove your assertions.

As always, let us address the points offered.

Your first:

"You have already started with assumptions. 1) “Shallow and incipient” are your words hinting at an infant state of the furculum. How will you definitively show me and others that the Allosaurus fragilis furculum was really a “robust-furculum-in-progress?” 2) Was or was not the furculum of Allosaurus fragilis a development of Neotetanurae and how will you prove your answer by the fossil record? Also, you will recall I originally asked for “the non-existence of, then the gradual development of, and finally, the full arrival of a furculum.” What then is the ancestor of Allosaurus fragilis wherein the furculum is not present, and how does the fossil record connect the two?"


I will start with the "assumption" that the furcula (please note that the singular of furculae is NOT furculum, but furcula) in Allosauroidea is shallow, and incipient. In the case of Allosaurus fragilis, there is no other way to describe the furcula--it 'is' both shallow and incipient. Had one looked at the element, which I highly doubt you have done, one would see this.

Now, you proceed to make several demands: first, how will one demonstrate that from the incipient level seen in Allosaurus fragilis, a robust furcula may have been derived. The answer is most obviously by comparative analysis with other clades. If furculae are apomorphic of Neotetanurae the fossil record should demonstrate that furculae are limited in distribution to members of this lineage. And that is precisely what we see. Furculae remain exclusively neotetanuran traits. The implications, are such: if furculae are synapomorphic of Neotetanurae, then in derived members of this clade they would be symplesiomorphies. The common ancestor of the major neotetanuran lineages would have possessed a furcula, as evidenced by its immediate presence in basal Carnosauria (i.e., Allosauroidea) and basal Coelurosauria (e.g., Scipionyx samniticus). The shared presence of this trait allies Neotetanurae as a clade (among other such synapomorphies). Thus is settled the question of whether furculae are indeed characters of Neotetanurae.

You then demand that one provide the outgroup of Neotetanurae, in which furculae were absent, and data to support their affinity. The outgroup taxon to Neotetanurae is Spinosauroidea (sensu Sereno), and the shared tetanuran status of these sister clades is based on the following list of synapomorphic characters (after Dodson et al 1990):

a) Lack of an enlarged dentary fang
b) Presence of a maxillary fenestra
c) Dentition restricted to the antorbital region of the skull
d) Scapula straplike
e) Proximal half of metacarpal I contacts metacarpal II
f) Fourth manal digit absent
g) An obturator process of the ischium is present
h) A pubic "boot" is present
i) Metatarsal III proximally compressed
j) Ascending process of the astragalus well-developed

Compare this to the synapomorphic list of Neotetanurae:

a) Foramen or foramina opening laterally at the angle of the lacrimal
b) Surangular deep
c) Axial neural spines reduced
d) Chevrons possess craniodorsal prongs
e) The glenoid is expanded from the narrow and parallel/subparallel scapula
f) The brevis shelf of the ilium is narrowed
g) The femoral head is inclined dorsally from the greater trochanter
h) The lesser trochanter is winglike
i) The extensor groove of the distal femur is well-developed
j) Furculae present

Spinosauroidea, while possessing the characters listed as synapomorphic of Tetanurae (and thus qualifying as tetanurans) do not possess the characters present in the latter list, and thus cannot be grouped with Neotetanurae--they are the outgroup thereto. That should wrap up your first point.

You then assert that:

"Exactly what line do you intend on developing the avian furculum through? Have we now shifted to Coelurosauria and Scipionyx samniticus? If so, we are left with a major gap or are you counting on the “incipient” furculum found in a “cousin” Allosaurus fragilis to address this problem? I am not sure you should be allowed to do this. What if we were dealing with kiwis and emus, both of the order Struthioniformes, where, say, kiwis were progenitors of true flight but emus were a bifurcation? Should I not insist that you stay with kiwis and demonstrate the gradual development of avian features through its lineage alone? I see your change in direction as a problem."


This entire diatribe is wholly irrelevant--I have not "shifted" anything. Coelurosauria is a component clade of Neotetanurae, and I have been explicit all along that furculae are neotetanuran traits. Your lack of familiarity with the phylogenetics of Theropoda will not underwrite attempts to inject non-existent ambiguities and cladistic waffling into my argument. Had I argued something along the lines of discussing furculae in, say, Spinosauria, and Neotetanurae, and claiming a gradualistic progression from one to the other, THEN my argument would be inexcusably "shifting" the phylogenetic map to fit my conclusion. However, as I have done no such thing, the allegation you present in this paragraph is entirely specious.

You then go on to say:

"Aside from that however, you are still faced with a gap. How will you move Allosaurus fragilis along in the fossil record to Scipionyx samniticus and convincingly present the gradual development of the furculum from “incipient” to “rather more robust?” And, in a temporal sense, will this be a lateral movement or a forward movement?"


Since both are Neotetanurae, one has no need to artificially ally Allosaurus fragilis and Scipionyx samniticus--they are both members of the same containing clade. The physically more robust furcula of the latter is congruent with the prediction of theropod origin that in Coelurosauria, the furcula became hypertrophied, in the par-avian and finally avian manner. Graphically speaking, this is both a movement along the y-axis of the cladogram, and the x-axis of the cladogram.

Vindex Urvogel

Continued:

Your next point:

"Gaps, parallel evolution, and reverse evolution, suggesting temporal discontinuity, all plague your paragraph. Why has our train of thought jumped tracks over to Tyrannosauroidea, unless it is to include a few instances of a near robust furculum in antecedents of Sinornithosaurus millenni and Archaeopteryx? Again, I do not know that you should be allowed to do this. Why are you not able to trace a single line of fossil data from Coelurosauria to Avialae without introducing offshoots and parallel branches within clades and families? And please offer a full explanation of why the “gracile” furculum in Daspletosaurus torosus apparently throws the evolutionary movement into regression, yet you do not view it as problematic. If you are counting on Daspletosaurus to fill a slot in your continuum, then you are presented with a temporal inconsistency."


First and foremost your assertion that homoplasy and parallelism reflect "temporal discontinuity" must be addressed. It is, quite frankly, entirely unsubstantiated. These processes of yielding similar yet non-homologous traits channeled by either function or shared ancestry (respectively), have 'nothing' to do with any given temporal distribution. They refer to morphological variation alone, and your claim to the contrary, demands that you produce citations to support such a radical conflation of temporal distribution and homoplasy/parallelism.

Now we can address why Tyrannosauroidea are discussed. As the outrgroup of Maniraptora, they are crucial in determining character polarity in the latter clade, and establishing synapomorphies with which to unite Maniraptora such that it is holophyletic. Together, Tyrannosauroidea and Maniraptora constitute Maniraptoriformes, and the presence and dervied morphology of furculae in both clades, supports arguments that furculae were further developed by selective pressures above the basal neotetanuran level. Your serious lack of familiarity with the phylogenetic map of Theropoda is further illustrated by your claim that Tyrannosauroidea are "antecedents of Sinornithosaurus millenni and Archaeopteryx." As Tyrannosauroidea is the sister clade of Maniraptora, this is quite incorrect, and neither I, nor any dinosaur paleontologist of whom I am aware, has made such a claim. If anything, your linking Tyrannosauroidae directly to birds (via the urvogel) smacks of Alan Feduccia's vitriolic strawmen. Similarly, your claim that I cannot present a single line from Coelurosauria to Avialae is erroneous--I have done just that, which you would recognize were you more inclined to actually look at the phylogeny of Theropoda. The clades I have discussed are nested within in each other: Allosauroidea and Coelurosauria within Neotetanurae, Tyrannosauroidea and Maniraptora within Maniraptoriformes, Avialae and Deinonychosauria within Maniraptora, and so on. They present precisely the "single line" you so vociferously demanded as they represent a robust and morphologically unambiguous lineage. Indeed, do not take my word for it, try actually referring to the sources I have so copiously cited.

Lastly for this paragraph, you address the possible character reversal to a gracile furcula in Daspletosaurus torsus. You will note that I did not authoritatively claim it was such, I suggested it as a possibilty. Compared to the furcula of Gorgosaurus libratus, that of Daspletosaurus is somewhat more gracile, and thus may represent a mild character reversal--though given the uncertainties regarding the exact phylogenetic position of Gorgosaurus vis-a-vis Daspletosaurus, this has yet to be demonstrated conclusively. As it were, this matter is neither a problem of temporal distribution as you claim, nor is it a fatal blow to the gradual derivation of the furcula from incipient state in basal neotetanurans to the avian state in derived Maniraptora.

You proceed to repeat yourself:

"Here is the question: Can you or can you not provide a fossil record which plainly and unmistakably establishes the non-existence of, then the gradual development of, and finally, the full arrival of an avian furculum in dinosaurs? If you are unable to do this as you claimed you could, and instead, you begin arguing from a gradualistic clade-to-clade or family-to-family approach, we will have no choice but to suspect that, whether intentionally or by default, you espouse punctuated equilibrium. To be sure, your argument here smacks of punctuated equilibrium already."

I have already done just that--which your unfamiliarity with theropod phylogeny has not negated. Let me present a simple list, charting the pattern of furcula development over time:

Neotetanurae
Carnosauria
Allosauroidea
Coelurosauria
Maniraptoriformes
Tyrannosauroidea
Maniraptora
Eumaniraptora
Deinonychosauria
Avialae
Archaeopteryx
Aves

The character state of the furcula at each node can be summarized as follows:

Neotetanurae: Furculae present; shallow and not hypertrophied.

Carnosauria+Allosauroidea: Furculae shallow though more derived than the neotetanuran norm, as indicated by an incipient cartilaginous ridge homologous to the ossified carina.

Coelurosauria: Furculae displaying incipient carina, and more robust than in basal neotetanurans and allosaurs.

Maniraptoriformes: Angle formed by clavicles increasingly acute, furculae more robust than in coelurosaurian outgroups and basal Coelurosauria, carina incipient or absent in some taxa.

Tyrannosauroidea: Furculae robust, though clavicle-angle shallow.

Maniraptora: Furculae as robust as that of Avialae, with clavicle-angle approaching the acuteness seen in Aves. Carina present and well-developed in some taxa.

Eumaniraptora: Furculae at least as robust as those of modern birds, carina well developed in some taxa.

Deinonychosauria: Furculae more robust in some component taxa, than those seen in basal-Avialae and Aves.

Avialae+Archaeopteryx: Furculae no more robust than those of Deinonychosauria

Aves: Furculae fully avian in morphology, including the derivation of a hypocleidium.

Together these lists should clarify for one not well versed in theropod phylogeny, the progression I have demonstrated and argued for.

On a final note, I hardly see how an argument which has asserted gradualistic change over time, "smacks" of punctuated equilibria. Only your introduction of non-existent temporal gaps has suggested anything like that. In reviewing your arguments as to the development of the dinosaur furcula, you have: a)failed to refute the presence of furculae, b)failed to refute the gradual change of the furcula in nested lineages approaching the avian condition, and c)failed to show that the progression I presented is not nested and therefore a "single line" to use your term, and moreover, indicated your lack of familiarity with the science of phylogenetic reconstruction for Theropoda.

Your comment on Gould, his version of punk eek, and creationism, interests me. In my many conversations with creationists, and my review of their literature, punk eek as presented by Gould has time and again been hailed as tacit admission by evolutionary biologists that the Darwinian paradigm of gradual morphologic variation is bankrupt. Gould has in fact been indirectly praised for giving creationism such ammunition, by no less than the likes of Morris and Denton (if memory serves, it was Denton, though I may be wrong). While the creationist movement may not have any official position on punk eek, it remains the viewpoint of most creationists I have debated with, that punk eek reflects the failure of evolution to account for the fossil record.

And finally, your refusal to address the derivatio of the avian sterna until you are "satisfied" with the discussion as to the derivation of the furcula, is a most excellent filibuster--you can delay ever having to discuss the sternum by endless obfuscating of the current topic.

The only reference cited herein, for which I have not provided a full citation in previous posts, is the following:

Dodson et al. 1990. The Dinosauria. University of California Press, Berkely.

Vindex Urvogel

Thanks for the correction. I can take some of my own medicine: a fool is most welcome in his own company. No, I had no doubt it was really "shallow and incipient." My point was actually, "Are you sure it was not created to be that way? If sure, can you prove otherwise."

No, it does not really. I wanted a gap-filler or several gap-fillers from zero "0" furcula to the "incipient" arrival.

You then assert that:

"Exactly what line do you intend on developing the avian furculum through? Have we now shifted to Coelurosauria and Scipionyx samniticus? If so, we are left with a major gap or are you counting on the “incipient” furculum found in a “cousin” Allosaurus fragilis to address this problem? I am not sure you should be allowed to do this. What if we were dealing with kiwis and emus, both of the order Struthioniformes, where, say, kiwis were progenitors of true flight but emus were a bifurcation? Should I not insist that you stay with kiwis and demonstrate the gradual development of avian features through its lineage alone? I see your change in direction as a problem."


This entire diatribe is wholly irrelevant--I have not "shifted" anything. Coelurosauria is a component clade of Neotetanurae, and I have been explicit all along that furculae are neotetanuran traits. Your lack of familiarity with the phylogenetics of Theropoda will not underwrite attempts to inject non-existent ambiguities and cladistic waffling into my argument. Had I argued something along the lines of discussing furculae in, say, Spinosauria, and Neotetanurae, and claiming a gradualistic progression from one to the other, THEN my argument would be inexcusably "shifting" the phylogenetic map to fit my conclusion. However, as I have done no such thing, the allegation you present in this paragraph is entirely specious.

You then go on to say:

"Aside from that however, you are still faced with a gap. How will you move Allosaurus fragilis along in the fossil record to Scipionyx samniticus and convincingly present the gradual development of the furculum from “incipient” to “rather more robust?” And, in a temporal sense, will this be a lateral movement or a forward movement?"


Since both are Neotetanurae, one has no need to artificially ally Allosaurus fragilis and Scipionyx samniticus--they are both members of the same containing clade. The physically more robust furcula of the latter is congruent with the prediction of theropod origin that in Coelurosauria, the furcula became hypertrophied, in the par-avian and finally avian manner. Graphically speaking, this is both a movement along the y-axis of the cladogram, and the x-axis of the cladogram.[/quote]

This is not good here. The gap is too wide. Never mind that they are of the same clade. The disparity of the anatomy needs more explanation. To graph with x and y coordinates does not solve the problem of gradualism.

Had one looked at the furcula in Allosauroidea, one would see that it is quite literally a distal fusion of two splint-like clavicles--there is no more basal form for a furcula. Considering that the clavicles of which furculae are comprised are alreadly splintlike in the basal Tetanurae, the sort of distal fusion of the clavicles yielding an incipient furcula seen in allosaurs, is precisely what should be seen, and is the intermediary stage from unfused clavicles to the first par-avian furcula. If this is not satisfactory, then perhaps you should explicitly detail what a proto-furcula or incipient furcula SHOULD look like.

What gap are you talking about? What anatomical disparity? Explicitly isolate the osteological characters which you feel produce a "gap" between the members of the clades I delineated, so as to preclude their presentation as a "single line" of neotetanuran descent, in which the furcula from basal condition, was subsequently modified to the avian condition. You utterly failed to refute any of the synapomorphies underwriting holophyly of the clades listed (which is precisely what one must do to discredit the validity of presenting furculae as neotetanuran traits), and moreover you failed to demonstrate how a pattern of punctuational as opposed to gradualistic change is seen in these material.

Needless to say, such a list will be most interesting to see, since a list so damning to the standard phylogenetic map of Neotetanurae has yet to be uncovered by multiple reviews of the taxon. Perhaps you have more insightful cladistic analyses to offer.

Vindex Urvogel

If I seem to be rushing, it's because I am. No, I think we will continue to have a difference of opinion here.

I disagree with your sources. Copiously citing them does not make them correct or necessarily mean the scientific world agrees. This nesting within clades gives a picture of producing gradually developing forms but the idea may not be upheld by all as the answer to the problem with fossils. Please don't get upset here. You have to admit that you "play" like a stuck record, because you do seem to have your "favorites" that you always read and always quote from, and hence, always believe. But to actually produce a evolutionary continuum for flight in dinosaurs is extremely controversial. Man, if you have really successfully done this or rather, your sources, have done it for you, why am I not hearing the victory shouts all over the scientific world? I am well aware that your sources have handed all this to you and have actually made your job quite easy for these postings, but you are simply going to have to entertain the thought that your sources are not popular with everyone.

I'm sorry, but you have gone to a lot of trouble, but I think your entire exercise is one in futility. By sending me clades, you have caused us to arrive again at the impasse we found ourselves in previously. This offering does not fulfull what I have asked of you. Each of these clades represents how many fossils? All more or less have a furcula but not necessarily in the form we are looking for. Oh yes, I know, below you will show me how there "seems" to be a gradual development over time, but isn't this just somehow "picking" the best fossils from the group to make the point? I know. I know, you will have some kind of academic "come back" to try and put me to shame. But here's the long and short of it - why, are you (or rather your sources) the first to discover and piece together such a perfect slice of evolution? Why am I hearing it from you alone? You must understand that that single fact throws suspicion on the entire endeavor. I can only think that what is being offered here is nothing more than a hypothesis that has been advanced. Do you mind if I wait for the peer reviews? Again, I have heard nothing in the scientific community that claims that a set of fossils has conclusively proved an evolutionary continuum.

Neotetanurae: Furculae present; shallow and not hypertrophied.

Carnosauria+Allosauroidea: Furculae shallow though more derived than the neotetanuran norm, as indicated by an incipient cartilaginous ridge homologous to the ossified carina.

Coelurosauria: Furculae displaying incipient carina, and more robust than in basal neotetanurans and allosaurs.

Maniraptoriformes: Angle formed by clavicles increasingly acute, furculae more robust than in coelurosaurian outgroups and basal Coelurosauria, carina incipient or absent in some taxa.

Tyrannosauroidea: Furculae robust, though clavicle-angle shallow.

Maniraptora: Furculae as robust as that of Avialae, with clavicle-angle approaching the acuteness seen in Aves. Carina present and well-developed in some taxa.

Eumaniraptora: Furculae at least as robust as those of modern birds, carina well developed in some taxa.

Deinonychosauria: Furculae more robust in some component taxa, than those seen in basal-Avialae and Aves.

Avialae+Archaeopteryx: Furculae no more robust than those of Deinonychosauria

Aves: Furculae fully avian in morphology, including the derivation of a hypocleidium.

Together these lists should clarify for one not well versed in theropod phylogeny, the progression I have demonstrated and argued for.

The foregoing remarks regarding PE may or may not be true about your clade list. I am actually going to submit it for review myself to some sources I know. I still think it looks a lot like PE. Sorry again if I upset you with that, but you have actually claimed something in evolution that I have never, ever seen anyone successfully claim, and it simply must go for further review. A more trained set of eyes will doubtless consider major weaknesses that I have easily overlooked. Thanks for trying. This has been fun and informative. You are quite the formidable opponent and I truly feel sorry for the next person who "takes you on." I hope to get back with you in the near future with further comments on your evolutionary miracle!

In submitting the foregoing, I want to make it clear to my opponent and to the Forum and to all who look in, that my comments are in no wise a capitulation or concession. Quite the contrary! It can best be described by this: My opponent and I find ourselves in utter disagreement about the supposed continuity preserved in the earth's fossil record regarding the science of macro evolution. Better minds of academia than either mine or my opponent's have gone to great lengths to verify that no such continuum exists. For me to suddenly break from that safety of knowledge they offer would be far from "good science" and to put it bluntly, "I can't go there." My opponent has offered something quite incredulous looking at first blush, and wisdom demands a thorough going over of the hypothesis and assertions before jumping to any conclusion that evolution has finally been proved, albeit on a small scale, i.e., dinosarus to birds. I will be back in the fray just as soon as I hear from some sources I trust. Good day to all.