Wednesday, April 27, 2016

Characteristics

Dinosaur to bird proponents take a characteristic and try to make a case that the characteristic evolved gradually from dinosaur to bird. But each time we look in detail at the actual evidence for that characteristic, we see that it is NOT a gradual change from any dinosaur.
In fact, we can see that the avian-like characteristics appear at Oviraptors/Paraves and are not in coelurosaur dinosaurs. 

1. Semilunate carpal. 
http://pterosaurnet.blogspot.ca/2016/04/semilunate-carpal.html

2. Feathers
https://www.academia.edu/3229283/A_pre-Archaeopteryx_troodontid_theropod_from_China_with_long_feathers_on_the_metatarsus
This suggests that large pennaceous feathers first evolved distally on the hindlimbs, as on the forelimbs and tail. This distal-first development led to a four-winged condition at the base of the Paraves. (Hu et al 2009)

http://people.eku.edu/ritchisong/554images/Early_feathers.jpg


3. Breathing sacs
http://pterosaurnet.blogspot.ca/2010/05/another-thing-to-watch-for.html

4. Uni-directional lungs


5. Miniaturization

Puttick et al were really surprised to discover that the key size shifts happened at the same time, at the origin of Paraves," (Puttick et al 2014). Before the origin of Aves, on the branch leading to Paraves, high rates of evolution led to a smaller body size and a relatively larger forelimb in Paraves. These changes are on a single branch leading to Paraves, representing a shift to a new smaller size and larger forelimb at this point.Paraves, rather than Aves alone, shifted to a different evolutionary model relative to other coelurosaurian theropods (Table 2). On all trees and for both femur and forelimb size, the model with a regime shift at Paraves, rather than Aves, is favored (Table S10). (Puttick et al 2014)

Michael J. Benton (2015)
These studies of bird origins [5659] used different datasets, different phylogenies, and different analytical techniques, and yet they converged on the same result. As an example, Puttick et al. [56] showed that miniaturization and wing expansion, critical anatomical requirements to be a bird, arose some 10 Myr before Archaeopteryx among the wider clade Paraves (figure 4), and that the rate of change was 160 times the normal evolutionary rate, suggesting a rapid, adaptive switch that enabled the diversification and success of this clade of tiny, possibly tree-climbing and gliding dinosaurs.


http://onlinelibrary.wiley.com/doi/10.1111/evo.12363/abstract;jsessionid=80C56E75E0B31D53B64124910A933623.f03t04
Using recently developed phylogenetic comparative methods, we find an increase in rates of body size and body size dependent forelimb evolution leading to small body size relative to forelimb length in Paraves

http://onlinelibrary.wiley.com/doi/10.1111/evo.12363/full
Paraves, rather than Aves alone, shifted to a different evolutionary model relative to other coelurosaurian theropods (Table 2). On all trees and for both femur and forelimb size, the model with a regime shift at Paraves , rather than Aves, is favored.
Our results suggest that the detected rapid branch-based increases probably arise from rapid branch-specific evolution at the clade origin, as we find no evolution for directional trends in Paraves.
6. Sternum

7. Enlarged brain



Notably, major bird characteristics often exhibit a complex, mosaic evolutionary distribution throughout the theropod tree, and several evolutionary stages are characterized by accelerated changes (70). For example, the early evolution of paravian theropods features cerebral expansion and elaboration of visually associated brain regions (71)

8. Ankle
More remarkably, however, this finding reveals an unexpected evolutionary transformation in birds. In embryos of the land egg-laying animals, the amniotes (which include crocodilians, lizards, turtles, and mammals, who secondarily evolved live birth) the intermedium fuses to the anklebone shortly after it forms, disappearing as a separate element. This does not occur in the bird ankle, which develops more like their very distant relatives that still lay their eggs in water, the amphibians. Since birds clearly belong within land egg-laying animals, their ankles have somehow resurrected a long-lost developmental pathway, still retained in the amphibians of today -- a surprising case of evolutionary reversal .
This work has revealed that the ascending process does not develop from either the heel bone or the ankle bone, but from a third element, the intermedium. In the ancient lineage of paleognath birds (such as tinamous, ostriches and kiwis) the intermedium comes closer to the anklebone, producing a dinosaur-like pattern. However, in the other major avian branch (neognaths), which includes most species of living birds, it comes closer to the heel bone; that creates the impression it is a different structure, when it is actually the same.

The ASC [ascending process of the astragalus] originated in early dinosaurs along changes to upright posture and locomotion, revealing an intriguing combination of functional innovation and reversion in its evolution.

In birds and theropods, a sheet of bone that braces the anterior face of the tibia is usually called the “ascending process of the astragalus” or simply the “ascending process.” It is less evident in adult neornithines than in juvenile (or embryonic) neornithines and Mesozoic birds. This sheet of bone is particularly conspicuous in basal birds, including Archaeopteryx. This common feature has consistently been regarded as one of the most striking homologies shared by birds and theropods (e.g., Paul 2002), but comparative anatomical research reveals that establishing the homologies of the ascending processes of theropods and birds is difficult.
In neornithines a triangular, late-developing cartilage appears, after fusion of the proximal tarsals, on the lateral face of the tibia, dorsal to the calcaneum (Martin et al. 1980, and references therein). Subsequently, this cartilage fuses with the calcaneum, with which it is primarily associated in both Mesozoic and modern birds (Martin et al. 1980Fig. 6). Morse (1872) called this structure the “pretibial.” Ostrom (e.g., 1976a,1985) argued that this structure is homologous with a similar structure in the tarsus of theropods (see also Paul 2002), but according to Martin et al. (1980:88) “differences in placement and (the pretibial's) late appearance during development suggest that it is a uniquely derived character for birds and is properly termed a pretibial bone, rather than an astragalar process.
In contrast to the situation in neornithine and Mesozoic birds, the ascending process of theropods is usually a broad sheet of bone, continuous and exclusively associated with the astragalus (compare Fig. 6A and B).

9. Fingers (digits)

10. Lengthening and thickening of the forelimbs
An Archaeopteryx-like theropod from China and the origin of Avialae
Xing Xu1,2, Hailu You3 , Kai Du4 & Fenglu Han2 (2011)
The discovery of Xiaotingia further demonstrates that many features previously regarded as distinctively avialan actually characterize the more inclusive Paraves. For example, proportionally long and robust forelimbs are optimized in our analysis as a primitive character state for the Paraves (see Supplementary Information). The significant lengthening and thickening of the forelimbs indicates a dramatic shift in forelimb function at the base of the Paraves, which might be related to the appearance of a degree of aerodynamic capability (Xu et al 2011) 
Archaeopteryx is widely accepted as being the most basal bird, and accordingly it is regarded as central to understanding avialan origins; however, recent discoveries of derived maniraptorans have weakened the avialan status of Archaeopteryx. Here we report a new Archaeopteryx-like theropod from China. This find further demonstrates that many features formerly regarded as being diagnostic of Avialae, including long and robust forelimbs, actually characterize the more inclusive group Paraves (composed of the avialans and the deinonychosaurs). 

11. Glenoid fossa and Scapulocoracoid

A REVIEW OF DROMAEOSAURID SYSTEMATICS AND PARAVIAN PHYLOGENY
Turner et al (2012)
Paraves, exclusive of Epidexipteryx hui, is marked by a suite of modifications to the shoulder girdle typically associated with the origin of the ‘‘avian’’ flight stroke (Ostrom, 1976b; Jenkins, 1993). The acromion margin of the scapula has a laterally everted anterior edge (char. 133.1) (fig. 55), the coracoid is inflected medially from the scapula forming an L-shaped scapulocoracoid in lateral view (char. 137.1) and the glenoid fossa faces laterally (char. 138.1) as opposed to the plesiomorphic posterior orientation (fig. 50). Additionally, the furcula is nearly symmetrical in shape as opposed to the asymmetry present in the furcula of more basal taxa (char. 474.1).(Turner et al. 2012)

Image result for bird glenoid fossa



12. Body mass

Paraves had a "very small primitive body mass around 1kg". And coleurosaurs had body size around "14kg". 

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4011683/
Rates of Dinosaur Body Mass Evolution Indicate 170 Million Years of Sustained Ecological Innovation on the Avian Stem Lineage
Roger B. J. Benson,1,* Nicolás E. Campione,2,3 Matthew T. Carrano,4 Philip D. Mannion,5 Corwin Sullivan,6 Paul Upchurch,7 and David C. Evans3,8

Table 36 Origin of small body size in Paraves, which has very small primitive body mass— around 1 kg (Anchiornis, 0.68 kg; Microraptor, 1.5 kg; Archaeopteryx, 0.97 kg (subadult)) 7 Origin of small body size in Coelurosauria (e.g., Ornitholestes, 14 kg ; Zuolong, 88 kg)

13. Flight Capabilty

The iconic features of extant birds, for the most part, evolved in a gradual and stepwise fashion throughout theropod evolution. However, new data highlight occasional bursts of morphological novelty at certain stages close to the origin of birds and an unavoidable complex, mosaic evolutionary distribution of major bird characteristics on the theropod tree. ........ Newly discovered fossils and relevant analyses demonstrate that salient bird characteristics have a sequential and stepwise transformational pattern, with many arising early in dinosaur evolution, undergoing modifications through theropods, and finally approaching the modern condition close to the origin of the crown group birds (Fig. 2). For example, the unusually crouched hindlimb for bipedal locomotion that characterizes modern birds was acquired in stepwise fashion through much of theropod evolution (67), and both the furcula (68) and the “semilunate” carpal (69) appeared early in theropod evolution. Notably, major bird characteristics often exhibit a complex, mosaic evolutionary distribution throughout the theropod tree, and several evolutionary stages are characterized by accelerated changes (70). For example, the early evolution of paravian theropods features cerebral expansion and elaboration of visually associated brain regions (71), forelimb enlargement (22, 67), acquisition of a crouched, knee-based hindlimb locomotor system (67), and complex pinnate feathers associated with increased melanosome diversity, which implies a key physiological shift (72). Together these features may suggest the appearance of flight capability at the base of the Paraves (22, 67). (Xu et al 2014) 
Several flight-related anatomical features, such as hollow bones and the furcula, originated in early theropods; basal paravians had many hallmark features necessary for flight, including extremely small body size (50, 70); a laterally oriented, long, and robust forelimb (22, 67); an enlarged forebrain and other derived neurological adaptations (71); and large flight feathers (Figs. 1 and 2). Particularly surprising are the recent discoveries of large flight feathers forming a planar surface on the legs of some basal paravians—for example, those with asymmetrical vanes on both the tibia and metatarsus of some basal dromaeosaurs, such as Microraptor (59); large feathers with symmetrical vanes on both the tibia and metatarsus of the troodontid Anchiornis (45), the basal bird Sapeornis, and several other basal paravians (135); and large vaned feathers on tibiae of several basal birds including Archaeopteryx, confuciusornithids, and enantiornithines (135). These structures clearly would have been relevant to flight origins.
several evolutionary stages are characterized by accelerated changes (70).
new data highlight occasional bursts of morphological novelty at certain stages close to the origin of birds 
It is possible that the SLC is not homologous throughout Tetanurae, in that different distal carpal elements may contribute to forming the SLC in different taxa or at least contribute to varying degrees (Chure 2001). 
However, the measured value of 76° in Caudipteryx suggests that the oviraptorosaur wrist may have independently evolved an even greater abductor bias than that existing in avialans.

REVERSALS Required


Ankle reversal 

More remarkably, however, this finding reveals an unexpected evolutionary transformation in birds. In embryos of the land egg-laying animals, the amniotes (which include crocodilians, lizards, turtles, and mammals, who secondarily evolved live birth) the intermedium fuses to the anklebone shortly after it forms, disappearing as a separate element. This does not occur in the bird ankle, which develops more like their very distant relatives that still lay their eggs in water, the amphibians. Since birds clearly belong within land egg-laying animals, their ankles have somehow resurrected a long-lost developmental pathway, still retained in the amphibians of today -- a surprising case of evolutionary reversal .
The anklebone (astragalus) of dinosaurs presents a characteristic upward projection, the ‘ascending process’ (ASC). The ASC is present in modern birds, but develops a separate ossification centre, and projects from the calcaneum in most species. These differences have been argued to make it non-comparable to dinosaurs. We studied ASC development in six different orders of birds using traditional techniques and spin–disc microscopy for whole-mount immunofluorescence. Unexpectedly, we found the ASC derives from the embryonic intermedium, an ancient element of the tetrapod ankle. In some birds it comes in contact with the astragalus, and, in others, with the calcaneum. The fact that the intermedium fails to fuse early with the tibiale and develops an ossification centre is unlike any other amniotes, yet resembles basal, amphibian-grade tetrapods. The ASC originated in early dinosaurs along changes to upright posture and locomotion, revealing an intriguing combination of functional innovation and reversion in its evolution.

Finger reversal

(Xu et al 2009)
Based on this study, the most parsimonious alignment is for the four digits of ceratosaurs to be I-II-III-IV and the three (and sometimes four) digits of all Tetanurae to be II-III-IV(V). Accepting such a topological shift at the base of Tetanura requires that the positional homology of the three digits of tetanurans is II-III-IV(-V), as suggested by Wagner and Gauthier34. Because the four digits of ceratosaurs are therefore most parsimoniously interpreted as I-II-III-IV, the small lateral metacarpal ossification of Guanlong35, Sinraptor36, and Coelurus represents the re-ossification of metacarpal V after it is lost at the base of Ceratosauria. The poor phylogenetic resolution for basal tetanurans in our study precludes us from hypothesizing whether this re-ossification event occurred once or more than once in the evolution of Theropoda. Likewise, the fourth metacarpal, which is reduced in primitive theropods and bears an unknown number of phalanges in Ceratosauria, re-acquires at least three phalanges in Tetanurans.

This implies the reduction of digit I before the divergence of the Ceratosauria and the
Tetanurae, the appearance of some polleciform features in digit II and the acquisition of a novel phalangeal formula (X-2-3-4-X) early in tetanuran evolution. Both modifications are partially indicated by the manual morphologies of ceratosaurs and more basal theropods. Also, they are indirectly supported by observations in living animals that a digit will display features normally associated with the neighbouring medial digit if the latter fails to chondrify in early development21, that phalangeal counts can vary even within species29, 42 and that secondarily cartilaginous elements can regain their ability to ossify43.

If BDR [Bilateral Digit Reduction] applies to the more inclusive Averostra, as the II-III-IV hypothesis suggests, early stages of tetanuran evolution must have involved loss of the already highly reduced metacarpal I, reduction in the length of metacarpal II, and the reappearance of additional phalanges on metacarpal IV. Both the I-II-III and II-III-IV hypotheses can claim a degree of support from morphological data, but the II-III-IV hypothesis is more parsimonious when developmental data from extant birds are considered.
For reference:


Rationalizations required:
Homoplasies (convergence, polyphyletic)
Ghost lineages
Reversals (reappearance) characters disappear and reappear (eg. SLC reappearance of distal carpal 4)
Homeotic transformations (eg hand and carpals) SLC "shift in position and composition"
Exaptations
Big morphological gap and sudden appearance of bird characteristics at oviraptor/paraves
See Appendix 7
Implausible rates of evolution
Evolvability
The recovered pattern of sustained evolutionary rates, and the repeated generation of novel ecotypes, suggests a key role for the maintenance of evolvability, the capacity for organisms to evolve, in the evolutionary success of this lineage. Evolvability might have also played a central role in the evolution of other major groups such as crustaceans  and actinopterygians , supporting its hypothesised importance in organismal evolution .
Rates of evolution declined through time in most dinosaurs. However, this early burst pattern, which characterises the niche-filling model of adaptive radiation [6],[7], does not adequately describe evolution on the avian stem lineage . The recovered pattern of sustained evolutionary rates, and the repeated generation of novel ecotypes, suggests a key role for the maintenance of evolvability, the capacity for organisms to evolve, in the evolutionary success of this lineage.

References:


Makovicky, P. J., and L. E. Zanno. 2011.
Theropod diversity and the refinement of avian characteristics. 
Living dinosaurs: the evolutionary history of modern birds 9–29.

Mark N. Puttick, Gavin H. Thomas, Michael J. Benton. 
HIGH RATES OF EVOLUTION PRECEDED THE ORIGIN OF BIRDS. Evolution, 2014; 

A REVIEW OF DROMAEOSAURID SYSTEMATICS AND PARAVIAN PHYLOGENY
Turner et al (2012)

Xu et al 2009

Xing Xu1,2, Hailu You3 , Kai Du4 & Fenglu Han2 (2011)
An Archaeopteryx-like theropod from China and the origin of Avialae

Xu et al 2014


Monday, April 25, 2016

Semilunate carpal

Xu et al (2014)
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4131224/
Homologies and homeotic transformation of the theropod ‘semilunate' carpal
Xing XuFenglu Han, and Qi Zhao (2014)
The homology of the ‘semilunate' carpal, an important structure linking non-avian and avian dinosaurs, has been controversial. 
The distribution of the morphological features pertaining to the trochlear facet across theropod phylogeny is consistent with a partial and gradual homeotic transformation of the ‘semilunate' carpal. Although no direct developmental data are available to support the occurrence of a homeotic transformation, this interpretation is suggested by the positional shift of the topologically unique articular surface from the medial side of the wrist to the lateral side (i.e. the trochlear facet shifts from medial carpals to lateral carpals). 
Interestingly, a key event in the carpal lateral shift appears to have been the reappearance of distal carpal 4 to contribute to the ‘semilunate' articular surface in derived maniraptorans.

The theropod wrist evolution is featured by the sequential occurrences of the following major modifications:
enlargement of distal carpal 2 together with reduction of distal carpal 3 and loss of distal carpal 4,
development of a transverse groove on a composite distal carpal composed of large distal carpal 2 and small distal carpal 3,
development of a transverse trochlea on a large distal carpal composed of distal carpal 2 and enlarged distal carpal 3,
development of a prominent transverse trochlea on a large distal carpal composed of distal carpals 2, 3, and the reappeared distal carpal 4,
and development of a prominent transverse trochlea on the proximolateral portion of the metacarpus composed of distal carpals 3 and 4 .
For comparison (from Figure 4):
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4131224/figure/f4/
Figure 4
1. distal carpal 2 with transversely trochlear proximal articular surface;
2. ‘semilunate' carpal with a prominent mediodorsal process;
3. ‘semilunate' carpal covering proximal end of metacarpal III;
4. distal carpal 4 incorporated into ‘semilunate' carpal to form a ventrolateral process;
5. ‘semilunate' carpal with a prominent ventrolateral process and fused to two lateral metacarpals.

Note that the description of node 4 applies to node 3 as well in the cladogram. In other words the significant change takes place at oviraptor/paraves. 


When you look at Table 1 (in Supplementary Information) you see that the distal carpal 4 (character 9) is present beginning at oviraptors and all the following taxa. But NOT present in the preceding coelurosur dinosaurs.

Table 1. Scorings for 18 characters for 31 theropod taxa
           

Character/taxon
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
Herrerasaurus
0
0
0
0
0
0
0
0
0
0
?
?
?
?
?
?
?
?
Coelophysis
0
1
?
0
0
0
0
0
0
0
?
?
?
?
?
?
?
?
Dilophosaurus
0
0
0
0
0
0
0
0
0
0
?
?
?
?
?
?
?
?
Xuanhanosaurus
1
?
1
1
0
1
0
0
1
?
0
0
0
0
0
0
0
0
Allosaurus
1
?
1
1
1
1
0
1
1
?
1
0
0
0
0
0
0
0
Guanlong
1
?
1
1
1
1
0
0
1
?
1
0
0
0
0
0
0
0
Tyrannosaurus
1
?
0
1
1
0
0
0
?
?
1
0
0
1
0
0
0
0
Coelurus
1
?
1
1
1
?
?
?
?
?
1
0
1
0
1
0
0
0
Harpymimus
1
?
1
0
0
1
0
0
?
?
?
?
?
?
?
?
?
?
Nqwebasaurus
1
?
0
0
0
0
0
0
?
?
?
?
?
?
?
?
?
?
Falcarius
1
?
0
1
1
0
1
1
1
?
1
0
1
0
1
0
0
0
Alxasaurus
1
?
0
1
1
0
1
0
1
?
1
0
1
0
1
0
0
0
Haplocheirus
1
?
1
1
1
1
0
0
1
?
1
0
1
0
1
0
0
0
Similicaudipteryx
1
?
0
1
1
0
1
2
0
0
2
1
1
1
1
1
0
0
Oviraptor
1
?
0
1
1
0
1
2
?
?
2
1
1
1
1
1
0
0
Microraptor
1
?
0
1
1
0
1
2
0
1
2
1
1
1
1
1
0
1
Linheraptor
1
?
0
1
1
0
1
2
?
?
2
1
1
1
1
1
0
0
Mei
1
?
0
1
1
0
1
2
0
1
2
1
1
1
1
1
?
?
Sinovenator
1
?
0
1
1
0
1
2
0
1
2
1
1
1
1
1
0
1
Archaeopteryx
1
?
0
1
1
0
1
2
0
1
2
1
1
1
1
1
?
1
Anchiornis
1
?
0
1
1
0
1
2
0
1
2
1
1
1
1
1
0
1
Jeholornis
1
?
0
1
1
0
1
2
0
2
2
2
1
2
1
1
0
2
Sapeornis
1
?
0
1
1
0
1
2
0
2
2
2
1
2
1
1
0
2
Confuciusornis
1
?
?
?
?
?
1
2
0
2
2
2
1
2
1
1
0
2
Protopteryx
1
?
?
?
?
?
1
2
0
2
2
2
1
2
0
2
0
2
Yanornis
1
?
?
?
?
?
1
?
?
2
2
2
1
3
0
2
1
2
Struthio
1
?
?
?
?
2
1
?
0
2
2
2
1
3
0
3
1
2
Gallicrex
1
?
?
?
?
2
1
1
0
2
2
2
?
3
0
3
1
2
Sinosauropteryx
1
?
0
0
1
?
?
?
?
?
0
0
0
0
0
0
0
0
Mononykus
1
?
1
1
1
?
?
?
?
?
2
1
1
1
1
1
1
1
Tanycolagreus
1
?
?
0
0
?
0
1
?
?
0
0
1
0
0
0
0
0

The same is true for characteristics 8, 11, 12 and 16. Things are different beginning at Oviraptors. They are different from the coelurosaur dinosaurs.


8.         Distal carpal 3, fusion to distal carpal 2: absent (0) or occurs late in ontogeny (1) or occurs early in ontogeny (2)
9.         Distal carpal 4: present (0) or absent (1)
10.         Distal carpal 4: fusion to medial distal carpals: absent (0) or present, late in ontogeny (1) or early ontogeny (2)
11.         ‘Semilunate’ carpal (distal carpal element with a transversely trochlear proximal articular facet), proximal margin of ventral surfacestraight (0) or moderately convex (1) or strongly convex (2).
12.         ‘Semilunate’ carpal, proximal margin of dorsal surface: straight (0) or moderately convex (1) or strongly convex (2).
13.         ‘Semilunate’ carpal, transverse width: significantly narrower than (0) or close in width (1) to proximal end of metacarpus
14.         ‘Semilunate’ carpal, proximodistal depth relative to transverse width: significantly less than half (0) or smaller but more than half (1) or subequal (2) or much greater (3).
15.         ‘Semilunate’ carpal, dorsomedial process: absent or weak (0) or prominent (1)
16.         Articular facet on proximal surface of metacarpus: medial, facet absent on lateral portion of proximal surface of metacarpus (0) or central, facet present across entire proximal surface of metacarpus (1) or lateral, facet absent on medial portion of proximal surface of metacarpus (2) or extremely lateral, facet absent on medial portion of proximal surface of metacarpus and extends onto poximolateral surface of metacarpus (3).  
17.         ‘Semilunate’ carpal, fusion to medialmost metacarpal: absent (0) or present (1)
18.         ‘Semilunate’ carpal, fusion to two lateral metacarpals: absent (0) or occurs late in ontogeny (1) or occurs early in ontogeny (2)

AND
the ‘semilunate' carpal is not formed by the same carpal elements in all theropods possessing this feature
Distal carpal 4 is not even present in earlier tetanurans:
Although our focus is the evolution of the ‘semilunate' carpal of tetanuran theropods, we also refer to Herrerasaurus and Coelophysis, which exemplify the primitive theropod condition.
And
Fusion, expansion, or reduction of basipodial elements is common in vertebrate evolution. However, it is rare for a shift in position and composition of a unique, functionally significant carpal or tarsal structure to occur without greatly disrupting the structure's topology (Fig. 4). 

Figure 1: Diagram showing the position and general morphology of the transversely trochlear proximal articular facet of the carpometacarpus in selected theropod hands with the phalanges omitted (upper: proximal view; lower: dorsal view; medial side of hand to left).
(a) The basal coelurosaurian condition (based on Guanlong). (b) The basal paravian condition (based on Sinovenator). (c) The neornithine condition (based on Crossoptilon). Yellow indicates the ‘semilunate' carpal; grey-yellow indicates the transverse groove; green indicates the metacarpals.


Sullivan et al (2010)

http://rspb.royalsocietypublishing.org/content/early/2010/02/24/rspb.2009.2281.full

taxonanglespecimen/source
Allosaurus fragilisChure (2001, fig. 2c)
Huaxiagnathus orientalis18°Hwang et al. (2004, fig. 8a)
Sinosauropteryx primaCurrie & Chen (2001, fig. 8a)
Guanlong wucaiiIVPP V14531
Alxasaurus elesitaiensis39°IVPP RV93001
Falcarius utahensis26°Utah Museum of Natural History, Salt Lake City, USA (UMNH) VP 12294
Caudipteryx sp.76°IVPP V12430
Haplocheirus15°IVPP V15988
Sinovenator changii35°IVPP V14009
Deinonychus antirrhopus31°YPM 5208
Eoconfuciusornis zhengi55°IVPP V11977
Meleagris gallopavo59°IVPP 1222

It is possible that the SLC is not homologous throughout Tetanurae, in that different distal carpal elements may contribute to forming the SLC in different taxa or at least contribute to varying degrees (Chure 2001).
the measured value of 76° in Caudipteryx suggests that the oviraptorosaur wrist may have independently evolved an even greater abductor bias than that existing in avialans.
Figure 2.
II–IV, metacarpals II–IV (numbering convention follows extant birds); d, distal carpal; i, intermedium; R, radius; r, radiale; s, semilunate carpal; U, ulna; u, ulnare.


In avians, the functional wrist joint is the articulation between the two proximal carpals, the scapholunar and cuneiform, and the trochlea of the carpometacarpus. The scapholunar is a slab-like bone homologous to the radiale plus intermedium of non-avialan tetrapods (Kundrát 2009), but for convenience is referred to as the radiale hereafter. The cuneiform is probably a neomorphic element rather than a homologue of the primitive ulnare (Gishlick 2007Kundrát 2009).


Turkey:






VARGAS
http://journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.1001957

New Developmental Evidence Clarifies the Evolution of Wrist Bones in the Dinosaur–Bird Transition



When birds diverged from nonavian dinosaurs, one of the key adaptations for flight involved a remodelling of the bones of the wrist. However, the correspondence between bird and dinosaur wrist bones is controversial.
In view of recent developmental evidence for 1, 2, 3 [12][14], we will use 1, 2, 3 to refer to the digits and, especially so, their associated distal carpals (here, dc1, dc2, and dc3). However, it must be kept in mind that most developmental studies traditionally refer to the same distal carpals as dc2, dc3, and dc4 [3],[8],[15].
 http://journals.plos.org/plosbiology/article/figure/image?size=medium&id=info:doi/10.1371/journal.pbio.1001957.g009







http://dujs.dartmouth.edu/2014/12/the-evolution-of-bird-wrists-from-dinosaurs-wrists/#.V7tAj_krKUk
First, the findings confirm work from the 1970s that suggested that two dinosaur bones, known as distal carpal 1 and distal carpal 2, combined, or “ossificatied,” to form the semi-lunate bone in birds. This bone gets its name from its half-moon shape. Additionally, the study found that two dinosaur bones, the radiale and the intermedium, merged to create a single bird bone called the scapholunare. The previous name of this bone, the radiale+intermedium, mistakenly suggests that the bone is formed by a fusion in the embryonic development, rather than by an evolutionary process. For this reason, the authors of the study suggested “scapholunare” as a more accurate name (2).
The third bone in bird wrists is known to embryologists as “element x.” Originally, embryologists thought that it replaced the dinosaur bone known as the ulnare. However, developmental data from the Vargas study found that the ulnare and element x coexist in bird embryos. Further, they found that element x corresponds to the dinosaur bone known as distal carpal 3 (2).
The researchers discovered that the fourth bone in bird wrists, the pisiform, had a rare evolutionary history. They found that it was lost in dinosaurs, but re-evolved in early birds. The purpose of the re-evolution of the pisiform was probably to facilitate flight. The pisiform enables a forceful downbeat of wings, and restricts the flexibility of the wings on the upbeat (2).



http://www.stuartsumida.com/BIOL524/GatesyAndMiddleton2007.pdf
The two proximal carpals fuse in all but the most primitive pterosaurs.
pterosaur wrist originally contained five carpal bones in two rows



The pterosaur wrist and the basal Paraves wrist are very similar.

http://www.pterosaur.org.uk/PDB2012/I/wings/carpal.htm
The carpal bones form a structure which allows a limited few degrees of movement at the wrist joint.  They are essentially two apposing saddle shaped bones which rock in two planes.  This can be illustrated in the sketch below.
The proximal carpal is seen articulating with the Ulna and Radius.  This carpal in turn articulates with the Distal Carpal in a saddle like gliding joint.

http://www.visualdictionaryonline.com/human-being/anatomy/skeleton/types-synovial-joints_2.php

The Complete Dinosaur

The [bird] semilunate carpal forms a grooved trochlea that articulates with a wedge-shaped radiale in the wrist. A sliding articulation between the groove and the radiale allows the carpometacarpus to be folded up close to the ulna. (Naish)

Witton book "Pterosaurs"

Pterosaur carpal bones "bore a sliding joint permitting at least 30 degrees of rotation between them” (page 33) 



http://onlinelibrary.wiley.com/doi/10.1111/j.1096-3642.2008.00409.x/full

Three-dimensional geometry of a pterosaur wing skeleton, and its implications for aerial and terrestrial locomotion

The intersyncarpal joint is a sliding articulation. The articular surface of the proximal syncarpal bears a prominent ridge that runs anteroventrally, with concave facets to either side, resembling a short section of a left-handed corkscrew in the right-hand limb (Fig. 10A). The corresponding articular surface of the distal syncarpal fits very closely when the radius/ulna and wing metacarpal are in line, indicating that only a thin layer of cartilage was present. The joint axis is tilted back from the vertical by 40°, and the maximum range of angulation is about 25°. Flexion of the joint retracts the wing metacarpal by 20°, and depresses it by 15°, and is accompanied by a slight posteroventral translation of the distal syncarpal with respect to the proximal.

The very tight fit between the proximal and distal syncarpals has led many workers to believe that it was incapable of muscle-controlled movement (Hankin & Watson, 1914Bramwell & Whitfield, 1974Padian, 1984). In this case, the joint would have functioned as a shock absorber, reducing the risk of breakage of the wing in turbulent conditions, for example. Opponents of this idea (Unwin, 1988Bennett, 2001) have argued that the range of permitted movement is too large to be accounted for solely by nonvoluntary movement. The maximum theoretical range of 25° estimated for the intersyncarpal joint here would indeed be large for a passive joint, but it must be remembered that this range may have been restricted in life by the presence of ligaments. The evidence from the bones alone is clearly inconclusive, and until a detailed reconstruction of these soft tissues is carried out, a definitive pronouncement on this matter cannot be made. 
The pterosaur wrist comprises four elements: the proximal syncarpal, formed by the fusion of the two proximal carpals (Bennett, 1993); the distal syncarpal, formed by the fusion of three distal carpals (Bennett, 1993); the block-like medial carpal (Padian, 1984), also termed the distal lateral (Wellnhofer, 1985) and preaxial carpal (Bennett, 2001); and the long, slender pteroid, which in life supported a membranous propatagium (forewing) in front of the arm (Wellnhofer, 1991a).
In the transition from pterosaur to basal paraves, the two proximal carpals were unfused. One distal carpal was lost. The other two distal carpals continued to be fused. 
The lateral carpal needs more analysis.


ALSO:
http://pterosaurnet.blogspot.ca/2014/10/wrists.html


http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4181960/
Resolving the Flap over Bird Wrists

Robin Meadows 
Somewhere along the way from early dinosaurs to birds, wrists changed so much that we could be excused for thinking birds don't even have them. Wrists went from straight to bent and hyperflexible, allowing birds to fold their wings neatly against their bodies when not flying. Underlying this change is a drop in the number of wrist bones from nine to just four. Paleontology and embryology tell different stories about how this happened, however. Now, in this issue of PLOS Biology, Alexander Vargas and colleagues resolve this flap, drawing on both fields to clarify the identity and evolution of bird wrist bones.

Video of bird wing folding:

https://www.youtube.com/watch?v=GFCgwglikcY





Material about the claimed evolution of the semilunate carpal from dinosaur to bird is found in a few studies including:
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4131224/
Homologies and homeotic transformation of the theropod ‘semilunate' carpal
Xing Xu,a,1 Fenglu Han,2 and Qi Zhao1
"Interestingly, a key event in the carpal lateral shift appears to have been the reappearance of distal carpal 4 to contribute to the ‘semilunate' articular surface in derived maniraptorans."

and

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4181957/
New Developmental Evidence Clarifies the Evolution of Wrist Bones in the Dinosaur–Bird Transition
João Francisco Botelho, Luis Ossa-Fuentes, Sergio Soto-Acuña, Daniel Smith-Paredes, Daniel Nuñez-León, Miguel Salinas-Saavedra, Macarena Ruiz-Flores, and Alexander O. Vargas
"We confirm the proximal–posterior bone is a pisiform in terms of embryonic position and its development as a sesamoid associated to a tendon. However, the pisiform is absent in bird-like dinosaurs, which are known from several articulated specimens. The combined data provide compelling evidence of a remarkable evolutionary reversal : A large, ossified pisiform re-evolved in the lineage leading to birds, after a period in which it was either absent, nonossified, or very small, consistently escaping fossil preservation."

Not only does the dinosaur to bird theory require a “homeotic transformation” and “reappearance of distal carpal 4”, but it also requires a “remarkable evolutionary reversal” of a pisiform.