The troodontid Sinornithoides: finally a taxon nesting that almost matches tradition

Lately
we’ve been having trouble nesting taxa where they have traditionally nested. Earlier we looked at some reasons why that might be so.

Figure 1. Sinornithoides youngi figure modified from Russell and Dong 1993.

Figure 1. Sinornithoides youngi figure modified from Russell and Dong 1993. The skull is tucked under the tail and matrix supporting the gastralia, so it is probably complete, just not exposed. The ‘killer’ toe claw is not so large n this specimen. 

Today
I’m pleased to announce the nesting of Sauronithoides youngi (Russell and Dong 1993, Early Cretaceous, Aptian/Albian, IVPP V9612), about where it nests in other cladograms, between the dromaeosaurids and the pre-birds + birds.

One little problem
In the large reptile tree, however, the order has been shifted around compared to the cladogram of Turner, Makovicky and Norell (2012) in which Anchiornis, Xiaotingia, Jinfengopteryx and Mei nest as basal troodontids, rather that pre-birds and birds, while Sauronithoides nests in a derived node with Troodon. Their cladogram, like the large reptile tree, nests the above named pre-birds closer to birds. The major difference is the separation of dromaeosauridae from the quite similar overall Sauronithoides by a long list of intervening transitional taxa. That can happen in cladistic analysis. Parsimony rules, of course.

Note the further separation
of Velociraptor from Archaeopteryx. If valid, the retroverted pubis developed by convergence in both clades. Intervening and basal taxa have a ventral pubis without a pubic foot. We looked at bird and pre-bird convergence earlier here.

Figure 2. Sinornithoides cladogram. This taxon nests at the base of the pre-birds and birds, derived from the same ancestors as Velociraptor and Balaur.

Figure 2. Sinornithoides cladogram. This taxon nests at the base of the pre-birds and birds, derived from the same ancestors as Velociraptor and Balaur. We’re not getting a clade of troodontids, but a grade of pre-birds here. 

Sinornithoides youngi
 
is one of the most complete troodontid theropod dinosaurs. It was preserved in a bird-like resting posture. In the large reptile tree (632 taxa, Fig. 2) it nests derived from Tanycolagreus and the Velociraptor clade and basal to the pre-birds and birds. Distinct from the predecessor taxa, the rostrum and nares were low, the forelimbs were shorter, the pubis lacked a foot, the pelvis was smaller. Sinornithoides was one of the earlier bird-like dinos to come out of China. It, too, was fossilized in a resting posture with both tail and neck wrapped around its presumably warm-blooded body.

Everything here, of course, is provisional
as are all scientific hypotheses. That the present cladogram (Fig. 2) makes sense in terms of sister taxa appearing similar and of roughly the same size and that predecessors to derived taxa demonstrate a gradually accumulating set of traits I think bodes well for it.

References
Russell D and Dong Z 1993. A nearly complete skeleton of a new troodontid dinosaur from the Early Cretaceous of the Ordos Basin, Inner Mongolia, People’s Republic of China. Canadian Journal of Earth Sciences, 30: 2163-2173.

wiki/Sinornithoides

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Mei long: not bird-like, but a real basal flightless bird!

Mei long (IVPP V12733, Xu and Norell 2004, Early Cretaceous, 130 mya, Figs. 1-3) is famous for its 3D preservation in a curled up sleeping posture. Originally considered a young juvenile, bird-like troodontid, Mei long instead nests in the large reptile tree between the Munich specimen of Archaeopteryx BSp 1999 I 50 and Scansoriopteryx along with other scansoriopterygid basal birds. A second specimen, DNHM D2154 (Gao et al. 2012), was also preserved in a sleeping posture.

Troodontidae
Wikipedia reports, “There are multiple possibilities of the genera included in Troodontidae as well as how they are related.” Adding to this problem, in the large reptile tree several taxa sometimes included in the Troodontidae instead nest sequentially basal to birds (Archaeopteryx), not in a single offshoot clade.

Figure 1. Two Mei long specimens, one in vivo, one in situ.  Click to enlarge.

Figure 1. Two Mei long specimens, one in vivo, one in situ.  Click to enlarge.

From Xu and Norell (2004):
“Mei long is distinguishable from all other troodontids on the basis of extremely large nares extending posteriorly over one half of the maxillary tooth row*; closely packed middle maxillary teeth; maxillary tooth row extending posteriorly to the level of the preorbital bar”; a robust, sub-‘U’-shaped furcula*; presence of a lateral process on distal tarsal IV; and the most proximal end of the pubic shaft is significantly compressed anteroposteriorly* and extends laterally just ventral to the articulation with the ilium*.” 

*These happen to be traits found in sister taxa, the Munich Archaeopteryx and/or Scansoriopteryx.

Figure 2. Mei long compared to the BSP 1999 I 50, Munich specimen of Archaeopteryx and Scansoriopteryx to scale. Click to enlarge.

Figure 2. Mei long compared to the BSP 1999 I 50, Munich specimen of Archaeopteryx and Scansoriopteryx to scale. Click to enlarge.

Scansoriopterygids
One branch of basal birds, the scansoriopterygids (Fig. 3), famous for their long third finger, now includes a new sister, Mei long. 

Figure 3.  GIF animation - the skull of Mei long IVPP specimen in situ and reconstructed.

Figure 3.  GIF animation – the skull of Mei long IVPP specimen in situ and reconstructed.

Juvenile?
The orbit is comparatively large in Mei long and several cranial and vertebral features are unfused. Gao et al. 2012 report, “Although the skeleton exhibits several juvenile-like features including free cervical ribs, unfused frontals and nasals, and a short snouted skull, other attributes, full fusion of all neurocentral synostoses and the sacrum, and dense exteriors to cortical bone, suggest a small, mature individual. Microscopic examination of tibia and fibula histology confirms maturity and suggests an individual greater than two years old with slowed growth. Despite being one of the smallest dinosaurs, Mei long exhibits multi-year growth and cortical bone consisting largely of fibro-lamellar tissue marked by lines of arrested growth as in much larger and more basal theropods.”

Distinct from its new sister taxa
Mei has shorter forelimbs and longer hind limbs. It is also a little larger even if not fully grown. Pedal digit 3 is much longer. The sacrum is much wider. The facial bones are much more gracile. The jugal may not have had an ascending process. Some of these are indeed juvenile traits that may have been retained into adulthood. Such fragility may have contributed to its general lack of fusion (less bone, lighter weight, but not for flying despite being (no doubt, but not preserved) fully feathered. Metatarsal 3 appears to be pinched between 2 and 4. Pedal 2.1 is less than half the length of p2.2 and pedal ungual 2 is quite long, but not tightly curved.

Shifting
Mei to any node prior to Archaeopteryx currently and provisionally adds at least 12 steps.

References
Xu X and Norell MA 2004. A new troodontid dinosaur from China with avian-like sleeping posture. Nature 431:838-841.
Gao C, Morschhauser EM, Varricchio DJ, Liu J, Zhao B 2012. Farke AA ed. “A Second Soundly Sleeping Dragon: New Anatomical Details of the Chinese Troodontid Mei long with Implications for Phylogeny and Taphonomy”. PLoS ONE 7 (9): e45203. doi:10.1371/journal.pone.0045203. PMC 3459897. PMID 23028847.

wiki/Mei_(dinosaur)

Another look at Cau et al – part 3

Concerned
that a 10x larger Cau, Brougham and Naish 2015 theropod tree and dataset did not match the theropod subset of the large reptile tree, we examined various problems here and here. Today I conclude with a report of scoring issues in Cau, Brougham and Naish 2015. (Yes, I had a rainy/snowy weekend with nothing more important to do).

The Cau, Brougham and Naish 2015 analysis
includes a very intimidating 1549 characters and 120 taxa. That’s so overwhelmingly huge that it does not invite examination and testing. So, I broke it up. I reexamined only the first 518 characters and I focused on only one taxon that appeared to be mis-nested, LimusaurusCau, Brougham and Naish nested meter long Limusaurus with the giant Majungasaurus (Fig. 1).

Figure 1. Limusaurus and Majungasaurus to scalel.

Figure 1. Limusaurus and Majungasaurus to scale. Cau, Brougham and Naish report these are sisters.

Even at first glance
when you look at Majungasaurus and Limusaurus in vivo, they don’t appear to be sister taxa, as the Cau, Brougham and Naish study recovers. Four aspects of these two taxa appear to unite them: 1) the dorsal vertebrate; 2) the ventrally robust scapula; 3) the tiny forelimb and 4) the four-fingered hand.

The dorsal vertebrae
Unless the Limusaurus specimen has been exposed from the other side of the plate, the dorsal vertebrae are essentially invisible, buried beneath exposed ribs. Nevertheless the Cau, Brougham and Naish study score the dorsal vertebrae of Limusaurus like the Majungasaurus vertebrae.

The scapula and tiny forelimb
Limusaurus and Majungasaurus have a similar scapula that is quite broad ventrally where it meets the coracoid. Such a shape produces similar scapular scores. No one is quite sure why tiny (vestigial) forelimbs sometimes correlate to a robust pectoral girdle, but they do here and in Effigia. The tiny forelimb scores are similar in Limusaurus and Majungasaurus, but these may be due to convergence, as recovered by the large reptile tree, rather than homology, as Cau, Brougham and Naish recover.

Four finger problem
Basal theropods have four metacarpals and sometimes four fingers (1-4), as seen in Majungasaurus. Limusaurus likewise has four fingers, but they are not the same four fingers. In Limusaurus a new medial finger, “finger 0,” lost for millions of years, has reappeared because the hand is essentially an embryo hand. So Limusaurus has fingers 0-3. By not accounting for that difference the Cau, Brougham and Naish study found similar traits in mislabeled digits.

Figure 2. Limusaurus also has four fingers and a scapula with a robust ventral area, like Majungasaurus, but those four fingers are not the same four fingers found in Majungasaurus.

Figure 2. Limusaurus also has four fingers and a scapula with a robust ventral area, like Majungasaurus, but those four fingers are not the same four fingers found in Majungasaurus. Note the many traits Limusaurus shares with Khaan (figure 3).

Other scoring problems 
In the first 518 characters employed by Cau, Brougham and Naish I found dozens of scoring errors surrounding Limusaurus and taxa nesting near it. Nearly all of these tended to and finally did nest Limusaurus with Khaan (Fig. 3), an oviraptorid, with which it shares not only an overall appearance and size, but the detailed scores also match pretty well.

Figure 3. Khaan, an oviraptorid that nests with Limusaurus in the large reptile tree AND the repaired Cau, Brougham and Naish tree.

Figure 3. Khaan, an oviraptorid that nests with Limusaurus in the large reptile tree AND the repaired Cau, Brougham and Naish tree.

Other scoring errors
In the Cau, Brougham and Naish analysis I found scores for invisible traits (i.e. three scores for only two choices). I found a lack of scoring for traits that are visible in certain taxa (i.e. when tooth details were described, there was no option for ‘teeth vestigial or absent,’ so in Limusaurus and Khaan these traits were left unscored). I found scoring for traits that were not exposed in the specimen (example above). I found some traits descriptions to be overly verbose, or just plain confusing (242: “dorsal rib ventral process” — is that the rib itself? or what? If you Google those four words in quotes they cannot be found in the system).

Even simple misspellings
Cau, Brougham and Naish misspelled “length” as “lenght” several times, which reveals that even spellcheck was not used in the character set manuscript. By all such evidence, Cau, Brougham and Naish did not give their character set enough attention.

To their credit
Cau, Brougham and Naish reported on characters that I had never considered before. In the large reptile tree those traits are not necessary to completely resolve the theropods. Some day those traits may be necessary and, if so, I will employ them.

To their discredit
Cau, Brougham and Naish employed ten times as many parsimony informative character traits (1549 vs 151) than were necessary, and still were unable to completely resolve their theropods. There should have been more method and less madness. Once they crossed the threshold of 150 or so characters without resolution (Wiens 2003) they should have looked for errors in their dataset. Hundreds of times I have found that data errors prevent full resolution. And reconstructions help to expose many of those errors.

One of the problems inherent with employing prior datasets
is you tend to inherit whatever errors were already present in that dataset. By accepting and trusting prior data, you avoid testing prior data. And testing prior data is what every good scientist should do. Otherwise you end up with what Cau, Brougham and Naish ended up with.

I examined only a small sample 
of the Cau, Brougham and Naish dataset. It is possible that there are no more errors in that dataset. It is also possible that the rest of their data has a similar, smaller or larger percentage of errors in it than I found in the one small sample.

Let us all hope that no one
employs the Cau, Brogham and Naish 2015 dataset without a thorough going over the data before adding novel taxa and additional characters. Let us all hope that someone someday finds complete resolution in any one of several subsets of the repaired Cau, Brougham and Naish dataset.

By such evidence and methodology
others might have chosen to blackwash every thing that Cau, Brougham and Naish do from this day forward, tarnishing their reputations, as Naish and others have done to ReptileEvolution.com. Blackwashing is never appropriate. Repairs can and should be made whenever and wherever they are discovered.

I will continue to repair my dataset,
as I have always done. That’s good Science.

References
Cau A, Brougham T and Naish D. 2015. The Phylogenetic Affinities of the Bizarre Late Cretaceous Romanian Theropod Balaur bondoc (Dinosauria, Maniraptora): Dromaeosaurid or Flightless Bird? PeerJ. 3: E1032. DOI: dx.doi.org/10.7717/peerj.1032
Wiens JJ 2003. Missing data, incomplete taxa, and phylogenetic accuracy. Systematic Biology 52: 528–538.

Datheosaurus and Callibrachion: two former haptodine synapsids get reassigned

A recent paper
by Spindler, Falconnet and Fröbisch 2016 correctly reassigned two former haptodine synapsids to the base of the Caseasauria.

Datheosaurus and Callibrachion, two basal caseasaurs, not synapsids, as all prior authors assert, but derived from millerettids, as the large reptile tree demonstrates. Image from Spindler, Falconnet and Fröbisch 2016

Datheosaurus and Callibrachion, two basal caseasaurs, not synapsids, as all prior authors assert, but derived from millerettids, as the large reptile tree demonstrates. Image from Spindler, Falconnet and Fröbisch 2016

Datheosaurus macrourus (Schroeder 1904, Spindler, Falconnet and Fröbisch 2016, Artinskian, Early Permian, 285 mya) was a basal caseasaur, basal to Ennatosaurus and Casea and a sister to Eothyris, all derived from a sister to Eocasea and before that, Milleretta RC70. It was originally and later (Romer and Price 1940) considered a sister to Haptodus. At present the part and counterpart fossils have not been fully worked out.

Callibrachion gaudryi (Boule and Glangeaud, 1893b; Spindler, Falconnet and Fröbisch 2016) was similar and larger, but is less completely known.

Both of these taxa
were originally described over a hundred years ago and have not been studied much since then. Romer and Price (1940) evidently paid little attention to them and followed the earlier assignment to the haptodine synapsids. Please note that over a hundred years ago, when these taxa were first studied, there were very few other basal reptile specimens to compare them to, essentially just Mesosaurus and Protorosaurus. Other casesaurs first came to light in the late 1930s. It is good that they have been finally and correctly reassigned.

Unfortunately
Spindler, Falconnet and Fröbisch 2016 follow tradition (without testing) and nest the Caseasauria at the base of the Synapsida. The large reptile tree tests more possibilities and provides more opportunities. It nests all caseasaurs with Feeserpeton, Australothyris, Acleistorhinus and Eunotosaurus derived from millerettids, like Milleretta RC70, among the new Lepidosauromorpha, not with the Synapsida. We looked at the mistaken nesting of caseasaurs several years ago here.

Spindler et al. note: “These new observations on Datheosaurus and Callibrachion provide new insights into the early diversification of caseasaurs, reflecting an evolutionary stage that lacks spatulate teeth and broadened phalanges that are typical for other caseid species. Along with Eocasea, the former ghost lineage to the late Pennsylvanian origin of Caseasauria is further closed. For the first time, the presence of basal caseasaurs in Europe is documented.Here, we re-describe Callibrachion gaudryi and Datheosaurus macrourus for the first time in detail. The specimens are too poorly preserved to allow their inclusion in a phylogenetic analysis. Nonetheless, their assignment to Caseasauria is robust, therefore we attempt to discuss the historical findings as well as caseasaurian phylogenetic and evolutionary trends.”

I found no problem
including the more complete Datheosaurus in phylogenetic analysis in the large reptile tree (now 630 taxa). It nested right about where Spindler, Falconnet and Fröbisch 2016 said it would.

References
Boule M and Glangeaud P 1893a. Le Callibrachion Gaudryi, nouveau reptile fossile du Permien d’Autun. Bulletin de la Société d’Histoire naturelle d’Autun 6: 199–215.
Romer AS and Price LI 1940. Review of the Pelycosauria. Geological Society of America Special Papers 28: 1-538.
Schroeder H 1904Datheosaurus macrourus nov. gen. nov. sp. aus dem Rotliegenden von Neurode. Jahrbuch der Königlich Preußischen Geologischen Landesanstalt und Bergakademie 25 (2): 282–294. [reprint 1905]
Spindler F, Falconnet j and Fröbisch J 2016Callibrachion and Datheosaurus, two historical and previously mistaken basal caseasaurian synapsids from Europe. Acta Palaeontologica Polonica 61: xx-xx. http://dx.doi.org/10.4202/app.00221.2015
online pdf

Another look at Cau et al. 2015 – part 2

Concerned that a larger Cau et al. 2015 theropod tree did not match the theropod subset of the large reptile tree, yesterday we looked at a reduced Cau et al. 2015 theropod taxon list that matched taxa to the large reptile tree. This was done to delete potentially incomplete taxa that might reduce resolution. Yesterday only 518 of their 1549 characters were employed, but these covered all parts from head to toe. By comparison, the large reptile tree employes only 228 characters, of which only 151 are taxonomically informative to the theropod subset.

Earlier phylogenetic studies
(Wiens 2003) demonstrated only marginal advances in accuracy with any character or taxon list over 150 as the logarithm curves toward and plateaus at a line parallel to the X-axis.

Today we’ll add back
those missing 1000+ characters to the Cau et all (2015) study to match their 1549 character total. Against the expectations and conclusions of Wiens 2003, I’m hoping for more resolution in the Cau et al. tree with the addition of 1000+ theropod specific characters.

Figure 1. Cau et al 2015 trees complete with 1549 characters but the taxon list is still reduced to match the taxon list of the large reptile tree, thereby avoiding poorly preserved taxa. Loss of resolution and low Bootstrap scores are still a concern here. 1000+ additional characters do not appear to be able to split these taxa successfully.

Figure 1. Cau et al 2015 trees complete with 1549 characters but the taxon list is still reduced to match the taxon list of the large reptile tree, thereby avoiding poorly preserved taxa. Loss of resolution and low Bootstrap scores are still a concern here. 1000+ additional characters do not appear to be able to split these taxa successfully.

Still of great concern, 
the Cau et al trees still do not have greater resolution and higher Bootstrap scores with 3x as many characters vs. those 518 characters tested yesterday. By comparison the Cau et al tree employs 10x more parsimony informative characters employed by the large reptile tree (1549 vs 151). And yet the large reptile tree found complete resolution.

And, unfortunately,
the Cau et al and large reptile tree topologies still do not match each other in every detail when pruned to a similar taxon list (Figs. 1,2). I still wonder, why do these differences exist? The usual answer: “taxon inclusion/exclusion,” cannot apply in this case. Inaccurate scoring on one or both matrices is now a stronger possibility that will have to be explored.

The theropod subset of the large reptile tree, 
employing only 228 traits, remains fully resolved with a different topology (Fig. 2). The high bootstrap figures tell you that the tree topology remains largely fully resolved even when higher tree lengths are permitted. Smaller numbers appear at weaker nodes. None of the Bootstrap scores are in the 50s or 60s and only a few are in the 70s.

Figure 1. the nesting of Tanycolagreus in the large reptile tree (628 taxa).

Figure 1. the nesting of Tanycolagreus in the large reptile tree (628 taxa).

 

In future blog posts
I will attempt to dig deeper into this quandary, trying to figure out why the tree topologies still differ and why there is less resolution in the Cau, Brougham and Naish tree despite the higher and more specific character count. The devil is obviously in the details. I have no idea what I will eventually find here. I have already triple-checked the large reptile tree scores and reconstructions. Cau et al. did not provide evidence that they created reconstructions or examined every bone for every score they used. Rather, if they employed a prior dataset, they may have TRUSTED the data therein.  I don’t look forward to checking every score in the Cau et al. tree. That will take a rainy weekend, at least based on its great size. But I think it has to be done.

Thanks to Andrea Cau
for responding to my requests for data and characters. I will try to treat all aspects of this problem fairly and seriously without animosity.

References
Cau A, Brougham T and Naish D. 2015. The Phylogenetic Affinities of the Bizarre Late Cretaceous Romanian Theropod Balaur bondoc (Dinosauria, Maniraptora): Dromaeosaurid or Flightless Bird? PeerJ. 3: E1032. DOI: dx.doi.org/10.7717/peerj.1032
Wiens JJ 2003. Missing data, incomplete taxa, and phylogenetic accuracy. Systematic Biology 52: 528–538.

Another look at the Cau et al. 2015 theropod tree – part 1

Most of the time
the large reptile tree covers a wider gamut of taxa (628) with more characters (228) than the smaller more focused studies it is often compared to.

Not so
with a recent study of the Theropoda.

Andrea Cau, Tom Brougham and Darren Naish (2015)
took a recent look at the phylogenetic affinities of theropods using a modified set of 120 fossil theropod taxa and a whopping 1549 theropod characters gleaned from Lee, Cau, Naish and Dyke 2014. That list of characters greatly outnumbers the list in large reptile tree, which nested a mere 53 fossil and extant theropods (including birds) with 228 characters generalized to apply to most reptiles.

Of great concern, 
the tree topologies do not match each other in every detail when pruned to more closely resemble each others’ taxon list (Figs. 1,2). You have to wonder, why do these differences exist? The usual answer: “taxon inclusion/exclusion,” cannot apply in this case. Inaccurate scoring is another possibility.

Cau, Brougham and Naish 2015 reported
“The modified Lee et al. (2014) analysis recovered 1,152 shortest trees of 6,350 steps each (CI = 0.2672, RI = 0.5993). The strict consensus of the shortest trees found is in general agreement with the Maximum Clade Credibility Tree recovered by Lee et al. (2014), the most relevant difference being the unresolved polytomy among Aurornis, Jinfengopteryx, Dromaeosauridae, Troodontidae and Avialae.”

I employed the Cau, Brougham and Naish 2015 data 
and (so far) have included only the first 518 of the complete set of 1549 characters. That’s still more than twice as many characters as in the large reptile tree, and all are specific to theropods. I stopped at 518 because, at that point, all the body parts were listed in order from skull to toes. Thereafter the next 1000+ characters appear to have been tacked on in no particular order. Hopefully I will have an opportunity to add those characters in the next few days or weeks.

With 518 Cau, Brougham and Naish characters
I ran PAUP until it recovered 500+ MPTs and then stopped the analysis. I did not wait for the 1,152 MPTs reported by Cau, Broughan and Naish.

As a quick reminder
the large reptile tree recovered a single, fully resolved MPT and the Theropod subset was similarly fully resolved based on fewer taxa and fewer characters (Fig. 2). More on this below.

Thinking that poorly preserved taxa
might be causing the loss of resolution in the Cau, Brougham and Naish tree, I deleted all of their theropods not duplicated in the large reptile tree (and I made their Syntarsus stand in for my Coelophysis.)

Then I ran another analysis
The most parsimonious consensus tree was still not fully resolved (Fig. 1). Two additional permitted steps produced (also in Fig. 1) recover ever greater loss of resolution – and this with more than twice as many theropod characters, Unfortunately there was lots of lumping in the Cau, Brougham and Naish study, and not much splitting.

Figure 1. GIF animation of the shortest strict consensus tree using 518 characters from Cau, Brougham and Naish and theropods from the large reptile tree. Two other less resolved tree are shown demonstrating the lack of strength at several nodes.

Figure 1. GIF animation of the shortest strict consensus tree using 518 characters from Cau, Brougham and Naish and theropods from the large reptile tree. Two other less resolved tree are shown demonstrating the lack of strength at several nodes.

The theropod subset of the large reptile tree, 
employing only 228 traits, remains fully resolved with a different topology (Fig. 2). The high bootstrap figures tell you that the tree topology remains largely fully resolved even when higher tree lengths are permitted. Smaller numbers appear at weaker nodes. None of the Bootstrap scores are in the 50s or 60s and only a few are in the 70s.

Figure 1. the nesting of Tanycolagreus in the large reptile tree (628 taxa).

Figure 1. the nesting of Tanycolagreus in the large reptile tree (628 taxa).

 

In future blog posts
I will attempt to dig deeper into this quandary, trying to figure out why the tree topologies differ and why there is less resolution in the Cau, Brougham and Naish tree despite the higher and more specific character count. The devil is obviously in the details. I have no idea what I will eventually find here.

Thanks to Andrea Cau
for responding to my requests for data and characters. I will try to treat all aspects of this problem fairly and seriously without animosity.

References
Cau A, Brougham T and Naish D. 2015. The Phylogenetic Affinities of the Bizarre Late Cretaceous Romanian Theropod Balaur bondoc (Dinosauria, Maniraptora): Dromaeosaurid or Flightless Bird? PeerJ. 3: E1032. DOI: dx.doi.org/10.7717/peerj.1032

 

 

 

2015 readership stats

Slow news day… 
so here is a summary look back to 2015, and a tentative look forward to 2016.

If you ever wondered…
Pterorsaurheresies.wordpress.com had 130,000 (not unique) visitors in 2015. If I was counted each time I accessed the blog to write or correct it, then you can probably halve that number.  :-)  There were about 300 unique readers a day, rising to 500+ on hot news and controversy.

ReptileEvolution.com had

  1. 58,494 unique visitors
  2. 1.64 visits per visitor (average)
  3. 2.94 pages/visit (average)
  4. 14.03 hits/visit average (1,351,877 hits in total) about the same as in other years.
  5. Click here to add to the 2016 visitor totals at ReptileEvolution.com.

While I appreciate the readership,
for the most part both sites are forums for me to learn about various taxa and report what I find. Sometimes the results align with published work. Sometimes… not so much. The blog and website are my hobby and my pleasure. What other science offers the opportunity to make discoveries from your desktop? Data change, so the digital data change as necessary. You can’t do that in paper media. You have to live with your mistakes…forever!. Plus you can’t animate a pterosaur take-off in paper media.

Frankly,
with my recent venture into theropods, I think most of the reptile topics and clades have been covered by now. Not sure that 2016 could ever be as rich as 2015 was.

Bottom line:
A wide gamut cladogram of the Amniota/Reptilia is still needed in Academia. Now at 628 taxa the large reptile tree (+59 synapsids off to the side) is still fully resolved. Now at 221 taxa the large pterosaur tree is also in pretty good shape, demonstrating gradual accumulations of derived traits for all derived taxa. These studies are still far too large to get published in a paper medium. No one would want to check those 140,000 scores — especially if the results upset someone’s status quo.No one would want to be the referee on such a wide ranging analysis. No one is an expert on all those clades. It remains impossible for me or any one paleontologist to visit every taxon from the present inclusion set in one lifetime.  So, the study remains stuck in online limbo in its present shape — which is probably better than being tucked away on a college library bookshelf. No one has to approve my methods or results. But they can take advantage of the work for their own independent needs.

I still hope,
perhaps in vain, that some of the taxa and clades recovered here will someday inspire someone to at least consider adding a few taxa to their own more focused study beyond whatever traditional taxon list they feel compelled to use. Then I’ll report clade confirmation whenever that happens or rejection if that ever happens.