Thanks for the Inspiration. #365 is Today.

On this anniversary blog
Doggone it!! We still don’t know where pterosaurs came from, that according to Wikipedia and most pterosaur workers. Wiki states, “Because pterosaur anatomy has been so heavily modified for flight, and immediate “missing link” predecessors have not so far been described, the ancestry of pterosaurs is not well understood.” 

Not Sure Where This Came From
Wiki also reports, “Two researchers, Chris Bennett (1996) and David Peters (2000), have found pterosaurs to be prolacertiformes or closely related to them. Bennett only recovered pterosaurs as close relatives of the prolacertiformes after removing characteristics of the hind limb from his analysis, in an attempt to test the idea that these characters are the result of convergent evolution between pterosaurs and dinosaurs.” This account follows Hone and Benton (2007, 2008) as it rewrites history. Bennett (1996, Fig. 2) actually found that pterosaurs nested with Scleromochlus, but when hind limb traits were removed, Bennett (1996, Fig. 3) found that pterosaurs nested between Proterosuchidae and Erythrosuchidae. It’s true. You can look it up. You’ll remember that Hone and Benton (2008) also gave Bennett credit for the Prolacertiform hypothesis after Hone and Benton (2007) gave that credit to Peters (2000). I’ll never understand that turnabout. What were they thinking??

Wiki concludes with the latest in pterosaur origins: “Sterling Nesbitt (2011) found strong support for a clade composed of Scleromochlus and pterosaurs.” We covered this improbability earlier. Note the tiny fingers and the lack of a pedal digit 5 in Scleromochlus for starters.

Doggone it.
After a year of evidence, I still haven’t convinced the Wiki writers that we have a nice series of taxa in the Fenestrasauria/Tritosauria/Lepidosauria clade that demonstrates a gradual accumulation of pterosaurian traits. And please, we need to forget about prolacertiformes. They are not a part of this story. With the Fenestrsauria we can remove the skull, remove the post-crania, look at just the feet or the pectoral girdle and still find that Cosesaurus and kin nest with pterosaurs. It’s rock solid.

In all sincerity
I want to take a moment to sincerely thank the following professors for inspiring me to go online with these daily heresies.

Dr. David Hone
Dr. Michael Benton
Dr. Sterling Nesbitt
Dr. Mike Taylor
Dr. David Marjanovic
Dr. David Unwin
Dr. Chris Bennett
Dr. Kevin Padian
Dr. Mark Witton
Dr. Eberhard Dino Frey
Dr. Peter Wellnhofer
Dr. Robert Reisz
Dr. Michel Laurin
Dr. Darren Naish
Dr. Michael Habib

The web has been a great place to respond quickly, publish in color and provide animations and overlays. I should have done this earlier!

A Little Backstory
More than a year ago I was soundly derided for comparing baseball’s desegregation in 1947 to adding taxa to phylogenetic analyses to test relationships. All I said was you can’t know for sure if pterosaurs are not lizards if you don’t permit lizards into your phylogenetic analyses. That attitude of exclusion is still out there. I started this blog because paleontology needs a ‘Branch Rickey’ to see if pterosaurs are indeed archosaurs or lizards, to see if casesaurs are indeed synapsids or millerettids and to see if Vancleavea is indeed an archosaur or a thalattosaur. Testing is the only solution. Put them all together in one big tree, let the taxa interact, and THEN we’ll see where things nest. Exclusion is not the best policy in both baseball and paleontology. Not sure why that thought continues to go unaccepted a year later.

I was also derided and sent packing from the Dinosaur Mailing List for suggesting a test between seeing a specimen first hand and studying a specimen from photographs. I think insights can be gained both ways, as has been demonstrated several times in the past year, as in the discovery of the first flightless pterosaur, Sos 2428 and in a new understanding of Vancleavea as a thalattosaur.

More eyes on the ground finds more fossils.
More eyes on family trees finds more relationships. Oversight happens. Hypotheses based on evidence should always be welcomed and considered. THEN we an talk about it and come to a consensus. Unfortunately thinking outside the mainstream has been shunned and derided (from my experience). It’s perplexing the thinking that goes on out there. Perhaps there’s something about ‘defending the castle’ out there even when the status quo doesn’t have the answer, as widely acknowledged by the paleo establishment (see above with regard to pterosaurs). Note my detractors never point to two sisters on the large reptile tree that clearly have no business nesting together (other than M. Mortimer who pointed out two rather closely related taxa should be more closely related, but this hardly upsets the tree topology). Rather they dismiss my “methods,” (Hone and Benton 2007, 2008) while falsifying, misrepresenting and bungling the facts. That’s dismissing the messenger while ignoring the message.

Not Enough Characters
Mickely Mortimer has kindly suggested that I need to add more characters to my study. As you know, there are potentially millions of characters out there to be tested (femur length to jaw length, for instance). Thankfully the current character list of 228 has been sufficient to completely resolve the tree (save for some very incomplete taxa). I understand the need for more characters someday, but I’m going to leave that Herculean task for the next worker to handle. Anyone is free to add characters to the existing data matrix (available by request). No one needs to start from scratch here.

I hope the interesting topics keep coming. 
Thank you all for your support and comments. It’s been a joy and it has kept me in “the game.” We’ve covered a lot of heretical topics, from Daemonosaurus to Jeholopterus. I only hope these posts inspire further study. And if any mistakes are found, please continue to bring them to my attention. I will make those corrections.

Viewership runs a minimum of 200 per day. More than occasionally 400 will stop by. 1,113 views came this way on the busiest day, January 26, 2012. That was a report on the synapsid, Biseridens. 80,739 views all-time (as I write this June 28 about a week away.)

Thank you, one and all,

David Peters

Hone DWE and Benton MJ 2007. An evaluation of the phylogenetic relationships of the pterosaurs to the archosauromorph reptiles. Journal of Systematic Palaeontology 5:465–469.
Hone DWE and Benton MJ 2008. Contrasting supertree and total evidence methods: the origin of the pterosaurs. Zitteliana B28:35–60.
Nesbitt SJ 2011. The early evolution of archosaurs: relationships and the origin of major clades”Bulletin of the American Museum of Natural History 352: 1–292. DOI:10.1206/352.1.
Peters D 2000b. A Redescription of Four Prolacertiform Genera and Implications for Pterosaur Phylogenesis. Rivista Italiana di Paleontologia e Stratigrafia 106 (3): 293–336.

5 thoughts on “Thanks for the Inspiration. #365 is Today.

  1. You’re right about Bennett, and Hone and Benton’s paper is horrible. You might be right about your basal ‘fenestrasaurs’ being close to pterosaurs, but no one’s done a good analysis to show it. I bet if I look through your matrix for those archosauriform, archosaurian, ornithodiran, etc. characters in pterosaurs that e.g. Nesbitt (2011) used, I’ll find you used a minority of them. So just as Nesbitt (2011) isn’t a test of whether pterosaurs are lizards because it doesn’t include lizards, your analysis isn’t a test of whether they’re archosaurs because it doesn’t include most of their archosaurian characters.

    “Note my detractors never point to two sisters on the large reptile tree that clearly have no business nesting together.”

    This is a lie you continue to repeat. Remember Scelidosaurus and Scutellosaurus, with characters listed which you did not include? ( ) You even replied “In the list of other suprageneric taxa you earlier offered I overlooked your Scelidosaurus/ Scuttellosaurus referral. It was stuck in the middle. Apologies.”, so I know you read it. I don’t really care if you continue using ‘sister group’ the wrong way, keep on thinking the goal of an analysis is to get one most parsimonious tree as opposed to testing one hypothesis against another using all of the suggested data for both sides, or keep using your Digital Segregration Method to see structures which are usually misidentified, but please stop lying. When I go through the effort of digging through your character list and that of Butler (or Benson for ophiacodonts in another comment) and take the time to write out the characters you didn’t include that could unite two taxa in your tree differently, and you continually act as if no one has done so, it is insulting. And misleading. I’ve been civil when commenting on your blog. The least you can do is stop lying about me.

    I’m glad you finally “understand the need for more characters someday”, but the problem is that this attitude clashes with the one you present most often. On Darren’s blog, you claim “And thus, many of the mysteries of paleontology have been solved. Pterosaurs were lizards. Mesosaurs lost their diapsid fenestra. Caseasaurs were closer to millerettids than synapsids. It’s all there.” You can’t both be so sure of your accuracy while at the same time claiming to only be the Wright Bros. of amniote phylogeny, leaving the task of doing a good job to future workers.

    I know I keep harping on the issue, but I’d like you to think about your quote “Exclusion is not the best policy in both baseball and paleontology. Not sure why that thought continues to go unaccepted a year later.” in relation to your analysis and the characters you’ve excluded. There is actually a long-running debate in phylogenetics whether adding more taxa or more characters is most useful, with one of the more comprehensive entries being here- . They concluded “Thus, one indeed may be better off sequencing an additional 500 nucleotides for 30
    taxa than randomly adding another 30 taxa with the same 500 nucleotides. In contrast, however, if one already has 5,000 nucleotides sequenced across 30 taxa (under the conditions simulated by Rosenberg and Kumar), then it would be much better to collect data on another 30 taxa than to collect data on another 5,000 nucleotides for the same taxa.” Needless to say, with your number of characters actually being less than your number of taxa, you’re an example of the first condition.

    • Things have taken a while lately, but have settled down now. Really, Mickey, Scelidosaurus and Scuttelosaurus were two nodes away from each other. There’s bigger fish to fry here.

      • That there are WORSE wrong sisters in your tree doesn’t mean you can keep claiming no one has identified ANY wrong sisters and the characters that could move them. It’s still a lie. And remember Ophiacodon and Varanosaurus too.

  2. It’s been five days. Correct your false statement. I don’t care if it was an actual lie or (which seems more likely) you simply forgot about what Mickey said because you’re so excited; correct it. You cannot trust everyone to read the comments.

    Wiki concludes with the latest in pterosaur origins: “Sterling Nesbitt (2011) found strong support for a clade composed of Scleromochlus and pterosaurs.” We covered this improbability earlier. Note the tiny fingers and the lack of a pedal digit 5 in Scleromochlus for starters.

    Why can’t those be autapomorphies of Scleromochlus? Why do you act as if Nesbitt’s analysis said that the last common ancestor of Pterosauria and Scleromochlus must have been identical to Scleromochlus? Why do you believe Nesbitt’s analysis says something as crazy as “S. had to stop evolving immediately after it and the pterosaurs parted ways”?

    I keep explaining the difference between sister group and ancestor, the difference between sister and mother, to you – and you never react; you simply repeat your confused misconception at the next opportunity. Why?

    All sister taxa

    Every monophyletic taxon has one single sister taxon, unless it forms part of a hard polytomy ( = a real one, as opposed to one that only signifies insufficient data).

  3. Comment corrected and forgiveness requested.

    To the Scleromochlus issue: 1) Those can’t be autapomorphies of Scleromochlus because the ancestral taxa also lack a large finger four and toe five (and a dozen other traits) for several nodes essentially back to Proterosuchus and Prolacerta and perhaps further (as pterosaurs would rather nest with Pachypleurosaurus than any archosaur given the choice as I tested earlier). 2) There is a more parsimonious list of taxa, the Fenestrasauria, that produces a gradual accumulation of pterosaurian traits that Nesbitt did not include. 3) Take away the current sister taxon and you another takes it’s place ad infinitum. Some “sister taxa” include branching several genera and I want to name names. The current sister taxon often depends on whose tree you’re looking at, or if the sister is a suprageneric clade, hence the cloud that forms around the term. Sorry to be so frustrating. I’m just trying to ground this thing to point out its foibles.

    On the other hand, take away Longisquama and Sharovipteryx makes a dandy outgroup sister to “the Pterosauria” or the most basal pterosaur now known. Take away both and Cosesaurus still makes a great sister with lots of pterosaurian traits. Then there’s Langobardisaurus, Jesairosaurus, Huehuecuetzpalli, etc. etc. as we fadeout…

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