Monday, February 11, 2008

Are Rhamphorhynchoids Real?


I was musing this morning, as I often do, about pterosaurs, when a thought struck me. Is "Rhamphorhyncoidea" a natural group? Supposedly it forms a sister group to the Pterodactyloidea, but what if pterodactyloids are derived directly from rhamphorynchoids? Pterodactylus is still, as far as I know, the earliest known pterodactyloid, and it doesn't show up until the Late Jurassic, whereas rhamphorhynchoids are known since the Late Triassic, and in all likelihood, the group originated well before that. Were pterodactyloids an actual sister group, that would imply a very long ghost lineage leading back to the origins of the Pterosauria.
But then you look at anurognathid pterosaurs, who are "short-tailed rhamphorhynchoids," and wonder where that group perhaps shares a more direct relationship with pterodactyloids. Were that the case, then "Rhamphorhychoidea" would be paraphyletic. I'm not suggesting that some rhamphorhynchoids don't share some common ancestry. Rhamphorhynchus and Dorygnathus are certainly sister taxa. Dimorphodon and Peteinosaurus seem close enough. Certainly the scaphognathines form a monophyletic clade. But how do all these smaller groups relate to one another? What if rhamphorhynchoids form a stepwise progression leading to Pterodactyloidea, much like we know understand Prosauropoda to be a paraphyletic grade of animals leading to Sauropoda?
The name "Rhamphorhynchoidea" would have to be abandoned, unless we start calling Pteranodon a pterodontid ornithocheiroid pterodactyloid rhamphorhyncoid pterosaur. That wouldn't work.
Has any work been done on the interrelationships between the various families of the Rhamphoryhncoidea and that group's relationship to the Pterodactyloidea? And while we're on the subject of pterosaurs, does anybody have a good paper detailing Nyctosaurus' reindeer antler? I'm restoring that monster for the upcoming Archosauria art show.

19 comments:

Christopher Taylor said...

I don't think the rhamphorhynchoids were ever supposed to be a monophyletic group - they've always been thought of as the ancestral group to the derived pterodactyloids.

As for exactly how the pterosaur groups are related to each other, I think the main contenders are presented in two chapters in the 2003 Evolution and Palaeobiology of Pterosaurs, one chapter by Kellner, the other by Unwin, finding quite different phylogenies from each other. Both agree that the rhamphorhynchines are the sister group to the pterosaurs. The Kellner tree has anurognathids as the basalmost branch, while Unwin puts the Triassic heterodont taxa in that position. Kellner has scaphognathines paraphyletic and quite basal among pterosaurs, Unwin has the monophyletic scaphognathines sister to the rhamphorhynchines.

Kellner:
0--Anurognathidae
`--+--Sordes
    `--+--Preondactylus
       |--Scaphognathus
       `--+--Dorygnathus
          `--+--Dimorphodontidae
             `--+--Campylognathoididae
                `--+--Rhamphorhynchus
                   `--Pterodactyloidea

Unwin:
0--Preondactylus
`--+--Dimorphodontidae
    `--+--Anurognathidae
       `--+--Campylognathoididae
          `--+--Rhamphorhynchidae (Scaphognathinae + Rhamphorhynchinae)
             `--Pterodactyloidea

And for the record, I think that's the most html I've written in my life.

Christopher Taylor said...

Offhand, both chapters did deal with phylogeny within pterodactyloids as well.

Zach Miller said...

Interesting. I'll have to get that book, Chris. Thanks for the details. Looks like my suspicions have been confirmed! :-)

Alkalynic said...

Or you could have confirmed your suspicions by referring to virtually every paper every published on pterosaur phylogeny in the past two decades.

You also could have done a Google Search for "pterosaur phylogeny".

Very first result!

Zach Miller said...

Well, the last tome I read about pterosaurs was Unwin's "Pterosaurs from Deep Time," in which he hints that pterodactyloids may be derived directly from "rhamphorhynchoids," but otherwise treats the latter as a coherent group. Also, being in Alaska, my access to scientific publications (even Science and Nature) is extremely limited. In fact, I get the majority of my new research from you, the readers.

Also, there's really no need for a sarcastic attitude, alkalync.

Alkalynic said...

I detected no sarcasm in my previous comment. Please learn how to spell the pseudonyms of others properly though.

Also, being in Alaska, my access to scientific publications (even Science and Nature) is extremely limited.

Even when I was a young teen, I was able to get many articles I wanted without ever setting a foot into any institution just by emailing authors or requesting the articles from people who did have access to them. Several years later, I don't find it too hard to get the articles I want.

You could also always check what interlibrary loan services are available through your public library or the local college or university libraries.

However, my main point was clear and you seem to have ignored it, by doing a simple search with a search engine like Google, you might have gained something.

Zach Miller said...

Google searches are fine and dandy, alkalynIc, and I often use them (and Wikipedia), but I like to confirm my suspicions with people who know what they're talking about, too. I have emailed several authors about getting papers with much success over the years. Phil Currie in particular has been very kind in sending me a veritable volume of his work on deinonychosaurs.

But people don't always email me back, and interlibrary loans up here often cost some money, which I'm unwilling to pay for what will likely appear online as free access content months or years later.

In the meantime, I think I'll continue posing questions on my blog, and if people want to answer me, great! I don't know that I should be chided for doing so, though.

Alkalynic said...

The second and third results from searching for "pterosaur phylogeny" using Google are abstracts of the very papers mentioned by Christoper Taylor.

Should I take it that you mean to say that Alexander Kellner and David Unwin don't know what they are talking about?

Zach Miller said...

Hmmm...perhaps next time I'll just farm the Interweb looking for answers, instead of forcing you to comment on my lack of...I'm not sure what. Clearly, Chris was inconvenienced beyond belief in being forced to answer my query. By gunpoint. Next time one of my blogger buddies asks a question on THEIR blog, instead of cheerfully answering them, I shall usher them to Google, and in fact post, in HTML, several relevant search results, thus spending MORE time berating their ignorance then just answering the original question.

I apologize profusely to Chris, who could have spent those five minutes doing any number of other, more important things.

My hat is off to you, alkalynic. You have shown me the error of my ways.

ScottE said...

Alkalynic appears to feel that since information is trivial to find, it must therefore be unworthy of much discussion.

For what it's worth (since I don't pay all that much attention to pterosaurs, I did find this rather enlightening), I think this is exactly the sort of outreach more and more scientists are doing; it doesn't matter how easy it is to find answers, since finding answers and understanding them can often be two very different things, especially for people who may not necessarily know much about pterosaur phylogeny (yo).

Since Alkalynic seems to see no value in an ongoing discussion (since talk can replaced with a simple Google search); I just wanted to offer my thanks for the post.

Sometimes it's cool to see people enthuse, even if it means just talking about the obvious.

ScottE said...

(At Zach, since this comment is somewhat relevant,though I wont' say why in order to keep it spooky: Have you given any thought to color patterning for your contributions to the art show?)

Alkalynic said...

Hmmm...perhaps next time I'll just farm the Interweb looking for answers, instead of forcing you to comment on my lack of...I'm not sure what.

Research? What you were pondering on has been the consensus ever since before you were probably born and could have been easily found online.

When I pointed this out, you needlessly went on the defensive, and now you're just being dismissive. I would really hope someone interested in the sciences would have a much more open mind.

If you had followed the links in my most recent previous comment, you would have seen at least two possible answers to your question; and as well, you would have been able to get contact information for both authors who are rather receptive to requests.

Unwin's paper is:

Unwin, David M. 2003. On the phylogeny and evolutionary history of pterosaurs. Geological Society, London, Special Publications 217: 139-190.

Kellner's paper is:

Kellner, Alexander W. A. 2003.
Pterosaur phylogeny and comments on the evolutionary history of the group. Geological Society, London, Special Publications 217: 105-137.


I would not consider either to be the final word. Unwin's work is marred by his use of a hypothetical outgroup and many suprageneric OTUs. However, his work provides many useful references to existing works, as well as noting what specimens were employed to code his OTUs. Kellner's outgroup selection may be slightly more informative, but reflects poor choices. The references and specimens used to code his OTUs are also not provided, but more taxa were scored as individual OTUs, and the analysis has more characters as well. Kellner's work has also been expanded (though not very much) by recent collaborations on his part with other authors- see Wang et al. 2005, 2007.

But also, am I not cheerful?

scotte: Your distortion of the circumstances is just a distraction. Why engage in sycophancy? There was no implication or obvious statement in my comments for what you seem to believe I am promoting.

Tartos said...

The main problem with google searches seems to me to be, that the ones who are doing them, normally are starting to research in the specific field they are googleing for. They thus lack the knowledge to estimate the relevancy of the articles they might discover in this way.

As for example with the two articles Alcalynic mentioned, they are relatively recent, but he himself stated that there are some problematic issues in them. This at least is something someone new to a specific field is relatively easy to miss. It is also almost impossible, without prior knowledge, to ascertain that the articles one finds are still relevant, or if they are outdated, with the new research hidden away somewhere on page 200 of the search results.

Thus it seems to me the more rational way to just ask someone, who has more knowledge, to point out relevant facts and articles, than just hoping you get a lucky shot with the stuff you find googleing. And having said that i am not even starting to discuss the possible pitfalls one might encounter using the Wikipedia without prior knowledge.

Alkalynic said...

Christ. How hard is it to spell "alkalynic" right?

Neil said...

This is why I sort of loathe blogs....

lantaro said...

Wow, Mr. Miller. It must suck to have such, uh...an environmentalist commenting in a sarcastic manner on your blog. Apparantly some people like to argue that they're right when there isn't necessarily a real argument to begin with.

How dare you, sir. How dare you think aloud on your own blog about something that other people have talked about.

I didn't understand much of your thoughts, but I found it enjoyable reading, as always.

Traumador said...

How hard is it too spell alkalynic... well come to think of it, as a VERY common word in day to day use, you're right. Not very hard at all!

That would be an example of sarcasim, which doesn't quite match the level you've been using in your comments.

Zach I love your question and post on the subject. As a person who loves the Mez era, but never done much reading on Pterosaurs I'd never thought about the classification of the flying reptiles, and just assumed that there was a clear cut difference between Rhams and Pteros.

Alkalynic said...

traumador, I am amazed that no one can really offer a decent attack towards the intended content of my comments, and only towards their presenting style, or alternatively myself.

Frankly, lantaro, I find the use of the term "environmentalist" as an insult to be absolutely ridiculous. Is that the best you could offer in response?

That aside, noting Zach Miller's recent acquisition of more than a handful of papers from myself (some of which he has been kind enough to acknowledge recently on this blog), I believe some of my earlier comments have been seen as justifiable.

To clarify the situation, I do not have any personal disagreements with Zach Miller, I was merely at odds with his views towards the accessibility of materials, and the views of others who have posted in regards to the utility of search engines in finding peer reviewed research.

Yes, tartos, while the first result for "pterosaur phylogeny" is a Wikipedia article, it is a Wikipedia article that is referencing two peer-reviewed articles on pterosaur phylogeny, which at the very least, the abstracts of these could be read for free without a subscription, and both of which, Zach Miller now has possession of, thanks to myself.

I hope you enjoyed those articles, incidentally.

Oddly enough, in the past few days, I have been crawling the Internet for paleontology-related PDFs using Google, and have come across more than a fair share of them. I'd be more than happy to aggregate the links for interested parties.

Alkalynic said...

two peer-reviewed articles on pterosaur phylogeny, which at the very least, the abstracts of these could be read for free without a subscription, and both of which, Zach Miller now has possession of, thanks to myself.

To clarify, I was referring to the articles themselves in the final bit since I sent him those articles as PDFs. Again, hope you enjoyed them.