A bit more about the AMNH Exhibit

Many thanks to Dave Hone for posting the great photos from Steve Cohen of the new AMNH Exhibit. I have been meaning to post about the exhibit over a month now, but April-May is the skeletomuscular course in the medical program at USC, so blogging has been on the back burner.

In any case, as Dave mentioned, I had a role in the new exhibit. In fact, I had a relatively substantial role. As full disclosure, I was a paid consultant on the exhibit (titled "Pterosaurs: Flight in the Age of Dinosaurs"). I worked with the staff there for a little over a year on the interactive flight simulations, and I did recorded interviews for use in the theater and iPad interactive displays. I also helped rather extensively with the script used for the theater presentation (which is mostly about flight). One thing that neither myself, nor Alex Kellner (the co-curator on the exhibit) were approached about were the promo images. I won't detail any politics on that front now, but some of you may be aware that there some issues that arose on that front. What I can say is that the animation and video folks were not involved in that process, either (and used entirely different models for their reconstructions), nor were the sculptors so far as I am aware. So the promo images seem to be a bit of an isolated entity.

In any case, the exhibit opened on April 5th, 2014. Here is the official website for the exhibit: http://www.amnh.org/exhibitions/current-exhibitions/pterosaurs-flight-in-the-age-of-dinosaurs

They ran a promo video here: https://www.youtube.com/watch?v=AsI8ZtsSVqY

On April 1st there was a media preview event, with a panel composed of myself, Alex Kellner, Mark Norell and Michael Novacek. It was well attended, and yield quite a bit of press for the exhibit. Some of the popular articles can be found at:

http://news.nationalgeographic.com/news/2014/04/140405-pterosaur-flying-reptile-museum-exhibit-paleontology-science/

http://www.nytimes.com/2014/04/11/arts/design/natural-history-museum-explores-the-wonders-of-pterosaurs.html

http://worldsciencefestival.com/blog/pterosaurs_take_to_the_skies_of_new_york_city

http://mentalfloss.com/article/56005/qa-michael-habib-pterosaur-flight-expert

http://www.livescience.com/44556-how-pterosaurs-ruled-the-skies.html

http://mentalfloss.com/article/56021/10-pterosaur-facts-new-exhibit-american-museum-natural-history

As always, there is some variation in the quality of coverage, but overall I thought the writers did a good job of talking up the exhibit while hitting some of the interesting science involved. There will likely be more coming from Scientific American, as well, since I have chatted with them pretty extensively in the weeks following the opening (but more on that when the article(s) hit print).

Some things to look forward to in the exhibit (which stays at the AMNH through early January, at which point it will travel to other museums):

- Excellent specimens. Dave covered this already (see previous post) so I won't belabor it here. They have some awesome stuff, though (including the Dark Wing, which is on display outside Europe for the first time).

- Motion capture interactive animations that allow you to control launch, feeding, and flight in Pteranodon and Jeholopterus. The floating position of the Pteranodon was originally quite bird-like. It was updated using the floating paper by Hone and Henderson at my suggestion. The Pteranodon launch is a water launch and looks pretty wicked. The flight simulation includes basic physics like stall, L:D ratio transitions, and basic rate of climb estimates.

- A full-scale fleshed out reconstruction of Quetzalcoatlus northropi hanging from the ceiling just above reach, with a cutaway to show plausible flight muscle attachment. It's a great sculpture. Sadly, it came together just a little too soon to incorporate the updated proportions from my project with David Krentz. They did, however, feature David's 3D digital model on a sign near the sculpture showing how our reconstructions of Quetzalcoatlus have evolved over time.

- An amazing sculpture diorama (full size) of Tupuxuara - the models are by Jason Brougham, who is fantastic at paleo-reconstruction. The pair is shown feeding on fish in a traditional pluck-grab mode. As some know, Mark Witton and I both prefer an alternative ecology for these animals, but the sculptures are still magnificent (and to be fair, their feeding ecology is contentious - they can't just side with me every time). 

If you are in NYC, the exhibit is well worth a visit (the specimens alone make it worthwhile).

Cheers,

--MBH

Pterosaur fact checking

I will keep this brief, since Mark already did a great job of responding to the media release from the recent Chatterjee et al. presentation.  One thing to look for in any sort of functional morphology argument is whether the anatomy, the numbers, and the behavior all match up.  One reason the Chatterjee et al. abstract is so immediately concerning is that their own information doesn't jive internally.

Example 1: one of their concerns with the quad launch hypothesis is clearance for the wings after launch.  Now, I've calculated the expected clearance and everything seems fine, but that doesn't mean I'm right.  Maybe someone will find an error at some point.  What is clearly not going to be true, however, is the idea that keeping the feet on the ground (biped running launch) is going to give more clearance than a leap.  It simply isn't possible to get more clearance by not jumping (it might be true that jumping still isn't enough, but it's not going to be worse).  So Chatterjee et al. have a mismatch between their own conclusions and their arguments with the competing model.  The numbers and the behavior don't match up.

Example 2: Chatterjee et al. argue that pterosaurs can't work as scaled up bats, and argue instead that they should work like scaled up birds.  Anatomically, pterosaurs don't match either of these, so the bat argument is a straw man, and the bird argument is moot.  The anatomy and the behavior don't match up.

These are the sorts of arguments that raise red flags in scientific discourse.  On a final note, there are some basic fact checking items that should be looked out for, such as claims about living animals.  From the media story, Chatterjee is quoted as saying "Like albatrosses and the Great Kori bustards, which weigh 20 to 40 pounds, ground takeoff was agonizing and embarrassing for Quetzalcoatlus."

Aside from the problem with the pterosaur analogy, there is the obvious problem that Kori bustards don't have trouble taking off (though they might find it embarrassing; I haven't asked them).  In fact, Kori bustards can leap into flight at a steep angle.  Check this out.  Yes, the bustard tries running to escape, first, but when pressed, it just leaps into the air.  No big runway, no "agonizing" takeoff.  In fact, there is no correlation between running launch and size in living birds or bats.  More on that some other time, but in general, if a YouTube search quickly demonstrates that your commentary is flawed, that's a bit worrisome.

Meet Bellubrunnus: New Pterosaur in PLoS ONE

Dave Hone and colleagues have just published a fantastic description of a new pterosaur in PLoS ONE.  You can read (and download, if desired) the paper here.  This new critter is particularly fun because it has wingtips that curve anteriorly; which is unique among pterosaurs known to date.  Very cool stuff, and if you want to know more, obviously read the full paper, as well as the discussion by Dr. Hone himself at Archosaur Musings.

Here is a section of the Abstract from the original article:

Methodology/Principal Findings
The specimen was examined firsthand by all authors. Additional investigation and photography under UV light to reveal details of the bones not easily seen under normal lighting regimes was completed.
Conclusions/Significance

This taxon heralds from a newly explored locality that is older than the classic Solnhofen beds. While similar to Rhamphorhynchus, the new taxon differs in the number of teeth, shape of the humerus and femur, and limb proportions. Unlike other derived non-pterodacytyloids, Bellubrunnus lacks elongate chevrons and zygapophyses in the tail, and unlike all other known pterosaurs, the wingtips are curved anteriorly, potentially giving it a unique flight profile.

Cheers!

--MH

The Beauty of Big

One rather obvious trait of pterosaurs, compared to other flying animals, is that they had a tendency to get rather large.  There has been much to do about how they could get so large (as most readers of this blog know, I and quite a few others now prefer the explanation that pterosaurs were quadrupedal launchers).  However, it's a bit trickier to tackle the problem of why some of them became so large. 

What might select for giant size in pterosaurs?  It's probably not something that can be answered definitively, but there are some plausible options.  One of them relates to the issue of long-range travel.  I talked a bit about this potential advantage here. The gist is this: being large makes long-distance travel more feasible for most animals, particularly flyers.  Some reasons this happens include:

1) Large flyers can carry more fuel.

2) Large flyers travel at higher speeds, on average.

3) Large flyers are less affected by adverse weather conditions.

4) Large flyers use less fuel per unit body mass, per unit time.

This means that, on average, a big flying animal can go longer between stops on long migrations, and gets to their destination more quickly, than a small flyer.  This might be particularly important for a flyer which feeds on resources that are patchy in their distribution.  This, in turn, might suggest (very tentatively) that animals like azhdarchids had a tendency to travel long distances between food sources.

Of course, there are a host of other advantages to being large, as well: big animals are harder for predators to kill, can eat larger prey, and can (in some cases) better defend young.  For egg-laying animals, large size often improves fecundity.  So there is no way to say for certain exactly why some pterosaurs grew quite large, but it does raise questions of general biological interest.