[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

Re: Matt Wedel on the perils of doing documentaries



Yes, the repetition is very painful. One thing I have learned doing interviews and consulting for these productions is that each episode only sets out to make three or four points, on average. Try as we might, it is very difficult to get them to include more material, and it's even harder to keep the crew from making what is included from transforming into something sensationalized.

As it turns out, though, the Quetz launch is not one of those sensational bits - that comes directly from my work on pterosaur launch, and they used my calculations for timing, muscle content, and overall launch kinematic (they made the leap a bit more dramatic, but I did get a lot of input and it wasn't bad - best one on tv to date. The flapping amplitude after launch is too large, and the animal needs insulative covering, but it isn't half bad). While we don't have the muscles to check anaerobic content, it turns out that there is a pretty tight scaling curve for anaerobic power percentage in flight muscles across all living flying animals - from dragonflies to bats and birds. Marden worked this out in the 90's (see Marden, 1994). So, I calculated the likely range of potential fast twitch fiber content from that known relationship, and the CotD folks used the upper end, of course, but they didn't overstep - 80% is within the confidence interval for the curve calculation.

I've had a few people look at me funny over the single-leap launch, but the structural mechanics support it, as do the muscle reconstructions. It may seem odd and incredible, but keep in mind that adding hops does not really help much, and large pterosaurs are better built to leap than to run (plus running launch, in the extended version, is mostly related to water takeoff in living birds). It's also worth considering that while Quetz was huge for a flyer, it's not really that big for a leaper - 400 lbs puts it in the same ballpark as large antelope, mid-sized tigers, and a handful of other animals that can spring several times body length. Quetz doesn't have limbs that can highly flex like those of a tiger, of course - the limbs of a pterosaur are much stiffer than that - but it did have an awful lot of its body mass tied up in limb power, and the limbs are very long. In the end, you get an animal that can combination push and pole vault pretty effectively. Animal takeoff is greatly misunderstood, especially with regards to the effects of size.

In terms of prey for Quetz, there are multiple lines of evidence indicating that it was eating something small, numerous, and easy to digest. Some kind of small animal therefore fits the bill (literally), and work by Witton and Naish suggests that much of the prey was captured on the ground. Therefore, baby dinosaurs were probably on the menu. Lots of other things probably were, too, such as squamates, small crocs, other pterosaurs (if grounded), mammals of various types, etc.

Cheers,

--Mike


Michael Habib
Assistant Professor of Biology
Chatham University
Woodland Road, Pittsburgh PA  15232
Buhl Hall, Room 226A
mhabib@chatham.edu
(443) 280-0181



On Dec 15, 2009, at 1:22 PM, Andrew Simpson wrote:

I was so exited when I stumbled upon Clash of the Dinosaurs. I watched Perfect Predators. My sis was there to hear me counter much of the science. There was one or two things that were interesting enough that I didn't know for sure one way or the other and wanted to ask ya'll on the list about said but those questions are forgotten. Something about T-Rex I had never heard before. Oh and I'm not sure I believe a Quetzalcoatlus could leap into the air so easily. Did it really have super fast twitch muscles? Even if it had I think it would have needed some hops to get going. Even the bad CGI seems to suggest this.

And why do we think it was a baby eater? It might have been but have we found babies in it's tummy?

In the end I had to turn off the series 5 minutes into the 2nd episode for the reasons stated. Bad science, repetitive narration and the pain of watching the same 5 clips shown over and over and over and over and over and over and over and over and over was too much for me. When a dinosaur fiend like myself can't watch you're dinosaur show then you get an epic FAIL as your grade.

Andrew Simpson




----- Original Message ----
From: "Thomas R. Holtz, Jr." <tholtz@umd.edu>
To: dinosaur@usc.edu; VRTPALEO@usc.edu
Sent: Tue, December 15, 2009 6:30:14 AM
Subject: Matt Wedel on the perils of doing documentaries

http://svpow.wordpress.com/2009/12/15/lies-damned-lies-and-clash-of-the-dino
saurs/

Thomas R. Holtz, Jr.
Email: tholtz@umd.edu    Phone: 301-405-4084
Office: Centreville 1216
Senior Lecturer, Vertebrate Paleontology
Dept. of Geology, University of Maryland
http://www.geol.umd.edu/~tholtz/
Fax: 301-314-9661

Faculty Director, Earth, Life & Time Program, College Park Scholars
http://www.geol.umd.edu/~jmerck/eltsite/
Faculty Director, Science & Global Change Program, College Park Scholars
http://www.geol.umd.edu/sgc
Fax: 301-314-9843

Mailing Address:    Thomas R. Holtz, Jr.
           Department of Geology
           Building 237, Room 1117
           University of Maryland
           College Park, MD 20742 USA