For everyone who missed it (or wanted to see it again), the NOVA documentary on Microraptor is available for viewing online here. I started watching it, but there were so many little things that irked me that I couldn't keep my trap shut. My primary gripe is that documentaries are still using Deinonychus and large dromeosaurs as the model for the bird ancestor, especially since birds like Confuciusornis were already flying by the time the larger, terrestrial predators were on the scene.
Further, while the trees-down/ground-up issue continues to be a thorny one, I find it absurd to say that dinosaurs couldn't climb. Why couldn't they? I see no reason to impose such a limit, and as suggested by Manning et al. I wonder if the hyper-extended "killer claw" of dromeosaurs (a feature also possessed by Archaeopteryx if the Thermopolis specimen is any indication) was originally an adaptation to climbing and then exapted in bringing down/holding down prey. Even if such speculation is incorrect, I really don't see any reason why small theropods couldn't have climbed trees if they desired to do so.
As Peter Dodson wrote eight years ago, all the exquisitely-preserved feathered dinosaur fossils coming out of China are fascinating, but more attention should be paid trying to find mid-late Jurassic relatives of Archaeopteryx. This may prove to be difficult, especially if these fossils are not preserved with feathers, but I think there are enough osteological clues that could allow relatives of Archaeopteryx to be identified and the earlier evolution of birds (and dromeosaurs) to be filled out. I'll write more about what I thought of the documentary later when I finish it, but I think that some aspects of this NOVA show have been made unnecessarily confusing.
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Sadly I can not add any thoughts to this topic as the link to the video only lets American net connections view the video...
So if you're an international don't bother with NOVAs site. It'll just tell you to buy the DVD.
The climbing thing was my biggest problem with the show too, Brian. Especially now that a few arboreal theropods ARE known--among them Microraptor--but also Sinornithosaurus, Epidendrosaurus, perhaps Mahakala...
I watched the NOVA program earlier this week, and I was anticipating your impressions of it, Laelaps. My background is comparative (modern) vertebrate anatomy and developmental biology, and not paleontology, so I related more on an experimental level to Dial's studies with Chukars. The program was set up such that some of the alternative hypotheses were only presented at the very end, and I found that frustrating, because I kept saying to myself "What if the Microraptors are just a side branch? Why do they have to be shoved in to the whole evolution-of-flight-in-birds pathway, even if they might not fit?"
I'd recommend to watch the program all the way through, even given this type of irritation, because the wind tunnel experiments with the model Microraptor are extremely entertaining. The construction of the model itself blew me away, I was so fascinated...is this sort of exquisitely detailed model-building common in paleontology?
Thanks Barn Owl. I intend on watching the whole documentary, I just stopped because the video froze and I didn't have time to restart it. You're right about the documentary focusing a bit too-heavily on Microraptor for the origins of flight (although Microraptor present some interesting problems of its own!).
Detailed model building isn't infrequent in paleontology, and sometimes models constructed for television can help with biomechanical studies (have a look at the link I provided to the Manning et al. study). How accurate the studies are is contingent on properly reconstructing the animals and other factors, but it is a fairly common way to try and get at paleobiology.
Huh. I took a dinosaur class as an elective last quarter and I recall my professor saying something about how some theropod groups had clavicles similar to primates, suggesting an arboreal lifestyle. He made it sound like such an idea was pretty widely accepted.
> I wonder if the hyper-extended "killer claw" of dromeosaurs (a
> feature also possessed by Archaeopteryx if the Thermopolis
> specimen is any indication) was originally an adaptation to
> climbing and then exapted in bringing down/holding down prey.
Seriemas have a similar sickle claw and are said to use it for climbing, Darren has blogged about this, see here: http:
//darrennaish.blogspot.com/2006/11/more-on-phorusrhacids-biggest-fastes