Chris Glen - Research


Vertebrate Functional Morphology and Evolution

My art site: chrisglenART

Includes my scientific illustrations, architectural renderings, wildlife art and palaeoart etc. Also has my art CV and links to other artists.

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 LINKS:

Researchers & interesting science sites

My studies:

Currently completing a PhD on bird claw form and function  and among other things seeing what this may tell us about their ancestors (non-avian dinosaurs) used theirs for.

...More on this 

NEWS

(15th Nov 2007):

Finally published 'dino-bird' claws paper:

Glen, C.L. & Bennett, M.B. (2007) 'Foraging modes of Mesozoic birds and non-avian theropods', Current Biology 17: R911-912.
(Note the link on the Current Biology listing to the long online Suppementary Data document which details methods and reasoning.)

Main points of note:

Ground foraging bird ancestry: I was suprised at the strong finding that the 12 fossil species we examined that can be regarded as transitional 'stages' between dinosaurs and birds had relatively straight claws like modern birds that live on the ground, or are predominantly ground foragers. This group of fossils included non flying species like Caudipteryx, adorned with proto-feather fuzz, through intermediates such as the famous feathered Archaeopteryx that had some gliding and/or flying abilities, to the early birds such as Confusciusornis and Vescornis with beaks, a shortened tail (pygostyle, i.e. 'parson's nose') and well developed flying abilities.

Behavioural categorisation: Categories such as 'groundwellers', 'perchers' and 'climbers', can be useful when describing and sumarising the behaviour of a living bird. However, such categorisation  can hamper studies that try to compare between birds of differing behaviour by the large overlap (many birds visist trees and the ground) and the criteria used to destinguish a species as one or another may differ from the criteria used in another group of birds.

To avoid such problems, we found we could categorise birds according to the amount of foraging they do on the ground and/or in trees. This allowed us to break down the differences of behaviour into a 'spectrum' (rather than a 'one or the other' dichotomy) comprising birds that forage on the ground only,  mostly on the ground (but sometimes in trees), mostly in trees (but sometimes on ground), and only trees.

The advantage of such a categorisation is that it singles out behaviour dependant upon hindlimb locomotion rather than flight, which is useful to us as we're interested in functions of feet and claws. For nearly all birds that spend time in trees or on the ground, flight is prefered mode of transport for getting from point A to B or escaping predators. These birds only bother 'walking' or 'running' when they're foraging.

In summary, this then allowed us to categorise hundreds modern birds based on published discriptions, then measure their 'claw angles' (a measure of claw curvature) and make comparisons to fossils (results sumarised above).

There's some further discussion on the paper at these blogs (Links):

Evolving Thoughts

Greg Laden's Blog

When Pigs Fly - Returns

A DC Birding Blog

Laelaps

 

News article links:

The Economist (as printed in 8th Nov edition, p101)

LiveScience (reproduced on most news websites that week)

 Suite101 - Sue Cartledge  (science news article)

 
UQ media release: 

UQ News University of Queensland's media source.

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The Lab I reside in:

I'm in an unusual lab - the Bennett Lab - most of the other students are focused on shark and stingray research, but the lab has included postgrads studying turkey locomotion, the Australian lungfish, and the effects of knee replacement surgery... 

 

This site is under construction   

 

CONTACT ME:

email me on: 'C dot GLEN at UQ dot EDU dot AU' (all lower case, remove the spaces and replace 'dot's with fullstops and 'at' with @)

Contents:

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Linking birds and dinosaurs

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 Handy hints on...  To 'construct' science documents, having a good grasp of EndNote and Word can really help