Wing decay

This is a photo from last summer’s fieldwork in Xinjiang in western China and it makes rather a nice point about taphonomy and preservation. Obviously the preservation of feathers is a rather important aspect of dinosaur palaeontology so an understanding of how they act in living (well, dead) birds is a great source of data for us. As noted in the past, feathers can and do both articulate and even attach to the bones of both birds and dinosaurs and this can be seen in a few fossils and very clearly in living taxa.

You can see this rather well here. Whatever bird these wings came from is long gone, as has the skin and muscles, but the feathers, while a bit tatty, are still there. Not only are they still there, but they’re also still articulated on the bones in a pretty natural position. So feathers are structures that are remarkably resistant to decay and resistant to moving from their natural positions. This of course tells us two things about fossils.

First this tells us that we can reasonably assume that fossils like Microraptor maintain their feathers in a natural position when fossilised. Even in such a heavily weathered and battered specimen like the one shown here the wing feathers at least suck it all up without any real trouble. So a near complete and articulated specimen with all manner of small feathers etc. in situ really is about as natural as you can reasonably expect.

Secondly, this also explains why you often get fossils with feathers and not much else in the way of soft tissues. Things like muscles and skin are exceptionally rare as specimens (as indeed are other things like pterosaur wings or amphibian gills) and even in the kinds of localities that preserve such things, feathers are still more common. Look at Archaeopteryx for example – several specimens have beautiful arrays of feathers but no other soft tissues at all – not even necessarily good claws or bits of cartilage which are pretty robust as non-bony things go. Well that’s not quite true as most of the feathers preserved in these are as impressions, though some original bits remain, though this is very much true of various Liaoning specimens for example.

Still this does show you what can be learned from just a few scraps of dead animal lying in the dirt. Obviously what I’m talking about here is based on papers published on the subject of bird decay, but this lone bit of bird is a good example of how this goes and what it can tell us about fossils 150 million years in the ground.

@Dave_Hone on Twitter


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