Archaeopteryx not so close to birds as previously thought (1 Viewer)

[Mysticete]

a new fossil and phylogenetic analysis has booted the famous Archaeopteryx from the Avialae (the clade from which all modern birds descended) and into the Deinonychosauria (the same group that includes the famous Velociraptor).

http://www.nature.com/news/2011/110727/full/news.2011.443.html

This idea isn't completely novel...it's been argued that Archaeopteryx might not be as special as previously thought, now that we know a lot of it's features are widespread among carnivorous dinosaurs.

If the results hold up, it will mean either "booting" Archaeopteryx from Aves, or alternatively expanding our definition of birds to include things such as Velociraptor (which of course is not nearly as odd as it might sound). I would actually favor the second option.

 

[Keith Dickinson]

If I'm remembering correctly wasn't one of the original archaeopteryx specimens labelled as a deinonychus for years before it was reclassified?

 

[jmorlan]

It just depends on what the meaning of "bird" is.

If a bird is defined as a creature that grows feathers, then Archaeopteryx
is clearly a bird.

If birds are defined as a monophyletic group, then most dinosaurs (with or
without feathers) were actually birds.

But if someone wants to make a splash, they can define birds using some arcane
skeletal structure possessed only by modern birds. Then Archeopteryx and
most of the dinosaurs are not birds.

 

[Mysticete]

Nope. At least one of the specimens was misidentified as Compsognathus for a quite awhile.

Archaeopteryx's original identification as a bird largely is a matter of history. We really didn't have good fossils of most of the birdlike dinosaur groups until the last half a century with a few exceptions, and the widespread presence of feathers has only really been documented in the last couple of decades.

You can actually define a monophyletic bird group without most dinosaurs, however you can't define a monophyletic dinosauria without including birds. From an evolutionary science viewpoint, that is what is so cool. We have gotten to the point in our knowledge of dinosaur evolution that the cut off point for what is or isn't a bird has become completely arbitrary. This transition is now perhaps the most solid piece of evolutionary change from the fossil record.

 

[fugl]

From an evolutionary science viewpoint, that is what is so cool. We have gotten to the point in our knowledge of dinosaur evolution that the cut off point for what is or isn't a bird has become completely arbitrary. This transition is now perhaps the most solid piece of evolutionary change from the fossil record.

Cool indeed! (& nicely put)

 

[Richard Klim]

Dececchi & Larsson 2011

Dececchi & Larsson 2011. Assessing Arboreal Adaptations of Bird Antecedents: Testing the Ecological Setting of the Origin of the Avian Flight Stroke. PLoS ONE 6(8): e22292. [pdf]

 

[Mysticete]

Darren Naish also just published a new paper which also kicks Archaeopteryx out of Avialae

http://blogs.scientificamerican.com/tetrapod-zoology/2011/08/09/say-hello-to-samrukia/