"First Bird" Fossil, Archaeopteryx, More Closely Related to Dinosaurs

["Philip Veerman" <>]

Curious. That implies that what has happened in prehistory is strangely somehow influenced by what someone believes. It is hard to imagine how the nature of a person's thought process in the 21 century could maybe change what has happened.

What if I believe in the rainbow serpent or that geese change into barnacles every year? The idea that they were all created at exactly the same instant is only one of many culturally induced suggestions (not the only alternative automatic to evolution as Martin suggests) and no reason to think that one is any better than others. Sadly for that idea, there is nothing in the fossil record consistent with the idea that they were all created at exactly the same instant.

Another idea is that if dinosaurs were alive today, that birds would simply be classified as another order within the class of vertebrates, most of which are dinosaurs and the difference between them is really not so great. Because birds are mostly comparatively small and delicate, there are not many fossils showing that important period. As more fossils are found, we may understand the process better and the dividing line will become harder to place.

 

I wonder what Urvogel means, certainly vogel (in German & Dutch) simply means bird but what does ur mean? Is it a precursor of that awful brand of lazy grammar horror of kids' SMS text speak for "you are"? As in "You are bird"?

 

Of course Archaeopteryx is ancient wing and not an English word.

 

Philip

 

 

-----Original Message-----
From: martin butterfield [
Sent: Tuesday, 2 August 2011 8:09 AM
To: Tony Lawson
Cc: Canberra Birds
Subject: Re: [canberrabirds] "First Bird" Fossil, Archaeopteryx, More Closely Related to Dinosaurs

Tony asked "What is now the first bird?". 

I have two answers to this.  

If one believes that evolution
is an analogue process with many infinitesimally small differences over small
periods of time the answer is "unknowable".  As long as palaeontologists
are promoted on the basis of number of published papers there will always be
debate as to exactly where to draw the line defining where something ceased to
be a dinosaur and became a bird.  

On the other hand if one doesn't
believe in evolution the answer is "All of them" as they were all created at
exactly the same instant.

It is interesting to read http://en.wikipedia.org/wiki/Archaeopteryx. 
There appear to have been only 11 fossils of Archaeopteryx ever found, so the
sample sizes are not great!  (Incidentally this must be one of the very few
cases in which a German name - Urvogel - is shorter and easier to spell than the
usual name in English.)

Martin

On Tue, Aug 2, 2011 at 7:41 AM, Tony Lawson <> wrote:

Yet another account - if you'r not sick of them by now - & Geoffrey, in my view it reads pretty well.

But what now is the first bird?

Tony
"First Bird" Fossil, Archaeopteryx, More Closely Related to Dinosaurs
| July 27, 2011 | 2


By Matt Kaplan of Nature magazine


Analysis of fossil traits suggests that Archaeopteryx is not a bird at all. The latest discovery of a fossil that treads the line between birds and non-avian dinosaurs is leading paleontologists to reassess the creature that has been considered the evolutionary link between the two.


Archaeopteryx has long been placed at the base of the bird evolutionary tree. It has traits that have helped to define what it is to be a bird, such as long and robust forelimbs. Yet in recent years, the discoveries of numerous small, feathery dinosaurs have created a conundrum for paleontologists, raising questions about which animals are the ancestors of modern birds and which are just closely related cousins.


The fossil that is driving the latest Archaeopteryx rethink is called Xiaotingia zhengi, and is described in Nature today by Xing Xu , a paleontologist at the Institute of Vertebrate Paleontology and Paleoanthropology in Beijing, and his colleagues. It was found in western Liaoning, China, in rocks dating to the Late Jurassic epoch, 161 million-145 million years ago. Like many similar fossils, it is surrounded by feather impressions in the rock, but has claws on the ends of its forelimbs and sharp teeth.


These traits by themselves do little to help place the fossil in the dinosaur-bird transition, but Xu reports that it also has extremely long middle and last finger bones and a wishbone with an L-shaped cross-section at one end. These characteristics, Xu argues, identify Xiaotingia as very closely related to Archaeopteryx and another feathery relative, Anchiornis.


After analyzing the traits present in Xiaotingia and its relations, Xu and his colleagues are suggesting that the creatures bear more resemblance to the dinosaurs Velociraptor and Microraptor than to early birds, and so belong in the dinosaur group Deinonychosauria rather than in the bird group, Avialae. Many features led the team to this decision, but the most immediately noticeable are that Xiaotingia, Archaeopteryx and Anchiornis have shallow snouts and expanded regions behind their eye sockets. Microraptor has similar traits, but the early birds in Avialae have very different skulls.


Out of first place

The first Archaeopteryx specimen was discovered in 1861, just a few years after the publication of Charles Darwin's On the Origin of Species . Its combination of lizard-like and avian features made it the ideal 'missing link'; with which to demonstrate evolution from non-avian dinosaurs to birds. But the latest rearrangement knocks it from its position as the earliest bird. "I think Archaeopteryx's placement was the result of both history and relatively poor sampling at the dinosaur-bird transition," explains Xu.


Even so, he acknowledges that the move is bold. "Because it has held the position as the most primitive bird for such a long time, I am kind of nervous about presenting this result," says Xu. But immediate responses from others in the field suggest that the decision will be widely embraced.


Archaeopteryx was a bird because it had feathers and nothing else had them. But then other animals started being found that had wishbones, three-fingered hands and feathers. Heck, even T. rex had a wishbone. So one by one we've learned Archaeopteryx's uniquely avian traits weren't so unique. The writing was really on the wall," says Lawrence Witmer, a paleontologist at Ohio University in Athens.


Whether this change will be permanent depends on what other animals are discovered in the future, says Thomas Holtz , a paleontologist at the University of Maryland in College Park. "I don't think this is going to be the last word on this subject. You take this new Chinese species out of the mix and the argument falls apart, so the new placement is precarious at best until further evidence is dug up."


This article is reproduced with permission from the magazine Nature. The article was first published on July 27, 2011.

http://www.scientificamerican.com/article.cfm?id=first-bird-fossil%2C-archaeopter&WT.mc_id=SA_CAT_EVO_20110801