Saturday, October 1, 2011

150 Years of Archaeopteryx

This year marks the 150th anniversary for the description of the iconic "first bird" (or not) Archaeopteryx.

First, a quick diversion. Filled with anachronisms and Misplaced Wildlife, but very catchy. Points for getting the term "Maniraptora" into a children's song!
Naturally, I've prepared a special presentation for this special occasion, this time brought to you by resident Archaeopteryx Savape!
Eh... so I really have to do this, don't I? I would argue that this is the equivalent of grabbing a human passing by on the street on the such and such anniversary of the description of Homo sapiens and asking it to talk all about the research done on its own species. But part of the joy of being a fictional character is that you come with all the knowledge your creator wishes to grant you, so I might as well proceed. You all know the story. A fossilized feather was unearthed in the Solnhofen Plattenkalk in Germany, described in 1861, and named Archaeopteryx lithographica.
The feather, photographed by H. Raab, from Wikipedia.
A couple of years later an actual skeleton of Archaeopteryx was described. It was preserved with feathers, so it was assumed that this was the type of animal the original feather belonged to, but this is less certain now. First feathered fossil to be discovered! Eat it, Yixian. These days they call this specimen the London Specimen. They really like to keep track of us Archaeopteryx specimens, and all published specimens have been given nicknames like that. These specimens are actually named after the museums they're held at and have nothing to do with where they were discovered. Names like Solnhofen Specimen I and Solnhofen Specimen II just don't stick. (One specimen is called the Solnhofen Specimen, actually. You'll see it later, if nothing has happened to it.)
The London Specimen, photographed by H. Zell, from Wikipedia.
The specimen that gets all the publicity though is the Berlin Specimen. This is the one you see depicted everywhere. Notice in this historical photo that the specimen preserves nice leg feathers and some long body feathers, but those were destroyed during prep. You never see those in modern photos of the specimen, nor in some of the more mediocre Archaeopteryx depictions.
Historical photo of the Berlin Specimen from Vogt, 1880.
As is quite common in paleontology, new names were given to new Archaeopteryx specimens left and right. Names like "Jurapteryx", "Archaeornis", Archaeopteryx "bavarica", Archaeopteryx "macrura", and others that almost no one uses anymore. One that you might still see occasionally is Wellnhoferia, and this is the Solnhofen Specimen mentioned earlier. For most part though, the only Archaeopteryx species still commonly in use is the original Archaeopteryx lithographica.
Wellnhoferia, or the Solnhofen Specimen, photographed by H. Raab, from Wikipedia.
Because Archaeopteryx was the first Mesozoic maniraptor fossil found with feathers, we played a big part in early studies on the evolution of birds. It was noted early on that we had many theropod dinosaur characteristics, and famously in the 1970s Dr. John Ostrom compared the skeletal features of Archaeopteryx and other theropods, providing evidence that birds are theropod dinosaurs.
Comparison between the hands of the dromaeosaurid Deinonychus (left) and Archaeopteryx (right) by John Conway, from Wikipedia. Not to scale.
Due to these significant impacts, Archaeopteryx is often thought of as a "special" fossil, a creature with both "reptile" and "bird" characteristics that shows how modern birds evolved. This concept has led to some awful, awful restorations that depict us as looking something like weird lizard-bird hybrids. But now in 2011, we really aren't that special anymore. It's now known that a lot of other maniraptors (including even things like Velociraptor) had the exact same combination of "reptilian" and "avian" features (feathers, wings, teeth, wing claws, long tail) that we do. As far as Mesozoic paravians go, we're really quite generic, not unusual looking at all. If it had been something like Sinornithosaurus, Microraptor, or Caudipteryx that had been discovered back in the 1800s, they'd have received the same special treatment we do today. But too late for them now.
Modern restoration of Velociraptor by Matt Martyniuk.
Even our traditionally held "first bird" status is no longer ours. Mind you, as far as known maniraptors go, 150 million years ago in the Late Jurassic is still quite old. But other paravians (including some probable avialians), such as scansoriopterygids, Pedopenna, Anchiornis, and Xiaotingia, are now known from even older parts of the Late Jurassic. As Archaeopteryx was known to have had feathers early on, when no feathered non-bird dinosaur fossils were known, it was assumed that we must have been avialians (i.e.: closer to modern birds than other types of theropods are). Up until recently, this was still widely considered to be true. But several recent analyses have suggested that we may actually be non-eumaniraptor paravians or even deinonychosaurs. It's worth saying that the latter result in particular only has weak statistic support, but suffice it to say that you guys really don't have any good idea what exactly type of basal paravian we are. Me, I'll enjoy observing the chaos in the next few years. Such confusion is only to be expected. As I hinted earlier, we don't really have that many modern bird traits, at least not much more than definite deinonychosaurs do. Study of one of the latest described Archaeopteryx specimens, the Thermopolis Specimen, even shows that we have a retractable second toe and a barely reversed first toe (contrary to the way many specimens are preserved), similar to definite deinonychosaurs but unlike modern birds. Studies of our forelimb motion and wing feathers suggest that there isn't even any evidence that we were any better at flying than were small definite deinonychosaurs such as Microraptor!
The Thermopolis Specimen, photographed by Stephan Schulz, from Wikipedia.
Other recent research has been done on Archaeopteryx, There have been studies of our brain structure, showing that we have a good sense of balance and spatial perception, which makes sense for small gliding and clambering animals like ourselves. Studies of our growth show that we grew slower than modern birds (similar to most other Mesozoic dinosaurs, including many other Mesozoic birds). There has even been study of the possible size and shape of our eyeballs that reveal we were active during the day (like many modern birds but unlike many deinonychosaurs). So there you have it. Archaeopteryx is one of the most significant dinosaur discoveries and has a long, rich history and continues to be studied blah blah blah. Not bad for a pigeon-sized protobird if I say so myself. Last but not least, I must leave a token of my appreciation for the Acme Museum, which has provided me with this wonderful opportunity and put me up to this arduous chore.

7 comments:

  1. Happy birthday to my favorite transitional form!

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  2. I love it! Great presentation and the cartoons are well drawn. Excellent work.

    Happy Anniversary, Archaeopteryx! You're still high on my favorite prehistoric critter list regardless of what you get classified as.

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  3. Well written post. I enjoyed it. Happy anniversary you crazy important single fossilized feather, you.

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  4. "First, a quick diversion. Filled with anachronisms and Misplaced Wildlife, but very catchy. Points for getting the term "Maniraptora" into a children's song!"

    My only major problem w/that song is that Archaeopteryx is referred to as "the 1st dinosaur w/feathers" at the beginning. Maybe they meant "the 1st Mesozoic dinosaur to be discovered w/feathers", but I doubt it.

    -JD-man

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    1. That bothered me as well. I actually interpreted it as "the earliest known dinosaur with evidence of feathers", which would have been true at the time the video was posted if not for Pedopenna. Either way though, "first feathered dinosaur ever" is wrong.

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    2. BTW, there are other, even better songs from the same source. The following are all of the other maniraptor-related ones that I know of. It's especially hard to pick a favorite btwn the 1st 2.

      http://www.youtube.com/watch?v=8YKAalZAqO4&feature=plcp

      http://www.youtube.com/watch?v=rkz-nlN5kM8&feature=plcp

      http://www.youtube.com/watch?v=lKkG8Xbb8Fc&feature=plcp

      -JD-man

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    3. I've seen those. I really like those two as well.

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