Archaeopteryx

Last week I saw a drawing of a very strange bird in the wildlife hospital.  It looked like a small bird, but it had an oddly shaped tail, talons on its wrists, and a jaw containing teeth!  It was a drawing of Archaeopteryx, one of the most primitive birds known.  Although there is still some debate in the scientific community as to whether this speciies was actually a dinosaur or a bird, these fossils provide some great examples of the transition from reptiles, particularly Theropod dinosaurs, to birds.

 Photo of the Berlin Archaeopteryx by H. Raab, rev. 20 Sep, 2010,  from the Wikipedia website 

Although many names have been given to the various specimens found, the most commonly used species designation is Archaeopteryx litographica.  The genus stems from the Greek words “archaios”, which means “ancient,” and “pteryx”, which means “wing.”  The first fossilized Archaeopteryx skeleton was discovered in 1861, in a very unique limestone formation that is only found in Solnhofen, Germany.  At the time, this valuable limestone was hand quarried for use in lithography.  It was through this quarrying process that many fossils, including Archaeopteryx, were discovered.

Archaeopteryx was an important discovery also because it was the first fossil ever found where you could clearly see feathers.  Because feathers are softer than bone they usually biodegrade well before the fossilization process can take place.  So, before Archaeopteryx it was impossible for archaeologists to trace the ancestry of birds.

Photo of Archeopteryx model on display at the Oxford University Mueum of Natural History by Michael Reeve, 30 May 2004 from the New World Encyclopedia website 

Archaeopteryx lived around 150 million years ago during the late Jurassic period.  Then, Europe was just an archipelago of islands located much closer to the equator than today.  Archaeopteryx has features that are common to dinosaurs in the theropod family.  It had a jaw with sharp teeth and a long tail containing bones.  It also had three fingers with claws on the front edge of each wing, which it probably used to hold onto the sides of trees.   Archaeopteryx also had a hyperextendable middle talon on each foot that worked a little like a switchblade.  The flight feathers are highly evolved, meaning they already looked and probably worked like the flight feathers of birds of today.  This demonstrates that dinosaurs of this family probably had feathers even earlier than the late Jurassic period.

 

Archaeopteryx seems to lack strong breast muscles or structures that would enable it to have the strong wing upstroke needed for flapping flight.  So, this animal probably used its feathers mostly to glide.  Although Archaeopteryx may not be the direct ancestor of modern birds, it is at least closely related to that ancestor and provides a very clear demonstration of how birds originated. 

Submitted by Leah Sainz, World Bird Sanctuary Trainer/Naturalist