From Earth to Air: Dinosaurs and Birds

Berlin specimen of  Archaeopteryx lithographica 

The First of the Birds:

In the early 19th century, a curious fossil was found in Germany. Known also by its German name, Urvogel, or "first bird", the specimens of Archaeopteryx lithographica were a strange combination. The body was that of an apparent avian dinosaur, a dinosaur with both wings and feathers, teeth and claws.

Each wing showed a multitude of feathers and still obvious claws. The hind legs and long reptilian tail were also remarkably covered in feathers. The observations made of these fossils showed scientists of a step between dinosaurs and birds, a snapshot of the evolution of modern avians.

Over the following years, more specimens of A. lithographica and possibly related species were found in the rich fossil deposits of Germany. Some were incomplete, but showed remarkable detail of portions of this long extinct species.

The Birds and Birders of MOSI Outside

At MOSI Outside, we often write about the modern birds that frequent the property. In fact, the MOSI Outside Assistant Coordinator Jill and her husband are quite the birding pair. They have traveled to some really neat locations to photograph birds and Jill also writes for Birds and Blooms magazine and their blog. 

MOSI Outside Coordinator Kristen prefers to enjoy birds from a distance. She is pretty convinced that Woodpeckers and a number of the Florida wading birds looks a bit too much like dinosaurs to trust them at all.

Seriously, let's just look at a baby bird for a minute:

A Great Egret chick in the nest with mom's legs to the right. Photo by Jill Staake

Similarities of Birds and Dinosaurs

Since then, many theropod dinosaur fossils with feathers have been found and show that modern birds retain a number of the same developmental qualities of juvenile theropods. Birds are now commonly considered to be the descendants of dinosaurs, namely the theropods. Reptiles and birds have a remarkable number of similarities. Baby birds, before their feathers grow in, are nearly a snapshot of the qualities that mark them as the descendants of dinosaurs.

Here are some of the similarities between modern birds and their avian dinosaur ancestors:

• Feathers: Fossilized feather have been found on many species of dinosaurs, These feathers are similar if not sometimes identical to the structure of modern bird feathers.
• Skeleton: The skeletons of the avian dinosaurs and modern birds show remarkable similarity in

  

  Lineated Woodpecker. Photo by Jill Staake

  both shape and structure. Light, hollow bones are found as fossils, just like those found in modern birds.
• Lungs: The complex and multi-chambered air sac lungs thought to be unique to modern birds have been found in the fossils of theropod dinosaurs. 
• Reproduction: The avian dinosaurs and modern birds both lay eggs and seem to have similar reproductive behavior. Laying a clutch of eggs and protecting them while the eggs hatch and the young developed into adults. Fossil records show family groups of adult and juvenile avian dinosaurs mixed together in much the same way that adult and juvenile modern birds can be found today.
• Gizzard Stones: Both modern birds and their avian dinosaur ancestors use gizzard stones to help break down their food in the digestion process.
• Sleeping Posture: The sleeping posture of some preserved avian dinosaur fossils shows them with heads tucked under their arms or wings. Modern birds use this same position to help keep their heads warm and protected during sleep. 

Magnificent Frigatebird in flight. The profile of this modern bird is likely rather similar to the profile an Archaeopteryx lithographica would have had in flight.

See More:

If you'd like to take a look at some more dinosaur insides, visit us at MOSI and visit the Dinosaurs in Motion exhibit. #MOSIdinos and a trip to the MOSI Outside gardens for birdwatching makes for a great afternoon. Learn more about Dinosaurs in Motion at MOSI here.
Learn more: 

• Dinobuzz: Are Birds Really Dinosaurs?
• Dinobuzz: Maniraptora- Birds and Their Closest Relatives
• Scientific American: How Dinosaurs Shrank and Became Birds
• NBCNews: Nine Links in the Transition of Dinosaurs to Birds
• Discovery: Modern Birds are Really Baby Dinosaurs