Video: The Case of the Flying Dinosaur (AV# 89035)

 

1.         Why are the fossils found in the Solenhofen limestone quarry in

Germany so valuable?  What kinds of fossils are found there?

 

Pteradactyls (Òwing-fingerÓ) and Archaeopteryx are two of the important fossils found there.  They are valuable because they are preserved in very find detail and allow scientists to study the origin of these winged animals in more detail.

 

2.  What are Pterodactyls and Pterosaurs?  Describe some of their features, including their size.

 

They are Òwinged lizardsÓ, extinct flying reptiles.  They range in size from sparrows to 40 feet wing spans.  They have membrane wings that are attached to 1 long finger.  They evolved about the same time as the first dinosaurs

 

3.         How different are the wings of Pterosaur and bird wings?

 

Very different.  Birds have feathery wings that are attached to the forearm and hand and Pterosaurs have membrane wings that are attached to 1 long finger.

 

4.         What is Archaeopteryx? Describe some of its features.  How does it

fit with Darwin's evolutionary theory?

 

It is a Jurassic fossil that is part reptile and part bird.  It has a long bony tail and sharp teeth like a reptiles but wings and feathers like birds.  Darwin predicted missing links and intermediate/transitional forms as exemplified by Archaeopteryx. 

 

5.         What is convergent evolution?

 

Unrelated animals evolve similar features, e.g. some birds may resemble dinosaurs even though they may not have directly descended from dinosaurs.  Wings appear in both birds and pteradactyls even though these two animals are not directly related.

 

6.         What are thecodonts?  What are theropod dinosaurs and what evidence

supports that dinosaurs are related to birds?

 

Thecodonts are reptiles that are ancestral to dinosaurs and may be the ancestors to birrst, the ancestral stock.  Theropods,  like Deiononychus are carnivores,  bipedal dinosaurs.  They have a 3-clawed toe, a moon-shaped wrist bone and similarities in the arms,  shoulders and to the theropods.

 

7.         What are some arguments against dinosaur-bird relationships?

 

The dinosaurs that are most similar to birds evolved in the Cretaceous, much later than the appearance of the oldest bird fossil.  Half-moon shaped bone in the wrist only looks similar, it may have evolved from a more primitive bone and it functions differently than a similar bone in dinosaurs/Archaeopteryx.  Birds may have evolved in the Triassic from a crocodile.

 

8.         How did birds learn to fly?  How did the scales evolve?

 

Possibly from the ground-up through running with powerful leg muscles.  Maybe early birds were climbers without a good flapping mechanism and flew from trees-down by gliding.

 

 

10.       What did Prof. Chattergee and his students find in their field

excavations?  What is Protoavis?

 

They found a small bird skeleton, Protoavis, that has a skull and other bones more similar to modern birds than Archaeopteryx.  This ÔprotobirdÕ may replace Archaeopteryx as the oldest bird.