Nova Article: Fossil Evidence        NAME__________________________________________  PER_______

1)      Define “tetrapod:”

Animals with four limbs

2)      IN YOUR OWN WORDS, define “transitional form:

A transitional form is a fossil that is an intermediate between two different types of animals, adding support for evolutionary relationships.

3)      Based on the FIRST paragraph, what is the PURPOSE of the article?

he purpose is to describe how transitional fossil forms supported the theory that fish evolved into tetrapods. 

 

4)      What are the THREE evolutionary “gaps” described in this article? List them:

 

1)      Fish to amphibians   2) reptiles to mammals 3) reptiles to birds

 

5)      In the pictures, which one is the “transitional” form? First, middle, or end?

Middle

 

6)      What features of the Tiktaalik rosae transitional form resembled fish? What features resembled tetrapods? LIST THEM IN THE TABLE:

Features of fish (list  2)

Features of amphibians (list  3)

-          Breathed through gills

-          Lobe-fins

-          Wrist and finger bones

-          Breathed through lungs

-          Stronger limbs

 

 

7)      What features of the Thrinaxodon transitional form resembled reptiles? What features resembled mammals? LIST THEM IN THE TABLE:

Features of reptiles (1)

Features of mammals (list at least 3)

-          Lizard-like appearance

 

-          Probably covered in fur

-          Warm blooded

-          Differentiated teeth

-          Strong jaw, could chew

 

8)      What was Archaeopteryx ‘s closest dinosaur relative?

Velociraptor

 

 

9)      What features of the Archaeopteryx transitional form resembled reptiles? What features resembled birds LIST THEM IN THE TABLE:

Features of reptiles (3)

Features of birds (1)

-          Sharp claws

-          Long hind legs

-          Stabilizing tail

 

-          Feathers

 

 

10)   Define “cetacean:”

p including dolphins, porpoises, and whales

 

11)    Pakicetus was able to venture into the water. Why was this considered an “adaptation.” Use the word “fitness” in your answer:

This ability allowed the organism to hunt aquatic prey that other land mammals could not, increasing its fitness!

 

12)   The article does not discuss the transition from amphibians to reptiles. Based on the information in the article AND a CREDIBLE online source of your choice, create a possible amphibians to reptiles transitional form. What features would it have? LIST THEM IN THE TABLE:

Features of amphibians (At least 3)

Features of reptiles (At least 3)

 

 

 

 

 

 

 

 

 

13)   DRAW YOUR TRANSITIONAL FORM, with the features in your table: