Identifying Vertebrates Using Classification Keys
Name _______________
Background Information:
Organisms such as vertebrates are classified into groups according to
certain characteristics. Using these characteristics, classification keys can be
developed. Biologists and science students can use these classification keys to
identify unfamiliar organisms. Such keys are also useful in studying common
characteristics and relationships among organisms. In this investigation, you will learn to use
simple classification key to identify some organisms.
Problem:
How a classification is key used to identify various animals?
Materials: Pencil and lab
Procedure:
Animals with backbones, also called vertebrates, can be divided into five major groups: fish,
amphibians, reptiles, birds, and mammals. Fish, amphibians, and reptiles are coldblooded
because their body temperatures change with the environment. Mammals and birds are warmblooded because their body temperatures remain fairly constant. Some animals in each of
these groups have become extinct, or completely died out, primarily because of the activities of
humans. Ten such extinct animals are pictured on the back pages.
1- Study these animals and identify their characteristics by completing
the Data Table.
2- Using the information from the pictures and the Data Table, the
accompanying classification key was developed. See if you can classify
each animal by placing it in its correct position in this key.
3- Answer the lab questions.
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Identifying Vertebrates Using Classification Keys
Observations:
Data Table
Observe each animal and place a check
√ in the box if it has that characteristic, but leave
blank if it does not.
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Identifying Vertebrates Using Classification Keys
Classification Key for 10 Extinct Animals
1a Is warmblooded……………………………………………………
Go to 2
1b Is coldblooded ……………………………………………………..
Go to 6
2a Has feathers …………………………………………. …………..
Go to 3
2b Has hair or fur …………………………………………. …………….
Go to 4
3a Has narrow, straight beak ………………………………………….
______________________
3b Has wide crooked beak ………………………………………………
______________________
4a Has horns ………………………………………………………………
Go to 5
4b Has no horns …………………………………………………………...
______________________
5a Horns have many branches ………………………………………….
______________________
5b Horns have no branches ………………………………………….
______________________
6a Breathes with gills …………………………………………………..
Go to 7
6b Breathes with lungs ………………………………………………..
Go to 8
7a Has large, fan-shaped fins just below the head………………
______________________
7b Has small pectoral fins………………………………………….
______________________
8a Has scaly skin …………………………………………………………….
Go to 9
8b Has smooth (no scales) skin………………………………………….
______________________
9a Has front and hind legs ………………………………………….
______________________
9b Has no legs ………………………………………….
_______________________
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Identifying Vertebrates Using Classification Keys
Conclusions:
1. Cold blooded organisms cannot generate all their body heat and rely on the
environment to maintain the proper temperature. Which of the 10 animals in this lab
are cold blooded?
2. The Palestinian painted frog is an amphibian. How are amphibians different from
reptiles?
3. Mammals are warm blooded, have hair or fur, breathe with lungs, give birth to live
young. Which of the 10 animals in this lab are mammals?
4. The two classes of vertebrates that are warm blooded are the birds and the mammals.
Which of the 10 animals are warm blooded?
Which of the 10 animals are birds?
5. Which one of the following pairs of vertebrates are most like each other (share the most
characteristics)? Circle your choice.
Birds and Fish
Amphibians and Reptiles
Reptiles and Mammals
Fish and Mammals
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Identifying Vertebrates Using Classification Keys
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Identifying Vertebrates Using Classification Keys
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