Mississippi Science ZOO.10.2
The Standard
- ZOO.10
- Students will understand the structure and function of phylum Chordata, class Mammalia, and how they demonstrate the characteristics of living things.
Describe the characteristics of the first true mammal.
2026 Mississippi College- and Career-Readiness Standards for Science · Phylum Chordata, Class Mammalia
Teacher's field guide
What This Standard Means
What Students Need to Do
- Students describe the earliest mammals as small animals with fur, milk for their young, and different kinds of teeth. They identify the single-bone lower jaw as a clue in skull fossils.
What Mastery Looks Like
- Given a skull diagram, a student points out the jaw and different tooth shapes. They explain that a skull fossil does not show whether the animal had fur or produced milk.
Common Misconceptions
- Students may assume the earliest mammals looked just like modern mice. They may think all mammals give birth to live young, or that a skull fossil can show milk production.
How to Assess It
- Show two skull sketches, one with a single-bone lower jaw and varied teeth, the other with several lower jaw bones and similar teeth. Ask students to choose the early mammal, name two clues, and name one trait the skull cannot show.
Lesson moves
Ways to Teach It
Use clay to make a one-piece lower jaw with three tooth shapes, then label the teeth and their likely jobs.
Ask: What can a skull fossil tell us about an early mammal, and what must scientists infer? Write two examples of each.
Sort cards showing a jaw, teeth, fur, and milk into clues a skull can show and traits it cannot show.
Compare photos of a cat skull and an early mammal skull, then circle matching tooth shapes and predict what each tooth did.
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Related Standards
- ZOO.8.9
Identify the amniotic egg as the major derived characteristic of reptiles.
- ZOO.10.3
Distinguish between monotremes, marsupials, and eutherians, and describe the importance and differences in the placenta in marsupials and eutherians.
- ZOO.10
Students will understand the structure and function of phylum Chordata, class Mammalia, and how they demonstrate the characteristics of living things.
- ZOO.10.1
Understand the characteristics and behaviors that distinguish mammals from other phyla and use characteristics and behaviors to distinguish the major orders, in...
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