The Arthropod Story

Overview

• The Arthropod Story examines the evolutionary history of arthropods, their taxonomy, paleontology, natural history, and principles of evolution.
• It covers various aspects from introducing arthropods to their evolutionary success and constraints.

Key Sections

Introducing the Arthropods

• Sheer Numbers: Arthropods are abundant in numbers.
• Habitat and Distribution: Widely varied habitats and global distribution.
• Ecological Niches: Fill numerous ecological roles.
• Success Story: Evolutionary success due to their adaptability.

What is an Arthropod?

• Five Branches of the Arthropod Tree: Diversity within arthropods.
• Inherited Characteristics: Traits like bilateral symmetry, segmented bodies, hard exoskeletons, jointed legs, and multiple limbs.
• Arthropod Checklist: Defining features of arthropods.

Meet the Cambrian Critters

• Cambrian Explosion: Emergence of diverse arthropods.
• Noteworthy Species:
  • Sanctacaris: An arthropod.
  • Opabinia: Unique body structure, not an arthropod.
  • Pikaia: A chordate, not an arthropod.
  • Hallucigenia: Possibly an onychophoran.
  • Naraoia: An arthropod.
• Classifying Cambrian Critters: Understanding evolutionary relationships.

Tools for Success: The Exoskeleton and the Jointed Limb

• Trilobites: Extinct but had excellent exoskeletons.
• Crustaceans: Adapted the arthropod limb layout, acting as living toolboxes.
• Adaptability: Key to evolutionary success.

An Evolutionary Constraint: Small Size

• Constraints: Limitations imposed by physical laws and inheritance.
• Molting: Essential yet challenging due to vulnerability during the process.
• Exoskeleton Strength: Physics of failure and strategies for overcoming limitations.
• Respiration: Challenges of oxygen acquisition.

Conclusion

• Arthropods and You: Their role in ecosystems and relation to humans.
• Amazing, But Not Unusual: Overview of their evolutionary journey and significance.

Additional Resources

• Teaching Resources: Guides and tools for teaching evolution.
• Learn Evolution: Further reading and educational materials.

Connect

• Opportunities for further engagement and learning through newsletters and social media.

Copyright

• All content is protected and credited to the UC Museum of Paleontology Understanding Evolution team.