Sponges and Paleontology

Multicellularity evolved in animals, starting with the sponge, and also evolved independently in other groups. “Simple multicellularity has evolved numerous times within the Eukarya, but complex multicellular organisms belong to only six clades: animals, land plants, some red algae, laminarialean brown algae, and two groups of fungi. Phylogeny and genomics suggest a generalized trajectory for the evolution of complex multicellularity.… The fossil records of animals and plants document key stages of this trajectory." Read full abstract at: Annual Reviews - Earth and Planetary Sciences, The Multiple Origins of Complex Multicellularity.

Sponges were the first animals but they don’t fossilize well. Researchers think this sponge-like fossil may represent the first animals. But early sponges built sponge reefs (like some modern species), and paleontologists have discovered some fossil sponge reefs.

General Info

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    Book with pencil

Role in Ecosystem

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    Bee with arrows around it

Climate

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    Thermometer and waves

Human Interaction

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    Human next to globe

Paleontology

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    Skull of dinosaur
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    Lesson Plan
    What Is An Animal
    In this lesson students discuss the definition of an animal. What characteristics do all animals have in common? To introduce the subject the teacher gives a brief discussion of the five kingdoms (see reference below). What evidence is needed to decide that an organism is an animal? Students watch the video Sponges: Origins and reconsider the definition of an animal.

    Full Lesson Plan