Paleozoic Plant Evolution

First Forays:Intertidal

Marine Algae

Problems with Moving to Land1. Conserving water - not drying out

2. Obtaining & circulating water, food & gases

3. Overcoming gravity

4. Reproduction

5. Exposure to UV

Sunlight above groundNutrients below ground

Plant Solutions to Dry Living1. Conserving water - not drying out

2. Obtaining & circulating water, food & gases

3. Overcoming gravity

4. Reproduction

5. Exposure to UV

Developed waxy coating

Vascular tissue and roots, and pores

Thicker cells - wood/cellulose

First spores, then pollen, seeds, & flowers

Pigments

First Colonists: Bryophytes

No “Plumbing System” - small low to the ground

Early Plants:

1. Stabilized soil - reduced erosion

2. Began the process of creating soil

3. Provided food for animals to move to land

Vascular Plant Evolution

Vascular Plants

Rhynia

“Plumbing” and woody material allowed for increase in size

First Plants ReproducedUsing Spores

(Still required water)

Horsetails(Calamites)

Annulariastellata

Ferns

Pecopteris sp.

Clubmoses:Lepidodendron

Miss/Penn Forests(Ferns, Horsetails & Clubmoss)

Illustration by Mary Parrish

Gymnosperms

Pollen (male)

Seed Cone (Female)

Seed Ferns

Neuropteris sp.

Ginkos

Conifers

Angiosperms

The “Not-So-Naked” Seed

Fossil Leaves and Flowers

Plant Summary

1. Paleozoic - Plants move to land- Dominated by bryophytes & seedless vascular Plants

2. Mesozoic - Dominated by gymnosperms- Angiosperms arise

3. Cenozoic - Dominated by angiosperms

First in Flight - Pennsylvanian

Cretaceousdragonfly

Meganeura monyi (roughly to scale)

The largest insect in history

More to come in the Mesozoic…