1. Paleozoic Life
Vertebrates & Plants

2. Paleozoic Vertebrate Introduction
Vertebrate evolution
Fish  amphibian  reptile
Transition from H2O to land
Plants preceded animals
Method of reproduction
Evolution of the seed = plants
Amniote egg = animals
Time of major extinctions (end of Paleozoic Era)
Marine invertebrates
Many amphibians and reptiles

3. Paleozoic Vertebrate Fish Evolution
Ancestors
Similar to amphibians
May have evolved from sessile suspension feeders
Class Agnatha – Jawless fish
Class Acanthodians – 1st Jawed fish

4. Paleozoic Vertebrate Fish Evolution
Most primitive vertebrate -- fish
Oldest fish  Upper Cambrian
Phosphatic; Jawless fish, class Agnatha
Shallow near-shore marine deposits
Earliest non-marine  Silurian
Ostracoderm
Anatolepis piece, U. Cambrian
Jawless fish

5. Paleozoic Vertebrate Devonian Seafloor

6. Paleozoic Vertebrate Evolution of Jaws
“Evolutionary Opportunism”
Early jaws for respiration
Open mouth wider; more O2
Led to ↑ food consumption
Class Acanthodians
Placoderms
L. Silurian
Extinct Permian
Major Advancement
Active predators
Eat plants
New niches

7. Paleozoic Vertebrate Late Devonian Seafloor

8. Paleozoic Vertebrate Cartilaginous & Bony Fish
Class Chondrichthyes (cartilaginous)
Devonian
Related to sharks, rays, skates
Primitive sharks – L. Devonian
Class Osteichthyes (bony fish)
Devonian
Two groups
Ray finned
Lobe finned

9. Paleozoic Vertebrate Bony Fish
Ray finned
Lobe finned
Thin bone spread from body
Muscular fins; no radiating fins
Fresh-H2O beginning
Articulating bones
2 types of lobe-finned
Trout, bass

10. Paleozoic Vertebrate 2 Types of Lobe-Finned
Lung fish
Lobe-Finned Types
Lung Fish
Lungs evolved from sac-like bodies
Adapted for H2O variations
Rhipidistian
Crossopterygians
Most important
Amphibian evolution

11. Paleozoic Vertebrate Lobe-finned & Amphibian Similarities

12. Paleozoic Vertebrate Amphibians
1st Vertebrates on land – L. Devonian
Plants 1st land organisms
Spiders and insects before vertebrates
Crossopterygians

13. Paleozoic Vertebrate Transition from H2O to Land
Major Barriers
Dessication
Reproduction (need H2O)
Effects of gravity
Extraction of O2 from atmos.
Crossopterygians overcame Barriers
Backbone
Limbs
Lungs
Amphibians exploit new niches

14. Paleozoic Vertebrate Evolution of Reptiles
Amphibians limited to colonizing land
Recent gelatinous egg
Gelatinous egg laid in H2O
Amniote egg
Embryo surrounded by liquid
“Anion” provided yolk (food sac)
Miniature adult
Bypass larval stage
Led to colonization all parts of land
No need to return to H2O

15. Paleozoic Vertebrates Reptiles
Pennsylvanian reptile, Hylonomus
Evolution
Reptiles evolve in Late Mississippian
Protorothyrids = earliest reptiles
Diversified in Permian—displaced amphibians—more successful
Pelycosaurs evolve from protorothyrids
Extinct in Permian
Pelycosaurs succeeded by therapsids
Mammal-like reptile
Both carniverous and herbivorous
Endothermic—warm-bloooded
Could occupy both cold and warm niches—high and low latitudes
2/3 reptiles and aphibians extinct at close of Permian.

16. Paleozoic Vertebrate Plant Evolution
Marine  fresh H2O  land
Problems to solve
Dessication
Support
Effects of gravity
Reproduction (needs H2O)
Vascular (seedless)
Earliest  middle Silurian
Specialized cells
Movement of H2O
Non-Vascular
Earliest plants mid-late Ord
No specialized cells
Live in low, moist areas

17. Paleozoic Vertebrate Seed Evolution
Gymnosperms (flowerless seed plants)
Late Devonian
Male and female cones
Seed plants no longer restricted to wet areas

18. Paleozoic Vertebrate Permian Floras
Major source of world’s coal
Results from alteration of plants living in low, swampy areas