DEVONIAN FISHES AND MESOZIC REPTILES

Devonian Fishes and Mesozoic Reptiles

• 1. 1. • The Devonian period, which is frequently referred to as the "Age of Fishes," and the Mesozoic era, which is commonly associated with the "Age of Reptiles."

The Devonian Period: The Age of the Fish

• The period of approximately 419 to 359 million years ago.
  
  

1. Diverse Fish Population

• During this period, a diverse array of fish was observed, including jawless fish like hagfish and lampreys. These are a few of the initial fish.
• The majority of fish today have swim bladders and bones to assist with flotation.

Sharks and rays have cartilage-based skeletons.

2. The Evolution of  Fish

• Several fish, such as lobed-finned fish, evolved during this period and are considered the progenitors of amphibians.
• They have fleshy appendages that may one day enable them to move on land.
• The term "holy fish" denotes fish that possess unique characteristics that enable them to adjust to their environment.

3. Evolution of Fish Predators

• Predators evolved in tandem with the fish.
• A significant predator in Devonian waters was the Dunkleosteus, an enormous armoured fish.

4. Marine Ecosystems

• The Devonian waters were teeming with a variety of fish species, crustaceans, and coral reef.
  
  

5. Transition to Land

• Fish made significant progress in their evolution by exploring the land.
• They developed robust fins and lungs, which led to the development of the first amphibians after the Devonian.
  
  

The Mesozoic Era: The Age of Reptiles

• Time period: approximately 252 to 66 million years ago.Triassic, Jurassic, and Cretaceous comprise this epoch.

Mesozoic Era

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1. Dinosaurs 

• The Mesozoic period is renowned for its dinosaurs, which were both large and small.
• There were two primary groups.
•  The saurischians group includes sauropods, including T. rex and Brontosaurus.
• The Ornithischians group includes crested dinosaurs like Triceratops and armoured dinosaurs like Stegosaurus.

2. Flying Reptiles

• Pterosaurs, which possessed long appendages and skin-covered wings, dominated the skies.
• They varied in size from the scale of a crow to that of a tiny aeroplane.

3. Marine Reptiles

• Pleiosaurus, a species of reptile renowned for its large bodies and long necks, was prevalent in the ocean.
• Ichthyosaurs could swim at a swift pace, akin to dolphins.

4. The Evolution of Birds and Mammals

• Mammals were first observed during the Mesozoic era.
• The animals were diminutive and covered in fur.
• The link between reptiles and birds is illustrated by the fact that birds were derived from diminutive theropod dinosaurs at the close of the period.

5.  Plant Life

• The era witnessed the emergence of flowering plants (angiosperms) and conifers, which altered the environment and enabled dinosaurs to access new food sources.
  
  IMAGE SOURCE (THUMBNAIL)