Reptiles Birds Mammals Flashcards

Amniotes

• Amniotes consist of birds, reptiles, and mammals.
• Characteristics include an amniotic egg, internal fertilization, and water-tight skin.

Amniotic Egg

• Defined as an egg with a waterproof shell.
• Contains several key parts: amnion, chorion, allantois, yolksac, yolk, and embryo.

Parts of the Amniotic Egg

• Amnion: Membrane that surrounds the developing embryo.
• Chorion: Facilitates gas exchange during development.
• Allantois: Primarily responsible for waste disposal.
• Yolksac: Surrounds the yolk, providing nutrients.
• Yolk: Nutrient source for the embryo.
• Embryo: Develops into the young of the species.

Reptiles

• Belong to the class Reptilia.
• Scales are made of keratin.
• Exhibit ectothermic body temperature, meaning their temperature is regulated by the environment.
• First appeared during the Carboniferous period, about 300 million years ago.
• Likely evolved from amphibians.
• Experienced great diversity during the Mesozoic Era, known as the Age of Reptiles.

Diversity of Mammals

• The extinction of dinosaurs, around 65 million years ago, led to the diversity of mammals.

Orders of Reptiles

• Four main orders: Order Testudines, Order Squamata, Order Crocodilia, Order Rhynchocephalia.
• Order Testudines includes turtles and tortoises; turtles inhabit water, while tortoises are larger and terrestrial.
• Turtle shells consist of carapace (top) and plastron (bottom).

Order Squamata

• Comprises lizards and snakes.
• Possesses a Jacobson Organ for chemical detection, aiding in predation.
• Lizards can regrow their tails through a process known as autotomy.

Order Crocodilia

• Includes crocodiles and alligators, the closest living relatives to dinosaurs.
• These reptiles hunt by stealth and exhibit parental care.

Order Rhynchocephalia

• Native to New Zealand and features a parietal eye that serves as a thermostat.

Birds

• Classified under class Aves and maintain endothermic body temperature controlled internally.
• Evolved from dinosaurs during the Mesozoic Era, around 150 million years ago.
• The oldest known bird fossil is Archaeopteryx, distinguished by clawed forelimbs, teeth, vertebral tail, and feathers.
• Feathers are modified scales.

Flight Styles in Birds

• Birds demonstrate five types of flying styles:
  • Rapid altitude changes.
  • Soaring and gliding.
  • Hovering.
  • Short flights.
  • Flightless species.