reptiles n.
Skip this Video
Download Presentation

Loading in 2 Seconds...

play fullscreen
1 / 20

Reptiles - PowerPoint PPT Presentation

  • Uploaded on

Reptiles. Diversity. Diversity Found on every continent but Antarctica Mainly found in tropics and subtropics Produce some heat Do not generate enough to maintain constant body temp (still ectothermal /cold-blooded) Good for reptiles—don’t have to eat to maintain body temp. Diversity.

I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
Download Presentation

PowerPoint Slideshow about 'Reptiles' - atara

Download Now An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
  • Diversity
    • Found on every continent but Antarctica
    • Mainly found in tropics and subtropics
    • Produce some heat
      • Do not generate enough to maintain constant body temp (still ectothermal/cold-blooded)
      • Good for reptiles—don’t have to eat to maintain body temp
  • Diversity
    • Reptiles included amniotes – those animals who produce a shelled, amniotic egg
      • Do NOT INCLUDE birds and mammals
    • Examples include:
      • Crocodiles, alligators, lizards, snakes, and turtles, Komodo dragon
    • Grouped together as the class Reptilia
      • Latin repere means "to creep"

General Characteristics

  • Reptiles are tetrapods
    • Vertebrates with four legs
  • Contain tough keratinized skin
    • Provides protection against injury
    • Scales or bony plates (well-developed dermal layer)
    • Contain chromatophores
  • Excretory system
    • Two small kidneys.
    • Uric acid is the main waste product.

General Characteristics

  • Contain powerful jaws
    • Desgined for applying crushing or gripping force
    • Used to kill/capture prey
    • FYI: Fish/Amphibian jaws designed for quick closure (with little pressure/force)
    • Reptile muscles (in jaw) are larger, longer and arranged to apply a strong grip

General Characteristics

  • Circulatory system
    • Most reptiles have closed circulation
    • Contain a three-chamber heart
      • Consisting of two atria and one ventricle.
    • There is little mixing of oxygenated and deoxygenated blood in the three-chamber heart.

General Characteristics

  • Organs for water retention
    • Metanephric kidneys:
      • excretes uric acid or urea which allows them to occupy terrestrial habitats
    • Salt glands:
      • Located near nose/eyes
      • Secretes a salty fluid
  • All reptiles have better body support and more efficiently designed limbs for travelling on land

General Characteristics

  • Circulatory system
    • Exceptions to these characteristics:
      • Crocodilians have a complicated four-chamber heart
        • This heart is capable of becoming a functionally three-chamber heart (during dives)
      • Some snake and lizard species (e.g., monitor lizards and pythons) have three-chamber hearts that become functional four-chamber hearts (during contraction)

General Characteristics

  • Respiratory system
    • All reptiles breathe using lungs.
      • VERY well developed lungs
      • Only a few use skin to breathe (sea snakes)
    • Most reptiles do NOT have a muscular diaphragm (like mammals)
      • Crocodilians have a muscular diaphragm
    • Turtles & Tortoises.
      • Aquatic turtles have developed more permeable skin, and even have gills in their anal region

General Characteristics

  • Nervous system
    • Advanced nervous system compared to amphibians.
    • 12 pairs of cranial nerves.
    • Hearing is underdeveloped
    • All other senses are highly developed
    • Small brain (but, cerebrum is large)
    • Contain Jacobson’s organ
      • Specialized organ for smell (odors carried to this organ via the tongue)

General Characteristics

  • Reproduction system
    • Most reptiles reproduce sexually.
    • Asexual reproduction has been identified in in six families of lizards and one snake.
    • No larval stages.
    • Internal fertilization (copulatory organs)
      • Sperm – testes, Egg - ovaries

General Characteristics

  • Reproduction system, cont.
    • Contain amniotic egg
      • Permits rapid development of large young in relatively dry environments
      • Provides nourishment for growing embryo
      • Provides protection (shell) from environment
      • Allows for sufficient gas exchange
      • Reduces water loss
  • Kingdom Animalia
  • Phylum Chordata
  • Class Reptilia
    • They are represented by four surviving orders:
      • Crocodilia
      • Rhynchocephalia
      • Squamata
      • Testudines
  • Order Crocodilia
      • Ex: crocodiles, caimans and alligators
      • 23 surviving species
      • Body shape: elongated, robust, reinforced skull and massive jaw muscle structure
      • Teeth in sockets
      • Four-chambered heart
      • Can vocalize
      • Oviparous (eggs are guarded heavily by mother)
      • Will lay 20-50 eggs at a time

Male Crocodile courtship

  • Rhynchocephalia
      • Ex: tuataras from New Zealand
      • 2 surviving species
      • Lizard-like body form
      • Slow-growing animals that live in burrows
      • VERY good eyesight (have cornea, lens and retina)
  • Squamata
      • Ex: lizards, snakes, (specific ex: gila monster, python, monitor lizard)
      • Approximately 7,600 species
      • Most diverse group of reptiles
      • Kinetic skull (mobile/moveable)
      • May contain fangs (with poison)
      • May contain heat-sensing organs (pit organs – in pit vipers)
  • Testudines
      • Ex: turtles, tortoises
      • Approximately 300 species
      • Enclosed in shells consisting of carapace and plastron (breastplate)
      • No teeth, but contain keratinized plates inside mouth for gripping food
      • Oviparous
        • Nest temperatures determine sex of offspring
        • Low temp = males, high temp = females