BASC107A- Origin and Developmnent of the Horse
37 Questions
1 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

Which digit was enlarged and developed in the horse during its evolution?

  • First digit (thumb)
  • Second digit
  • Third digit (median) (correct)
  • Fifth digit

    • What structural change in the horse's limbs aided in faster running?

  • Lengthening of forearm
  • Lengthening of limbs and perfection of hoof (correct)
  • Elongation of femur
  • Reduction of radial bone

    • Which bone reduction in the hind limb contributed to the horse's evolutionary adaptation?

  • Reduction of the patella
  • Reduction of the femur
  • Reduction of the fibula and strengthening of the radius
  • Reduction of the fibula and strengthening of the tibia (correct)

    • What significant locomotion change occurred in horse evolution?

    <p>From digitigrade to unguligrade</p> Signup and view all the answers

    Which skull trait developed to support a larger brain in horses?

    <p>Increase in size and complexity of the brain</p> Signup and view all the answers

    To which order do horses belong?

    <p>Perissodactyla</p> Signup and view all the answers

    Which genus includes horses, zebras, and asses?

    <p>Equus</p> Signup and view all the answers

    During which epoch did the very first horse evolve?

    <p>Eocene</p> Signup and view all the answers

    Which category of the scientific classification does 'Chordata' refer to for horses?

    <p>Phylum</p> Signup and view all the answers

    Which animals are included in the order Perissodactyla along with horses?

    <p>Rhinos and tapirs</p> Signup and view all the answers

    Which of the following horse ancestors existed 60 million years ago?

    <p>Hyracotherium</p> Signup and view all the answers

    Which horse ancestor was slightly larger than Eohippus and had 3 toes?

    <p>Mesohippus</p> Signup and view all the answers

    Which horse ancestor had a single toe that developed into a hoof and could run faster?

    <p>Merychippus</p> Signup and view all the answers

    What is the earliest known ancestor of the horse?

    <p>Hyracotherium</p> Signup and view all the answers

    Which horse ancestor lived on grasslands approximately 5 million years ago?

    <p>Pliohippus</p> Signup and view all the answers

    During which geological epoch did Mesohippus live?

    <p>Oligocene</p> Signup and view all the answers

    Which horse ancestor is characterized by having four toes well spread for walking on soft ground?

    <p>Hyracotherium</p> Signup and view all the answers

    How many toes did the front feet of Eohippus have?

    <p>Four</p> Signup and view all the answers

    Which feature is common in the modern horse Equus?

    <p>Single hoof</p> Signup and view all the answers

    Which of the following ancestors of the horse is known for having lived between 23 and 2 million years ago and was well adapted to grasslands?

    <p>Hipparion</p> Signup and view all the answers

    Which characteristic is true of Mesohippus?

    <p>Had six grinding cheek teeth with a premolar in front</p> Signup and view all the answers

    What was the main function of the toes of Eohippus?

    <p>To keep the feet off the ground and bear the animal's weight</p> Signup and view all the answers

    Which ancestor of the horse still survives today in a wild form similar to Equus but with distinct features?

    <p>Przewalski horse</p> Signup and view all the answers

    Which statement is true about the dentition of Eohippus?

    <p>They had low-crowned and low-cusped teeth for soft vegetation</p> Signup and view all the answers

    What evolutionary change is evident in Mesohippus compared to Eohippus?

    <p>Elongation of face, snout, and neck</p> Signup and view all the answers

    Approximately how tall was Eohippus?

    <p>14 inches</p> Signup and view all the answers

    Which evolutionary stage of the horse had longer legs and neck compared to other species?

    <p>Eohippus</p> Signup and view all the answers

    Which horse species lived during the Miocene Epoch about 30 million years ago?

    <p>Merychippus</p> Signup and view all the answers

    What feature made Pliohippus's teeth better suited for eating grass?

    <p>Teeth became better fitted for eating grass</p> Signup and view all the answers

    Which evolutionary stage of the horse was an effective grazer and runner?

    <p>Merychippus</p> Signup and view all the answers

    Which stage of the horse evolution had three toes on each foot where the middle toe was long and useful?

    <p>Merychippus</p> Signup and view all the answers

    During which epoch did Pliohippus live?

    <p>Pliocene</p> Signup and view all the answers

    Which prehistoric horse is considered directly linked to the genus Equus?

    <p>Pliohippus</p> Signup and view all the answers

    In what regions have fossils of Pliohippus been found?

    <p>Great Plains of the US and Canada</p> Signup and view all the answers

    What significant change occurred in the horse's body modification during its evolution?

    <p>Increased in size and height</p> Signup and view all the answers

    Which characteristic distinguishes Equus from its predecessor Pliohippus?

    <p>Does not have a dished face</p> Signup and view all the answers

    What are some uses of the modern-day horse, Equus, that continue from 3000 years ago?

    <p>Travel</p> Signup and view all the answers

    Study Notes

    Early Evolution of Horses

    • Eohippus (50 million years ago): small, 4-toed, lived in forests, about the size of a cat or a dog, with an arched back and snout-like nose
    • Eohippus had a dentition adapted to feed on soft vegetation, with 4 toes on the front feet and 5 toes on the hind feet, with the 1st and 5th toes not touching the ground
    • Hyracotherium (60 million years ago): the ancestor of the horse, with a similar size and characteristics to Eohippus

    Evolutionary Stages

    • Mesohippus (35 million years ago): slightly larger than Eohippus, with 3 toes, and a stronger middle toe
    • Merychippus (10 million years ago): larger, with a single toe, and a hoof, lived on grasslands
    • Pliohippus (5 million years ago): single-toed or hooved, with strong leg ligaments for increased speed and power, and a dished face
    • Equus (present): the modern horse, evolved from Pliohippus, with a single hoof, long legs, and a fast runner

    Key Characteristics

    • Increase in size and height over time, from rabbit-like to 6-feet grassland animal
    • Lengthening of limbs and perfection of hoof for fast running in grasslands
    • Enlargement and development of the 3rd digit (median) and reduction of the lateral digits
    • Reduction of the ulna (fore) and fibula (hind) and strengthening of radius and tibia
    • Change from digitigrade to unguligrade locomotion for fast running

    Body Modifications

    • Increase in size and height, from rabbit-like to 6-feet grassland animal
    • Development of the hooves and leg ligaments for increased speed and power

    Evolution

    • Evolution means change, a dynamic process full of twists, transitions, and dead ends (extinctions)
    • Result of genetic adaptation to environmental changes
    • Horses belong to the order Perissodactyla, the odd-toed ungulates, which includes horses, rhinos, and tapirs today

    Scientific Classification of Horse

    • Kingdom: Animalia
    • Phylum: Chordata
    • Class: Mammalia
    • Order: Perissodactyla
    • Genus: Equus, which includes horses, zebras, and asses

    Studying That Suits You

    Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

    Quiz Team

    Description

    This quiz covers the early evolution of the horse, from Eohippus to Equus, including the stages of development and the characteristics of each horse ancestor.

    More Like This

    Use Quizgecko on...
    Browser
    Open
    Browser
    Browser