evolution and domestication of horses Flashcards
evolution of horses is reflected in their
limbs and teeth
modern horses belong to genus
equus
eohippus aka hyracotherium
oldest known ancestor, fox sized, omnivore dentition, hoof life structures
hyracotherium (eohuppus) forelimb and hindlimb digits
forelimb; 2-5 weight bearing, 1 vestigial
hindlimb; 2-4 weight bearing, 1 and 5 vestigial
after hyracotherium what came next
orohippus
(coexisted with hyracotherium(
orohippus digits
same as hyracotherium
forelimb; 2-5 (4 digits)
hindlimb; 2-4 (3 digits)
most dramatic change between hyracotherium and orohippus
teeth; premolar 1 smaller and premolar 4 became more molar
crests more pronounced
greater grinding ability
after orohippus what was next
mesohippus
mesohippus
3 digits on front and back feet but majority on 3rd digit
legs longer
faster
flatlands; so no protection from predators
3 premolars more molar like
sharp crests
better hrinding
after mesohippus what was next
miohippus
miohippus
extra crest in upper molars
after miohippus what was next
parahippus
parahippus
small pony size
still had 3 digits on front and back but digit 3 larger and stronger, most weight bearing
elongated skull
after parahippus what was next
merychippus
merychippus
looked like modern horse
first known grazing horse
still had 3 digits on front and back
high crowned cheek teeth
what was first known grazing horse
merychippus
horse teeth
Have shallow rooted teeth but big crowns and layers different, note enamel and cementum; like its been folded
When worn down there’s v sharp enamel ridges; enables them to grind up grass
after merychippus whats next
pliohippus
pliohippus
v similar to equus
still 3 digits present, but 2 and 5 barley visible
what was the grandfather of modern horse
pliohippus because it gave rise to dinohippus which led to equus
after pliohippus came
dinohippus
dinohippus
closest relative to genus equus
equus
only surviving genus
modern domestic horse
equus caballus
equus fossils found on every continent except
aus and antarctica
2 equus wild species in modern time
tarpan (extinct)
przewalksis horse but actually feral because domesticated by botai culture
domestication occurred
twice, but only one event gave rise to modern horses
early evidence of domestication
botai culture: evidence includes
- cannon bones (metacarpals)
- milk consumption ; milk residue found inside their ceramics
- bit wear on premolars
horses _____ are key indicators of domesticity
metacarpals (cannon bones)
narrower on domestic horses
horses domesticated by botai are
NOT related to modern horse; they gave rise to przewalski’s horse
spread of domesticated horses is aligned with
the sintashta migrating into asia
warrior culture
sintasha conquered central asia with superior horses and chariots
explain the thorough.bred gene
- myostatin gene; inhibits muscle cell growth
- C/C best suited to fast, short distance sprints
- C/T best in middle distance
- T/T greater stamina better for long distance