Dichotomous Key/Placentalia

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Parent key: Mammalia

Subclasses

Marsupialia - Monotremata - Placentalia

Key: Mammalia

Orders

Afrosoricida - Artiodactyla - Carnivora - Cetacea - Chiroptera - Dermoptera - Insectivora - Lagomorpha - Macroselidae - Perissodactyla - Pholidota - Primates - Proboscidea - Rodentia - Scandentia - Sirenia - Xenarthra

Dichotomous Key: Mammalia
Kingdom: Animalia Phylum: Chordata Subphylum: Vertebrata Class: Mammalia Subclass: Placentalia

[edit] 1

• Pulp cavity
  • Not present (thin tubes of dentine instead) - Orycteropus afer
  • Present - 2

[edit] 2

• Limbs
  • Adapted for flight or gliding - 3
  • Adapted for land movement or swimming - 4

[edit] 3

• Capability of true flight
  • Yes - Chiroptera
  • No - Dermoptera

[edit] 4

• Limbs adapted for swimming
  • Yes - 5
  • No - 6

[edit] 5

• Legs
  • Present or vestigial - #16
  • Absent - Sirenia

[edit] 6

• Number of fingers
  • Five - Primates
  • Other amounts or none - 7

[edit] 7

• Hooves
  • Present - 10
  • Not present - 8

[edit] 8

• Trunk presence
  • Yes - Proboscidea
  • No - 9

[edit] 9

• Incisors
  • Developed, located at the front of the jaw - 12
  • Undeveloped, side teeth used for grazing - 11

[edit] 10

• Number of toes
  • Any odd number - Perissodactyla
  • Any even number - Artiodactyla

[edit] 11

• Teeth growth
  • Throughout lifetime - 12
  • Only during maturation - 13

[edit] 12

• Number of incisors in upper jaw
  • Four - Lagomorpha
  • Two - Rodentia

[edit] 13

• Presence of bony scales
  • Yes - 14
  • No - 15

[edit] 14

Could be of the order Pholidota or an armadillo (family Dasyopodidae)

[edit] 15

• Dentition
  • Prominent canines and carnassials - Carnivora
  • Other - 16

[edit] 16

• Legs
  • Vestigial - Cetacea
  • Present - #17

[edit] 17

Could be of the orders Afrosoricida, Macroscelidea, Xenarthra, Scandentia, Insectivora, Cetacea