Lab #7: Mammal bones - Feet

Question 1

Manus = xxx
Pes = xxx

Answer 1

Manus = FOREFOOT
Pes = HINDFOOT

Question 2

Animal feet is closely linked to different …

Answer 2

locomotion strategies
-> bone structure, joint configuration, digit number, overall shape evolving to optimize movement in specific environments

Question 3

TERRESTRIAL animals walk differently depending on how much of their foot touches the ground. This results in 3 main foot postures. What are they?

Answer 3

(1) PLANTIGRADE
(2) DIGITIGRADE
(3) UNGULIGRADE
-> Do not strictly apply to marine mammals

Question 4

(1) PLANTIGRADE

Answer 4

ENTIRE FOOT (heal/talon to toe) contacts the ground
-> e.g. humans, bears, gorillas

Question 5

(2) DIGITIGRADE

Answer 5

Animals walk ON ITS DIGITS, the heel is lifted off the ground
-> e.g. dogs, cats

Question 6

(3) UNGULIGRADE

Answer 6

Only the TIP of the digits (hooves) touch the ground
-> Fused or reduced bones in the lower limb (e.g. cannon bone)
-> e.g. horses, deer, antelopes

Question 7

What about marine mammals? are they plantigrade, digitigrade or unguligrade?

Answer 7

SOME marine mammals DO retain a PLANTIGRADE-like stride on land
-> seal and sea lions “walk” using entire limbs placed flat on the ground, especially their hind flippers

Question 8

In animals, the FOREFOOT (MANUS). is comprise of … (3)

Answer 8

(1) Carpals
(2) Metacarpals
(3) Phalanges

Question 9

Carpals def

Answer 9

Small bones that make up the wrist
-> Often arranged in rows

Question 10

Carpals articulate with the … proximally and the … distally

Answer 10

radius/ulna, metacarpals

Question 11

Metacarpals def

Answer 11

Long bones that extend from the wrist to the base of the phalanges.

Question 12

Most mammals have …. metacarpals

Answer 12

5
-> one for each digit
-> number can vary depending on evolutionary adaptations (e.g. artiodactyls have the cannon bone)

Question 13

The HINDFOOT (PES) includes…

Answer 13

Tarsals (aka ankle bones), (metatarsals, phalanges)

Question 14

Tarsals: form the joint between the … and the …

Answer 14

tibia/fibula, metatarsals

Question 15

The most prominant tarsals are: (2)

Answer 15

Calcaneus & Astragalus

Question 16

Calcaneus & Astragalus help for the …

Answer 16

ankle joint

Question 17

Each digit typically has multiple …

Answer 17

phalanges
=> Their shape and number are often highly specialized (e.g. in ungulates, phalanges support hooves - sabots)

Question 18

Most mammals have … phalanges per digit

Answer 18

3 (proximal, medial, terminal/distal)
-> Though the THUMB usually has two

Question 19

Phalanges function

Answer 19

Allow for the articulation at the joints of the digits, enabling grasping, walking, perching, running… (depending on species)