Ungulates

Question 1

‘Ungulates’ are comprised of what taxonomic groups?

Answer 1

Artiodactyla (even-toed ungulates)
o Pigs, hippos, camels, ruminants)

Perissodactyla (odd-toed ungulates)
o Rhinoceros’, hippos, tapirs

Question 2

Key characteristics of the order Artiodactyla feet and toes

Answer 2

o 1st digit lost (only 4 toes)
o Cloven-hoof (2 weight-bearing toes)
o Toes 3 & 4 well-developed, 2 and 5 reduced or absent
o Plane of symmetry passes between toes 3&4

Question 3

Key characteristics of the order Artiodactyla teeth

Answer 3

o Upper incisors always reduced or absent
o Canines small or incisorform
o Cheek teeth tend to be selenodont

Question 4

Key characteristics of the order Artiodactyla Stomach

Answer 4

o 4-chambered??

Question 5

What are ‘Cetartiodactylas’?

Answer 5

• The combination of artiodactyla and cetaceans into one order because of fossil-evidence

Question 6

What are the two suborders of Artiodactyla?

Answer 6

Suiformes (non-ruminants)
o Pigs, hippos, peccaries

Ruminantia
o Ruminants – 4 chambered stomachs

Question 7

What are the three families that comprise the ruminants?

Answer 7

Cervidae
o Moose, elk, mule-deer, white-tailed deer, caribou

Bovidae
o Bison, mountain goats, bighorn sheep, thinhorn sheep, cows

Antilocapridae
o	Pronghorn (not in bc – ab/sk)

Question 8

How do Perissodactylas vary from Artiodactylas with respect to feet & toes?

Answer 8

• 3rd digit is most prominent (plane of symmetry passes through this digit)
• First digit is lost in all species
• Horses have single functional toe on each foot, rhinos have 3
• Unguligrade: heel and sole of foot never touches ground

Question 9

How do Perissodactylas vary from Artiodactylas with respect to teeth

Answer 9

• Lower canines usually present

- Lophodont

Question 10

How do Perissodactylas vary from Artiodactylas with respect to stomach

Answer 10

• Mono-gasteric stomach (no chambers)

- Enlarged cecum (hind-gut fermenters)

Question 11

Define selenodont

Answer 11

Lophs run side to side to create more surface area

Question 12

Define lophodont

Answer 12

Have lophs that run between cusps (elongated ridges)

Question 13

Define brachyodont

Answer 13

Low-crowned teeth (humans)

Question 14

Define hypsodont

Answer 14

high-crowned teeth, lots of extra material for wear (cows and grazers)

Question 15

Define bunodont

Answer 15

cheek teeth with low-rounded cusps

Question 16

Define aquatic

Answer 16

Animals swim (otters)

Question 17

Define volant

Answer 17

Animals glide

Question 18

Define Cursorial

Answer 18

Animals that run rapidly for long distances

Question 19

Define scansorial

Answer 19

Animals are climbers (mountain goats and woodpeckers)

Question 20

Define arboreal

Answer 20

Animals spend most of their time in trees (squirrels)

Question 21

Define saltatorial

Answer 21

Animals are hoppers (Deer mice)

Question 22

Define fossorial

Answer 22

Animals are diggers, live in burrows (pocket gophers, badgers)

Question 23

What two factors determine speed an animal can travel?

Answer 23

• Length of stride

- Rate of stride

Question 24

Describe the 4 main adaptations to lengthen stride – be as thorough as possible

Answer 24

Length of stride: based on three basic patterns of cursorial movement (above)

Lengthen limb elements
o Elongation of metapodials (metatarsals + metacarpals)

Include the scapula as part of the limb
o Allows scapula to absorb shock as opposed to rest of body
o Clavicle is reduced or lost in animals that do this

Flexing the spine
o Bounding or galloping

Question 25

Describe the 2 main adaptations for increasing frequency of steps – be as thorough as possible

Answer 25

# of joints
o	Each new joint yields increase in foot speed

Muscles acting on bones behave as force and lever systems
o Muscles close to joints move joint through wide angle and make bones move faster

Question 26

What are the 4 main chambers of a ruminant’s stomach and what are the purpose of each chamber?

Answer 26

Rumen
o Fermentation chamber
o Anaerobic environment, constant temp and pH
o No bacterial juices but does have bacteria and protozoa which can break down cell walls
o About 70% of cellulose is absorbed directly into the bloodstream from the rumen

Reticulum
o Compacts food into cuds for further breaking down by teeth

Omasum
o More breakdown by bacteria and micro-organisms

Abomasum
o The true stomach
o Has glands that secrete hydrochloric acid, pepsin, lipase
o Secretes lysosome – breaks down bacterial cell-walls
o Plant protein is transformed into animal protein

Question 27

When and where does rumination occur and why are these an advantage?

Answer 27

• Rumination typically occurs when the animal is resting and not eating, which is a considerable fraction of the animals lifespan

Question 28

How does digestion vary between artiodactylas and perissodactylas?

Answer 28

• Perissodactyls are hind-gut fermenters With only 1 chamber
• Microbial symbionts in caecum help break down cellulose
• Purpose of caecum is to ferment complex carbohydrates of the herbivorous animals into fatty acids and to absorb these for use in the body

Question 29

How do antlers and horns vary from each other, with respect to:
Taxonomic group and genders containing them

Answer 29

Antlers:
o Found in Cervidae
o Only in males

Horns:
o Occur in all male species of Bovidae (often females)
o Present in both sexes often for large species but only male for small

Question 30

How do antlers and horns vary from each other, with respect to
Structure

Answer 30

Antlers:
o Bony, branched structures
o Shed annually

Horns:
o Bony core with a sheath of Keratin
o Horns are never branched

Question 31

How do antlers and horns vary from each other, with respect to
How they grow

Answer 31

Antlers:
o	Grow from pedicels
o	Regulated by testicular and pituitary hormones
o	Start growing in April or May
o	Grow with skin and hair (velvet)
o	Velvet dies
o	Pituitary hormone stimulation decreases in winter (day-length)
o	Pedicel loses calcium and antlers shed

Horns:
o Horns never shed
o Start as ossicones (small lumps of cartilage)
o Fuse secondarily to skull bones

Question 32

What triggers the antler growing process?

Answer 32

• Testicular and pituitary hormone

Question 33

What family do antelope belong to and how does this family vary from other members of the artiodactyla?

Answer 33

• Antilocapridae
  o Horns are branched
  o Consist of a bony core and keratin sheath but sheaths are shed annually