Lec 14 Flashcards
Order Artiodactyla
“Even-toed ungulates”
Living artiodactyls far more diverse than perissodactyls (240 vs 17 species)
Cetaceans sister to hippos
Suborder Tylopoda Family Camelidae Suborder Suiformes Family Suidae Family Tayassuidae Suborder Ruinantia Family Antilocapridae Family Giraffidae Family Cervidae Family Bovidae Suborder Whippomorpha Family Hippopotamidae Infraorder Cetacea Parvorder Mysticeti (baleen whales) Parvorder Odontoceti (toothed whales)
Order Artiodactyla
Suborder Tylopoda
Family Camelidae
Tylo = soft, poda = foot: Soft-footed
Distribution: Asia, Africa, S America = DISJUNCT distribution
Instead of unguligrade, camels are digitigrade
ONLY extant, fully digitigrade ungulate
Equivalent to human wearing snowshoes
Secondarily digitigrade
Distal-most toe/finger bones come into contact with ground
Disjunct distribution
-Old world deserts and S. America
Secondarily evolved a digitigrade foot posture
Distinctive divergence of metapodials
-Fused 3rd and 4th
60 to 650 kg
Long limbs and neck
Broad diastema
Upper lateral incisor is caniniform
Elliptical erythrocytes
- Protects from dehydration
- -Able to metabolize fat stored into humps to obtain water
- Elliptical shape prevents cells form lysing when camels finally have water available, camels can gulp up water without cells bursting
Miniaturized antibodies
- 1/4 size of typical mammal antibody
- Called “nanobodies” or single-domain antibodies
Adaptation prevents dehydration
Which Metapodial(s) comprise the cannon bone from a horst (F. Equidae)?
Only the third
Order Artiodactyla
Suborder Suiformes
Family Suidae
Pig family
Old world, introduced into almost all regions of the world
Canines are very tusk-like, stick out laterally and curve dorsally
Appear in late Eocene of Asia
Thick bodied, with relatively short limbs
Weigh up to 350kg
Long skull - orbits posterior
Large, tusk-like canines (in some
-Evergrowing, curved upwards
Typically omnivorous
Most have BUNODONT molars
Order Artiodactyla
Suborder Suiformes
Family Tayassuidae
Appear pig-like
Javalinas and peccaries
New world
Tropical forests to deserts
Highly socail
Omnivorous
Rapid, agile runners
Canines do NOT curve upward
Interlocking upper and lower canines
Chacoan peccary “re-discovered” in 1975
Order Artiodactyla
Suborder Ruminantia
Ruminants:
1) Chew their cud
2) Have stomachs with four chambers
3) Selenodont cheek teeth
Includes giraffes, deer, antelope, sheep, goats, and cattle
Generally committed to an herbivorous diet and to highly cursorial locomotion
Headgear present in many taxa
Horns
Hollow sheath of keratinized epidermis with core of bone
Found in sheep and cattle
BOTH sexes
Grow continuously
NOT shed (except in antilocapridae, shed sheath)
True horn: Keratin sheath surrounding bony core, not branched, permanent
Antlers
Branched
Composed of SOLID BONE
During growth, covered with highly vascular soft skin called velvet
usually only males (BOTH have antlers in caribou)
Order Artiodactyla
Suborder Ruminantia
Family Antilocapridae
Monotypic
Entirely North American fossil record
-Endemic to N America
BOTH sexes have horns
External sheath of horn shed annually
Cheek teeth high crowned
Orbits far posterior on skull
-Able to watch for potential predators
Horn is pronged
Hipsodont cheek teeth: used for rough herbivorous diet
Among the fastest cursorial mammals
- Speeds up to 85kmh (53mph)
- Extremely good at long-distance running
- Speeds of 65kph(45mph) over 10k
- Endurance runners
- Evolutionary adaptations for running:
- -Enlarged airways
- -Greater lung surface area
- -Greater capillary density
- -Higher concentration of hemoglobin
Evolved in the presence of the American cheetah; American cheetahs were capable of running up to speeds comparable to modern cheetahs
Order Artiodactyla
Suborder Ruminantia
Family Giraffidae
2 genera and 2 species
Sub-Saharan Africa
Short “horns” covered with fur on parietals
- NOT true horns
- Ossicones formed from ossified cartilage
- -Forms off frontal bone of skull
- Horns never shed
- Horns on both sexes
Elongate neck and limbs in giraffes but not seen in okapi
Ossicones derived from cartilage
-Hair covers these
Order Artiodactyla
Suborder Ruminantia
Family Cervidae
Males have antlers (females too in caribou)
Includes moose, mutjace, caribou, elk, etc.
19 genera
New World, Europe, Asia, NW Africa
Muntjacs, deer, elk, caribou, moose
Early Miocene of Eurasia
All males have antlers
- Antlers grow and are shed annually
- Female caribou also have antlers
Some cervids have short antlers and enlarged canines
-Trade-off b/w antlers and tusks
Antlers grow from frontal pedicles
Antler growth under hormonal control
- Triggered by changes in daylength
- Antlers begin growth in Spring
- Initially covered with “velvet”
- -Fur-covered skin
- Lost after rut
Order Artiodactyla
Suborder Ruminantia
Family Bovidae
50 genera; 150 species
Africa, Asia, parts of Europe and N America
First appear in Oligocene of Asia
Reached New World in Pleistocene
-Crossed Bering Strait land bridge
Primarily grazers
Cheek teeth hypsodont
Canines reduced or absent
True horns
- Keratinized sheath covers bony core
- Horns never branched
- Horns never shed
- Females may bear horns
- -In heavier species
- Used for ritualized sparring and defense from predators
Order Artiodactyla
Suborder Ruminantia
Family Hippopotamidae
Amphibious lifestyle
-Submerged most of the time
Skin glands secrete oily, pink substance
- Hipposudoric acid and norhipposudoric acid
- “Blood sweat”
Orbits and nostrils on dorsal skull
Enlarged tusk-like incisors and canines
Bunodont molars
- What can bunodont molars tell us about thier diet?
- Short-crowned = eating soft aquatic plants
More humans killed by hippos than African lions
Fast on land, very territorial and protective of young
Can open jaws more than 90 degrees
Hippos are gregarious
Spend much of day in water, forage on land at night
Produce a variety of sounds
Profoundly alter their environments
- Overgrazing near waterways
- Create deep channels and paths
