Lec 10, 11, 12 Flashcards
Advent of molecular techniques critical to current understanding for how these groups of carniverons are related
T or F
True
Order Carnivora
When did FIRST carniverous mammals appear
Paleocene (65-55Mya), right after extinction of non-avian dinosaurs (Allowed for massive adaptive radiation)
- Plentiful availability of herbivorous mammals
- -Herbivores evolved around here, too, many plants became available
- Flesh is energy-rich food source
- -Changes in ecosystem allowed for adaptive radiation, too
Order carnivora
Skull adaptations
Expanded braincase
Large conical canines
3/3 incisors
VERY good:
- Vision
- Hearing
Need larger brain to process information
Many are social, need to be able to process relationships
Order carnivora
Have _____________ cheekteeth
Secodont
Blade-like for CUTTING and SHEARING
Carnassials
Present in carnivorans
4th upper premolar, 1st lower molar
Order Carnivora
Jaw Joint
Jaw joint tight to prevent lower jaw from disarticulating from the cranium as the prey is fighting to get away
Tight dentary-squamosal jaw joint
Most Recent (recent time period) carnivorans are PREDACIOUS
Acute sense of smell
Expanded braincase
3/3 incisors (sea otter has 3/2)
Canines large and conical
Carnassials present
Tight joint of dentary/squamosal articulation
Order Carnivora
Suborder Feliformia
Family Felidae
- – Hyaenidae
- – Eupleridae
- –Viverridae
- –Herpestidae
Order Carnivora
Suborder Caniformia
Family Canidae
- – Ursidae
- – Procyonidae
- – Mustelidae
- – Mephitidae
- – Ailuridae
- – Odobenidae
- – Otariidae
- – Phocidae
Order Carnivora
Suborder Feliformia
Family Felidae
Cats
Highly efficient predators
Worldwide except Antarctica, Australia, NZ, Madagascar, and some oceanic islands
Adapted for hypercarnivory
- Rostrum short, blunt
- Reduced number of teeth
- Anterior-most upper premolar is strongly reduced or lost
- Carnassials well-developed:
- -Secodont
Teeth only used for slicing/shearing
Anterior-most premolar REDUCED or LOST
Foot posture DIGITIGRADE
- Common in cursorial mammals
- Only the digits come in contact with the ground
Use sharp claws to capture prey
Few exceptions to retractile claws
Sharp claws recurved and retractile
Catch prey with stealthy stalking and quick burst of speed
Claws are SEMI-retractile in cheetahs
-Use claws as cleats, use to make quick turns
Excellent senses of smell, sight, hearing
Many species nocturnal
- Tapetum lucidum present
- -Reflective layer at retina of eye
- -ANCESTRAL character (even snakes have it)
Order Carnivora
Suborder Feliformia
Family Hyaenidae
Hyenas, aardwolfs
Africa, Turkey, Middle East, parts of India
Large-bodied, forelimbs longer than hind limbs
Robust skull and jaws
Carnassials well-developed
Feet with 4 toes and flunt, non-retractile claws
EXCEPTION:
- Aardwolf:
- -Don’t need robust skulls/jaws or developed carnassials because they eat termites/ants; very delicate skulls compared to spotted, brown, and striped hyenas
Strong saggital crest = very large surface area for temporalis and masseter muscles
Hyena equivalent of a nut-cracker; used to open bones
Aardwolf skull
Reduced dentition, simple cheek teeth
Delicate skull, inflated auditory bullae
Eats soft-bodied insects (ants and termites)
-Would need grinding teeth if it ate hard-bodied insects
Order Carnivora
Suborder Feliformia
Family Herpestidae
Mongooses
Old world distribution
-Introduced elsewhere
Small, long-bodied carnivores
Diurnal, terrestrial
Anal scent glands well-developed
Some species engage in highly structured social behavior
-Constant vigilance allows mongooses to be active during the day despite many aerial and terrestrial threats
Some species known for ability to fight and kill venomous snakes
-Indian gray mongoose fights venomous snakes, has immunity to venom
Jamaican mongooses were introduced by humans to Jamaica
Order Carnivora
Suborder Feliformia
Family Viverridae
Civets and genets
Old World tropical and southern temperate regions
Some are agile climbers, some semiaquatic, others terrestrial
Mostly carnivorous and nocturnal
–Viverrids tend to be more carnivorous
Long rostrum
Large premolars
Tail long and bushy
Well-developed anal glands
Kopi Luwak
Civet poop coffee
$300+/lb
African palm civet
Partially digested coffee beans fermented in digestive tract
This particular civet eats coffee cherries, which contains coffee beans
Order Carnivora
Suborder Feliformia
Family Eupleridae
Adaptive radiation leads to diversification and convergence:
- Cat-like forms
- Mongoose-like forms
- Civet-like forms
- Nocturnal and diurnal species
Includes: Fossa, Malagasy ring-tailed “mongoose”, Malagasy broad-striped “mongoose”
Mostly endemic to Madagascar
-One species not endemic
Most are nocturnal and terrestrial
Fossa is agile climber with retractile claws
-Feeds on small lemurs
The rare falanous has reduced dentition
-Primarily feeds on soft-bodied invertebrates
Order Carnivora
Suborder Caniformia
Family Canidae
Nearly worldwide distribution
Fossils date to Eocene of North America
Broadly adapted carnivores
-Some members only eat insects
Digitigrade
Cheek-teeth for shearing and crushing = indicated broad diet
Robust canines
Carnassials present
Molars retain crushing surfaces
- More flexible diet
- -Omnivores
- –Small or moderate size and usually nonsocial
- -Carnivores
- –Up to 80kg; typically cursorial
- –May or may not be social
- -Insectivores
- –Small and social
Order Carnivora
Suborder Caniformia
Family Ursidae
North America, Eurasia, Malay Peninsula, China, parts of South America, NW Africa (Atlas Mtns, likely extinct)
Large body size
Mostly omnivorous diet (except polar bear and giant panda)
Black bears: Omnivores
Polar bears: Strict carnivores
Panda bears: Primary food source bamboo, can exploit other food sources (insects, chicken, etc.)
Black bear skull: Bunodont cheek teeth (rounded cusps for crushing); supports omnivorous diets
Omnivorous feeding habits, but…
- Polar bear diet restricted to seals
- Giant panda diet mostly bamboo
Northern species may “hibernate”
- Heart rate and metabolism slows
- Live off accumulated fat reserves
- Body temp drops slightly
- Arouse easily
Bears in S CA do NOT “hibernate” because food is plentiful year-round
Giant panda diet mostly bamboo
“False thumb” is an enlarge radial sesamoid
Order Carnivora
Suborder Caniformia
Superfamily Pinnipedia
Used to be in its own order, now in order Caniformia
Highly adapted to marine lifestyle
Large (45-3,600kg)
-Favorable surface area:volume ratio
Body insulated with blubber (fur in some)
Pinnae small or absent
Fusiform body
- External genitalia and mammary nipples withdrawn beneath body surface
- All mammae internal
Tail rudimentary
Forelimbs flipper-like
Monophyletic group:
- Family Odobenidae (walrus)
- Family Otariidae (eared seals)
- Family Phocidae (earless seals)
Probably evolved from bear-like ancestor in the Northern hemisphere 24-18Mya
Highly adapted to a marine lifestyle
Order Carnivora
Suborder Caniformia
Superfamily Pinnipedia
Family Odobenidae
Walrus
Use vibrissae to find mollusks
Mate in the water (just past surfline)
Males congregate at surfline and vocalize, females hear and go out to mate
Both sexes have tusk-like upper CANINES
Feed on mollusks taken from sea floor
Gregarious and polygnous
-1 male mates with a number of females
Groups may reach 1000 individuals
Vocal in and out of water
Purpose of large canines: NOT mating (then it would only be in males); more likely used for diet
Order Carnivora
Suborder Caniformia
Superfamily Pinnipedia
Family Otariidae
Eared seals and sea lions
External ear flaps
Mating systems: Usually harems; males will protect females from being mated with by other males
Sneaker males: Males will wait on outside of harem, slip in when bull male distracted; bull comes over, juvies on other end of harem slip in
Have longest fins, like wings; used for steering; most mobile pinniped on land
Better able to move on land than phocids (true seals); back flippers can move underneath and act as legs
Homodont, peg-like cheek teeth
Notable sexual dimorphism in some species
-Prominent sagittal crest in males
Males 3-4 times larger, sagittal crest increased in size = more muscles
Order Carnivora
Suborder Caniformia
Superfamily Pinnipedia
Family Phocidae
True seals
No external ear flaps
Hind flippers useless on land
Some have a more specialized diet (crab-eater seal, leopard seal)
Order Carnivora
Suborder Caniformia
Superfamily Musteloidea
Ailuridae
-Red panda
Mephitidae
-Skunks and stink badger
Procyonidae
-Raccoon, ringtail, and relatives
Mustelidae
-Weasels, badgers, otters, and wolverine
Order Carnivora
Suborder Caniformia
Superfamily Musteloidea
Family Ailuridae
Red pandas
Monophyletic
-Red panda
Restricted to northern Myanmar and parts of China
Not related to giant pandas
Evolved from Simocyon-like ancestor
-Simocyon was found in N America
Arboreal and largely CREPUSCULAR
Mostly eat bamboo leaves; also berries, flowers, and other plant material
Enlarged radial sesamoid evolved for arboreal grasping (“false thumb”)
Mostly solitary
Endangered throughout their range
-Most is from human influence, some from climate change
Used to be grouped in same family as Giant pandas due to similarities
Giant pandas more closely related to black bears and brown bears
Order Carnivora
Suborder Caniformia
Superfamily Musteloidea
Family Mephitidae
Skunks and stink badgers
Family found in different places around the world
Moderately small: 0.5-4kg
Conspicuously colored
-Black and white spots or stripes
Formerly placed within Mustelidae
Skunks inhabit most of Western hemisphere
Stink badgers (2 species) inhabit Indonesia, Malaysia, and Philippines
Adapted for digging
Muscular legs, long claws
Nocturnal, solitary, omnivorous
Anal glands spray noxious odor
Order Carnivora
Suborder Caniformia
Superfamily Musteloidea
Family Procyonidae
Raccoons, ringtails, coatis, kinkajous
Pro = early, cyon = dog: early dogs
New World - Southern Canada through much of South America
Omnivorous and agile climbers
Plantigrade feet, non-retractile or semi-retractile claws
Dexterous forefeet in some species
Tail long - prehensile in kinkajous
Bunodont cheek teeth indicate omnivorous diet in raccoons
Order Carnivora
Suborder Caniformia
Superfamily Musteloidea
Family Mustelidae
Weasels, stoats, badgers, marein and river otters, wolverine
Nearly cosmopolitan - except Madagascar, Australia, oceanic islands
Typically fairly small, long-bodied carnivores with short limbs and a pushed-in face
Long braincase and short rostrum
Carnassials sectorial in many species
Aggressive hunters
Anal scent glands well developed
Induced ovulation common:
-Typically requires prolonged copulation
Delayed implantation of embryo common
- May be delayed up to 10 months (badgers)
- Implantation of the blastocyst takes place in response to environmental cues
Glenoid/mandibular fossa: Deep, creates tight ball-and-socket joint to have good clamping
Sea otter: Cheek teeth bunodont (used for crushing); they eat invertebrates
Braincase is more than half of the size of the skull
Mate in fall, don’t give birth until spring when snow has melted
Induced ovulation: Occurs as a result of prolonged copulation (usually a traumatic copulation (i.e. males have spines on testicles to induce ovulation)
Nasal turbinates
Delicate, scrolled-up bones in nasal cavity support all of the soft tissue and blood vessels (acts as countercurrent mechanism) needed for good olfaction; exhale through nose to preserve body heat, blood vessels recapture the heat from the air that is being expired
Family Felidae: Summary
Highly efficient predators
Nearly cosmopolitan distribution
Excellent senses of smell, sight, and hearing
Catch prey with stealthy stalking and quick burst of speed
Many species nocturnal
-Tapetum lucidum present in eye
Digitigrade; most have retractile claws
Many species are agile climbers
Most species solitary
-African lions are social - live in prides
Family Hyaenidae: Summary
Africa, Turkey, Middle East, parts of India
Large-bodied, forelimbs longer than hind limbs
Robust skull and jaws
Carnassials well-developed
Feet with 4 toes and blunt, non-retractile claws
Both scavengers and predators
Spotted hyenas form large packs or clans
- Highly social
- Mostly nocturnal
Striped hyenas more omnivorous
Aardwolf feeds on termites
- Reduced dentition, simple cheek teeth
- Delicate skull, inflated auditory bullae
Family Herpestidae: Summary
Old World distribution
Small, long-bodied carnivores
Diurnal, terrestrial
Anal scent glands well-developed
Some highly social species
Some species fight and kill venomous snakes
Family Viverridae: Summary
Old World tropical and southern temperate regions
Some are agile climbers, some semiaquatic, others terrestrial
Mostly carnivorous and nocturnal
Long rostrum
Large premolars
Tail long and bushy
Family Canidae: Summary
Nearly Worldwide distribution
Fossils date to Eocene of North America
Broadly adapted carnivores
Large nasal chamber (excellent sense of smell)
Robust canines
Carnassials present
Molars retain crushing surfaces
-More flexible diet
Limbs generally long
Feet digitigrade
Blunt, non-retractile claws
Family Ursidae: Summary
5 genera and 8 species
Distribution includes: North America, Eurasia, Malay Peninsula, China, parts of South America, northwest Africa (Atlas mountains, likely extinct)
Large body size
Mostly omnivorous diet (except polar bear and giant panda)
-Polar bear is hypercarnivore
Long rostrum
Post-carnassial teeth robust and adapted to crushing
Limbs powerful, feet plantigrade
Claws non-retractile
Tails very short
Superfamily Pinnipedia: Summary
Monophyletic group:
- Walrus
- Eared seals
- Earless seals (true seals)
Probably evolved from bear-like ancestor in the northern hemisphere 24-18 Mya
Highly adapted to marine lifestyle
- Only distal limbs protrude from body
- Torpedo-shaped body
- Orbits large
- Manus and pes fully webbed
- Diving and swimming ability highly advanced
Superfamily Musteloidea: Summary
- Red panda
- -Arboreal and largely crepuscular; mostly solitary
- -Restricted to northern Myanmar and parts of China
- -Mostly eat bamboo leaves; also berries, flowers and other plant material
- -Mostly solitary
- Skunks and stink badger
- -Conspicuously colored (black and white spots or stripes)
- -Adapted for digging (muscular legs, long claws)
- -Nocturnal, solitary, omnivorous
- -Anal glands spray noxious odor
- Raccoon, ringtail, and relatives
- -New World - Souther Canada through much of South America
- -Omnivorous and agile climbers; dexterous forefeet in some species
- -Plantigrade feet, non-retractile or semi-retractile claws
- -Tail long (prehensile in kinkajous)
- Weasels, badgers, otters, and wolverine
- -Nearly cosmopolitan - except Madagascar, Australia, oceanic islands
- -Typically fairly small, long-bodied carnivores with short limbs and a pushed-in face
- -Long braincase and short rostrum
- -Carnassials blade-like in many species
- -Aggressive hunters
- -Anal scent glands well developed
Paenungulata
Nested in superorder afrotheria
Subungulates
CLADE of mammals
Paenungulata = “almost having hooves”
- Ungulata = “having hooves”
- -Hooves = protective coverings made of keratin to protect the distal-most phalanges
- -Hoof AKA unguis
Plantigrade = tarsals, metatarsals, phalanges contact ground
Digitigrade = tarsals, metatarsals, phalanges contact ground
Digitigrade = tarsals, metatarsals raised; just phalanges contact ground
Unguligrade = unguis (hoof covering the distal-most phalanx) only touches ground
Depoperate = NOT very diverse
Order Proboscidea - Elephants
Order Sirenia - Manatees and sea cows
Order Hyacoidea - hyraxes
–Formerly diverse, included huge species
Order Desmostylia - Desmostylians
- Amphibious, hippo-like, had proboscis to stick up over water
- EXTINCT
Common ancestor of paenungulates was probably an amphibious hyracoid that spent a lot of time underwater and used their proboscis for breathing
-Modern elephants do this (up to 6 hrs)
Probably evolved 40-50Mya in the Tethys Sea
Paenungulata: Synapomorphies
NO clavicles
Short nails on digits, four toes on forefeet
All are non-ruminating, herbivorous, hind-gut fermenters
Africa turned into giant island in Late Cretaceous ~70-66Mya
Mammals have fermentation chambers to break down plants
Ruminant = brings food back up to chew again; seen in all foregut fermenters, easy to “burp up” food and chew again
Hindgut fermenters = cecum of large intestine becomes fermentation chamber is NOT present in ruminants (can’t burp it up it it’s behind the gut); all of these are HINDGUT fermenters
Order Desmostylia
Stocky four-legged animals that resembed hippos externally, but their skull structure suggests they are closely related ot elephants and manatees
Ancient paradox: Skull reminiscent of elephant group around this time 40Mya
Assignment of Desmostylia to Afrotheria problematic from a biogeographic standpoint:
- Africa was the locus of the early evolution of the Afrotheria
- Desmostylia fossils have only been found along the Pacific Rim
Order Proboscidea
Elephants
- Fossils record begins in Eocene of North Africa ~50Mya
- Diversifies in late Eocene ~40Mya
- Expands out of Africa in late Oligocene
- Reached North America in Miocene
Modern elephants are NOT diverse, historically VERY diverse
Evolutionary Trends in Proboscidea
Graviportal: Locomotion found in large, heavy mammals; legs are directed directly beneath the mass of the body to support heavy weight
Columnar limbs/graviportal locomotion
Enlarged skull and reduced neck
Elongate proboscis
Incisors become tusk-like
Numerous cross lophs on cheek teeth
Sequential replacement of cheek teeth
Order Proboscidea
Family Elephantidae
Largest living land mammals (up to 7000 kg)
Long, muscular trunk
Large ears (smaller in Elephas)
Digitigrade posture with dense heel pad
-Foot pad: Cushioned layer of connective tissue that the bones rest on
Skull is very high relative to the width
Skull unusually short, high
Contains large air cells
Large air cells allow the skull to be lighter but still have structural integrity
-May also be used in resonance and protection of braincase
Feed on trees, shrubs, grasses, and aquatic plants
Highly social
- Matriarchal kinship groups
- Capable of communicating using infrasound over long distances
- Audible, tactile, and visual communication at short range
Males will travel in groups; as they get older, they get less cooperative with other males
Social unit of elephants is based on related females and their young
Female elephants spend their entire lives in tight-knit matrilineal family groups
22 month gestation - longest of any mammal
Known for memory and ability to recognize selves in mirror
Visit gravesites? Mourn dead relatives?
-We don’t know if they are actually “mourning”
Adult male elephants form bachelor herds or are solitary
Musth
- Periods of heightened aggression and sexual activity in males
- Temporal gland secretions
Cracks in skin: Method to retain water as an evaporative cooling mechanism
-Water is absorbed instead of just going in every direction
Elephant Tooth Replacement
NO canines or incisors in the lower jaw
1 huge cheek tooth gets replaced by posterior cheek tooth
Anterior most end has been broken off and worn down
Elephant teeth are:
- Hypsodont: high-crowned
- Lophodont: Lophs/ridges
- Polyphyodont: Replace teeth multiple times (6)
An elephant will have 6 cheek teeth over the course of its lifetime
There are no more teeth to come after m6; elephants will rarely live past 5 decades because their cheek teeth don’t accommodate that
Elephants in captivity may liver longer due to soft diet
Order Sirenia
Competely aquatic; the paenungulate version of cetaceans
Dugongs and manatees
Completely aquatic herbivores
Fossils date to early Eocene of Jamaica
-Early sirenians likely capable of terrestrial locomotion
2 genera and 4 living species
5th recent species, Steller’s sea cow, became extinct in 1768
Fossils date to early Eocene of Jamaica
-Early sirenians likely capable of terrestrial locomotion
Distribution around the world:
-East coast of N and C America, African coasts, European coasts
Weighs over 1500kg (3000lbs)
Nearly hairless, thick skin
Nostrils Valvular
-Found in aquatic and semi-aquatic mammals; can close nasal openings to preven water coming in
Deep dentary bone
Middle ear bones massive
Horizontal orientation of lungs
-Allows for even buoyancy; if it was only in chest, only chest would have ballast
Dense, heavy bones provide ballast
- Ribs are pachyostotic (thick)
- Ribs, limbs, neural arches are osteosclerotic (dense)
- Ballast = lets them sink down, obtain neutral buoyancy
Only completely aquatic herbivores
Inhabit coastal seas, large rivers and lakes
Make complex sounds
Long-lived with low reproductive rate
Slow moving grazers
Slow metabolism and little body fat
-Restricted to warmer waters
2 families
Synapomorphies:
1) 5-toed manus enclosed in flipper
2) Pelvis reduced
3) Hind limbs absent
4) Tail is horizontal fluke
Order Sirenia
Family Trichechidae
Manatees
Rounded, spoon-shaped tail fluke
Only 6 cervical vertebrae
No functional incisors
Cheek teeth covered with enamel
Indefinite number of cheek teeth
-Replaced from behind as needed
Order Sirenia
Family Dugongidae
Dugongs
Notched flukes
7 cervical vertebrae (normal number)
Incisors present, tusk-like
Cheek teeth large, columnar, and covered with cementum (no enamel)
2-3 cheek teeth in each jaw quadrant
Teeth NOT indefinite
Tusk-like incisors
Order Hyracoidea
Family Procaviidae
Hyraxes
Africa and Middle East
Earliest fossils from Eocene of Morocco (Northwestern Africa)
Diverse in Paleogene of Africa
-Mouse-sized to horse-sized
Diversity declined in Miocene
- May have resulted from competition from ungulates that first appeared at this time
- Diversity declined, possible due to ungulates; ungulate foregut fermentation more efficient in obtaining nutrients
Tree hyrax:
- Solitary
- Arboreal
- Mostly nocturnal
Rock hyraxes:
- Live in family groups
- Inhabit kopjes
- Mainly diurnal
- use each other’s body heat to stay warm
Rabbit-sized
Deep mandible
Incisors ever-growing, tusk-like
Diastema present
herbivorous
Nimble climbers
Use behavioral thermoregulation (basking)
Rock hyraxes
- Diurnal with polygynous family groups
- -Females will care for other young (even of different species!)
- Heterohyrax and Procavia share rock outcrops and share nurseries (mixed groups of young)
Elastic pads on soles of feet = allow for better traction
Note nails on front feet
-Nails are a paenungulate feature
