exam 3 big notes
Lecture 11 -Afrosoricida, Eulipotyphla, Macroscelidea, Scandentia, and Dermoptera
At one time Order Insectivora contained 6 families but then was split into 3 orders:
Many of the characteristics of this assemblage are ancestral, and polyphyletic
Afrosoricida - golden moles, tenrecs, otter shrews
Erinaceomorpha - hedgehogs, gymnures
Soricomorpha - solenodons, shrews, moles and desmans
This group share the following characteristics:
Generally small
Pentadactyl with plantigrade locomotion
Long rostrum (snout)
Pelage is consisted of only guard hairs (modified as spines in some forms)
External pinnae are small or absent
Small braincase with smooth cerebral hemispheres
Auditory bullae are absent - ring-shaped tympanic bone
Testes are usually abdominal or if in scrotum = anterior to penis like marsupials
Cloaca present in some
Jugal is reduced or absent
Pubic symphysis is reduced
Some retain tribosphenic molars = close-rooted teeth
Their molars are either W-shaped (dilambdodont) or V-shaped (zalambdodont)
3.1.4.3 (44 teeth)
To add to the confusion, recent molecular analysis suggests placing Afrosoricida in the SuperOrder Afrotheria
Now we have a new “order” = Eulipotyphla (Insectivora)
Family Solenodontidae - solenodonts
Family Talpidae - desmans, moles, shrew moles
Family Soricidae - white-toothed shrews, red-toothed shrew, African white-toothed shrews
Family Erinaceidae - hedgehogs, moonrats and gymnures
Three other orders were in the Order Insectivora:
Macroscelidea - elephant shrews or sengis
Scandentia - tree shrews
Dermoptera - colugos
Order Afrosoricida:
Family Tenrecidae - tenrecs and otter shrews
All 27 species of tenrecs are restricted to Madagascar
Have a cloaca
Body temperature sufficiently low that they don't require a scrotum to cool the sperm
Heterothermic
Web-footed tenrec = semi aquatic
Stridulation = rubbing together body parts (specialized quills on their backs) to make a high pitched ultrasound to call each other
Also communicate using tongue clicks
50-64 days gestation period with relatively underdeveloped young
Females usually have 12 teats but some species have up to 30
Otter shrews are found in west-central Africa
Resemble river otters
Giant otter shrew = largest living insectivore (even though it is carnivorous)
Flaps covering nostrils and feet are not webbed
Family Chrysochloridae - golden moles
Live almost exclusively underground
Short legs with powerful digging claws, dense fur and toughened skin (specially on the head)
Eyes are non-functional and covered with skin and fur
Have enlarged leather-like pad to protect nostrils (like marsupial moles)
Some species swim through loose sand and some construct permanent and complex burrows
Grant’s golden mole → during very hot weather, they retreat to depths of around 50 cm and enter a state of torpor to conserve energy
Skull characterized by early fusion of cranial bones and wedge shape
Well developed zygomatic arches and zalambdodont upper molars
Low metabolism and efficient renal function = reduce water requirements so most species don't need to drink
Primary sense is touch, have disproportionately large auditory ossicles for detecting ground vibrations
Order Eulipotyphla:
Family Erinaceidae - hedgehogs, gymnures
Hedgehogs = barbless spines
nocturnal , terrestrial or semi arboreal
Spines are soft at birth and harden after
Perform anointing → encounters a new scent, licks and bites the source forming a froth in its mouth and pastes it on its spined with its tongue
This camouflages the hedgehog with the new scent and provides possible poison/infection to predators
Erinaceus europaeus → only insectivore to use true hibernation
Gymnures, hairy hedgehogs or moon rats = no spines
Body plan believed to resemble that of earliest mammals:
Large toothy head, naked hairless tail (balance and thermoregulatory purposes) and plantigrade stance
Gymnures = primarily carnivorous, nocturnal, use smell to find prey
Family Solenodontidae - solenodons
2 species, 1 restricted to Cuba and the other one to Haiti and Dominican Republic
Venomous, nocturnal, burrowing, insectivorous mammals
Submaxillary glands that produce toxic saliva which flows into the bite via grooved 2nd incisor
Look like very large shrews:
Elongated cartilaginous snouts, long naked scaly tails, small eyes and coarse dark hair
Haitian solenodon ⇒ has ball and socket joint at the base of snout to increase mobility
May be capable of echolocation (high frequency clicking sounds)
Family Talpidae - moles, shrew-moles, desmans
Ranges from fossorial shrews and moles to semi-aquatic desmans
Shrew-moles = smallest of the family are fossorial but also forage on surface and can climb small shrubs
Neurotrichus gibbsii → smallest North American shrew-mole
Mole’s diet = earthworms and small invertebrates in the soil using their toxic saliva that paralyzes the prey (which can be stored for later consumption)
Use underground “larders”
Fossorial morphology:
Modification of pectoral girdle and appendages (rotation of the fore-feet)
Pinnae reduced or absent
Keeled sternum
Fusiform
Small eyes
Most talpid moles appear to have six fingers on each foot but actually have five
Real thumb looks like the other four fingers and what appears to be the thumb is actually a larger than normal version of the radial sesamoid bone of the wrists (like pandas)
Star-nosed moles have Eimer’s organs ⇒ eleven pairs of pink fleshy appendages on their snout used as a touch organ with multiple sensory receptors
Desmans → small and semi aquatic that construct burrows in banks of bonds/streams
Functionally blind like other moles and obtain sensory input from the touch sensitive Eimer’s organs
Webbed hind feet and flattened tail for swimming
Family Soricidae - shrews
2 subfamilies:
Soricinae ⇒ red-toothed shrews
Crocidurinae ⇒ white-toothed shrews
2 forms have webbed feet (Nectogale elegans and Sorex palustris)
Most have short legs, platingrade, small eyes, pointed rostrum, short dark pelage
No auditory bullae
No jugal = incomplete zygomatic arch
Red-toothed shrews have a characteristic pigmented enamel (due to iron pigment to harden to enamel)
Dentation:
First upper incisor = hooked and posterior cusp
First lower incisor = long and procumbent
Upper molars are dilambdodont
Only one set of teeth throughout their lifetime
Shrews are opportunistic predators - eat anything that is available
Very active animals with voracious appetites and unusually high metabolic rates (eat 80-90% of their body weight daily)
Generally terrestrial but some can climb trees, live underground or even hunt in water
Small eyes which means poor vision but have excellent hearing and smell
Do not hibernate but are capable of entering torpor, can lose a lot of body weight during the winter
Some species of shrew (Blarina and Neomys) are venomous conducted into the would by grooves in the teeth
Blarina’s saliva contains a protease used to paralyze and subdue/kill its prey
Only non-flying terrestrial mammals known to echolocate = two genera of shrews (Sorex & Blarina) and the tenrecs
Shrews emit ultrasonic squeaks, low amplitude and frequency modulated (unlike bats)
Contain no echolocation clicks with reverberations and are used for simple, close range spatial orientation
Shrews only use echolocation to investigate their habitat rather than pinpoint food
Order Macroscelidea - elephant shrews or sengis
Long flexible snout, large eyes and ears
Live in pairs (solely for reproduction) and defend territories
Important differences between elephant shrews and “insectivores”:
Have auditory bullae and complete zygomatic arches
Olfactory lobes of the brain are small
Have a cecum
Are mouse to rat-sized
Have large eyes and ears
Have a long and mobile snout
Have high-crowned cheek teeth (hypsodont)
Molars are quadrate and dilambdodont
During hot weather they become nocturnal to avoid the heat, reduce energy and water losses
During cold weather they undergo periods of torpor where their body temperature and metabolic rate drops
Order Scandentia - tree shrews
Were considered part of the Order Insectivora for a long time then moved to the Primates due to certain internal similarities:
Large braincase, postorbital bar
Scrotal testes
Similar structure of carotid and subclavian arteries
Tribosphenic molars, lower procumbent incisors (used for grooming)
Unperforated palate
2 families:
Family Tupaiidae - treeshrews
Omnivorous with poorly developed canines and unspecialized tribosphenic molars
Upper molars are dilambdodont
Lower incisors are procumbent and used for grooming
Have good vision (binocular in more arboreal species)
Family Ptilocercidae - pen-tailed treeshrew
Malaysian pen-tailed treeshrew ⇒ chronically consumes alcohol
Drinking naturally fermented nectar of the Bertam palm (used to make palm wine) but does not become intoxicated (metabolized by a pathway not used by humans)
Order Dermoptera - flying lemurs or colugos
Family Cynocephalidae:
Classified with bats, primates and insectivores in the past
2 genera (Cynocephalus and Galeopterus)
Colugos have a large patagium that runs from the shoulder blades to the fore-paw (gliders)
Have a keeled sternum
Herbivores with a well developed ceca (4x body length) and intestines (9x body length) which helps them extract nutrients from leaves
They are very specialized arboreal folivores with long gut retention times
Lack opposable thumbs so are very clumsy climbers
Have procumbent lower incisors that are very distinctive = comb-like in shape (pectinate)
Second upper incisors have two roots which is unique among mammals
Young are born after 60 days of gestation and are very small and undeveloped, spend a lot of time clinged to mother’s belly (take a long time to mature)
Lecture 12- Chiroptera
Bats were formerly lumped into Superorder Archonta and Superorder Laurasiatheria
Laurasiatheria → group based on DNA analysis
Order Erinaceomorpha -hedgehogs and gymnures
Order Soricomorpha - moles, shrews, solenodons
Order Cetartiodactyla - combined Cetacea and Artiodactyla
Clade: Pegasoferae (derived from pegasus)
Order Pholidota - pangolins or scaly anteaters
Order Chiroptera - bats
Order Carnivora - carnivores
Order Perissodactyla - odd-toed ungulates
Phylogeneticists have proposed an alternate view of chiropteran phylogeny and classification but more research is needed
Genetic evidence indicates megabats belong in one of four major lines of microbats with two new suborders based on molecular data:
Suborder Yinpterochiroptera ⇒ includes megabat family (Pteropodidae) as well as Rhinolophidae, Hipposideridae, Megadermatidae, Rhinopomatidae and Craseonycteridae
Suborder Yangochiroptera ⇒ includes all the remaining families of bats (all that use laryngeal echolocation)
This Chiropteran phylogeny is controversial because it implies two unlikely hypotheses:
1. Suggests laryngeal echolocation evolved twice in Chiroptera, once in Yangochiroptera and once in the rhinolophids
2. Suggests laryngeal echolocation had a single origin in Chiroptera but was subsequently lost in the family Pteropodidae (all megabats that use tongue clicks instead) and later evolved as a system of tongue clicking in the genus Rousettus
About 70% of bats are insectivores while the rest are frugivores
Few species are carnivores or piscivorous, many are nectarivorous and one group is sanguinivorous
All these feeding habits are found in the Family Phyllostomidae
Bats are present throughout most of the world and perform vital ecological roles (pollinating, seed dispersal)
Range from smallest = bumblebee bat to largest =“large flying fox” (among the largest species by wingspan)
Morphology:
Under the old classification scheme, size was an obvious distinction between the two suborders except that the size ranges overlapped
Other differences:
Microchiropterans:
Use echolocation
Primarily insectivores
Tragus often well developed
Nose/facial ornamentation often evident
helps direct echolocation pulses
Generally small body size with small eyes
Megachiropterans: (old world fruit bats)
No echolocation except genus Rousettus
Primarily frugivores or nectivores
No tragus, continuous inner ear margin
No nose or facial ornamentation
Generally large body with large eyes
rely more on vision
Skeletal modifications for flight:
Elongation of the radius, metacarpals and phalanges and reduction of the ulna
Radius cannot rotate and the wrist only moves forward and backward
Flexion and extension
Last cervical and first two thoracic vertebrae are fused
T-shape manubrium (top of the sternum) and first two ribs form a rigid pectoral ring to anchor of the wings
Scapula, pectoral ring and humerus interlock for flight
Calcar supports the uropatagium
Hind limbs rotate 180 degrees so knees point backward
Legs are attached so the knees bend opposite way of humans
Enables bats to move more rapidly on all fours or squeeze into narrow crevices
For species with a tail membrane = backward flexing knees enables them to move the attached membrane downwards in flight to aid food catching and aerial maneuvering
Vision and olfaction:
Most microbats have small and poorly developed eyes (poor visual acuity) but none are blind
Vision is used to navigate long distances beyond the range of echolocation
Some species are able to detect ultraviolet light
They also have excellent senses of smell and hearing
Hunt at night to avoid competition with birds
Wings:
Finger bones are much more flexible than other mammals since the cartilage in their fingers lacks calcium near the tips increasing their ability to bend without splintering
Cross-section of the finger bone is flattened and very flexible
Humans have a circular cross-section
Skin on wing membranes has more elasticity
Wings are thinner than birds so they can maneuver more quickly and accurately than birds (also very delicate but can regrow)
Their wings have Merkel cells ⇒ touch sensitive receptors on small bumps found in most mammals (human finger tips), these allow the bat to detect and collect information about the air flowing over its wings
Different kind of stretch receptor cell found in the wing membrane of species that use their wings to catch prey
Other attributes:
Teeth of microbats resemble insectivorans → very sharp to bite through hardened armor of insects or skin of fruit
All mammals have one-way valves in veins to prevent blood from flowing backwards
Bats also have one-way valves in arteries
Some have very long tongues → beneficial in terms of pollination
When the tongue retracts it coils inside their rib cage
Flight:
High degree of maneuverability facilitated mode of foraging for insects not exploited by birds → fly slower than birds
In order to fly = generate lift → overcome gravity
Reduce drag → sufficient thrust and aerodynamics of wings
Avoid stalling → sufficient thrust and aerodynamics of wings
Aspect ratio = proportion of wing length to width
High aspect ratio ⇒ long, narrow wings = sustain fast flight
Low aspect ratio ⇒ short, wide wings = maneuverability, slower
Wing loading → ratio of body mass of bat to total surface area of wing
Lower wing load = more maneuverability
Echolocation:
Perceptual system where ultrasonic sounds are emitted specifically to produce echoes
By comparing outgoing pulse with returning echoes = brain and auditory nervous system can produce detailed images of bat’s surroundings
Allows bats to detect, localize and classify their prey in complete darkness
Bat calls are some of the most intense airborne animal sounds
Physical aspects of sound and sound modulation:
Amplitude = volume
Frequency = pitch
Pulse duration
Interpulse interval
Two functions necessary for active echolocation:
Sending and receiving
Bats emit two types of ultrasonic signals:
Constant frequency
Longer pulse
No frequency modulation
Ex: horseshoe bat (Rhinolophus sp)
frequency -modulated sweep or broadband
Short pulse (<5 ms)
Range of frequencies
Ex: big brown bat (Eptesicus)
Target information obtained through echolocation:
Distance:
Time between pulse emitted and echo received
Use rapid frequency-modulated sweeps
Gives other info as well
Pulse-echo determination at higher frequencies
Absolute size:
Computed from distance (pulse-echo delay) and angular size (amplitude)
Elevation:
Competed from two cues, compare echoes
Received when:
Ears are moved to various positions
Ear flaps in pinnae are opened variably (can pick up the angle of elevation)
Velocity:
Computed from Doppler shift of echo frequency
Doppler shift = perception of the sound frequency shifts
↑ on approach = waves compress
↓on retreat = waves expand
Reproduction:
Most have a single breeding season
spring for species that live in temperate climate
One to three litters in a season depending on species and environmental conditions
Females have one young at a time since female needs to fly while pregnant
They nurse their young until nearly adult size since they cant forage on its own until wings are fully developed
Females use a variety of strategies to control timing of pregnancy and birth of young to coincide with maximum food availability and other ecological factors
Some species have delayed fertilization = sperm is stored in reproductive tract for several months after mating
Mating occurs in the fall and fertilization does not occur until following spring
Some have delayed implantation = until external conditions become favorable for giving birth and caring for offspring
In another strategy fertilization and implantation both occur but delayed fetal development until favorable conditions
Feeding:
Majority of food types consumed by bats:
Insects
Aerial insectivores
Bat catches insect mid-air with its mouth and eat it in the air or uses its tail membrane/wings to scoop insect (takes it back to roost)
Forage gleaners
Bat flies down and grasps prey off the ground with their teeth and take it to nearby perch to consume
These usually don't use echolocation to locate prey, rely on sounds instead
Fruits and flower nectar
Frugivory is a habit found in two families (megachiroptera and microchiroptera)
Fruits preferred are fleshy and suit but not particularly smelly or colorful
They pull the fruits off the trees with their teeth and fly it back to the roost
Seed dispersal
Some specialize on nectar and have long muzzles and extrusible tongues with fine bristles
Helps pollination by having pollen get stuck on their fur and dusted off
One species of rainforest vine has evolved specialized acoustic features = dish-shaped leaves to attract bats
Leaves are efficient at bounding back the sound pulses bats use to navigate
Vertebrates
Typically eat a variety of animals but normally frogs, lizards and birds
Some feed on fish by using echolocation to detect ripples in the water’s surface and swoop them with their enlarged hind feet claws
Blood
Sanguinivorous = include common vampire bat, white-winged vampire bat and hairy-legged bat
Capable of using heat-adapted nerves on upper lip and nose
TRPV1 = heat-sensitive molecule that helps them detect high temperatures
Track where the vein is so they dont waste energy trying to locate it
Drinking:
Bats do drink water ⇒ skim the surface of a body of water and lowers its jaw to drink
Families:
Pteropodidae → flying foxes
Roost in large numbers in trees
All species of flying foxes feed on = nectar, poller and fruit
Explains their limited tropical distribution
They do not use echolocation
Foxlike face with long snout
Smell and eyesight are very well-developed
Navigate visually (large eyes) and may be sensitive to UV light
Mostly nocturnal but some diurnal
Crashes into foliage to grab food
Microchiroptera
Small size with small eyes
Rostrum specialized
Ears have tragus
Postorbital process small
Dentition varies and most are insectivorous
Rhinolophidae → old world horseshoe bats
Distinct facial ornamentation (horseshoe shape)
Insectivorous
Agile fliers
Hipposideridae → old world leaf-nosed bats
Live in arid desert environments
Distinctive facial ornamentation
Insectivorous
Megadermatidae → false vampire bats
No upper incisors
Prominent nose-leaf, large eyes and ears and a wide uropatagium but no tail
Primarily insectivorous but also eat wide range of small vertebrates
Rhinopomatidae → mouse-tailed bats
Very long tails
Insectivorous
Become torpid during cold weather but don't truly hibernate
One or two young per year
Craseonycteridae → bumblebee bat
Smallest species of bat and mammal
Solitary and insectivorous
Pig-like snout (hog nosed)
Large uropatagium to help flying and catching insects but no tail bones or calcars to help control during flight
Nycteridae → slit-faced or hollow-faced bat
Grouped in a single genus = Nycteris
Long slit through the center of their faces from between the eyes to the nostrils (may assist with echolocation)
Large ears and complex nose-leaf
Tail ends in a T-shape
Unique feature among mammals
Emballonuridae → sac-winged bats
Sac in propatagium (near elbow) that may be glandular
Prominent in males due to pheromones
Colonies have a single male with multiple females
Phyllostomidae → new world leaf-nosed bats
Most varied and diverse family within order Chiroptera
Most species are insectivorous but phyllostomid bats include true predatory species as well as frugivores
Ex: spectral bat (Vampyrum spectrum) is the largest bat in the Americas and eats vertebrate prey including birds
Names derive from their often large lance-shaped noses (reduced in some nectar and pollen feeders)
Echolocate nasally and their nose-leaf is thought to serve some role in modifying and directing the echolocation call
Species without the nose-leaf usually have a prominent lip
Most roost in fairly small groups and do not hibernate
Some of these bats are referred to as short-tailed fruit bats
Mormoopidae → mustache or naked-backed bats
Insectivorous with long narrow wings for fast flight
Leaf-like projection from their lips instead of nose
In some species, the wing membrane join over the animal’s back making it appear hairless
Noctilionidae → bull-dog or fishing bats
Hindlimbs large with sharp recurved claws
Furipteridae → smoky or thumbless bats
Only two species = smoky bat and thumbless bat
Closely related to the bats in Natalidae and Thyropteridae
Reduced and functionless thumbs enclosed by wing membranes
Broad funnel-shaped ears
Thyropteridae → disk-winged bats
Sucker discs on thumbs and feet
Tail does not extend beyond uropatagium
Reduced thumbs, funnel-shaped ears
Myzopodidae → old world sucker-footed bat
Only found in Madagascar
Suction cups on wrists and ankles that allows them to roost inside rolled leaves
Suction cups appear to have evolved independently
Toes only have two phalanges and are united for most of their length
Mystancinidae → new zealand short-tailed bats
Most “un-batlike”
Spend too much time on the ground and are unique in being able to fold their wings into a leathery membrane when not in use
Have a projection on some claws to help digging or climbing
Lesser short-tailed bat → one of the only two bats in the world that use a lek breeding system
Males aggregate close to groups of females for the purpose of sexual display
Males also cover themselves in their own urine to attract females
Hammerhead bat ⇒ the other species that uses leks
Vespertilionidae → common bats
Most widely distributed
Small eyes, nose-leaf usually absent, large ears, well developed tragus
Adapt well to urban areas
Species hibernate in temperate regions
Mollosidae → free-tailed bats
Large eyes that point forward
Tragus but no nose-leaf
Tail extends well beyond posterior border of uropatagium
Don't hibernate but may migrate
Natalidae → funnel-eared bats
Adult males have glandular “natalid organ” on the forehead with unknown function
Ears are broader and shaped like three-quarters of a funnel
13 different species of bats documented in Florida:
Family Vespertilionidae (common bats)
Family Molossidae (free-tailed bats)
Most common solitary roosting bats in northern Florida ⇒ eastern red bat
Unlike most bats, sexually dimorphic in color (males are brighter)
Inhabit forests, forest edges and hedgerows
Another common solitary roosting bat ⇒ Seminole bat
Found throughout the state and are a deeper auburn-mahogany color
Found in lowland, semi-forested and forested areas
Emerge early to forage
Northern yellow bat ⇒ most common species of solitary bat found in southern Florida
yellow/dirty blonde colored and larger than red and seminole bats
Roost in Spanish moss, specially in longleaf pine and oak trees
Forage over open areas favoring forest edges, pastures, lake edges and golf courses
Hoary bat ⇒ fur is a mixed brown-gray color with heavy white fringe (frosted appearance)
Not considered residents since are only found in Florida during spring and autumn when they migrate to and from Mexico and South America
Forage above treetops along streams, lake shores and urban areas where there are a lot of trees
Only 3 Florida species use caves for roosts:
Gray bats live in caves year-round
Forage over riverbanks and often over water
Southeastern myotis
Eastern pipistrelle
Florida's smallest bat, individual hairs are tri-colored
Big brown bat ⇒ found in a wide range of habitats of the northern two-thirds of Florida
Rafinesque’s big-eared bat ⇒ can't be mistaken for any other Florida bat
Inhabits pine flatwoods and hardwood hammocks, roosting in hollow trees, crevices behind bark, buildings and other manmade structures
These are gleaners
Evening bat ⇒ species found throughout the state
Small sized found in temperate deciduous woodlands or mixed woodlands and open areas
Family Vespertilionidae
Pallas mastiff bats ⇒ only found in the Florida Keys
Found in roofs and wall spaces of buildings
Family Molossidae
Wagner's mastiff bat ⇒ Florida’s largest bat, only found in south Florida
Loud piercing call easily picked up by humans
Roosting preferences = barrel-tile roofs, tree hollows and holes/shafts of royal palm trees
Seldom forage lower than 30 feet
Can take flight from horizontal surfaces (which most bats can’t do easily)
Protected within the state of Florida
Brazilian free-tailed bat ⇒ one of the most abundant bats in Florida
Tolerate warm temperatures very well
Most often found roosting with evening bats
Lecture 13 - Primates
21 pages, 108 slides
Primates are one of the oldest mammalian orders
Probably originating in the Cretaceous
2 suborders = Strepsirhini (only found in Madagascar) and Haplorhini
Distinguishing characteristics of the Order Primates:
Increased reliance on vision
Diurnal species have color vision while nocturnal species don't
Forward-facing eyes for binocular vision = allows depth perception
Binocular vision = see with both eyes simultaneously
Have either a postorbital bar (Suborder Strepsirrhini) or postorbital plate (Suborder Haplorhini)
Reduced noses (olfaction less important), smaller and flatter snouts, loss of vibrissae and small hairless ears
Opposable thumbs for power grip and precision grip
Flattened nails for fingertip protection
Development of sensitive tactile pads on digits
Primitive limb structure:
One upper limb bone, two lower limb bones
To support the limbs as they move through brachiation = well developed clavicle
Primates are sometimes called claviculate
Progressive expansion and elaboration of the brain (especially of cerebral cortex)
Region with greatest increase in size = cerebrum
Visual cortex is very well developed
Increase in absolute and relative brain size =large, dome-shape skulls
Increase in brain size led to complex behaviors and gestational changes
Greater facial mobility and vocal repertoire
Complicated social organization
Complex social behaviors require increased communication skills (vocal and visual)
Vocal communication → leads to variety of anatomical modifications to the larynx, lips and tongue
Visual communication → expressive faces and color, rely on flexible learned behaviors
Reproduction occurs at a slower rate, delayed sexual maturity and longer life spans
Reduced litter size - usually just one
Prolongation of postnatal periods
Development
Efficient fetal nourishment, longer periods of gestation, smaller numbers of offspring, delayed maturation, longer life spans
Greater parental investment in offspring
Tendency to live in social groups
Tendency for diurnal activity patterns
Dentition:
Bunodont and brachydont (short with rounded cusps)
Adapted for biting (incisors), grinding (premolars and molars) and shearing (canines)
Old World monkeys = 2 premolars
New World monkeys = 3 premolars
Strepsirhini have a dental comb ⇒ formed by procumbent (forward projecting) incisors and canines on dentary
Other primate characteristics:
Social and mating systems have diverse array of complex socio-spatial and breeding patterns
Most live in tropical or subtropical areas = arboreal
Exception = Japanese macaque that lives in areas that have considerable snow
No non-human primate is adapted to a fully terrestrial environment
All spend some time in the trees
Tendency toward erect posture ⇒ sitting, standing, leaping and some bipedalism
All primates sit upright
Many can stand upright without support from their arms
Some can walk upright for short periods
When walking upright, they swing their limbs in opposition to each other for balance
Retention of some bones (clavicle) and certain abilities (forearm rotation) which are often lost in specialized mammals
Hip and shoulder morphology which allows wide range of movements = knuckle walking, brachiation, bipedalism
Hands and feet are prehensile
Five digits on hands and feet but some show diminished thumb and second finger
Partially opposable thumb and most have fully divergent partially opposable big toe
Nails instead of claes with tactile pads with nerves at ends of fingers
Primate anatomical traits evolved as adaptations to environmental circumstances
Angiosperm radiation hypothesis
Suggest basic primate traits were developed in conjunction with the rise of angiosperms
Arboreal hypothesis
Suggests arboreal living was the most important factor in the evolution of primates
Visual predation hypothesis
Suggests that forward facing eyes enabled primates to judge distance when grabbing for insects and hands were designed for grasping objects
What was going on in the Cretaceous?
During that time, small arboreal mammals began to exploit the angiosperms (flowering plants) due to the huge diversification of species that brought new resources
Large fruits with stored nutrients appeared and bats, rodents and primates become important arboreal seed dispersal agents
These early primates had nails rather than claws and an opposable hallux (first toe) suggesting a pattern of climbing by grasping
Postorbital bar shielded the back of the eyes and fields of vision were oriented more forward
These early primates were small omnivores
Summary of the two suborders:
Strepsirhini = tooth combs, wet naked noses, nostrils crescentic slits, postorbital bar
Postorbital bar ⇒ no bony plate between the orbit and temporal fossa
Haplorhini = spatulate incisors, nostrils ringed, dry hairy noses, postorbital plate
Postorbital plate ⇒ separates the orbit from the temporal fossa
Suborder Strepsirhini → lemurs, galagos, lorises, bushbabies
Previously called the prosimians (“before the monkeys”)
Large eye sockets, small braincase, elongated snout and adaptations for well-developed senses of hearing and smell
Characteristics:
Wet rhinarium
Nocturnal
Prominent whiskers
Large ears and eyes (tapetum lucidum)
Highly developed sense of smell
Divided upper lip
Dog-like faces with protruding snout (rostrum)
Specialized scent glands for non-visual communication
Tooth comb formed from lower incisors and canines
Postorbital bar
Vertical clinging and leaping, slow quadrupedalism
Grooming claw on second digit of foot and flat nails everywhere else
Strepsirhines have a bicornuate uterus that contrasts with the simplex uterus of haplorhines
Also have an epitheliochorial placenta
They have neonates that are smaller relative to maternal mass than haplorhines
The seven extant families are concentrated on Madagascar but include species found in Africa, Southeast Asia and the Malay Archipelago
Strepsirhini Families:
Family Cheirogaleidae → dwarf and mouse lemurs
Smallest primates
Live in Madagascar
Have small ears, large close-set eyes with long hind legs
Have fine claws on the second toe of the hind legs
Nocturnal and arboreal
Excellent climbers and can jump far with their long tails for balance
Usually solitary
Family Lemuridae → lemurs
Live in Madagascar
Hind Legs are longer than forelegs
Sociable animals in larger groups (dominance hierarchies in some)
All lemurs except ring-tailed lemur lack a tapetum lucidum
Family Lepilemuridae → sportive lemurs
Live in Madagascar
Closely related to the other lemurs
Generally solitary, some territory marking with anal glands
Locomote bt vertical clinging and leaping from one tree to the next
Family Indriidae → indriid lemurs, sifakas
Live in Madagascar
All species are arboreal but come to the ground occasionally
Large cecum and fewer premolar teeth than other lemurs
Mate monogamously for many years
Family Daubentoniidae → aye aye
Rodent-like continuously growing teeth
Long thin middle finger to fill the same ecological niche as a woodpecker
World’s largest nocturnal primate
Lives on the east coast of Madagascar
Family Lorisidae → lorises, potto
Large eyes that face forward
Small ears partially hidden in the fur
Pseudo-opposable thumbs with reduced index finger
Second toe of the hind legs has a fine claw for grooming (typical for strepsirhines)
Tails are short or missing completely
Live in Southeast Asia
Lorids are nocturnal and arboreal
But never jump
Most are solitary or live in small groups
New species of small nocturnal slow loris discovered = only primate with a toxic bite
Secretes toxin from glands in their elbows
Family Galagidae → bushbabies, galagos
All live in Africa
Arboreal and nocturnal
Well developed limbs and a long tail for balance n
Large eyes and acute hearing
Communicate by calling to each other and marking their paths with urine
Suborder Haplorhini
Characteristics:
Dry rhinarium, nostrils are more rounded
Upper lip is continuous and not attached to gums
Free lip allows for more expressive face
Eyes lack tapetum lucidum and don't reflect light
Larger brain
Reduced snout and less reliant on sense of smell
Binocular and stereoscopic vision
Trend towards longer arms and legs
Delayed sexual maturity, usually one offspring with extended maternal care
Extended life span
Haplorhini Families:
Family Tarsiidae → tarsiers
Found in the Malay Archipelago
Small animals with enormous forward facing eyes
Reduced snout, very long hind limbs
Associated with vertical clinging and leaping movements
Can rotate their head 180 degrees
Elongated fingers with the third finger being the same length as the upper arm
Nocturnal species that lack a tapetum lucidum
Only entirely carnivorous primate
Family Cebidae → capuchins and squirrel monkeys
Arboreal and rarely travel on the ground
Long limbs with curved nails, thumb is not opposable and sometimes its absent
Omnivorous
Family Aotidae → night or owl monkeys
Central and South America
Genus name means earless = no external pinna
Only truly nocturnal monkeys = have big eyes
No color vision, have better spatial resolution at low light levels than other primates
Monogamous and forms pair bonds
Family Pitheciidae → titis, sakis and uakaris
Diurnal and arboreal
Mostly herbivorous (fruits and seeds) although some eat insects
Diastema between canine and premolar but titis don’t
Uakaris and bearded sakis = polygamous in large groups (hierarchy)
Titis and sakis = monogamous in smaller family groups
Family Atelidae → howler, spider and wooly monkeys
Central and South America
Almost hairless prehensile tail with sensitive tactile pad on the underside
All species are diurnal and arboreal
Employ semibrachiation = brachiating but they use their prehensile tail as a third arm
Polygamous where one male mates will multiple females = harem
Species of the genus Aloutta are known for their loud calls
Modified larynx and hyoid
Males that generate these calls (sexual dimorphism)
Family Cercopithecidae → old world monkeys (baboons and macaques)
Native to Africa and Asia
Medium t0 large sized, range from arboreal forms to fully terrestrial
Smallest = talapoin
Largest = male mandrills
Burmese snub-nosed monkey → new species with unusual upturned nostrils
Rainwater gets in their nose and they sneeze
Most have tails but they are never prehensile
All partially omnivorous and partially herbivore
In most species the daughters remain with their mothers for life ⇒ matrilineal group
Males leave the group during adolescence and find a new troop to join
Group sizes are variable depending on the species
High degree of epigamic adornment → modifications (typically visual) of the body that serve to attract mates
Hypothesized that epigamic adornment developed to such degree in primates to compensate with the evolutionary reduction in olfaction and pheromonal perception
Females show prominent perianal swelling
Huge noses
Colorful genitalia
Family Hylobatidae → gibbons, siamang
Also called the lesser apes
Smaller and pair-bonded, with low sexual dimorphism
Masters of brachiation, also don’t make nests
The fastest and most agile of all tree-dwelling, non-flying mammals
Wrist is comprised of a ball and socket joint that allows for biaxial movement
Long hands and feet with a deep cleft between the first and second digits of their hands
Some species (siamang) have an enlarged throat sac that inflates and serves as a resonating chamber when the animals call
Family Hominidae → gorilla, chimps, orangutan, humans
Considered the great apes, large and tailless primates
Smallest = bonobo
Largest = gorillas
Degree of sexual dimorphism varies among species but males are larger on average than females
Bornean orangutans have been seen using spears to catch fish
More solitary than the other species of orangutan
Gorillas inhabit tropical or subtropical forests of central Africa
DNA of gorillas is 98-99% identical to humans
Next closest living relatives to humans after the two chimpanzee species
Move around by knuckle walking and have individual fingerprints like humans
Silverbacks = strong dominant males
Blackbacks =other mature males in the troop
Common chimpanzees live in large communities
Lives in a fission-fusion society where mating is promiscuous
Testicles are unusually large for their body sized (larger than gorillas)
Both arboreal and terrestrial
Highly territorial and can kill other chimps
Habitual gait is quadrupedal
Are knuckle walkers like gorillas while orangutans and bonobos are palm walkers
Bonobos:
Endangered and found in the wild only in the Democratic Republic of the Congo
Closest extant relative to humans along with the common chimpanzee
Matriarchal species that commonly engages in casual sexual activity
Head is smaller than a common chimpanzee with less prominent brow ridges
Has a black face with pink lips
They walk upright 25% of the time, the rest of the time they palm-walk
Also has highly individual face features like humans
Lecture 14- Cingulosa, Pilosa, Pholidota and Tubulidentata
Superorder Xenarthra
Order Pilosa:
Suborder Folivora:
Sloths:
The slowest mammals in the world and are primarily folivores
Both species show incomplete zygomatic arch with the jugal bone having upper and lower processes on the posterior edge
Squamosal is missing
Fur specialized adaptations:
Outer hairs grow in a direction opposite from that of other mammals
Grows away from the extremities providing protection from the elements while the sloth hangs upside down
When moist the fur hosts several species of symbiotic cyanobacteria
May provide camouflage, appear to have a green tinge
May also provide nutrients to the sloth since they are consumed
Families:
Family Megalonychidae → 2-toed sloths
Not a close relationship between the two families, each adopted their arboreal lifestyles independently
First reached North America by island-hopping prior to the formation of the Isthmus of Panama
Really good swimmers
Some lineages increased in body size as time progressed (ground sloth) but went extinct around the end of the Pleistocene
Have a reduced ever-growing dentition with no incisors or true canines
First tooth is canine-like = caniniform molar
Separated from the other molariform teeth by a diastema
Only 2 toes on their forefeet and 3 on their hind feet
Larger than 3-toed sloths, with a prominent snout, longer fur and absence of a tail
They have 5-7 cervical vertebrae
Generally nocturnal, somewhat more active than 3-toed sloths
Cannot shiver to keep warm have low metabolic rates and reduced musculature
Have large sacculated stomachs with multiple chambers and use foregut fermentation
Food can take up to a month to digest due to their slow metabolism
Urine and feces may account for 30% of the animal’s weight
Come to the ground to urinate and defecate about once a week
Mothers give birth to a single young and it is born with its eyes open, teeth present and claws fully formed
Family Bradypodidae → 3-toed sloths
Have a short tail and three toes on both front and hind feet
Have 8-9 cervical vertebrae with a very flexible neck that rotates 270 degrees
No incisors or canines = just a set of peg-shape teeth not clearly divided into molars and premolars (molariforms)
No caniniform molar
Very agile swimmers
Cannot walk on all four legs ⇒ use their front arms/claws to drag themselves across the forest floor
Almost completely arboreal
Pygmy three-toed sloth = only found on a small island off the coast of Panama
Almost half the size of normal three-toed sloths and specialize on mangroves
Suborder Vermilingua:
Family Myrmecophagidae → true anteaters
Family name refers to their vermiform (worm-like) tongue
Have elongated snouts with long, narrow tongues
No teeth but have sticky saliva to trap insects as well as backward-pointing spines on their tongues
Ants and termites are their primary food and water source
Have a keen sense of smell but poot sight and hearing
They don't sleep in any fixed space, instead curl up in abandoned burrows
Have five digits on each foot, with the middle three digits of the forefeet having elongated claws
Walks on its knuckles giving it a shuffling gait
Their tongue can reach two feet in length
An anteater crushes insects by using sand and small rocks inside their muscular stomach
These items are ingested to aid digestion
Unlike other mammals, the giant anteater’s gastric acid does not contain hydrochloric acid
Uses formic acid produced by the ants
Give birth to a single young that climbs onto the mother’s back
2 species of tamandua
They are semi-arboreal and possess partially prehensile tails
Family Cyclopoedidae → silky anteater
Smallest of the anteaters with a partially prehensile tail and two very enlarged claws in each forepaw
Opportunistic but eat mostly ants
Order Cingulata:
Family Dasypodidae → armadillos
Armadillo means “little armored one”
Largest → giant armadillo
Smallest → pink fairy armadillos
All species are native to the Americas
The armor is formed by plates of dermal bone covered in small overlapping epidermal scales (scutes)
In most species there are rigid shields over the shoulders and hips with a number of bands separated by flexible skin covering the back and flanks
The underside is never armored, simply covered with soft skin and fur
Armadillos use their claws for digging and finding food
Only the South American three-banded armadillos rely on their armor for protection and roll up into a ball when threatened
Other species can’t roll up because they have too many plates
Armadillos have a large number of peg-like cheek teeth with no enamel which are not divided into molars and premolars
They also don’t have incisors or canines
Giant armadillos → 80-100 teeth, most teeth of any mammal
Simple stomach, small intestine, cecum, colon and rectum
They can use their stomach as an extra air reservoir when underwater
Well-developed sense of smell and hearing while vision acuity varies within species
They produce several forms of vocalizations
Pink fairy armadillo ⇒ nocturnal, solitary until they mate (polygamous)
Nine-banded armadillo ⇒ solitary, nocturnal
Feeds primarily on ants and termites but supplement their diet with amphibians, small reptiles, fungi, tubers and carrion
Giant armadillo → largest living species of armadillo
Has 1-2 babies per litter
Xenarthrans:
Xenarthrans were previously classified with pangolins and aardvarks in the order Edantata (meaning toothless)
Now pangolins and aardvarks are placed in individual orders
They share several characteristics that are not present in other placental mammals ⇒ suggests they descend from subterranean diggers
Their name means “unusual joint”
Refers to their vertebral joints that have extra articulations unlike other mammals
Presence of extra “xenarthrous” intervertebral articulations (xenarthrans) on the lumbar and posterior thoracic vertebrae
These provide extra rigidity to the axial skeleton
Their limb bones are very robust with large processes for muscle attachment
Have single color vision ⇒ monochromatic
Considered to be among the most primitive of placental mammals
Females show no clear distinction between uterus and vagina
Males have testicles inside the body between the bladder and rectum
Possess the lowest metabolic rates among therians
Unique dentition:
Lack incisors and canine teeth
Either lack teeth entirely (anteaters) or have homodont cheek teeth lacking enamel
This exposes dentine creating flat grinding surfaces for processing insects (armadillos) or leaves (sloths)
Dentine = less resistant to wear than enamel
Have open-rooted teeth that grow continuously
First premolar of the two-toed sloth is a pseudo-canine (caniniform)
Xenarthrans are primarily found in South and Central America except the nine-banded armadillo found in the US
Megalonyx → spread as far north as the Yukon and Alaska
Orders Pilosa, Cingulata, Pholidota and Tubulidentata
Members of this collection of orders share characteristics related to a common feeding mode = myrmecophagous (ants and termites)
Most members have long snouts with sticky tongues, reduced dentition
Coronoid process of the mandible is reduced
Hyoid elements (bones and muscles of the tongue) often enlarged
Strong heavily-clawed forefeet used to dig or hold on to branches (sloths), small pinnae and valvular nostrils to reduce problems with the insects
Integument also offers protection = armored carapace (cingulata), thick fur (pilosa), reptile-like scales (pholidota) or tough sparsely haired hide (tubulidentata)
All have simple (sometimes sacculated) stomachs, a thickened keratinized pyloric region to aid with digestion and protect against formic acid
These groups have low reproductive capacities = one young per litter with extended maternal care
Excellent examples of convergent evolution (ecomorphs) since these groups are not closely related
Order Pholidota
Family Manidae → pangolins
Have keratin scales covering their skin and are the only mammals with this adaptation
Can curl up into a ball when threatened (scales are razor sharp)
Found in tropical regions of Africa and Asia
Most poached illegal traded species due to their scales
Nocturnal animals with a well-developed sense of smell to find insects
Can live in burrows or be tree-dwelling depending on the species
Closest living relatives = Carnivora
Form the clade Ferae
They have short legs with sharp claws which are so long they walk with their fore paws curled over them to protect them
They can also emit a nasty smelling acid from the glands near their anus similar to skunks
Lack teeth and have no jugal
Tongue is extremely elongated and extended into the abdominal cavity
By convergent evolution pangolins, the giant anteater and the tube-lipped nectar bat all have tongues which are detached from their hyoid bone and extend past their pharynx deep into the thorax
This extension lies between the sternum and the trachea
Order Tubulidentata
Family Orycteropodidae → aardvark
Native to sub-Saharan Africa also known as the antbear or earth pig
Closest living relatives = elephant shrews, sirenians, hyraxes, tenrecs and elephants (Suborder Afrotheria)
Dentition:
Instead of having a pulp cavity each tooth has a cluster of thin upright parallel tubes of vasodentin with individual pulp canals held together by cementum
The teeth have no enamel coating and are worn away and regrow continuously
They are born with conventional incisors and canines which fall out and are replaced
Adults only have 5 oval shaped cheek teeth at the back of the jaw (unique feature hence their family name)
Front feet have lost the pollex (thumb) resulting in four toes while the hind feet have all five toes
Each toe possess a robust nail that appears to be the intermediate between claw and hoof
Nocturnal and solitary, feeds on termites and ants
Lecture 15 - Carnivora
Most diverse in size of any mammalian order
From weasel to southern elephant seal (200,000 times bigger)
Evolved about 55 MYA during late Paleocene in North America and split into cat-like and dog-like
Although most do eat meat, it is not a defining character of the Order
All share several morphological characteristics including the specialization of the teeth
When hunting individuals may be solitary, paired or in small groups
Methods of hunting range from concealment with surprise ambush (felids) to a stalk followed by a short swift run (weasels) to a prolonged chase (wolves or hyenas)
One of the functions of pelage coloration is concealment and those that hunt through concealment often have spots or stripes
Living carnivores are divided into two suborders based on the structure of their auditory bullae and carotid circulation (carotid rete)
Related to a counter-current heat exchange system - better in Feliformes
Pinnipeds are recognized as a Super Family
Morphological characteristics:
Defining morphological characteristic = specialization of their fourth upper molar (P4) and first lower molar (m1) as carnassial teeth for shearing and cutting
Carnassials are well developed in the predaceous felids, canids and hyaenids but very much reduced in the omnivorous ursids and procyonids
Skulls are heavy with strong facial musculature for crushing, cutting and chewing flesh, ligaments and bone
Felid skull → short rounded rostrum
Canid skull → long rostrum
Carnivores often have a deep, sharply defined C-shaped mandibular fossa
Minimizes lateral movement of the jaw
Auditory bullae are formed from either the tympanic bone alone or from the tympanic and endotympanic bones together
The structure of the bullae is used to distinguish the 2 suborders of carnivores:
Feliforms → both tympanic and endotympanic bones form the bullae with a septum where the two meet
Caniforms → bullae are formed only from the tympanic bone and there is no septum
Almost all carnivores have a well developed baculum and this may be most important in species with induced ovulation. Most also have distinctive anal sacs used for defense and intra-specific communication
They have well developed claws on all digits
Most felids and some viverrids have retractile claws
Centrale, scaphoid and lunate bones of the wrist are fused to form a scapho-lunar bone = ads support for cursorial locomotion
Clavicle is reduced or lost to increase stride length
Meat is easy to digest so carnivores have simple stomachs with an undeveloped cecum
Order Carnivora
Suborder Feliformia
Family Felidae → cats
Strictest carnivores in this order
Extant felids belong to one of the two subfamilies:
Pantherinae → tigers, lion, jaguar, leopard
Felinae → cougar, cheetah, serval, lynxes, caracal, ocelot and cosmetic cat
Eight lineages have been identified
Aside from the lion, wild felids are solitary , often secretive animals and nocturnal
Agile climbers
Wild felids are native to every continent except Australia and Antarctica
Good binocular vision
Their tongue is covered with horny papillae to help rasp meat from their prey
Fully retractile claws except the Cheetah
Family Hyaenidae → hyenas
Native to Africa and Asia
About 5-7 MYA hyenas were outcompeted by canids which traveled from North America to Eurasia
The remaining ancestral hyaenids survived by adapting to an insectivorous diet to which a few canids had specialized
Later evolved bone-crushing teeth which allowed them to avoid competition with the canids
Spotted hyenas and to a lesser extent, striped and brown hyenas have powerful carnassial teeth
The aardwolf (insectivorous-termites) has greatly reduced cheek teeth
Hyena mandibles are much stronger at the canine tooth than canids (crack bones)
Digitigrade and have non-retractable claws
They have long necks with long forelimbs and shorter hindlimbs
They lack a baculum
Spotted hyena societies = more complex than other carnivorans
Centered around females which are dominant to and larger than the males
Males disperse while females stay with natal groups
Other hyena species show little sexual dimorphism with males only being slightly bigger than females (spotted hyena is the exception)
Both sexes of spotted hyenas have an erectile phallus = pseudopenis or “peniform clitoris” in females
Females are extremely “masculinized” due to high levels of androgens
Aggression benefits high ranking females
All hyaenids have protrusible anal scent glands that excrete oily yellow substance onto objects to mark their territories
Scent marking is also done by scraping the ground with the paws which deposits scent form glands on the bottoms of the feet
They do not raise their legs up when urinating like dogs do
Besides aardwolf (termite feeder), all living hyena species are hunters and scavengers = very powerful digestive system
Family Herpestidae → mongooses, suricates
Native to southern Eurasia and Africa
Some species lead predominantly solitary lives seeking out food only for themselves while others travel in groups and share food
Suricates live in troops of 20-30
One meerkat serves as a sentinel that climbs to a vantage point and watches for danger to protect foraging individuals
Loud alarm to warn the troop if danger is detected
Indian mongoose popularly fight and kill venomous snakes like cobras due to their agility and thick coat
Family Viverridae → civets, genets, bearcats
Among the more primitive families of carnivora
Resemble long-nosed cats, most with retractile or partially-retractile claws, a baculum and an anal scent gland ,
Have excellent hearing and vision
Some are carnivores, some omnivores and palm civets are almost entirely herbivorous
As a result = their carnassial teeth are relatively undeveloped
Civets retain several primitive features including short and unspecialized limbs
They also have perianal glands that produce a fluid known as civetone to mark their territory → used in the perfume industry
Family Eupleridae → madagascar mongooses (newer family along with nandiniidae)
The Fossa and the Malagasy civet are believed to be the most ancient surviving species within this group
Fossa → largest mammalian carnivore in Madagascar, can be compared to a small cougar
Has semi-retractable claws and flexible ankles that help climb up and down trees
All species of Eupleridae were formerly classified as viverrids
Family Nandiniidae → african palm civet
Omnivorous, solitary and nocturnal
Although resembling other civet species (Family Viverridae) the African palm civet is generally distinct
Diverged from other civets before the cats did
outgroup
Suborder Caniformia
Family Canidae → dogs
Includes the carnivorous and omnivorous wolves, foxes, jackals, coyotes and domestic dogs
Borophaginae ⇒ “bone crushing dogs” that had powerful teeth and jaws and hyena-like features
Their fossils are abundant and widespread, most likely a top predator at some point
Modern representatives of this family are divided into:
“Wolf-like” or “dog-like” of the tribe Canini (true dogs)
“Foxes” of tribe Vulpini
Two species of the Basal Caninae are more primitive and do not fit into either tribe
Bat eared fox and raccoon dog
Wild canids are found on every continent except Antarctica
Red Tibetan mastiff → one of the world’s oldest and most venerable breeds
One was the most expensive dog ever sold
Except bush dogs, raccoon dog and some domestic breeds = canids have relatively long legs adapted to chase prey
All are digitigrade, possess bushy tails, non-retractile claws, pollex and hallux are reduced and a dewclaw on the front feet (except the African wild dog)
Have a baculum that helps create a copulatory tie during mating
Young canids are altricial with their eyes opening a few weeks after birth
Have an elongated rostrum with well developed canines and carnassials
Almost all canids are social animals and live together in groups
African wild dogs have the largest packs = up to 90 animals
Foxes are not usually pack animals, they live in small family groups
Canids communicate by scent signals, visual clues and gestures and by vocalizations
Groups have a home territory that is marked with urinary scent marks
Foxes are omnivores and cache excess food
Family Mustelidae → weasels, otters, badgers
Largest family in the Order Carnivora
Vary greatly in size and behavior
Reproduction involved induced ovulation and delayed implantation
Common characteristics:
Typically small animals with short legs, round ears and thick fur
They are digitigrade with non retractile claws
Most are solitary and nocturnal animals
With the exception of the sea other, Mustelids have anal scent glands that produce a secretion used for sexual signaling and marking territory
Predominantly carnivorous although some will eat plant materials sometimes
Possess strong carnassials and strongly C-shaped mandibular fossa
Several members of this family are aquatic to varying degrees
From the semi-aquatic mink to the highly aquatic sea otter
Sea others are one of the few non-primate mammals known to use tools while foraging
Black-footed ferret = entirely dependent on a single keystone species, the prairie dog
A single family of ferrets eats 250 prairie dogs a year
Family Mephitidae → skunks, stink badgers
Best known for their ability to secrete a liquid with a strong foul-smelling odor from their anal scent glands
Two glands, one on each side of the anus
Produce a mixture of sulfur-containing chemicals (mercaptans)
4 genera:
Mephitis → hooded and striped skunks (Florida species)
Spilogale → spotted skunks (Florida species)
Mydaus → stink badgers
Conepatus → hog-nosed skunks
Skunks are omnivorous and change their diet as the seasons change
Primary predators of the honeybee, relying on their thick fur to protect them from stings
Nocturnal and solitary when not breeding, shelter in burrows during the day
Not true hibernators but tend to den up for extended periods of time where they are generally inactive and feed rarely
Overwinter in a huddle of multiple females while males den alone
Have excellent senses of smell and hearing but poor vision
Family Procyonidae → raccoon, coati, kinkajous
New World family that inhabit a wide range of environments usually near water
Generally omnivorous
Poorly developed carnassial teeth, specially the raccoons
Most are smallish animals with slender bodies and long tails
Except the kinkajou = all procyonids have banded tails and distinct facial markings
Plantigrade with non or semi retractile claws
Family Ursidae → bears
8 living species of bear and appear in a wide variety of habitats
Common characteristics of modern bears:
Large body with stocky legs
Long snout, shaggy hair, plantigrade paws with five non-retractile claws and a short tail
Polar bear = mostly carnivorous
Giant panda = feeds almost entirely on bamboo
Remaining six species are omnivorous
Despite the shared name, habitat name and diet as well as an enlarged bone called the pseudo thumb (helps them grip the bamboo shoots they eat), the giant panda and the red panda are only distantly related
Molecular studies have placed the red panda in its own family not under Ursidae
Closest relative to the giant panda is the spectacled bear
The only surviving species of bear native to South America
Typically solitary animals with the exceptions of courting individuals and mothers with their young
Generally diurnal but may be nocturnal or crepuscular
Have excellent sense of smell and can run very quickly despite their heavy gait
Adept climbers and swimmers
Family Ailuridae → red panda
Studies show the red panda is actually relatively close to the raccoon but should be a monotypic family
A small arboreal mammal with reddish-brown fur and a long shaggy tail
Waddling gait due to its shorter front legs
Mainly eats bamboo but is omnivorous
Solitary and mainly nocturnal, largely sedentary during the day
Found in forests of India and China
Superfamily Pinnipedia
Family Phocidae → true seals
More specialized for aquatic life than otariids
Front flippers are used for steering while hind flippers are bound to the pelvis (can't walk on them)
Very deep divers
Have fewer teeth than land-based carnivorans but retain powerful canines
Some species lack molars altogether
They don't really chew their food, teeth are more for gripping prey
Crabeater seals → specialized teeth to sieve krill
Family Otariidae → eared seals (sea lions and fur seals)
Adapted to semi-aquatic lifestyle, feeding and migrating in the water but breeding and resting on land/ice
Absent in the North Atlantic
Not deep divers
Have proportionately much larger fore flippers and pectoral muscles than phocids
Have the ability to turn their hind limbs forward and walk on all fours
Further distinguished by a more dog-like head with sharp and well-developed canines and visible external pinnae
Post canine teeth are generally simple and conical in shape
Visual carnivores
Some species have some of the most extreme cases of sexual dimorphism with males being 8 times larger than the females
Family Odobenidae → walrus
Very large and are exceeded in size only by the two species of elephant seals
Aside from the vibrissae (very well developed), walrus is sparsely covered with fur and appears bald
Skin is wrinkled and thick with a thick blubber layer
Can turn their flippers forward and move on all fours like otariids
Swimming technique is more like that of true seals however, relying less on flippers and more on sinuous whole-body movements
Lack external ears like phocids
Tusks are the most prominent feature
Elongated canines present in both sexes
Longer and thicker among males for fighting, dominance and display
Relatively few teeth other than the tusks
Not particularly deep divers
Superorder Caniformia is characterized by:
Non-chambered or partially chambered auditory bullae
Non-retractile claws
Well developed baculum
More premolars and molars in an elongated skull
Less specialized carnassial teeth
Diet is varied and most tend to be omnivorous
All families besides Canidae and few species of Mustelidae are plantigrade
Most species are simply colored with no spots or rosettes
Tend to range in the temperate and subarctic biomes
Hence the lack of the carotid rete
Most are terrestrial although a few species like procyonids are arboreal
Suborder Feliformia is characterized by:
Spotted, rossetted or striped coats
Tend to be found in tropical habitats (explains carotid rete)
Although a few do inhabit temperate and subarctic habitats
Many are arboreal or semi-arboreal
Majority are digitigrade
Felid claws are retractile or rarely semi-retractile
Usually strict carnivores specially Felidae family
Have fewer teeth and shorter skulls with specialized carnassials for shearing meat
Superfamily Pinnipedia is characterized by:
Medium to large aquatic mammals
Smallest pinniped = Galapagos fur seal
Largest = male southern elephant seal
Body is insulated with thick layer of blubber and coarse hair
Digits are not separate but are transformed into paddles
Pinnae very small or lacking and the vibrissae are well developed
Molariform teeth are mostly homodont with well developed canines
Carnivorous
Leopard seal → most carnivorous and predatory pinniped
Tail is short or absent
External genitalia are hidden in slits or depressions in the body