BIOL11000: Mammals Diversity & Evolution

Name the families that are in the order Eulipotyphla...

Families: 1. Shrews 2. Solenodons 3. Hedgehogs & moonrats 4. Moles & desmans

🐒 Describe the Suborder Haplorrhini & name the two infraorders that it is split into including any parvorders...

1. Infraorder Tarsiiformes 2. Infraorder Simiiformes Includes two parvorders Platyrrhini & Catarrhini

🐬 Describe the Order Cetartiodactyla including its two sub-orders...

77 species in 2 suborders: ❖ Baleen whales (10 spp) - Mysticeti: - e.g. Gray whale, Blue whale & Humpback whale - Have horny plates instead of teeth to filter plankton & invertebrates from the sea. ❖ Toothed whales (67 spp) - Odontoceti: - e.g. Dolphins, Belugas & Sperm whale - Feed on fish & squid. ❖ Closest living relatives are Artiodactyls.

Describe Lions as an example of the Felidae family within the order Carnivora....

Cats (Felidae): ❖ 36 species ❖ Most carnivorous of the carnivorans. ❖ Cats share several adaptations inherited from their common ancestor, including blunt, flattened faces, large eyes, claws that can be sheathed, & large, sensitive ears ❖ Tongue is coated with sharp-pointed papillae that retain & lacerate food & rasp flesh off a carcass Lion social organisation: ❖ Core of pride is 4-12 related females, on average as closely related as cousins. ❖ Subadult males tolerated in prides, but breeding male does not grow up in the pride that he holds. ❖ Females perform some allosuckling of relative's offspring (kin selection). ❖ Incoming males may kill young to gain paternity (infanticide).

🐨 Briefly, describe marsupial diversity & why there are ecological equivalents that resemble particular placental mammals? Include moles as an example...

Diversity: Marsupials, both alive & extinct, show huge diversity. e.g. This planigale is 20,000x lighter than an adult male Red kangaroo. Ecological equivalents: Convergent evolution has resulted in a diversity of marsupials that resemble placental mammals in similar ecological roles all across the world. e.g. There are two species of marsupial mole which have a very similar ecological role to the eutherian European mole.

Describe silver-backed jackals as an example of the Canidae family within the order Carnivora....

Dogs (Canidae): ❖ 36 species ❖ Lots of examples of pack living - "cooperative defence of territories or large carcasses, communal care of offspring Helping in silver-backed jackals: ❖ Juveniles stay in parental ranges as helpers, delay own reproduction by a year and help raise younger brothers and sisters. ❖ Pairs with 0 helpers average productivity 1 pup, 1 helper 3 pups, 3 helpers 6 pups. ❖ Helpers increase survival rates of kin by bringing in food and defending against predators. ❖ These jackals are opportunists, feeding on carcasses abandoned by lions or hyaenas, but are also expert rodent hunters ❖ Young may inherit parental territories - long term advantages may counteract short term cost of helping.

🐨 Describe the features of Echidnas & the Platypus....

Echidnas: ❖ Spines are modified hairs, fur beneath spines. ❖ Modified spines on back of tongue and roof of mouth crush insects. ❖ Eat invertebrates, ants & termites. ❖ Eggs hatch after 10 days, gestation 2 weeks (short). ❖ Young then move to a pouch, where they feed on milk for 6 months (long). ❖ In echidnas the venom apparatus is present but not functional Platypus ❖ Webbed feet, hunt for benthic invertebrates by electrolocation - detects electrical discharge from nerves of prey animals ❖ 2 eggs / burrow, incubation 10 days, no pouch, 3-4 month lactation. ❖ Males have spurs on rear ankles connected to venom glands in thighs. ❖ Their tails are used for fat storage.

🐨 Give an example of gliding ecological equivalents...

Sugar gliders & Flying squirrels: ❖ The sugar glider lives in Australia - Like other gliders, it possesses a thin, furred membrane, known as a 'patagium, which stretches from the wrist to the ankle. ❖ But is remarkably similar to the completely unrelated flying squirrel of north America - which glides by extending a similar fold of skin that stretches from the wrists to the ankles, using the flattened tail as a rudder. ❖ These traits have evolved completely independently of one another

🐨 Give an example of predator ecological equivalents..

Tasmanian devil & Hyaena: ❖ The Tasmanian devil is restricted to Tasmania & is an effective hunter of medium sized mammals such as wallabies & is not dissimilar to the hyaenas as both: - are robustly built. - have a broad head that supports powerful jaws. - have strong teeth capable of crushing all but the largest bones. - have hindquarters that slope downwards because their forelegs are longer than their hindlegs.

🐨 Describe tenrecs & golden moles...

Tenrecs ❖ Many extant species evolved in virtual isolation in Madagascar. ❖ Big adaptive radiation: species resembling shrews, hedgehogs & otters. Golden moles ❖ 18 species of burrowing insectivores in sub-Saharan Africa. ❖ Convergent with moles (Eulipotyphla), but not related to them

🐒 Describe the complex use of alarm calls in Vervet monkeys & Campbell's monkeys...

Vervet monkeys: ❖ Give acoustically different alarm calls in response to different predators. ❖ Each alarm evoked a response which was the best escape strategy from the predator in question. ❖ Animals on the ground respond to leopard alarms by running into trees, to eagle alarms by looking up, & to snake alarms by looking down. Campbell's monkeys: ❖ Have 5 types of specific predator alarms (hacks) ❖ Can combine hacks with other sounds to convey extra information - in much the same way humans use prefixes & suffixes. ❖ In the Campbell's monkey suffixation functions to broaden the calls' meaning ❖ Can combine different calls in various sequences to convey different information.

Briefly, describe Cavy-like rodents...

Very diverse, includes: cavies, capybara, agoutis, chinchillas, porcupines, guinea-pigs and African mole rats.

🐾 What is a mammal & their distinguishing features?

❖ "A group of animals with backbones, & bodies insulated by fur, which nurse their infants with milk and share a unique jaw articulation" (Macdonald 2009) ❖ Production of milk & jaw articulation are the key distinguishing features of mammals, as some mammals lack fur e.g. dolphins, while some non-mammals have backbones

Briefly, describe Perissodactyl features & diversity...

❖ 1 or 3 toes. ❖ As well as having lost 1st digit have also lost fifth in hindfoot too ❖ Rely on vocal communication unlike the artiodactyls who have a variety of scent glands for communication ❖ Includes: - Asses, horses & zebras (7 spp) - Tapirs (4 spp) - Rhinoceroses (5 spp)

Describe solenodons including factors that have caused their populations to decline...

❖ 2 living species ❖ Crude echolocation ❖ Toxic saliva to immobilize prey. ❖ Cartilaginous snout, articulates with the skull via a ball and socket joint in Hispaniola solenodon. ❖ 17th century - Spaniards introduced cats, dogs & rats. ❖ 19th century - mongoose bio-control of rats. ❖ Solenodons outcompeted for food & eaten. ❖ Predation & forest clearance are ongoing threats.

🐨 Describe elephants & their social organisation...

❖ 2 living species (maybe more): African (savannah/ forest) and Indian. ❖ Large ears dissipate heat. ❖ Trunk is fused upper lip and nose, used in gathering food (neck short). ❖ Tusks are elongated upper incisors. ❖ Vegetarians. ❖ Columnar limbs. Elephant social organization: ❖ Related females live together with immature offspring. ❖ Oldest female (matriarch) leads the group. ❖ May live to > 50y, and may show menopause - allows better care for her children and grandchildren, increasing the chances of survival for individuals who share her genes. ❖ Co-operative defence of young. ❖ Males line alone or in small groups. ❖ Communicate over long distances by infrasound.

🐾 Describe the structural difference of modern day mammalian skulls to their ancestors... Why does this change benefit modern day mammals?

❖ 2 occipital condyles where skull meets topmost neck vertebra but only one in ancestors. ❖ Occipital condyles = two knob-like protrusions on the back of the skull which articulate with the top of the spine. ❖ Having two condyles rather than one was beneficial as: - this reduced tension on the spinal cord when the head is moved vertically - also allowed for finer control of head movements although reduced lateral movement.

Describe the Order Carnivora...

❖ 283 species in 15 families. ❖ Skulls adapted for killing and crushing prey. ❖ Large canines, with cusps on last upper premolar & first lower molar form carnassial teeth for slicing meat. ❖ Carnivores, but also vegetarians, insectivores & omnivores. ❖ Many have complex social communication based on chemical signals (skin, urine & faeces)

😈 Describe the feeding biology of bats in terms Sanguivores....

❖ 3 species of vampire bats. ❖ Best known is Desmodus rotundus. ❖ Sanguivory may have evolved from feeding on flies that congregate around wounds. ❖ Sharp teeth for making small inscision. ❖ Laps blood & produces anticoagulants ❖ Agile on ground. ❖ Drink half of body mass in blood/night.

Describe shrews (family soricidae)...

❖ 384 species. ❖ There are Water shrews, burrowing shrews & typically land-running shrews ❖ Some emit ultrasonic clicks, may be crude form of echolocation. ❖ Mainly insectivorous, some have venomous bites that may have evolved to enable these animals to catch larger prey than their body size would normally permit. ❖ Smallest 'terrestrial' mammals are shrews - pygmy white-toothed shrew weighs just 2g!

🐨 Describe Anteaters & their adaptations...

❖ 4 extant species. ❖ No teeth - lap up insects with long tongues. ❖ Sticky saliva, & crush insects in gizzard-like pyloric region in stomach. ❖ As well as having a reduced metabolic rate & lowering their temperature to 32C with the aid of their big bushy tail which acts as a sun shade, they sleep for about 15 hours per day.

Describe Hyenas (Hyaenidae) as an example of a family within the order Carnivora....

❖ 4 species: Spotted, striped, brown & aardwolf. ❖ Strong teeth & jaws for crushing most bones to get at nutritious marrow. ❖ Highly concentrated hydrochloric acid in stomach effective at extracting nutrients from bone. ❖ Female spotted hyaenas have a pseudopenis & pseudotestes. ❖ Females mate & give birth through penis-like clitoris.

Describe moles & desmans....

❖ 42 species. ❖ Moles (40) subterranean, desmans (2) aquatic. ❖ Poor vision, richly endowed tactile organs such as Eimer's organs on muzzles, vibrissae on muzzles, tails (and legs - desmans)

🐒 Describe the Order Primates, including adaptations...

❖ 424+ species. ❖ Early primates arboreal - flexible limbs, prehensile hands and feet, claws transformed to nails, tail often used for balance. ❖ Early species were nocturnal & lived in trees for protection, they were also insectivorous, with primitive triangular shaped molars. ❖ Became more omnivorous, with square & bunodont molars to facilitate crushing food.

🐨 Describe Sloths & their adaptations...

❖ 5 extant species. ❖ Two families: 2- & 3-toed. ❖ Numbers of fingers distinguish them (all have 3 toes) ❖ Large claws allow sloths to hang on without expending any energy. ❖ In parts of Panama they account for 2/3 of biomass and ½ energy consumption of all mammals. ❖ Arboreal, leaf eating lifestyle with few competitors. ❖ Sloths have similar problems with gathering enough energy from their leaf-eating diet & have evolved a low metabolic rate & are therefore incredibly slow. ❖ Cyanobacteria in longitudinal grooves in hairs aids with camouflage. ❖ Large stomachs, that account for almost a third of a sloth's body weight, with cellulose digesting bacteria. ❖ May digest meals for 1 month, pass urine & faeces once/week.

😈 Describe the feeding biology of bats in terms of insectivores....

❖ 70% of species insectivorous. ❖ High frequencies used in echolocation have short wavelengths, allow detection of small objects. ❖ Usually catch prey in flight, wing/tail membrane increases capture area. ❖ Many insects have evolved ears sensitive to ultrasound & thus veer away from distant bats, spiral out of flight paths of near ones. ❖ Have large stomachs to store prey as an adaptation to the short period of high availability of prey in the night. ❖ Short intestine permits a rapid digestion & hence low flight weight.

🐒 Describe the Family Cercopithecidae AKA Old world monkeys...

❖ 80 species., quite diverse. ❖ Guenons, macaques and baboons. ❖ Blue faces, blue balls. ❖ Brightness of colour often depends on the amount of testosterone & the social status rank of the individual, for example: - A similar blue colour appears in the scrotal skin of several guenons at adolescence as testosterone increases. - The vividness of the blue colour in vervet monkey balls is related to social status, they become paler when the animal slides down the social status ladder.

😈 Describe the Order Chiroptera (Bats) including the two traditional sub-orders...

❖ > 1400 species currently described. ❖ Traditionally two suborders were recognised: ❖ Megachiroptera: - e.g. Old World fruit bats: Pteropodidae - < 200 species in one family. - Old World tropics. ❖ Microchiroptera: - 17 families.

🐒 Describe the Family Hominidae...

❖ Apes & humans - share many derived features. ❖ Large, lack tails, tendency towards upright posture. ❖ Our closest living relatives: gorilla, common chimpanzees, bonobo, orang-utan.

🐒 Describe the Family Hylobatidae AKA Gibbons...

❖ Arboreal & located in southeast Asia ❖ Some are monogamous. ❖ Complex vocal system. ❖ Air (laryngeal) sacs. ❖ Calls, often performed as duets, may serve to develop and maintain pair-bonds. ❖ Arm swinging = brachiation.

😈 Describe the feeding biology of bats in terms frugivores....

❖ Bats are important dispersal agents for fruit in some ecosystems. ❖ Frugivory may have evolved from bats first catching insects around rotting fruit, then eating prey in fruit, finally specialising on fruit itself. ❖ Crushing/grinding molars. ❖ Critical for succession & forest regeneration & therefore potentially incredibly important economically.

😈 Describe bat evolution & what fossils indicate about this evolution...

❖ Bats had appeared by the end of the cretaceous & had begun to diversify some 70mya. ❖ Oldest complete fossils of bats are about 50mya e.g. the fossil Icaronycteris, is 52.5 million years old & has: - Well developed wings - Cochlea structure that suggests it was capable of echolocation. ❖ Fossil Onychonycteris finneyi (2008) has: - Claws on all digits. ❖ This indicates that the new bat may have been an agile climber that employed quadrupedal locomotion & under-branch hanging behaviour.

😈 Describe the hibernation of bats...

❖ Bats in temperate zones heterothermic. ❖ Greater horseshoe bats hibernate for up to 12 days at a time. ❖ Arouse periodically to drink, feed, move roost, defecate. ❖ Arousals energetically costly, therefore must be important. ❖ Could be to protect against parasites etc. by boosting their immune system

🐬 Describe the evolution of the Order Cetartiodactyla...

❖ By studying fossils, palaeontologists have been able to show how traits found in living whales evolved gradually, not all at once. ❖ Started off in freshwater then as moved into salt water also evolved shorter legs & longer tail. ❖ Some point around 40 mya tail fluke evolved then hind limbs lost completely although vestiges of bones still seen internally. ❖ Only after the split of odontocetes & mysticetes that echolocation evolved in the toothed whales & then later in the baleen whales

🐬 Apart from blubber, describe another feature that Cetaceans have to keep warm....

❖ Cetaceans have countercurrent heat exchangers associated with their flippers, flukes, fins & phalluses. ❖ In these systems arteries are closely surrounded by veins so that cold blood in the veins of these appendages on its way back to the heart gets warmed by the arterial blood coming from the body. ❖ Very effective way to prevent heat loss & therefore minimise energy expenditure.

🐨 Describe the super-order Afrotheria....

❖ Contains 6 of the 19 eutherian orders: - Tenrecs & golden moles - Sengis (aka elephant shrews) - Aardvark - Elephants - Hyraxes - Dugong & manatees ❖ Evidence: Afrotheria have 9bp deletion in BRAC1, breast-cancer gene (Madsen et al. 2001). ❖ Oldest clade in eutherian tree, ancient origin in Africa. 105 Mya.

🐨 Describe convergent evolution examples from Afrotheria & examples of close relatives having very different morphologies...

❖ Convergent evolution: Both the common tenrec & Eurasian pygmy shrew have converged on the same body plan & ecological niche but one lives in Madagascar & belongs to super-order Afrotheria & the other in Europe & is parts of Laurasiatheria ❖ Close relatives but different looks: As well as looking very similar to distantly related species, closely related species within Afrotheria can look very different from one another too e.g. hyraxes are closely related to manatees and both are closely related to elephants.

😈 Describe bat phylogeny including the issues with sub-orders & name the new suborders that have been proposed as a solution... Hint: yin & yang

❖ Current consensus is that bats are monophyletic as genetic analyses showed mega/micro split based on morphology now thought to be inaccurate. ❖ Horseshoe bats (with sophisticated sonar) are more similar to Pteropodidae than to other Microchiroptera in genetic analyses. ❖ New suborders proposed: - Yinpterochiroptera: includes Pteropodidae, horseshoe bats & relatives - Yangochiroptera: includes the remainder of the previously recognised Microchiroptera ❖ Could be that echolocation present in early bats, later lost in Pteropodidae. ❖ This means that echolocation must have evolved independently twice, or that echolocation was lost later in the evolution of old world fruit bats

🐒 Describe the Order Dermoptera, including adaptations...

❖ Dermoptera = "skin wing" ❖ Flying lemurs / colugos - glide instead of fly & are not actually lemurs ❖ 2 species, found in southeast Asia. ❖ Malayan colugo & slightly smaller Philippine colugo ❖ Extensive patagium allows gliding between trees - feed on leaves & flowers in rainforest canopy. ❖ Large eyes for good night vision & stereoscopic vision gives them good depth perception. ❖ The patagium can be folded near the tail into a pouch for carrying the young. ❖ Closest living relatives of primates.

🐬 Describe the Eared seals (Otariidae), including the two species within this family, their adaptation & how are these eared seals distinguished from true seals (Phocidae)...

❖ Eared seals are distinguished from true seals by a flap of skin called a pinna near the external ear opening ❖ Species: Fur seals (9) & sea lions (7). ❖ Fur seals have thicker undercoats than sea lions as they have a waterpoof coat overlying a thick, woolly underlayer which is used to trap warm air for effective insulation when underwater. ❖ Pinniped ears have evolved so that their hearing on land is almost as good as humans, but far superior underwater, being able to hear much higher frequencies than humans can detect.

🐒 Describe the Aye-aye as an interesting example from the infraorder lemuriformes ...

❖ Eats fruit & insect larvae ❖ Specialised dentition with continuously growing incisors that are able to break fruit shells ❖ Long spindly middle finger to extract larvae ❖ Have claws on all digits except big toes, which are nailed.

🐒 Explain why Scandentia, Dermoptera & Primates look so different, despite being reasonably closely related...

❖ Euarchonta = Primates, Scandentia & Dermoptera arose 87.9 million years ago (Mya). ❖ Scandentia separated 86.2 Mya. ❖ Primates split from dermopterans 79.6 Mya. ❖ Look & are so different because evolution has had nearly 80 million years to work on & effect the genes of these different orders

🐨 Describe Sengis...

❖ Evolutionary affiliations previously obscure - were thought to be close to lagomorphs. ❖ Create trails for foraging. ❖ Probe in ground with long noses for invertebrates. ❖ Nipples near shoulders.

🐨 Describe the Subclass Theria including a certain dental feature...

❖ Evolved from Trituberculata. ❖ Tribosphenic cheek tooth pattern - where there are three principal cusps in a triangle with the central cusp being dominant. ❖ Improved efficiency in cutting and crushing insects. ❖ Primitive marsupials & eutherians have similar teeth today. ❖ Similarities in tooth structure link trituberculates, marsupials & eutherian mammals in subclass Theria.

🐨 Describe marsupial adaptive radiation & why the majority of marsupials are now only found in Australia?

❖ Evolved in Laurasia in early Cretaceous when Pangaea largely intact, moving west to what is now North America. ❖ Late Cretaceous - spread to South America, Africa, across Antarctica to Australia when southern continents connected as Gondwana. ❖ South America & Australia became isolated & marsupials underwent considerable adaptive radiations there. ❖ >300 extant species in 7 orders. ❖ North & South America re-joined & placental mammals headed south & presumably outcompeted the native marsupials ❖ Thus many marsupials became extinct when coexisting with eutherians.

🐒 Describe the trends in primate evolution that are advantageous...

❖ Eyes faced forwards: - overlapping visual fields & stereoscopic vision. ❖ Cerebellum enlarged: - allows more precise muscular movements & dexterity. ❖ Cerebrum enlarged - associated with evolution of greater mental powers - allowed for complex social behaviour

🐾 Describe the Order Trichodonta, including why its are useful when trying to understand mammal ancestors...

❖ First mammals had cheek teeth with 3 conical cusps in a linear series (hence the name). ❖ Fossils found over much of world evolved when all present continents joined in Mesozoic as Pangaea. ❖ By comparing modern day mammal teeth to extinct fossils we can paint a picture of what some of the Mesozoic mammals would have fed on & use this to work out ecomorphologies, how their physical adaptations relate to their ecological role. ❖ Fossils show there to be a large amount of diversity & specialization within these first mammals.

🐨 Explain why the higher level phylogeny of eutherian mammals has undergone major changes?

❖ Has undergone radical changes in last 15 years, because of gene sequencing studies. ❖ Earlier phylogenies based on morphology are now thought to be incorrect, the outcomes of convergent evolution. ❖ Four placental super-orders recognised: - Afrotheria - Xenarthra - Laurasiatheria - Euarchontoglires

Describe Hedgehogs & moonrats....

❖ Hedgehogs & moonrats - 24 species ❖ Key difference is hedgehogs have spines moonrats (& gymnures) lack spines ❖ Hedgehogs covered in spines which are modified hairs with muscles at base which erect spine on contraction. ❖ Baby hedgehogs born with spines but stay hidden under the skin until out of birth canal then appear within hours of birth. ❖ Spines for defence & rolling into a ball. ❖ Spines have sharp tips and are largely hollow to reduce weight load. ❖ Temperate species heterothermic - hibernate in winter, reducing oxygen requirement to ~2% of active level.

Describe the cost of being small...

❖ High Surface Area to volume ratio - lose much heat relatively quickly ❖ Need to be almost constantly eating to replenish energy reserves e.g. Shrews eat equivalent of own mass in insects and worms each day. ❖ Associated with their high metabolisms they also have high respiration rates. ❖ e.g. "the respiration rate of a shrew can be more than 5,000 cu cm of air per kilogram of body weight per hour, compared with 200 cu cm for humans."

🐬 Describe the Elephant seal (Mirounga angustirostris) in terms of how it displays an interesting example of seal social organisation when on land...

❖ Highly polygynous (resource defence), Males 3x mass of females, huge proboscis. ❖ No paternal care after mating. ❖ Undertake bloody fights for dominant position on mating beaches. ❖ Few males monopolise. ❖ Alpha male may inseminate 100 females/season. ❖ Females may produce up to 14 pups in 12y lifespan. ❖ Peripheral, subdominant males hang around edges of harems and intercept females as they return to sea. ❖ Bulls so aggressive they attempt to mate with pregnant females, or may trample pups. ❖ Male pups attempt to steal milk from females which aren't their mothers, so they may grow to be big - not seen in females.

Describe the Order Rodentia, including the 2 suborders that can be split into 3 groups....

❖ Huge group as includes 42% of all mammal species. ❖ Suborder Sciurognathi includes: - Squirrel-like rodents - Mouse-like rodents ❖ Suborder Hystricognathi includes: - Cavy-like rodents

😈 Describe kin selection in bats...

❖ In many species, females return to natal area to give birth at maternity colonies. ❖ Can be long-lived (greater horseshoe bat 30 years). ❖ Matrilineal structure in colonies: related females may feed in same areas.

Describe Squirrel-like rodents, including their characteristics...

❖ Includes beavers, squirrels & springhare Most have simple teeth, lacking large cusps or sharp enamel of other rodents. ❖ Female rodents tend to be promiscuous, mating with more than one partner during a single oestrus period. ❖ To pass on their genes males need to make sure that at least of their sperms fertilises one of her eggs. ❖ Evolution has therefore resulted in males having massive testes as larger quantities of sperm are likely to father more of the offspring in a multi-paternal litter

🐬 Describe the features of the Toothed whales including their use of echolocation...

❖ Jaws extend as beak-like snout. ❖ Behind snout forehead rises in rounded curve - the melon. ❖ Possess single nostril single blowhole. Echolocation in toothed whales: ❖ Little light underwater. ❖ Sound travels further than in air. ❖ Echolocation evolved in at least 13 species of toothed whales. ❖ Brief clicks, < 1ms, at ultrasound frequency of 0.25 - 220 kHz. ❖ Sound produced by 'monkey lips' in nasal passages. ❖ Melon (waxy, lens-shaped body) focuses sound at forehead. ❖ Returning sounds channelled through oil-filled sinuses in lower jaw to inner ear. ❖ Inner ear isolated from skull by bubbly foam. ❖ Sperm whale produces intense ultrasound that may stun prey such as squid.

Describe the Order Lagomorpha, including it families & characteristic features...

❖ Lagomorph = "hare shaped" ❖ 92 species. ❖ 2 families: - Rabbits & hares - Pikas ❖ Distinguished from rodents by peg teeth, 2nd pair of incisors behind upper pair. ❖ Coprophagy - reingestion of faecal matter. ❖ Prolific breeders e.g. - 'induced ovulation' = eggs are released in response to mating - 'postpartum estrus' = become pregnant during lactation - evidence of 'superfetation' = capable of conceiving a second litter before the birth of the last young

😈 Describe Pteropodidae & its adaptations...

❖ Large eyes & orient themselves visually & also use sight to find food, usually fruits. ❖ Only some species of the genus Rousettus have developed a simple form of echolocation based on tongue clicks for roosting in deep caves. ❖ Large size: genus Pteropus can weigh 1.5 kg, wingspan 1.7 m.

🐬 Describe the features of the Baleen whales including their use of long-distance communication...

❖ Largest whales. ❖ Baleen grows as a series of horny plates from the sides of the upper jaw, occupying the position of the upper teeth in other animals. ❖ Thickness & number of baleen plates is related to the size & species of the prey taken ❖ E.g. extremely long & fine baleen indicates that the whale feeds on very small planktonic invertebrates ❖ Paired nostrils separate - thus has a double holed blowhole Long-distance communication: ❖ Large baleen whales use low frequencies (20-3000 Hz). ❖ Low frequencies travel far. ❖ Deep ocean channels form under specific water densities, temperature & currents, & may trap sound like a cylinder. ❖ Sound may travel 5600 km in such channels. ❖ Sound pollution (boat noise) sometimes interferes with this.

🐾 What are the benefits of using mammary glands to feed offspring?

❖ Likely to get a constant supply of food even if there are peaks and troughs in external food supplies for the mother thus increasing the likelihood of offspring survival ❖ This is because she can divert her own nutrition into making milk even if supplies temporarily dwindle in the environment. ❖ Great strategy for growing fast as sucking from a boob is pretty easy & requires very little energy ❖ So energy obtained from the milk can be put into growing rather than chewing or hunting, latter obviously has risks of injury or death.

🐒 Describe the Infraorder Tarsiiformes...

❖ Located in southeast Asia ❖ Classification has been controversial, now placed in Haplorrhini. ❖ Tend to be nocturnal & are unusual as they restrict their prey to insects (unlike other primates) ❖ Can communicate with ultrasonic calls.

🐾 Describe the use of mammary glands in mammals...

❖ Mammae AKA mammary glands = Developed form modified sweat glands, has the role of milk production ❖ Mammillae AKA nipple/teat = Delivers the milk, generally females have twice as many nipples as the average litter size in that species ❖ A weird exception is the paternal lactation in Dayak fruit bats, which is thought to be due to high levels of Estrogen in fruits the bats eat.

🐾 Describe mammal phylogeny....

❖ Mammals are a Class. ❖ Class mammalia is divided into 2 subclasses: - Prototheria (egg layers) - Theria (live young). ❖ Subclass Theria is further divided into 2 infraclasses: - Marsupalia (formerly known as Metatheria) - Placentalia (formerly known as Eutheria). ❖ Mammalian phylogeny undergoing radical changes. ❖ 27 Orders (1 prototherian, 7 marsupial, 19 placental). ❖ 5,488 species described at recent count (2008). ❖ Of this 2,300 are rodents, & 1,100 are bat species.

🐬 Suggest the purpose of seals using click vocalisations underwater, also describe the reproductive adaptations of seals....

❖ May be used for echolocation as an additional source of information when hunting fish etc. ❖ Typically pinnipeds breed in spring or early summer after a bought of heavy feeding to stock up their fat reserves ready for a terrestrial fasting phase ❖ Females exhibit delayed implantation as the Blastocyst remains dormant in the womb for about 4 months before implanting in the uterine wall ❖ This is a good strategy as it reduces the time that seals need to spend on land, compressing birth & mating into a single period ❖ Mothers suckle infants over a few days or several weeks (varies per species) before mating again with a dominant bull. ❖ Thus mother-pup contact can be pretty limited in true-seal species.

🐬 Describe the features of the Blue whale & why its large size is only possible in water...

❖ May reach 27m, weigh 150 tonnes (33 elephants). ❖ Only possible in water where supported by water's dense buoyancy as on land it would need limbs so huge that mobility would be greatly restricted. ❖ Streamlined, lost hind limbs (trace internally), no external ears, sexual organs are hidden away to reduce drag ❖ Horizontal fins, boneless tail fluke, some spp have upright boneless dorsal fin.

🐒 Describe the Infraorder Simiiformes including its two parvorders & how they can be destinguished from eachother...

❖ Monkeys, apes & humans. ❖ Mainly diurnal, fairly flat faces devoid of fur. ❖ Can sit on haunches. ❖ Large brains. 1. Parvorder Platyrrhini: - New world monkeys, including marmosets & tamarins. - Widespread nostrils & flat nose. - Retain all 3 premolar teeth in each side of jaw. - Arboreal, many use prehensile tail as 5th limb. 2. Parvorder Catarrhini: - Includes Old world monkeys, apes & humans. - Downward pointing nostrils in narrow nose. - 2 premolars on each side of jaw. - Within Parvorder Catarrhini there are 3 families: Circopithecidae, homonidae & hylobatidae ❖ The platyrrhini & catarrhini can be distinguished by the positioning of their nostrils. e.g. Platy means 'flat' as they have broad nostrils whereas the catarrhine have nostrils that slope downwards similar to a cats

🐨 What has the sequencing of an Opossum genome revealed about the development of advanced immune systems & the development of the modern eutherian mammals?

❖ Monodelphus domestica, genome sequenced in 2007. ❖ Advanced immune function genes: the common ancestor of marsupials & eutherian mammals therefore had all the basic building blocks that now make up the human immune system. ❖ Most genetic innovations that led to modern eutherian mammals were not new genes but changes in regulatory DNA sequences (which alter developmental gene EXPRESSION) & other noncoding elements.

🐒 Describe the Suborder Strepsirrhini, including the infraorder lemuriformes & its primitive features...

❖ More typical of ancestral primates, with longer snouts, better smell, & smaller brains. Includes: - Lorises (Asia); - Bush babies & pottos (Africa); - Lemurs & Aye-aye (Madagascar); Lemur family: ❖ 4 types/families on Madagascar. ❖ Isolated from African mainland for at least 80 Mya, & underwent major adaptive radiation. ❖ Many extinct, including giant sloth lemur. ❖ Extant species threatened by deforestation. ❖ Many are monogamous. ❖ Primitive features: - Most of claws have become nails. - Molars still triangular, hints of becoming bunodont. - Binocular field 114-130º, verses about 140-160º in monkeys.

😈 Describe Microchiroptera & its adaptations...

❖ Most are small (70% < 20g). ❖ World's smallest mammal is bumble-bee bat (2g). ❖ All use laryngeal echolocation for orientation, many for prey detection. ❖ Ears more conspicuous & many species also have nose appendages in connection with the specialised echolocation system.

Describe Artiodactyl features & diversity...

❖ Much more speciose & diverse than Perissodactyla. ❖ 196 species in 10 families. ❖ Three main types: - Pigs, peccaries & hippopotamuses - Camels & llamas - Ruminants ❖ Ruminants have a fermentation chamber within multi-chambered stomachs to aid with cellulose digestion. ❖ Hugely widespread although ironically many are threatened because they have been removed by humans only to have been replaced by domesticated versions of the same animal.

😈 Describe the feeding biology of bats in terms Nectarivores....

❖ Nectarivory could have evolved from insectivory as many insects visit flowers ❖ Nectar & pollen provides a good balanced diet of carbohydrate & protein. ❖ Some flowers have evolved features to attract bats (e.g. acoustic guides). ❖ Plants pollinated by bats often have pale nocturnal flowers. ❖ These flowers are often large and bell shaped, & some bats have evolved specifically to reach the nectar at the bottom of them e.g. long tongue of the tube-lipped nectar bat

🐨 Describe marsupial reproduction e.g. in kangaroos, including advantageous adaptations....

❖ Newborns poorly developed, but well developed forelimbs. ❖ Crawl to nipples in pouch & continues to develop. ❖ Females can become pregnant during lactation (postpartum estrus), & embryo can be arrested at blastocyst stage via embryonic diapause. ❖ This strategy is advantageous as: - If an infant in the pouch dies the female can give birth again very rapidly. - It means she can have rapid succession of offspring within the suitable environmental conditions. ❖ Mother can therefore have joey at heel, second offspring on other pouch nipple, arrested blastocyst in uterus.

🐾 Describe mammalian evolution, including which clade shares common ancestors with mammals.... How are temporal fennestra used to distinguish these ancestors?

❖ Not the last vertebrate class to appear: fossil mammals known from at least 160 Mya, which is older than oldest known bird fossils. ❖ Share a common amniote ancestor with reptiles. ❖ Anapsids, diapsids & synapsids, identified by the number of lateral temporal fenestra/ openings in the skull which are used to facilitate attachment of jaw muscles: - Anapsids = no temporal fenestra - Synapsids = 1 temporal fenestra - Diapsids = 2 temporal fenestra ❖ Only surviving group of anapsids are the chelonians. ❖ Diapsids diversified into the other reptilian clades - the squamates (lizards & snakes), the crocodilians & the tuataras as well as the birds. ❖ Synapsids, those with only one temporal fennestra gave rise to the mammalian clade.

🐬 Describe the Walrus (Odobenus rosmarus.) & its adaptations...

❖ Odobenus rosmarus = 'tooth-walking sea-horse' ❖ Both sexes have tusks, used in battle between males, defence & for hauling themselves out of the water onto the ice. ❖ Skull specialised for feeding on clams & other benthic invertebrates.

🐬 Describe the Order Sirenia & its adaptations...

❖ Only marine mammals to feed primarily on plants. ❖ Stomachs not compartmentalised, long intestines (45 m in manatees). ❖ Between small and large intestines is a large mid-gut caecum where cellulose digestion occurs. ❖ Can process 8-15% of body mass in low quality plant material daily. ❖ Expend little energy - 1/3 that expected for mammals of their size. ❖ Move slowly, live in warm tropical waters. ❖ Constant replacement of teeth, as in elephants, allows them to eat plants that contain much abrasive silica. ❖ Store much fat e.g. Amazonian manatee can fast for 6 months in dry season, when plants scarce due to having large amounts of blubber. ❖ Today only 4 sirenians left: 1 dugong & 3 manatees. ❖ Used to be Steller's sea cow but this was exterminated by humans a few hundred years ago

🐒 Describe how humans differ from the other primates within the Family Hominidae...

❖ Our DNA sequences differ by, on average, only 1.2 % from those of the chimpanzees. ❖ We are thought to have split from chimps around 5 million years ago. ❖ Before the advent of molecular data, the human-chimpanzee divergence was widely believed to have happened about 30 million years ago. ❖ One of the key things that sets us humans apart from non-human apes is language.

🐾 Describe how unique jaw articulation has evolved in mammals... Which two bones does articulation occur between in modern day mammals?

❖ Our pre-mammalian ancestors had many bones in their lower jaws such as the articular bone and the quadrate bone. ❖ Over time the dentary bone became enlarged and there was a reduction in the number & size of the other, post-dentary bones. ❖ Two of these other bones, the quadrate & articular shifted backwards, upwards & inwards & now form part of the working of our middle ears, the incus & malleus respectively. ❖ Having these bones in the middle ear created an ear structure that not only transmits sound waves but amplifies them & therefore allowed for more acute hearing. ❖ This resulted in articulation occurring between the squamosal & dentary bone joints in mammals. ❖ With just one joint between the lower jaw & the cranium, it has allowed for more efficient chewing.

Name & briefly describe the two orders the Ungulates (AKA hoofed mammals) are split into....

❖ Perissodactyla: - Axis of foot passes through 3rd (largest) toe. - Odd-toed ungulates. ❖ Artiodactyla (now cetartiodactyla): - Axis of foot passes between 3rd & 4th toes. - Even-toed ungulates.

🐬 Describe the Pinnipedes, including the three families (Odobenidae, Otariidae, & Phocidae) within the order Carnivora....

❖ Pinnipeds - a term meaning feather/fin/web-footed' ❖ 3 families: - Walrus AKA Odobenidae - Eared seals AKA Otariidae - True seals AKA Phocidae ❖ Note different gait of sea lions and seals. ❖ Feed offshore, give birth on land. ❖ Vision is very important to them and they tend to have large eyes the cornea is constantly lubricated by tears to protect them from salt and sand

Describe Panda as an unusual example of the Ursidae family within the order Carnivora....

❖ Prime example of a non-carnivorous carnivore, eating bamboo, although it will occasionally eat meat when available. ❖ Bamboo provides enough nutrition for survival, but little extra, so pandas in the wild eat up to 40 percent of their body weight ❖ So specialised that even one of their wrist bones has evolved into a 'pseudothumb' for handling bamboo stems.

🐨 Describe the different reproductive strategies that the Infraclass Methatheria (AKA marsupials) have evolved, in comparison to the eutherian mammals...

❖ Probably separated from common ancestor with eutherian mammals late in Jurassic period. ❖ Thereafter evolved very different reproductive strategies. ❖ Eutherians: intricate & relatively long-lasting placental relationship between foetal membranes & uterine linings. ❖ Marsupials: also have a placenta (in the form of the yolk sac), but only makes loose contact with foetus & it is short-lived. ❖ After a short gestation (13d opossum & 35d wallaby) they are born through a third, central uterine canal. ❖ Longer gestation in eutherians (about 45d shrew & 650d elephant)

Describe Mouse-like rodents, including their characteristics...

❖ Rats & mice; voles & lemmings; hamsters; gerbils; dormice; jumping mice, birchmice & jerboas; pocket gophers; pocket mice & kangaroo rats. ❖ >1/4 of all mammal species. ❖ Mainly seedeaters but exploit many other foods too. ❖ r-strategists: adapted for early & prolific reproduction.

🐨 Describe the features of the order Monotremata...

❖ Retain many reptilian features: - lay & brood eggs - single hole for discharge of faeces, urine & gametes - this is called a cloaca. ❖ Infants cannot suck milk, but lap milk discharged from nipple less mammary glands onto tufts of hair. ❖ Extant species lack teeth (have horny plates instead) & have venom glands. ❖ Five living species in 2 families: - Echidnas (4) - & Duck-billed platypus (1)

😈 Describe reciprocal altruism in bats such as sanguivores...

❖ Small groups of females associate in roosts. ❖ If one female is unsuccessful in obtaining blood, others will regurgitate some. ❖ Females who are regurgitated to will later return the favour, thus reciprocity is important. ❖ Kin selection also partly explains regurgitation. Bats only share with kin & reliable roosters.

😈 Describe gleaning as a method used by some insectivore bats...

❖ Some bats glean non-volant (non-flying) prey from surfaces. ❖ Echolocation ineffective for finding prey on complex surfaces, so gleaning species often have large ears to listen for prey-generated sounds. ❖ e.g. Greater mouse-eared bat (Myotis myotis), will fly low to ground listening for prey, often pursuing on foot.

🐨 Describe the super-order Xenarthra....

❖ Split into 2 orders: - Pilosa = anteaters and sloths - Cingulata = armadillos ❖ Evolved in South America, where most extant species live. ❖ Teeth reduced in size, or lost. ❖ Usually have large claws on toes. ❖ Often have diet low in energy content - anteaters & sloths have metabolic rates 33-60% of that expected for size, & can vary Tb 32.7-35C to reduce energy expenditure.

Describe the African mole rat as an example of Cavy-like rodents, including its sexual reproduction.....

❖ Subterranean, social structure resembles that seen in some social insects. ❖ In each colony, a single pair breeds. ❖ Remaining animals belong to castes, distinguished by size and function. ❖ Small animals in working-caste: carry food & nest material to communal nest. ❖ Larger animals in non-working caste: associate with breeding female & may be involved in colony defence. ❖ Young cared for by all females, only suckled by breeding female. ❖ Once young are weaned, all join working caste. ❖ Some remain there all life, others grow larger & become non-workers. ❖ Non-breeders are not sterile thus can form new colonies, & replace breeding animals if these die. ❖ Breeding prevented by chemical stimuli produced by the breeding female ❖ All animals in colony closely related as some forfeit reproduction to help propagate genes of close relatives (kin selection).

😈 Describe the feeding biology of bats in terms Piscivores & Carnivores...

Piscivory: ❖ 2-3 species, including greater bulldog bat. ❖ Bat detects ripples on water surface by echolocation. ❖ Probably evolved from insectivorous trawling species, e.g. Daubenton's bat. Carnivory: ❖ Some large species eat small mammals, geckos, even other bats. ❖ Frog-eating bat detects calling prey, & rejects poisonous species.

🐬 How does the locomotion of eared seals e.g. sea lions differ to the locomotion of true seals both in water & on land?

Sea lion locomotion: ❖ Large fore-flippers for propulsion. ❖ Hind-flippers play no part in sustained swimming. ❖ More agile than true seals on land. ❖ Can support weight on fore flippers, both fore- & hind-flippers used in terrestrial locomotion as they can turn their hind flippers forward & use them to walk. True seal locomotion: ❖ Use hind flippers for swimming. ❖ Main muscle mass at rear. ❖ Not agile on land as they cannot bring forward their hindflippers in order to walk when on land

🐾 Describe mammalian evolution, including the transition from Synapsids to Therapsids to the first Mammals...

❖ Synapsids: ・First mammal-like features in the Subclass ・Synapsida, over 300 million years ago (Mya) ・Synapsid order Pelycosauria included Dimetrodon. ・Pelycosaurs were replaced in late Permian (270 Mya) by more advanced synapsids, in the order Therapsida. ❖ Therapsids: ・Had several mammal-like characteristics: - Limbs beneath body (confers more rapid locomotion) - Secondary palate separating mouth from nasal passages (eat & breathe at same time) - Still had bones in lower jaw that became incorporated into malleus & incus of middle ear in mammals. ❖ First Mammals: ・Separated from therapsids in late Triassic, about 240 Mya. ・The first mammals (so those with a dentary squamosal articulation) were small, in general many times smaller than the smallest dinosaurs. ・Probably largely nocturnal & insectivorous - niche not available to ectothermic reptiles

🐾 Describe teeth as a feature in mammals...

❖ Teeth replaced once or never, not continuously. ❖ Typically placental mammals have two sets of teeth, the milk/deciduous set differing in form & function from the adult set (note molars not milk). ❖ Prismatic enamel on teeth. ❖ Types of teeth: incisors, canines, pre-molars & molars

😈 Describe bat wings & why the wing shape is important...

❖ The wing is modification of pentadactyl limb: - Thumb for climbing - Fingers for spreading wings ❖ Bats are the only mammals capable of powered flight ❖ Wing-shape determines flight speed & manoeuvrability e.g. ❖ Fast flying species have: - Long & narrow wings - Little drag on wings confers efficient flight. - High wing loading - carry much weight per unit wing area - Confers fast flight, low manoeuvrability. ❖ Conversely, species that fly in forests & confined spaces have: - A low aspect ratio & a low wing loading. - Low loading confers slow flight, & the ability to turn in small volumes of space

🐾 What big difference would we observe between modern mammals & our therapsid ancestors?

❖ There was expansion of the temporal skull opening & rearrangement of jaw musculature alongside the development of a zygomatic arch ❖ Reduction in ribs allowed for more flexibility in movement, especially dorsoventrally. ❖ Dentition changed from a homodont condition, where all teeth were the same, to a heterodont condition where there was tooth differentiation & food could be processed more efficiently. ❖ Also 'soft' changes too (physiology, metabolism) ectothermic synapsid to an endothermic mammal.

Describe the primitive features that small mammals within the order Eulipotyphla have retained...

❖ They have retained several features of ancestral eutherians including: 1. Nocturnal - poor vision - other senses well developed 2. Small brain - cerebrum has a smooth surface. 3. Many teeth - typically I3/3 C1/1 P4/4 M3/3 (AKA 12 incisors, 4 canines, 16 pre-molars, & 12 molars) - Only giant armadillo, bat-eared fox & toothed whales have more teeth. 4. Intra-abdominal testes = no scrotum. 5. Cloaca.

🐨 Where did marsupials originally evolve as based on fossil evidence...

❖ Today most marsupials are found in Australia. ❖ Oldest marsupial fossils found in modern day China & North America ❖ Fossil record, plate tectonic models & molecular phylogenetics. ❖ They analysed 53 retroposons & concluded that the Australian marsupials formed a monophyletic group but that it was nested within the south American marsupial branches of the phylogeny. ❖ South America was connected to Australia via what is now Antarctica ❖ Marsupials living in North America spread to South America before moving to antartica then on to Australia. ❖ Thus marsupials evolved in China as well as in North & South America

🐨 Describe Armadillos & their adaptations...

❖ Tough carapace develops from skin, & is composed of strong, bony plates (scutes) overlaid by horn. ❖ 21 species, 3-13 bands. ❖ Three-banded armadillos can roll themselves into a ball for protection. ❖ Penis is one of the longest among mammals, extending two-thirds of the body length in some species

🐒 Describe the Order Scandentia, including adaptations...

❖ Tree shrews - Confusing name as they are not shrews nor to they exclusively live in trees. ❖ 19 species, found in southeast Asia. ❖ Semi-terrestrial, squirrel-like mammals ❖ Omnivorous, often diurnal. ❖ Long linked to primates, now thought to be clearly distinct. ❖ The development of the placenta in tree shrews is quite unlike that of any primate species, & the offspring are born in a naked, helpless condition that contrasts markedly with the advanced condition of newborn primates. ❖ Canine teeth are poorly developed, primitive sharp-cusped molars reflect an insectivorous diet & forward-projecting lower incisors are used in feeding & grooming.

Describe the difference between deer & bovids...

❖ True deer (family Cervidae) have antlers which (like horns), are made of bone, but antlers are shed & regrown annually. ❖ Usually serve in intrasexual selection - carried by males. ❖ Only in reindeer do females have antlers as this allows females to dig craters in snow & reach lichens & vegetation in winter. ❖ Family Bovidae (cattle, goats, antelopes) have horns. ❖ Some, such as red deer use them to fight for mating rights & access to females.

🐨 Briefly, describe early radiation of Xenarthra...

❖ Underwent extensive adaptive radiation in South America when isolated & were extremely diverse (65 Mya-2.5 Mya) ❖ 38 Mya - 3 families of giant ground sloths, some as large as elephants. Some existed until historic times. ❖ These were possibly outcompeted by North American invaders, while some are likely to have been finished off by human hunters

😈 Describe the use of echolocation in bats...

❖ Used by all bats except most Pteropodidae for orientation (not navigation). ❖ Most species use frequencies 20-60 kHz, range (11-212 kHz). ❖ Wide range of signal designs, from frequency-modulated signals (excellent for localisation), to constant-frequency signals which are excellent designs for detecting & classifying insect targets. ❖ Short range because ultrasound attenuates rapidly in air. ❖ Higher frequencies = higher resolution but higher absorption.

🐨 Describe the subclass Prototherian in terms of the evolution of the monotremes....

❖ Within the subclass prototheria there is only one surviving order - the monotremes. ❖ Most primitive mammals alive today, few fossils. ❖ There is lots of debate about the origin of the monotremes but one idea suggests they evolved from creatures called Australosphenidans. ❖ Continents broke up in late Mesozoic era, ancestors of monotremes restricted to southern supercontinent, Gondwana.