Mammal

Where was the original metatherian/eutherian divergence? What are the three primary metatherian clades?

Asia. Ameridelphia, Australidelphia, and Deltatheroidea,

Why is precise occlusion and a diphyodont dentition impotant to suckling? Who pointed this out?

Polyphyodont teeth won't occlude perfectly until fully erupted. Need for precise occlusion means only one set of permanent teeth = diphyodont. Diphyodont (and reducing tooth sets) = liquid food so jaw can grow while teeth not necessary, until permanent teeth erupt. (= For precise occlusion, they need one set of permanent teeth which won't happen until teeth have fully erupted) Pond!

What was the longest surviving mammal clade (now extinct?)

allotherians, multituberculates

Are flying squirrels altricial or precocial?

altricial

The opossum belongs in which clade?

ameridelphia

What is myrmecophagous?

anteaters

What taxa are included in Xenarthra?

anteaters, sloths, armadillos

How do antlers and horns differ?

antlers=bony outgrowths, in males, velvet, branch, shed horns= bony core, keratin sheath, not shed, both sexes, no branching

What are the Dermoptera?

arboreal gliders

Explain sloths

arboreal, Eats buds, shoots, and leaves. Large, compartmentalized, slow stomach; digestion takes a month. Bacteria feeds on fur. Move only when need to, slow. Hang on tree with claws. Come down to pee once a week.

Scandentia fall into what clade?

archonta,

Which is the only species in N. America of armadillo

banded

What taxa are members of Peramelina?

bandicoot & bilbie

How can you distinguish between a bandicoot and a bilbie? Which look like "Australian marsupial rabbits?"

bandicoot-shorter legs, & bilbie, bilbie

Did synapsids radiate before or after diapsids?

before

what is the largest mammal

blue whale

What were the diprotodontians? What taxa fall into this group? What are the three main subclades discussed in class (know where the taxa fit)?

branch of australian marsupials, vombatiformes (wombat koala) phalangeriformes (possum) macropodiformes (kangaroo, wallabee)

What are some of the problems associated with muroids?

can cause food losses, carry pathogens

What are the clades and subgroups within Ferungulata?

carnivora, pholidota, perissodactyla, artiodactyla, cetacea

Which therapsid lineage gave rise to mammals? What happened to the rest of them? When?

cynodonts; went extinct during the end-permian

What are the three main clades of Australidelphia? Which taxa belong in these groups?

dasyuromorphia (marsupial cat/mice, tasmanian); peramelina (bandicoots, bilbies); diprotodontians (thylacoleo)

What features characterized theriodonts?

developed coronoid on dentary, flange near lower back jaw, larger temporal fenestra

Describe the wing of a chiropteran

digits with webbed membrane

Which of the three main subclades does a wombat fall into?

diprotodontians

What subclade does a kangaroo fall into? What is the main distinction between a wallaby and a kangaroo?

diprotodontians; kangaroo is larger with longer legs

Discuss climate shifts and ice ages during the Quaternary?

drastic cooling & climate fluctuation; 4 major, 20 minor ice ages, continental glaciers spread, ranges of plants & animals shifted towards equator, glaciers retreated 15k years ago

What are some typical characteristics of myrmecophagous taxa?

elongate jaws, reduced teeth, enlarged salivary glands, elongated tongue

What are the key features that link Pelycosaurs to more derived therapsids?

enlarged canine in maxillary bone, arched palate, flange on angular bone

What are the three primary radiations of Boreoeutheria?

euarchontoglires; laurasiatheria, ferungulata

What were borhyaenids?

extinct didelphoids

What is coprophagy and why is it necessary?

feeding on poop, get more nutrition such as b12 (no complex digestive)

What trait groups chiropterans in a category with birds and pterodactyls?

flight

What major change took place in the FLORA of the Cenozoic? How did the climate shift from the Eocene-Oligocene? What happened in the Miocene?

flowering plants came to dominate in forests except in cool regions; hot & humid at the beginning, cooler & drier halfway through

incisor

front teeth used for cutting, cropping, in rodent/tusks/horn/beaver; carnivores, many taxa (deer, tiger, pig)

What is the diet of most megachiroptera?

fruit

Name 2 myrmecophagous taxa in different clades.

giant anteater, silky anteater

What was diprotodon? What did he eat?

giant wombat, grazer of shrubs etc

Why would lactation be a selective advantage?

glands already secreting to protect eggs in nest; mutations that provided additional nutrients (fat, calories) were selected for

What are the clades and subgroups within Euarchontoglires?

glires, archonta

Be able to list/recognize the features of extant mammals

hair, mammary glands, live birth, dentary/squamosal jaw joint, large brain, large inner ear region, 3 ear bones, post canine teeth with divided roots, endotherms

What are the differences between a rabbit and a hare?

hares change color, have precocial young, simple nests but rabbits altricial, in colonies & dig burrows

Why are they called flying foxes?

have faces that resemble foxes or dogs

Why are rabbits able to move so fast?

have long legs & flexible backs

Lipotyphla includes what taxa?

hedgehogs, moles

Describe the feeding habits of a koala

herbivorous- eucalyptus

Name two of the smallest mammals

hog-nosed bat, etruscan shrew

How do rodent incisors self-sharpen?

inner surface sharper than outer enamel and wear away faster to create a sharp edge

What do most bats eat?

insects

Give 2 ways microchiroptera differ from megachiroptera.

lack under-fur, lack a claw on 2nd digit

Glires includes what two groups of taxa?

lagomorpha, rodentia

Give 10 derived features for therapsids (you'll be asked to list ~4, recognize all).

larger temporal fenestra, skull rigid, heterodont, longer upper canine, flexible neck, girdles lighter, limbs slender, longer stride, vascularized bones, trough in roof of mouth, enlarged choanae

What is the capybara? Which subclade is he in?

largest rodentia, caviidae like guinea pig

When (what eras AND how many years ago?) were mammals most abundant?

late carboniferous & permian

When did mammals first appear

late triassic/mesozoic

What are the clades and subgroups within Laurasiatheria?

lipotyphla, chiroptera

What is unusual about Xenartha metabolic rate?

lowest metabolism

heterodont vs homodont:

mammals have heterodont. We have molars, premolars, canines, and incisors

Provide the characteristics of a beaver and why this taxon may have a disproportionate effect on an ecosystem.

mate for life, have fam; medium size, semiaquatic, flat tail, webbed feet; herbivorous, build lodge (dams) which can create lakes & new habitat

How do Dermoptera differ from flying squirrels?

membrane extends through body and not just limbs

Which clade do vampire bats fall into?

microchiroptera

Which group of chiropterans echolocates?

microchiroptera

What are the only eusocial mammals?

naked mole rats

Describe/recognize the distinctive features of the mole-rat.

naked, blind, suckled for 4 weeks, fed poop by workers, no pain sensation in skin, low metabolism, tunnels, long life

How extensive is their patagium? for dermoptera

neck>forepaws, forepaws>hind feet & between toes

What physical structures would be important as suckling evolved?

nipple & sealed oral cavity for suction

Do flying squirrels actually fly?

no they glide

Did all forms of pelycasaurs have sails? Where did the sails come from? What was its function?

no, from elongation of neural spines, allow them to warm up quickly & retain heat by restricting blood flow

What other mammalian taxon echolocates?

odontocetes (whales & dolphins)

Monotremes today are separated into two families. What are those two families? Where are they found. What features do they share? What are some derived features/specializations of the platypus?

ornithorryhchidae & tachyglossidae; new guinea, australia; both lack teeth as adults and have leathery bill/beak, electroreceptors around bill for food binding; platypus has more electroreceptors, sperm are bird like and shaped like thread, males have venemous spurs on legs for defense

What were the three main SYNAPSID radiations?

pelycosaurs, therapsids, mammals

How are bats crucial for the ecosystem?

pest control, pollinate plants & distribute seeds

How does the queen prevent the other mole-rats from breeding?

pheromones

Which clade of cynodonts gave rise to mammals?

probainognathia

What is a lagomorph?

rabbit

What is the primary difference between a rat and a mouse (easy answer)

rats are bigger

To which clade do naked mole-rats belong?

rodentia

Archonta includes what 3 groups of taxa?

scandentia, primates, dermoptera

Where do mammary glands come from?

sebaceous glands

Describe the various skeletal modifications as therapsids became mammals

skull fenestration, condition of the lower temporal bar (zygomatic arch bows outward for attachment of jaw muscles), specialized hterodont dentitionnnn, diphydont, bony secondary palate (breathe & eat), parietal foramen (lost), position of limbs under body, shorter toes, lighter girdle

How big were the earliest mammals? What were they probably eating?

smaller than a mouse, insects

Why do burrowing marsupials tend to have backwards facing pouches?

so dirt doesn't enter

How does echolocation work?

sound waves produce echoes when they hit the prey

Where are Xenartha primarily found?

south america

Which rodent clade are scandentia most like?

squirrels

Mammals are derived from which clade of amniotes?

synapsid

What was the thylacine? What happened to it?

tasmanian wolf, extinct

When did rodents, marsupials, primates and ungulates (hoofed mammals) appear in North America?

tertiary period

Which taxon is a morphological link to between pelycosaurs and therapsids?

tetraceratops

What taxon replaced pelycosaurs?

therapsids

What clade represented the major predators during the late Permian/early Triassic?

theriodonts

How are microchiroptera able to find areas of highest blood concentration?

thermoreceptors on the nose

When are the young ready to leave the nest for flying squirrels?

10 weeks

How many species of chiroptera are there?

1100

How many armadillo species?

19

What/when were the two major radiations of mammals?

1st: jurassic to early cretaceous- morganucodonts, docodonts, triconodonts, symmetrodonts 2nd: cenozoic, therians & multituberculates

How many sensory (Eimers organs) organs are on a star-nosed mole's nose?

25,000

When did therapsids appear in the fossil record?

267 mya

How many lineages remain of the original mammal radiation?

3

What % of mammal species are comprised of rodents?

40%

There are approximately how many species of mammals?

4500

What were the dicynodonts? Where did they get their name?

Herbivore therapsids. Double tusks, no other teeth but had beak to grind plants.

What two major groups arose during the Cenozoic? The Laurasian radiation included which clades? The Gondwanan radiation included which clades?

Laurasian and Gondwanan. Laurasian included the Multituberculates and Therians. Gondwanan included the Monotremes and Metatherians.

What are some beneficial uses for muroids?

used in medical research, trained as bomb/drug sniffers, food for predators

Describe several features specific to its aquatic lifestyle of capybara

webbed feet for swimming, nostrils, eyes on top of head,