Main Points 1) Mammalian Characteristics (continued from last Wednesday) 2) Diversity, Phylogeny, and Systematics -- Subclasses Prototheria and Theria -- Infraclass Metatheria (Marsupialia) -- Orders Monotremata through Peramelina 3) Modern distributions of prototherians and metatherians -- adaptive radiations -- example: Wallace s line and continental vs. oceanic islands 4) Reproductive strategies in dasyuromorphs -- example: the evolution of semelparity Terms: pinna, Allen s rule, oviparous, cloaca, altricial, marsupium, adaptive radiation, continental island, oceanic island, monotypic, fossorial, iteroparity, semelparity, syndactyly Pre-reading: Wednesday 13 Sept = Wong 2002 Monday 18 Sept = Sykes et al 2014, Macleod 2014 1
Cryptic coloration Adaptive coloration 2
Cryptic coloration Adaptive Coloration 3
1) hair Some external characteristics of mammals 2) pinna (plural: pinnae) 4
Some external characteristics of mammals Allen s rule 5
Zoogeographic Regions 6
Subclass Prototheria 7
Subclass Prototheria 8
Subclass Prototheria, Order Monotremata Taxonomy: 5 species, 2 families Distribution: Australasian, in coastal, southeastern Australia and in New Guinea (echidnas only) long-nosed echidna short-nosed echidna duck-billed platypus 9
Subclass Prototheria, Order Monotremata Taxonomy: 5 species, 2 families Distribution: Australasian, in coastal, southeastern Australia and in New Guinea (echidnas only) Diagnostic characters: 1) oviparous 2) mammary glands lacking nipples 3) no pinnae 10
Subclass Prototheria, Order Monotremata Taxonomy: 5 species, 2 families Distribution: Australasian, in coastal, southeastern Australia and in New Guinea (echidnas only) Diagnostic characters: 4) cloaca 5) no teeth in adults 6) electroreceptors in snouts 11
Discoveries of New Mammals Attenborough s long-beaked echidna 12
Subclass Theria, Infraclass Metatheria 13
Subclass Theria, Infraclass Metatheria Taxonomy: 7 orders Distribution: 4 orders Australasian, 3 orders Neotropical 14
Wallace s Line 15
Discussion questions: which types of islands would you expect to have mammals more similar to the mainland? Which types of mammals would you most expect to see on islands? 16
Late Jurassic, ~150 MYA 17
Subclass Theria, Infraclass Metatheria sugar glider flying squirrel red kangaroo white-tailed deer rabbit-eared bandicoot black-tailed jackrabbit marsupial cat fishing cat 18
Subclass Theria, Infraclass Metatheria Taxonomy: 7 orders Distribution: 4 orders Australasian, 3 orders Neotropical Diagnostic characters: 1) dental formula = 5/4, 1/1, 3/3, 4/4 = 50 teeth 2) brain and braincase are relatively small 3) young are born altricial, and are carried in marsupium 4) cloaca 5) scrotum anterior to penis 19
Order Didelphimorphia: opossums Taxonomy: 63 species Distribution: Neotropical, 1 species Nearctic Characteristics: -- most generalized metatherians -- clawless hallux (big toe) -- prehensile tail 20
Order Paucituberculata: shrew opossums Taxonomy: 6 species Distribution: Neotropical (Andes mountains) Characteristics: -- no marsupium -- convergent with shrews 21
Order Microbiotheria: monito del monte Taxonomy: 1 species (i.e., monotypic order) Distribution: Neotropical (Andes mountains) Characteristics: -- genetically similar to Australian metatherians -- hibernates 22
Order Notoryctemorphia: marsupial mole Taxonomy: 1 species (monotypic order) Distribution: Australasian Characteristics: -- no pinnae -- eyes vestigal, ears reduced -- enlarged claws -- convergent with other fossorial mammals 23
Order Dasyuromorphia: marsupial carnivores Taxonomy: 2 (or 3?) extant families, 61 (or 62?) species Distribution: Australasian Tasmanian devil numbat Antechinus spp. 24
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Order Dasyuromorphia: marsupial carnivores Taxonomy: 2 (or 3?) extant families, 61 (or 62?) species Distribution: Australasian Characteristics: -- well-developed canines -- derived dental formulae (42-46 teeth) -- marsupium usually absent 26
prob. post-breeding survival 0.2 0.4 0.6 0.8 1.0 Evolution of semelparity 0 2 4 6 8 annual fecundity (# of kids per litter) 27
prob. post-breeding survival 0.2 0.4 0.6 0.8 1.0 Evolution of semelparity typical metatherian 0 2 4 6 8 annual fecundity (# of kids per litter) 28
prob. post-breeding survival 0.2 0.4 0.6 0.8 1.0 Evolution of Semelparity Antechinus spp. typical metatherian 0 2 4 6 8 0 2 4 6 8 annual fecundity (# of kids per litter) 29
Order Diprotodontia: kangaroos, wallabies, phalangers, possums, wombats Taxonomy: 117 species spotted cuscus Distribution: Australasian hairy-nosed wombat koala red kangaroo 30
Order Diprotodontia: kangaroos, wallabies, phalangers, possums, wombats Taxonomy: 117 species Distribution: Australasian Characteristics: --diprotodont teeth --syndactyly 31
Order Peramelina (Peremelimorphia): bandicoots Taxonomy: 21 species Distribution: Australasian rabbit-eared bandicoot Eastern barred bandicoot 32
Order Peramelina (Peremelimorphia): bandicoots Taxonomy: 21 species Distribution: Australasian Characteristics: -- hind limbs specialized for hopping -- have placenta, in addition to marsupium rabbit-eared bandicoot Eastern barred bandicoot 33