Main Points 1) Mammalian Characteristics: Diversity, Phylogeny, and Systematics -- Subclasses Prototheria and Theria -- Infraclass Metatheria (Marsupialia) -- Orders Monotremata through Peramelina 2) Modern distributions of prototherians and metatherians -- adaptive radiations -- example: Wallace s line and continental vs. oceanic islands 3) Reproductive strategies in dasyuromorphs -- example: the evolution of semelparity 4) Terms: sister group, oviparous, cloaca, altricial, marsupium, adaptive radiation, continental island, oceanic island, monotypic, fossorial, iteroparity, semelparity, syndactyly Pre-reading: Monday 14 Sept = Wong 2002 Wednesday 16 Sept = Sykes et al 2014, Macleod 2014 1
Zoogeographic Regions 2
Subclass Prototheria 3
Subclass Prototheria 4
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 5
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 6
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 7
Discoveries of New Mammals Attenborough s long-beaked echidna 8
Subclass Theria, Infraclass Metatheria 9
Subclass Theria, Infraclass Metatheria Taxonomy: 7 orders Distribution: 4 orders Australasian, 3 orders Neotropical 10
Wallace s Line 11
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? 12
Late Jurassic, ~150 MYA 13
Subclass Theria, Infraclass Metatheria sugar glider flying squirrel red kangaroo white-tailed deer rabbit-eared bandicoot black-tailed jackrabbit marsupial cat fishing cat 14
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 15
Order Didelphimorphia: opossums Taxonomy: 1 family, 15 genera, 63 species Distribution: Neotropical, 1 species Nearctic Characteristics: -- most generalized metatherians -- clawless hallux (big toe) -- prehensile tail 16
Order Paucituberculata: shrew opossums Taxonomy: 1 family, 3 genera, 6 species Distribution: Neotropical (Andes mountains) Characteristics: -- no marsupium -- convergent with shrews 17
Order Microbiotheria: monito del monte Taxonomy: 1 family, 1 genus, 1 species (monotypic order) Distribution: Neotropical (Andes mountains) Characteristics: -- genetically similar to Australian metatherians -- hibernates 18
Order Notoryctemorphia: marsupial mole Taxonomy: 1 family, 1 genus, 1 species (monotypic order) Distribution: Australasian Characteristics: -- no pinnae -- eyes vestigal, ears reduced -- enlarged claws -- convergent with other fossorial mammals 19
Order Dasyuromorphia: marsupial carnivores Taxonomy: 2 (or 3?) extant families, 15 genera, 61 species Distribution: Australasian Tasmanian devil numbat Antechinus spp. 20
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Order Dasyuromorphia: marsupial carnivores Taxonomy: 2 (or 3?) extant families, 15 genera, 61 species Distribution: Australasian Characteristics: -- well-developed canines -- derived dental formulae (42-46 teeth) -- marsupium usually absent 22
Evolution of Semelparity prob. post-breeding survival 0.2 0.4 0.6 0.8 1.0 0 2 4 6 8 annual fecundity (# of kids per litter) 23
Evolution of Semelparity prob. post-breeding survival 0.2 0.4 0.6 0.8 1.0 typical metatherian 0 2 4 6 8 annual fecundity (# of kids per litter) 24
Evolution of Semelparity prob. post-breeding survival 0.2 0.4 0.6 0.8 1.0 typical metatherian Antechinus spp. 0 2 4 6 8 0 2 4 6 8 annual fecundity (# of kids per litter) 25
constant year 1 year 1 year 2 year 2 # kids per litter prob survival mean # kids prob survival mean # kids 1 0.8 0.8 0.64 0.64 2 0.75 1.5 0.56 1.13 4 0.6 2.4 0.36 1.44 6 0.2 1.2 0.04 0.24 0.2 0.4 0.6 0.8 1.0 8 0 0 0 0 typical metatherian 0 2 4 6 8 26
constant year 1 year 1 year 2 year 2 # kids per litter prob survival mean # kids prob survival mean # kids 1 0.8 0.8 0.64 0.64 2 0.75 1.5 0.56 1.13 4 0.6 2.4 0.36 1.44 6 0.2 1.2 0.04 0.24 0.2 0.4 0.6 0.8 1.0 8 0 0 0 0 typical metatherian 0 2 4 6 8 27
constant year 1 year 1 year 2 year 2 # kids per litter prob survival mean # kids prob survival mean # kids 1 0.8 0.8 0.64 0.64 2 0.75 1.5 0.56 1.13 4 0.6 2.4 0.36 1.44 6 0.2 1.2 0.04 0.24 0.2 0.4 0.6 0.8 1.0 8 0 0 0 0 typical metatherian 0 2 4 6 8 28
estimated lifetime fecundity 12 10 8 6 4 2 typical metatherian Antechinus spp. 0 0 2 4 6 8 annual fecundity 29
Evolution of Semelparity prob. post-breeding survival 0.2 0.4 0.6 0.8 1.0 typical metatherian Antechinus spp. 0 2 4 6 8 0 2 4 6 8 annual fecundity 30
Order Diprotodontia: kangaroos, wallabies, phalangers, possums, wombats Taxonomy: 10 families, 117 species spotted cuscus Distribution: Australasian hairy-nosed wombat koala red kangaroo 31
Order Diprotodontia: kangaroos, wallabies, phalangers, possums, wombats Taxonomy: 10 families, 117 species Distribution: Australasian Characteristics: --diprotodont teeth --syndactyly 32
Order Peramelina (Peremelimorphia): bandicoots Taxonomy: 2 families, 21 species Distribution: Australasian rabbit-eared bandicoot Eastern barred bandicoot 33
Order Peramelina (Peremelimorphia): bandicoots Taxonomy: 2 families, 21 species Distribution: Australasian Characteristics: -- hind limbs specialized for hopping -- have placenta, in addition to marsupium 34