Main Points. 3) Reproductive strategies in dasyuromorphs -- example: the evolution of semelparity

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1 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

2 Zoogeographic Regions 2

3 Subclass Prototheria 3

4 Subclass Prototheria 4

5 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

6 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

7 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

8 Discoveries of New Mammals Attenborough s long-beaked echidna 8

9 Subclass Theria, Infraclass Metatheria 9

10 Subclass Theria, Infraclass Metatheria Taxonomy: 7 orders Distribution: 4 orders Australasian, 3 orders Neotropical 10

11 Wallace s Line 11

12 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

13 Late Jurassic, ~150 MYA 13

14 Subclass Theria, Infraclass Metatheria sugar glider flying squirrel red kangaroo white-tailed deer rabbit-eared bandicoot black-tailed jackrabbit marsupial cat fishing cat 14

15 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

16 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

17 Order Paucituberculata: shrew opossums Taxonomy: 1 family, 3 genera, 6 species Distribution: Neotropical (Andes mountains) Characteristics: -- no marsupium -- convergent with shrews 17

18 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

19 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

20 Order Dasyuromorphia: marsupial carnivores Taxonomy: 2 (or 3?) extant families, 15 genera, 61 species Distribution: Australasian Tasmanian devil numbat Antechinus spp. 20

21 21

22 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

23 Evolution of Semelparity prob. post-breeding survival annual fecundity (# of kids per litter) 23

24 Evolution of Semelparity prob. post-breeding survival typical metatherian annual fecundity (# of kids per litter) 24

25 Evolution of Semelparity prob. post-breeding survival typical metatherian Antechinus spp annual fecundity (# of kids per litter) 25

26 constant year 1 year 1 year 2 year 2 # kids per litter prob survival mean # kids prob survival mean # kids typical metatherian

27 constant year 1 year 1 year 2 year 2 # kids per litter prob survival mean # kids prob survival mean # kids typical metatherian

28 constant year 1 year 1 year 2 year 2 # kids per litter prob survival mean # kids prob survival mean # kids typical metatherian

29 estimated lifetime fecundity typical metatherian Antechinus spp annual fecundity 29

30 Evolution of Semelparity prob. post-breeding survival typical metatherian Antechinus spp annual fecundity 30

31 Order Diprotodontia: kangaroos, wallabies, phalangers, possums, wombats Taxonomy: 10 families, 117 species spotted cuscus Distribution: Australasian hairy-nosed wombat koala red kangaroo 31

32 Order Diprotodontia: kangaroos, wallabies, phalangers, possums, wombats Taxonomy: 10 families, 117 species Distribution: Australasian Characteristics: --diprotodont teeth --syndactyly 32

33 Order Peramelina (Peremelimorphia): bandicoots Taxonomy: 2 families, 21 species Distribution: Australasian rabbit-eared bandicoot Eastern barred bandicoot 33

34 Order Peramelina (Peremelimorphia): bandicoots Taxonomy: 2 families, 21 species Distribution: Australasian Characteristics: -- hind limbs specialized for hopping -- have placenta, in addition to marsupium 34