Main Points 1) Diversity, Phylogeny, and Systematics -- Subclasses Prototheria and Theria -- Infraclass Metatheria (Marsupialia), Orders Monotremata through Dasuyuromorphia 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 Prereading: Mon Sep 16 = Wong Weds 18 Sep = Sykes et al 2014 Terms: diagnostic, oviparous, cloaca, altricial, marsupium, adaptive radiation, continental island, oceanic island, hallux, monotypic, derived, iteroparity, semelparity 1 Evolutionary Distinctiveness of Class Mammalia evolutionary distinctiveness high low Holt et al. 2013. 2 Evolutionary Distinctiveness of Class Mammalia evolutionary distinctiveness high low Holt et al. 2013. 3 Six Zoogeographic Regions 4 Subclass Prototheria Gomez et al. 5 2016. Subclass Prototheria Subclass Prototheria Prototheria Gomez et al. 6 2016. Subclass Prototheria, Order Monotremata Taxonomy: 5 species Distribution: Australasian, in coastal, southeastern Australia and New Guinea (echidnas only) western long-beaked short-beaked echidna echidna duck-billed platypus 7 Subclass Prototheria, Order Monotremata Taxonomy: 5 species Distribution: Australasian, in coastal, southeastern Australia and New Guinea (echidnas only) Diagnostic characters: 1) oviparous 2) mammary glands lacking nipples 3) no pinnae 4) no teeth 5) cloaca 8 Subclass Prototheria, Order Monotremata short-beaked echidna nose poking 9 Subclass Prototheria Subclass Theria Infraclass Metatheria Metatheria Theria Gomez et al. 10 2016. Subclass Theria, Infraclass Metatheria Taxonomy: 7 orders Distribution: 4 orders Australasian, 3 orders Neotropical 11 Wallace’s Line and Oceanic vs Continental Islands 12 Discussion Q: what types of islands would you expect to have mammals more similar to the mainland? What types of mammals would you most expect to see on islands? 13 Late Jurassic, ~150 MYA 14 Subclass Theria, Infraclass Metatheria sugar glider flying squirrel white-tailed deer red kangaroo black-tailed jackrabbit rabbit-eared fishing cat bandicoot tiger quoll 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 16 Order Didelphimorphia: opossums Taxonomy: 63 species Distribution: Neotropical, 1 species Nearctic Characteristics: -- most generalized metatherians -- clawless hallux (big toe) -- prehensile tail Virginia opossum common opossum yapok 17 Order Paucituberculata: shrew opossums Taxonomy: 6 species Distribution: Neotropical (Andes mountains) Characteristics: -- no marsupium -- convergent with shrews 18 Order Microbiotheria: monito del monte Taxonomy: 1 species (monotypic order) Distribution: Neotropical (Andes mountains) Characteristics: -- genetically similar to Australian metatherians -- hibernates 19 Order Dasyuromorphia: marsupial “carnivores” Taxonomy: 61 (or 62?) species Distribution: Australasian Antechinus spp. Tasmanian devil numbat 20 21 Order Dasyuromorphia: marsupial “carnivores” Taxonomy: 61 (or 62?) species Distribution: Australasian Characteristics: -- well-developed canines -- derived dental formulae (42-46 teeth) -- marsupium usually absent Antechinus spp. Tasmanian devil numbat 22 Order Dasyuromorphia: marsupial “carnivores” Taxonomy: 61 (or 62?) species Distribution: Australasian Characteristics: -- well-developed canines -- derived dental formulae (42-46 teeth) -- marsupium usually absent -- some semelparity (not diagnostic) Antechinus spp. Tasmanian devil numbat 23 prob. annual survival annual fecundity (#ofper litter) kidsfecundity annual 0.2 0.4 0.6 0.8 1.0 0 2 4 6 8 Evolution of Evolution Semelparity 24 Evolution of Semelparity 1.0 vival 0.8 typical nual sur nual metatherian n 0.4 0.6 prob. a 0.2 0 2 4 6 8 annual fecundity (# of kids per litter) 25 Evolution of Semelparity 1.0 Antechinus spp. vival 0.8 typical nual sur nual metatherian n 0.4 0.6 prob. a 0.2 0 2 4 6 8 0 2 4 6 8 annual fecundity (# of kids per litter) 26 constant year 1 year 1 year 2 year 2 # kids per prob survival mean # kids prob survival mean # kids litter 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 8 0 0 0 0 .8 1.0 vival typical metatherian 0.6 0 nual sur nual n 0.4 prob. a 0.2 27 0 2 4 6 8 constant year 1 year 1 year 2 year 2 # kids per prob mean # kids prob survival mean # kids litter survival 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 8 0 0 0 0 .8 1.0 vival typical metatherian 0.6 0 nual sur nual n 0.4 prob. a 0.2 28 0 2 4 6 8 constant year 1 year 1 year 2 year 2 # kids per prob mean # kids prob mean # kids litter survival survival 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 8 0 0 0 0 .8 1.0 vival typical metatherian 0.6 0 nual sur nual n 0.4 prob. a 0.2 29 0 2 4 6 8 Evolution of Semelparity 1.0 Antechinus spp. ival 0.8 typical ual surv metatherian nn 0.4 0.6 ob. a pr 0.2 0 2 4 6 8 0 2 4 6 8 annual fecundity 30 12 10 typical cundity metatherian 8 6 lifetime fe Antechinus spp. 4 2 estimated 0 0 2 4 6 8 annual fecundity 31.