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 Evolution of Semelparity 1.0 vival 0.8 nual sur nual n 0.4 0.6 prob. a 0.2
0 2 4 6 8
annual fecundity (# of kids per litter)
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