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Flashcards in Vertebrate of BC Part 2 Deck (484)
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151

Therians

live birth, mammae, cochlea, external ear, tricuspid molars, major pectoral girdle modification

152

Types of therians

marsupials
placentals

153

mammae

a milk-secreting organ of female mammals

154

Tehran cochlea

>2.5 coils

155

Therian pectoral girdle

for increased mobility

156

Metatherians

Marsupials - opossum, Tasmanian devil, koala, kangaroo

157

Marsupial characteristic

arboreal, omnivorous, heterothermy,

158

Marsupial birthing

give birth to altricial young-- crawl into pouch-- fuse to nipple

159

marsupial origin

oldest fossils found in NA

160

marsupial radiation

NA-- Europe-- Africa-- SA in Cretaceous
Across Antarctica-- Australia in Paleocene

161

Europe/Asia/Africa extinction of marsupials

mid-cenozoic

162

why NZ has no marsupials

separated from Australia before origin of early mammals (monotremes)

163

Placentals

Eutherians

164

Eutherian characteristics

relative to marsupials: longer gestation, reduced lactation, fewer incisors&premolars, strict endothermy

165

Eutherian endothermy

almost entirely, except torpor (which is technically heterothermy)

166

early Eutherians

arose in Asia, shrew-like, insectivorous, minor contribution to fossil record until KTB

167

major groups of Eutherians

edentates, insectivores, primates, rodents, chiroptera, carnivora, ungulates, cetaceans, sirenians, proboscideans

168

edentates

anteaters

169

sirenians

manatee

170

proboscideans

elephant

171

Earth in late mesozoic

forests on all continents
N latitudes warm and wet
broad leaved vegetation
mt range uplift

172

late mesozoic distributions

crocodiles in arctic
dinos, arboreal/fossorial mammals
rodentia in late Cretaceous
Carnivora early Palaeocene

173

orogeny

Rockies, Andes, Himalays in the late Mesozoic, ~100mya

174

largest group of mammals

Rodentia - 40% of all current mammal species

175

most of major modern groups appeared in

early Eocene

176

earths temperature in Eocene

warm, colder towards end

177

genus numbers in the Cenozoic

fairly stable across paleocene, eocene
increase across oligocene
drops in middle of miocene

178

genus numbers and paleotemperature in Cenozoic

rise in oligocene ~correlated with decreased T (ice house world), slight lag

179

# marsupials

~200
opossum group -77
kangaroo, koala, wombat - 110

180

# rodentia

1800