Index Caribbean monk seal (Monachus tropicalis) 5:75 Japanese sea lion (Zalophus japonicus) 5:75–76 Steller’s sea cow (Hydrodamalis gigas) 5:76 taxonomy characteristics 5:65–66, 5:65T definition 5:64–66 habitat boundaries 5:65–66 mass extinctions 5:156–166 anthropogenic impacts 2:278–279 basic concepts 3:415–418 biogeographic impacts 3:421–422 causal factors 3:418, 5:2–3 climatic changes 3:422–423 crustaceans 2:413–415 data analysis and interpretation 5:157–158, 5:158F, 5:159F, 5:160F extinction theories 3:418–421 first-contact extinctions basic concepts 5:365 Madagascar 5:365 New Zealand 5:366 Pacific islands 5:365–366 fossil diversity curve 5:157F global biodiversity impacts 3:689–690 great mass extinctions biodiversity loss 4:657F end-Cretaceous 5:168F, 5:169F, 5:173–175, 5:174F Late Devonian 5:168F, 5:169–170, 5:169F Late Ordovician 5:167–169, 5:168F, 5:169F Late Permian 5:168F, 5:169F, 5:170–172 Late Triassic 5:168F, 5:169F, 5:172–173 Phanerozoic Eon 1:493, 1:493F, 1:494T research challenges 5:167–169 historical extinctions extinction paradoxes 5:367 Hawaii 5:367 New Zealand 5:366–367 number of species 5:368T historical research 5:156–157, 5:157F kill curve 5:160–163, 5:163F lesser mass extinctions Cenozoic 5:176 Mesozoic 5:169F, 5:176 Neoproterozoic 5:168F, 5:175–176 Paleozoic 5:168F, 5:175–176 significance 5:175–176 long-term consequences 3:421 magnitude measures end-of-geologic-period extinctions 5:158, 5:161F end-Permian mass extinction 5:158, 5:161F extinction events 5:158–160, 5:161F extinction intensities 5:162F general discussion 5:158 major mass extinctions 3:416T modern diversity crisis 5:165–166 modern extinctions 5:362–372 Africa 5:364–365 Australia 5:363–364, 5:364F current on-going extinctions 5:371 density-related traits 5:370–371 extinction cascades 5:367–368 first-contact extinctions 5:365 geographical bias 5:369 historical extinctions 5:365, 5:368T inadequate documentation 5:368–369 inherent biological limitations 5:369 introduced species 5:370 methodological limitations 5:369 North America 5:363 number of species 5:368, 5:368T population dynamics 5:370 postglacial extinctions 5:363 research challenges 5:368 species lifespans 5:362–363, 5:362T taxonomic and habitat bias 5:369 theoretical perspectives 5:369–370 time factors 5:371 uneven documentation 5:369 notable mass extinctions 5:167–177 background information 5:167 great mass extinctions 5:167–169 periodicity 3:422–423, 3:424F periodicity hypothesis 5:160, 5:162F Permian–Triassic mass extinction 5:4 Phanerozoic Eon 1:412–413, 1:413F quantification 3:417 recoveries characteristics 5:164 delayed diversification 5:164 disaster species 5:164–165 large-scale rebounds 5:164, 5:165F Lazarus species 5:164–165 research summary 5:166 scenarios abrupt extinction 5:157 general discussion 5:157 gradual extinction 5:157 stepwise extinction 5:157 self-organized criticality 5:160–163 temporal and biogeographic scales 5:3 victim–survivor patterns 5:163–164 megaherbivores 5:225T, 5:231–233, 5:232F modern extinctions 5:362–372 crustaceans 2:415–418, 2:416–417T current on-going extinctions 5:371 extinction cascades 5:367–368 first-contact extinctions basic concepts 5:365 Madagascar 5:365 New Zealand 5:366 Pacific islands 5:365–366 historical extinctions extinction paradoxes 5:367 Hawaii 5:367 New Zealand 5:366–367 number of species 5:368T postglacial extinctions Africa 5:364–365 Australia 5:363–364, 5:364F 665 North America 5:363 research challenges 5:368 species lifespans 5:362–363, 5:362T theoretical perspectives 5:369–370 natural extinctions 5:433–441 biodiversity trends 5:439–440 causal factors environmental changes 5:433–434 species–species interactions 5:434 geographic patterns 5:439 prevalence 5:433 selectivity factors body size 5:438 characteristics 5:436 dispersal ability 5:437–438 geographic range 5:436 local abundance 5:436 range–abundance relationships 5:436–437, 5:437F rarity 5:436 spatial structure/patchiness 5:437 specialization 5:438 speciation–extinction rate relationship 5:439–440, 5:440F species duration age factors 5:435–436 taxonomic groups 5:434–435, 5:434T, 5:435F oceanic islands 5:594, 5:595–597 plants 3:205–206, 6:62, 6:73F population diversity 6:172–173 pre-Quaternary mammal extinctions 5:1–9 Age of the Dinosaurs 5:5–6 causal factors background extinctions 5:2–3 distal and proximal causal factors 5:3–4 mass extinctions 5:2–3 pseudoextinctions 5:2 temporal and biogeographic scales 5:3 Cretaceous–Tertiary (K–T) mass extinction 5:6–7 early Paleocene faunal recovery 5:7 geologic timescale 5:1T late Triassic faunal turnover 5:4–5 Paleocene–Eocene thermal maximum 5:7–8 Permian–Triassic mass extinction 5:4 phylogenetic relationships 5:1F summary discussion 5:8 synapsids 5:1–2, 5:4 Tertiary faunal evolution 5:7–8 therapsid radiation 5:4–5 sixth extinction wave 2:351 extinct megafauna 4:591–593, 4:593F extractivism 6:608 extranuclear recombination 6:355 extraterrestrial impacts 3:418–421 extreme environments 4:111–120 biodiversity 4:118–119 characteristics 4:111 climate change studies 2:66, 2:93–94 geothermally heated systems 4:112–113 microbial activities 5:304 nematodes 7:429