T
- Tacheocampylaea tacheoides
- Tachybaptus rufolavatus — Alaotra Grebe
- Tadorna cristata — Crested Shelduck
- Talpa streeti — Persian Mole
- Tangara cabanisi — Azure-rumped Tanager
- Taphozous troughtoni
- Taphrolesbia griseiventris — Grey-bellied Comet
- Tapirus bairdii — Baird's Tapir, Central American Tapir
- Tapirus pinchaque — Andean Tapir, Mountain Tapir, Wooly tapir
- Tasmanipatus anophthalmus
- Taudactylus acutirostris — Sharp Snouted Day Frog, Sharp-nosed Torrent Frog
- Taudactylus eungellensis — Eungella Day Frog, Eungella Torrent Frog
- Taudactylus pleione — Kroombit Tinker Frog, Pleione's Torrent Frog
- Taudactylus rheophilus — Northern Tinker Frog, Tinkling Frog
- Tauraco bannermani — Bannerman's Turaco
- tree frog-red eyed tree frog, barking tree frog
- Telescopus hoogstraali
- Telespiza ultima — Nihoa Finch
- Telestes beoticus — Paskóviza
- Telestes polylepis
- Telestes turskyi
- Telmatobius atacamensis
- Telmatobius brevipes
- Telmatobius brevirostris
- Telmatobius ceiorum
- Telmatobius cirrhacelis
- Telmatobius colanensis
- Telmatobius culeus
- Telmatobius degener
- Telmatobius edaphonastes
- Telmatobius gigas
- Telmatobius hypselocephalus
- Telmatobius ignavus
- Telmatobius laticeps
- Telmatobius latirostris
- Telmatobius mayoloi
- Telmatobius necopinus
- Telmatobius niger
- Telmatobius pefauri
- Telmatobius pisanoi
- Telmatobius platycephalus
- Telmatobius schreiteri
- Telmatobius scrocchii
- Telmatobius sibiricus
- Telmatobius stephani
- Telmatobius thompsoni
- Telmatobius truebae
- Telmatobius vellardi
- Telmatobius zapahuirensis
- Telmatobufo bullocki
- Telmatobufo venustus
- Tenualosa thibaudeaui
- Teramulus waterloti
- Terenura sharpei — Yellow-rumped Antwren
- Terenura sicki — Orange-bellied Antwren
- Terpsiphone corvidougalli
- Thermosphaeroma dugesi
- Thermosphaeroma macrura
- Thermosphaeroma milleri
- Thermosphaeroma smithi
- Thersites mitchellae — Mitchell's rainforest snail
- Thinornis novaeseelandiae — Shore Plover
- Thorius arboreus
- Thorius aureus
- Thorius boreas
- Thorius dubitus
- Thorius grandis
- Thorius infernalis
- Thorius lunaris
- Thorius macdougalli
- Thorius magnipes
- Thorius minutissimus
- Thorius minydemus
- Thorius munificus
- Thorius narismagnus
- Thorius narisovalis
- Thorius omiltemi
- Thorius papaloae
- Thorius pennatulus
- Thorius pulmonaris
- Thorius schmidti
- Thorius spilogaster
- Thorius troglodytes
- Thoropa lutzi
- Threskiornis bernieri — Madagascar Sacred Ibis
- Throscodectes xederoides
- Throscodectes xiphos
- Thryothorus nicefori — Niceforo's Wren
- Thunnus maccoyii — Southern bluefin tuna
- Thylogale calabyi — Alpine Wallaby, Calaby's Pademelon
- Tilapia guinasana — Otjikoto tilapia
- Tiliqua adelaidensis — Adelaide Pigmy Blue-tongue Skink, Pygmy Bluetongue
- Tinostoma smaragditis — Fabulous Green Sphinx Moth, Fabulous Green Sphinx Of Kauai
- Tiradelphe schneideri — Schneider's Surprise
- Todiramphus gambieri — Tuamotu Kingfisher
- Todiramphus godeffroyi — Marquesan Kingfisher
- Tokudaia muenninki — Muennink's Spiny Rat
- Tokudaia osimensis — Ryūkyū spiny rat
- Tomichia cawstoni
- Tomichia natalensis
- Tomichia rogersi
- Tomistoma schlegelii — False Gavial, False Gharial, Malayan Gharial
- Tor yunnanensis
- Torreornis inexpectata — Cuban Sparrow
- Totoaba macdonaldi — Totoaba
- Touit melanonotus — Brown-backed Parrotlet
- Toxolasma cylindrellus — Pale lilliput naiad, Pale lilliput pearly mussel, Pale lilliput
- Toxostoma guttatum — Cozumel Thrasher
- Trachemys adiutrix — Carvalho's Slider
- Trachycystis clifdeni — Dlinza forest pinwheel
- Trachycystis haygarthi
- Trachycystis placenta
- Trachypithecus auratus — Ebony Leaf Monkey, Javan Langur
- Trachypithecus delacouri — Delacour's Langur, White-rumped Black Leaf Monkey
- Trachypithecus geei — Gee's Golden Langur, Golden Leaf Monkey
- Trachypithecus pileatus — Bonneted Langur, Capped Langur, Capped Leaf Monkey, Capped Monkey
- Trachypithecus poliocephalus — White-headed Langur
- Trachypithecus vetulus — Purple-faced Leaf Monkey
- Tragelaphus buxtoni — Mountain Nyala
- Treron psittaceus — Timor Green-pigeon
- Trichocichla rufa — Long-legged Thicketbird
- Tricula montana
- Trimenia wallengrenii — Wallengren's Copper
- Trimerotropis infantilis — Zyantc Band-winged Grasshopper
- Trimerotropis occidentaloides — Santa Monica Mountains Grasshopper
- Trimerotropis occulens — Lompoc Grasshopper
- Tringa guttifer — Spotted Greenshank
- Tristramella sacra
- Trithemis nigra
- Trochidrobia inflata
- Trochochlamys ogasawarana
- Trochoidea pseudojacosta
- Trochomorpha apia
- Trogopterus xanthipes — Complex-toothed Flying Squirrel
- Tropidophora articulata
- Tropidophora deburghiae
- Tropidoptera heliciformis
- Truncatellina arcyensis
- Tulotoma magnifica — Tulotoma
- Tupaia longipes — Bornean Tree Shrew, Long-footed Tree Shrew
- Tupaia nicobarica — Nicobar Tree Shrew
- Turdus helleri — Taita Thrush
- Turdus ludoviciae — Somali Thrush
- Turdus swalesi — La Selle Thrush
- Turnix olivii — Buff-breasted Buttonquail
- Tylomys bullaris — Chiapan Climbing Rat
- Tylomys tumbalensis — Tumbala Climbing Rat
- Tylototriton hainanensis — Hainan Knobby Newt
- Typhlatya iliffei
- Typhleotris madgascarensis
- Typhleotris pauliani
- Typhlomys chapensis — Chapa Pygmy Dormouse
- Typhlops monensis — Mona Blind Snake
- Tyrannus cubensis — Giant Kingbird
- Tyto nigrobrunnea — Taliabu Masked-owl
- Tyto soumagnei — Madagascar Red Owl
Read more about this topic: IUCN Red List Endangered Animal Species