Yacolla
Yaginumanis
Yaginumella
Yamatentomon
Yamatosa
Y-arrowi
Y-boysi
Y-draco
Y-kabakovi
Y-kryzhanoskiji
Y-longior
Y-niponensis
Y-peninsularis
Y-reitteri
Y-sinensis
Y-smetanorum
Yanbiania(EXTINCT)
Yanguna
Y-cometes
Y-cosyra
Y-erebus
Y-spatiosa
Y-tetricus
Y-thelersa
Yania
Yanjingatermes(EXTINCT) (Early Cretaceous of China)
Yanoancistroides
Y-fujianus
Y-sinica
Yara
Y-dybasi
Y-vanini
Yatapoxvirus
Yavanna
Yavnella
Y-argamani
Y-indica
Yepoella
Y-crassistyli
Y-tenuistyli
Yersinia mexicana
Yersiniops
Y-newboldi
Y-solitaria
Y-sophronica
Yichunentulus
Yinentulus
Ylangella(incertae sedis)
Yndolacia(incertae sedis)
Yoma
Y-algina
Y-sabina
Yongdingia(EXTINCT) (Early Cretaceous of China)
Yoraperla
Y-brevis
Y-han
Y-mariana
Y-nigrisoma
Y-siletz
Y-uchidai
Y-uenoi
Younginiformes(EXTINCT)
Yphthimoides
Y-[n. sp. 1]
Y-[n. sp. 2]
Y-acmenis
Y-affinis
Y-angularis
Y-argyrospila
Y-austera
Y-borasta
Y-celmis
Y-eriphule
Y-leguialimai
Y-maepius
Y-manasses
Y-mimula
Y-mythra
Y-neomaenas
Y-ochracea
Y-pacta
Y-patricia
Y-punctata
Y-renata
Y-straminea
Y-viviana
Y-yphthima
Yponomeutidae(ermine moths)
Yponomeutoidea(ermine moths and relatives)
Ypsistocerinae
Ypsolophidae
Ypthima
Y-affectata
Y-akbar
Y-albida
Y-albipuncta
Y-ancus
Y-antennata
Y-aphnius
Y-arctoa
Y-asterope
Y-atra
Y-avanta
Y-baileyi
Y-baldus
Y-beautei
Y-bolanica
Y-cantlei
Y-cerealis
Y-ceylonica
Y-chenui
Y-chinensis
Y-ciris
Y-condamini
Y-confusa
Y-congoana
Y-conjuncta
Y-daclaca
Y-dengae
Y-diplommata
Y-dohertyi
Y-doleta
Y-esakii
Y-evansi
Y-fasciata
Y-frontierii
Y-fulvida
Y-gavalisi
Y-granulosa
Y-hanburyi
Y-hannyngtoni
Y-horsfieldii
Y-huebneri
Y-hyagriva
Y-iarba
Y-imitans
Y-impura
Y-indecora
Y-inica
Y-insolita
Y-iris
Y-jacksoni
Y-junkoae
Y-kalelonda
Y-lamto
Y-lihongxingi
Y-lisandra
Y-loryma
Y-lycus
Y-masakii
Y-megalomma
Y-methora
Y-methorina
Y-microphthalma
Y-motscholskyi
Y-multistriata
Y-muotuoensis
Y-nareda
Y-nebulosa
Y-newara
Y-nigricans
Y-nikaea
Y-norma
Y-nynias
Y-pandocus
Y-parasakra
Y-pemakoi
Y-perfecta
Y-persimilis
Y-philomela
Y-praenubila
Y-praestans
Y-pseudodromon
Y-pulchra
Y-pupillaris
Y-putamdui
Y-recta
Y-rhodesiana
Y-risompae
Y-riukiuana
Y-sakra
Y-sarcaposa
Y-savara
Y-sensilis
Y-sesara
Y-similis
Y-simplicia
Y-singala
Y-singorensis
Y-sinica
Y-sobrina
Y-sordida
Y-stellera
Y-striata
Y-tappana
Y-tiani
Y-vuattauxi
Y-watsoni
Y-yangjiahei
Y-yatta
Y-yoshinobui
Y-ypthimoides
Y-yunosukei
Y-zyzzomacula
Ypthimina
Ypthimomorpha
Yramea
Y-cytheris
Y-inca
Y-lathonioides
Y-lynx
Y-modesta
Y-sobrina
Ytu
Y-angra
Y-artemis
Y-athena
Y-brutus
Y-cleideae
Y-cupidus
Y-cuyaba
Y-demeter
Y-godayi
Y-hephaestus
Y-itati
Y-mirandus
Y-mirim
Y-morpheus
Y-phebo
Y-reichardti
Y-yaguar
Y-ysypo
Y-zeus
Yunna
Yunnanochoerus(EXTINCT)
Yunnanosaurus(EXTINCT)
Yunnanotherium(EXTINCT)
Yunnanozoon(EXTINCT)
Yunnella
Yupanquia