| miniopterus natalensis | Yes | species | eukaryota | mammals | species | 291302 | click here | 
| miniopterus schreibersii | Yes | species | eukaryota | mammals | species | 9433 | click here | 
| miniopterus sororculus | Yes | species |  |  | species | 947061 | click here | 
| miniopterus sp. bbra-2009d | Yes | no rank | eukaryota | mammals | species | 647620 | click here | 
| miniopterus sp. smg-2014b | Yes | no rank |  |  | species | 1574122 | click here | 
| mirounga angustirostris | Yes | species | eukaryota | mammals | species | 9716 | click here | 
| molossidae | Yes |  |  | mammals | family | 9436 | click here | 
| molossops neglectus | Yes | species | eukaryota | mammals | species | 409036 | click here | 
| molossus | Yes |  |  | mammals | genus | 27621 | click here | 
| molossus ater | Yes | species | eukaryota | mammals | species | 270771 | click here | 
| molossus molossus | Yes | species | eukaryota | mammals | species | 27622 | click here | 
| molossus rufus | Yes | species | eukaryota | mammals | species | 124751 | click here | 
| monachus monachus | Yes | species | eukaryota | mammals | species | 248254 | click here | 
| monopterus albus | Yes | species | eukaryota | vertebrates | species | 43700 | click here | 
| mops condylurus | Yes | species | eukaryota | mammals | species | 258863 | click here | 
| mops leucostigma | Yes | species | eukaryota | mammals | species | 452596 | click here | 
| mops midas | Yes | species | eukaryota | mammals | species | 452595 | click here | 
| morelia spilota | Yes | species | eukaryota | vertebrates | species | 51896 | click here | 
| morelia spilota spilota | Yes | subspecies |  |  | subspecies | 1716564 | click here | 
| morelia viridis | Yes | species | eukaryota | vertebrates | species | 129333 | click here | 
| mormoops megalophylla | Yes | species | eukaryota | mammals | species | 59460 | click here | 
| mormopterus jugularis | Yes | species |  |  | species | 999964 | click here | 
| mormopterus sp. bbvv-2008 | Yes | no rank | eukaryota | mammals | species | 524134 | click here | 
| morone americana | Yes | species | eukaryota | vertebrates | species | 46260 | click here | 
| morone chrysops | Yes | species | eukaryota | vertebrates | species | 46259 | click here | 
| morone saxatilis | Yes | species | eukaryota | vertebrates | species | 34816 | click here | 
| motacilla alba | Yes | species | eukaryota | vertebrates | species | 45807 | click here | 
| murina cyclotis | Yes | species | eukaryota | mammals | species | 177185 | click here | 
| murina leucogaster | Yes | species | eukaryota | mammals | species | 187017 | click here | 
| murina suilla | Yes | species | eukaryota | mammals | species | 59489 | click here | 
| mus | Yes |  |  | rodents | genus | 10088 | click here | 
| mus minutoides | Yes | species | eukaryota | rodents | species | 10105 | click here | 
| mus musculus | Yes | species | eukaryota | rodents | species | 10090 | click here | 
| mus musculus domesticus | Yes | subspecies | eukaryota | rodents | subspecies | 10092 | click here | 
| mus setulosus | Yes | species | eukaryota | rodents | species | 10102 | click here | 
| mus triton | Yes | species | eukaryota | rodents | species | 473865 | click here | 
| musca domestica | Yes | species | eukaryota | invertebrates | species | 7370 | click here | 
| muscina stabulans | Yes | species | eukaryota | invertebrates | species | 57893 | click here | 
| mustela erminea | Yes | species | eukaryota | mammals | species | 36723 | click here | 
| mustela eversmannii | Yes | species | eukaryota | mammals | species | 77149 | click here | 
| mustela lutreola | Yes | species | eukaryota | mammals | species | 9666 | click here | 
| mustela nigripes | Yes | species | eukaryota | mammals | species | 77151 | click here | 
| mustela nivalis | Yes | species | eukaryota | mammals | species | 36239 | click here | 
| mustela putorius | Yes | species | eukaryota | mammals | species | 9668 | click here | 
| mustela putorius furo | Yes | subspecies | eukaryota | mammals | subspecies | 9669 | click here | 
| mustela sibirica | Yes | species | eukaryota | mammals | species | 36240 | click here | 
| mustelidae | Yes |  |  | mammals | family | 9655 | click here | 
| mustelinae | Yes |  |  | mammals | subfamily | 169418 | click here | 
| myiopsitta monachus | Yes | species | eukaryota | vertebrates | species | 176066 | click here | 
| myocastor coypus | Yes | species | eukaryota | rodents | species | 10157 | click here | 
| myodes glareolus | Yes | species | eukaryota | rodents | species | 447135 | click here | 
| myodes rufocanus | Yes | species | eukaryota | rodents | species | 527686 | click here | 
| myodes rutilus | Yes | species | eukaryota | rodents | species | 537920 | click here | 
| myonycteris angolensis | Yes | species | eukaryota | mammals | species | 58071 | click here | 
| myonycteris angolensis ruwenzorii | Yes | subspecies |  |  | subspecies | 1245033 | click here | 
| myonycteris torquata | Yes | species | eukaryota | mammals | species | 77243 | click here | 
| myotis | Yes |  |  | mammals | genus | 9434 | click here | 
| myotis albescens | Yes | species | eukaryota | mammals | species | 159322 | click here | 
| myotis altarium | Yes | species | eukaryota | mammals | species | 415933 | click here | 
| myotis austroriparius | Yes | species | eukaryota | mammals | species | 258936 | click here | 
| myotis blythii | Yes | species | eukaryota | mammals | species | 109482 | click here | 
| myotis californicus | Yes | species | eukaryota | mammals | species | 257882 | click here | 
| myotis capaccinii | Yes | species | eukaryota | mammals | species | 109477 | click here | 
| myotis chiloensis | Yes | species | eukaryota | mammals | species | 384634 | click here | 
| myotis ciliolabrum | Yes | species | eukaryota | mammals | species | 257884 | click here | 
| myotis dasycneme | Yes | species | eukaryota | mammals | species | 159324 | click here | 
| myotis daubentonii | Yes | species | eukaryota | mammals | species | 98922 | click here | 
| myotis emarginatus | Yes | species | eukaryota | mammals | species | 109480 | click here | 
| myotis evotis | Yes | species | eukaryota | mammals | species | 257883 | click here | 
| myotis goudoti | Yes | species | eukaryota | mammals | species | 203698 | click here | 
| myotis grisescens | Yes | species | eukaryota | mammals | species | 384635 | click here | 
| myotis horsfieldii | Yes | species | eukaryota | mammals | species | 138977 | click here | 
| myotis keaysi | Yes | species | eukaryota | mammals | species | 159327 | click here | 
| myotis keenii | Yes | species | eukaryota | mammals | species | 257881 | click here | 
| myotis leibii | Yes | species | eukaryota | mammals | species | 27668 | click here | 
| myotis levis | Yes | species | eukaryota | mammals | species | 153285 | click here | 
| myotis longipes | Yes | species | eukaryota | mammals | species | 587652 | click here | 
| myotis lucifugus | Yes | species | eukaryota | mammals | species | 59463 | click here | 
| myotis macrodactylus | Yes | species | eukaryota | mammals | species | 187014 | click here | 
| myotis muricola | Yes | species | eukaryota | mammals | species | 159330 | click here | 
| myotis myotis | Yes | species | eukaryota | mammals | species | 51298 | click here | 
| myotis mystacinus | Yes | species | eukaryota | mammals | species | 109479 | click here | 
| myotis nattereri | Yes | species | eukaryota | mammals | species | 109481 | click here | 
| myotis nigricans | Yes | species | eukaryota | mammals | species | 153286 | click here | 
| myotis oxyotus | Yes | species | eukaryota | mammals | species | 159332 | click here | 
| myotis pequinius | Yes | species | eukaryota | mammals | species | 392004 | click here | 
| myotis petax | Yes | species | eukaryota | mammals | species | 526407 | click here | 
| myotis ricketti | Yes | species | eukaryota | mammals | species | 203696 | click here | 
| myotis riparius | Yes | species | eukaryota | mammals | species | 124752 | click here | 
| myotis septentrionalis | Yes | species | eukaryota | mammals | species | 258941 | click here | 
| myotis sp. | Yes | species |  |  | species | 1911917 | click here | 
| myotis thysanodes | Yes | species | eukaryota | mammals | species | 153287 | click here | 
| myotis velifer | Yes | species | eukaryota | mammals | species | 9435 | click here | 
| myotis volans | Yes | species | eukaryota | mammals | species | 159335 | click here | 
| myotis yumanensis | Yes | species | eukaryota | mammals | species | 159337 | click here | 
| myrmecophaga tridactyla | Yes | species | eukaryota | mammals | species | 71006 | click here | 
| myrrophis chinensis | Yes | species | eukaryota | vertebrates | species | 192589 | click here | 
| myzus ornatus | Yes | species | eukaryota | invertebrates | species | 44658 | click here | 
| naja atra | Yes | species | eukaryota | vertebrates | species | 8656 | click here | 
| naja siamensis | Yes | species | eukaryota | vertebrates | species | 84476 | click here |