| Species (N=388) | GC (%) | AT (%) | G (bases) | C (bases) | A (bases) | T (bases) | Maximum lifespan (yrs) |
|---|---|---|---|---|---|---|---|
| Martes pennanti | 40.0 | 60.0 | 345 | 282 | 374 | 568 | 14.3 |
| Martes zibellina | 40.4 | 59.6 | 353 | 281 | 362 | 572 | 18.4 |
| Mazama americana | 37.0 | 63.0 | 315 | 265 | 391 | 598 | 17.1 |
| Megaptera novaeangliae | 38.7 | 61.3 | 342 | 274 | 398 | 577 | 95.0 |
| Meles meles | 37.3 | 62.7 | 324 | 265 | 402 | 586 | 18.6 |
| Melogale moschata | 40.5 | 59.5 | 346 | 289 | 380 | 554 | 19.0 |
| Melursus ursinus | 39.8 | 60.2 | 335 | 294 | 384 | 567 | 33.3 |
| Mephitis mephitis | 35.9 | 64.1 | 301 | 264 | 404 | 604 | 13.9 |
| Meriones unguiculatus | 35.6 | 64.4 | 296 | 267 | 433 | 585 | 6.3 |
| Mesocricetus auratus | 36.9 | 63.1 | 306 | 270 | 407 | 579 | 3.9 |
| Mesoplodon europaeus | 36.3 | 63.7 | 301 | 273 | 418 | 588 | 48.0 |
| Metachirus nudicaudatus | 35.6 | 64.4 | 311 | 247 | 409 | 602 | 3.0 |
| Mogera wogura | 36.6 | 63.4 | 307 | 271 | 393 | 608 | 3.2 |
| Monodelphis domestica | 35.8 | 64.2 | 312 | 253 | 420 | 594 | 5.1 |
| Monodon monoceros | 37.7 | 62.3 | 328 | 268 | 392 | 591 | 50.0 |
| Muntiacus muntjak | 35.2 | 64.8 | 291 | 261 | 419 | 596 | 18.8 |
| Muntiacus reevesi | 36.4 | 63.6 | 309 | 261 | 403 | 594 | 23.2 |
| Mus musculus | 35.4 | 64.6 | 304 | 256 | 417 | 605 | 4.0 |
| Mustela erminea | 39.0 | 61.0 | 341 | 271 | 379 | 577 | 12.5 |
| Mustela frenata | 38.4 | 61.6 | 338 | 265 | 385 | 581 | 8.8 |
| Mustela nigripes | 38.8 | 61.2 | 337 | 266 | 385 | 565 | 9.4 |
| Mustela nivalis | 38.6 | 61.4 | 337 | 270 | 391 | 574 | 9.1 |
| Mustela putorius | 38.5 | 61.5 | 335 | 270 | 392 | 573 | 11.1 |
| Mustela sibirica | 37.8 | 62.2 | 324 | 269 | 401 | 575 | 8.8 |
| Myrmecobius fasciatus | 37.3 | 62.7 | 324 | 264 | 401 | 587 | 11.0 |
| Mystacina tuberculata | 37.9 | 62.1 | 320 | 274 | 396 | 578 | 7.6 |
| Naemorhedus baileyi | 38.6 | 61.4 | 333 | 272 | 370 | 592 | 19.0 |
| Naemorhedus caudatus | 38.3 | 61.6 | 323 | 274 | 375 | 584 | 20.3 |
| Naemorhedus goral | 38.4 | 61.6 | 324 | 278 | 374 | 591 | 17.6 |
| Nandinia binotata | 39.4 | 60.6 | 360 | 262 | 354 | 601 | 21.0 |
| Nanger dama | 37.0 | 63.0 | 315 | 266 | 386 | 605 | 19.3 |
| Nanger granti | 37.5 | 62.5 | 322 | 267 | 381 | 601 | 19.7 |
| Nanger soemmerringii | 37.0 | 63.0 | 316 | 265 | 386 | 604 | 15.5 |
| Nannospalax ehrenbergi | 37.9 | 62.1 | 334 | 263 | 372 | 607 | 20.2 |
| Nasalis larvatus | 40.1 | 59.9 | 361 | 267 | 373 | 565 | 25.1 |
| Nasua nasua | 39.0 | 61.0 | 344 | 275 | 363 | 604 | 23.7 |
| Neofelis nebulosa | 39.3 | 60.7 | 332 | 286 | 379 | 576 | 19.8 |
| Neomys fodiens | 36.1 | 63.9 | 309 | 258 | 409 | 593 | 3.1 |
| Neophoca cinerea | 38.5 | 61.5 | 331 | 276 | 369 | 601 | 24.1 |
| Neophocaena phocaenoides | 37.8 | 62.2 | 302 | 258 | 375 | 545 | 33.0 |