| Species (N=917) | GC (%) | AT (%) | G (bases) | C (bases) | A (bases) | T (bases) | Maximum lifespan (yrs) |
|---|---|---|---|---|---|---|---|
| Tamandua tetradactyla | 41.3 | 58.7 | 329 | 142 | 299 | 370 | 19.0 |
| Tamias sibiricus | 37.8 | 62.2 | 297 | 133 | 365 | 344 | 9.6 |
| Tarentola mauritanica | 45.7 | 54.3 | 365 | 148 | 282 | 328 | 14.0 |
| Tarsius bancanus | 41.8 | 58.2 | 340 | 136 | 313 | 351 | 16.3 |
| Tarsius syrichta | 40.7 | 59.3 | 312 | 152 | 343 | 333 | 16.0 |
| Taurotragus derbianus | 42.4 | 57.6 | 332 | 151 | 291 | 366 | 20.3 |
| Taxidea taxus | 42.4 | 57.6 | 343 | 140 | 298 | 359 | 25.0 |
| Testudo graeca | 42.0 | 58.0 | 350 | 131 | 304 | 359 | 127.0 |
| Testudo kleinmanni | 42.2 | 57.8 | 357 | 134 | 304 | 369 | 21.0 |
| Testudo marginata | 41.6 | 58.4 | 347 | 129 | 305 | 363 | 21.2 |
| Tetracerus quadricornis | 39.8 | 60.2 | 312 | 142 | 315 | 371 | 17.4 |
| Tetrastes bonasia | 47.4 | 52.6 | 407 | 135 | 287 | 314 | 7.2 |
| Theropithecus gelada | 45.4 | 54.6 | 380 | 135 | 288 | 332 | 36.0 |
| Thraupis episcopus | 48.5 | 51.5 | 403 | 151 | 280 | 309 | 9.5 |
| Threskiornis aethiopicus | 47.6 | 52.4 | 406 | 138 | 282 | 317 | 37.0 |
| Thryonomys swinderianus | 40.1 | 59.9 | 318 | 138 | 337 | 345 | 5.4 |
| Thunnus alalunga | 46.8 | 53.2 | 361 | 173 | 326 | 281 | 13.0 |
| Thunnus albacares | 46.6 | 53.2 | 360 | 172 | 326 | 281 | 9.0 |
| Thunnus maccoyii | 45.9 | 53.0 | 354 | 170 | 325 | 280 | 20.0 |
| Thunnus obesus | 45.8 | 53.5 | 352 | 171 | 327 | 284 | 11.0 |
| Thunnus thynnus | 46.3 | 53.7 | 355 | 173 | 331 | 282 | 15.0 |
| Thymallus arcticus | 44.4 | 55.6 | 324 | 176 | 333 | 293 | 18.0 |
| Tomistoma schlegelii | 44.3 | 55.7 | 376 | 140 | 308 | 341 | 24.7 |
| Trachemys scripta | 40.7 | 59.3 | 335 | 129 | 321 | 355 | 41.3 |
| Trachypithecus cristatus | 42.3 | 57.7 | 356 | 127 | 320 | 338 | 28.3 |
| Trachypithecus francoisi | 40.8 | 59.2 | 335 | 130 | 340 | 336 | 26.3 |
| Trachypithecus johnii | 41.1 | 58.9 | 327 | 140 | 338 | 330 | 34.0 |
| Trachypithecus obscurus | 41.0 | 59.0 | 339 | 129 | 341 | 332 | 33.9 |
| Trachypithecus pileatus | 41.7 | 58.3 | 349 | 124 | 327 | 335 | 25.2 |
| Trachypithecus vetulus | 41.6 | 58.4 | 336 | 136 | 331 | 332 | 26.1 |
| Tragelaphus angasii | 42.5 | 57.5 | 327 | 158 | 302 | 353 | 18.5 |
| Tragelaphus eurycerus | 41.4 | 58.6 | 329 | 143 | 293 | 375 | 21.9 |
| Tragelaphus imberbis | 41.8 | 58.2 | 314 | 162 | 306 | 358 | 19.8 |
| Tragelaphus scriptus | 42.1 | 57.9 | 330 | 150 | 289 | 371 | 15.3 |
| Tragelaphus spekii | 41.3 | 58.7 | 320 | 151 | 304 | 365 | 22.6 |
| Tragelaphus strepsiceros | 41.1 | 58.8 | 318 | 151 | 304 | 366 | 23.5 |
| Tremarctos ornatus | 44.6 | 55.4 | 335 | 173 | 309 | 323 | 39.0 |
| Triaenodon obesus | 40.1 | 59.9 | 321 | 138 | 364 | 322 | 25.0 |
| Trichechus manatus | 46.2 | 53.8 | 374 | 153 | 296 | 317 | 65.0 |
| Trichiurus lepturus | 46.2 | 53.8 | 358 | 169 | 332 | 282 | 15.0 |