ARKive's most wanted species listed alphabetically by scientific name
| Scientific name | Common name | Status |
|---|---|---|
| Thelypteris aculeata | VU | |
| Thelypteris appressa | VU | |
| Thelypteris chimboracensis | VU | |
| Thelypteris conformis | VU | |
| Thelypteris correllii | VU | |
| Thelypteris dodsonii | VU | |
| Thelypteris elegantula | VU | |
| Thelypteris rosenstockii | VU | |
| Theodoxus baeticus | CR | |
| Theodoxus marteli | VU | |
| Theodoxus numidicus | VU | |
| Theodoxus prevostianus | EN | |
| Theodoxus subterrelictus | Metkovich Cave Nerite | EN |
| Theodoxus transversalis | Striped Nerite | EN |
| Theodoxus valentinus | CR | |
| Thermodiaptomus galeboides | VU | |
| Thermosphaeroma cavicauda | CR | |
| Thermosphaeroma dugesi | CR | |
| Thermosphaeroma macrura | CR | |
| Thermosphaeroma milleri | EN | |
| Thermosphaeroma smithi | CR | |
| Thermosphaeroma thermophilum | Socorro Isopod | EW |
| Theskelomensor creon | VU | |
| Thestor compassbergae | VU | |
| Thestor dryburghi | VU | |
| Thestor kaplani | Kaplan's Thestor | VU |
| Thestor pringlei | VU | |
| Thestor rossouwi | VU | |
| Thestor stepheni | VU | |
| Thestor strutti | VU | |
| Thestor swanepoeli | VU | |
| Thestor tempe | VU | |
| Thismia melanomitra | VU | |
| Thomasomys apeco | VU | |
| Thomasomys hylophilus | Woodland oldfield mouse | EN |
| Thomasomys incanus | Inca Oldfield Mouse | VU |
| Thomasomys ischyrus | Strong-tailed Oldfield Mouse | VU |
| Thomasomys kalinowskii | Kalinowski's Oldfield Mouse | VU |
| Thomasomys macrotis | VU | |
| Thomasomys monochromos | Unicolored Oldfield Mouse | EN |
| Thomasomys onkiro | VU | |
| Thomasomys pyrrhonotus | Thomas's Oldfield Mouse | VU |
| Thomasomys ucucha | VU | |
| Thorius arboreus | EN | |
| Thorius dubitus | EN | |
| Thorius grandis | EN | |
| Thorius lunaris | EN | |
| Thorius macdougalli | VU | |
| Thorius magnipes | CR | |
| Thorius minutissimus | CR |