- tactile
- talonid
- Tanala
- tanghin
- tanindrazana
- tany masina
- tapetum lucidum
- Taphonomy
- tarsus
- TAS
- tavy
- taxon
- Taxonomy
- Teleplanic
- telocentric
- temperate
- temporal bone
- terrestrial
- territory
- tessellate
- testaceous
- testes
- Tethys ocean
- thermocline
- thoracic
- tibia
- tingalla
- tinge
- tisma
- tooth comb
- Topology
- Topotype
- Tracks
- trano
- Transformation
- Transformation series
- Transition
- translucent
- Transversion
- Tree length
- trefoil
- tribes
- trigon
- trigonid
- trochlear
- troglobitic
- trombocyte
- tropical
- truncate
- Tsaratanana
- tsialinalina
- tsiamunanu
- Tsimanampetsotsa
- Tsimety
- Tsimiheta
- tsingy
- Tsingy de Bemaraha
- tsur
- tubercle
- tundra
- tympanic bulla
- type
- Type series
- Type species
- Type specimen
- typical
- Typology