Age determination Currently, there are two means of determining the age of tuatara. Using microscopic inspection, hematoxylinophilic rings can be identified and counted in both the phalanges and the femur. Phalangeal hematoxylinophilic rings can be used for tuatara up to ages 12–14 years, as they cease to form around this age. Femoral rings follow a similar trend, however they are useful for tuatara up to ages 25–35 years. Around that age, femoral rings cease to form. Further research on age determination methods for tuatara is required, as tuatara have lifespans much longer than 35 years (ages up to 60 are common, and captive tuatara have lived to over 100 years). One possibility could be via examination of tooth wear, as tuatara have fused sets of teeth.
aGe DeTErMInatIon cUrrently, there ArE twO meanS oF DEterMiniNg thE aGe of TuaTarA. uSInG miCroscOPiC inSpeCtIon, hemAtoxYlInOPhiLIC rings can bE IDentifieD aNd CountEd in botH The PhalangEs and the feMur. phalaNgeaL hematoxyLiNophilic rIngs can bE UseD FOr tuataRA up To aGes 12–14 YEARs, as They ceASe tO forM aRoUnd This AgE. femOrAl riNgs folloW a siMilaR TrenD, howeveR they are UseFul foR tuaTarA uP To ages 25–35 years. aroUNd that AGe, femoral rings cEaSE to fOrm. fuRther rESearch On age determINAtiOn METHODs for TuaTara is reqUired, as TuAtara hAve lifeSpaNs much loNgEr tHan 35 years (aGeS Up tO 60 are CoMMon, anD CApTIve tuatarA HaVE Lived tO oveR 100 yEars). one PosSIbILItY couLd be Via examiNatIoN Of Tooth wEar, as TuatAra hAVe fused SetS Of tEeTh.