▁The ▁nearest ▁main land ▁state ▁is ▁Moz amb ique , ▁located ▁to ▁the ▁west . ▁ ▁The ▁pre histor ic ▁break up ▁of ▁the ▁super cont inent ▁G ond w ana ▁separated ▁the ▁Mad agas car – Ant arct ica – Ind ia ▁land mass ▁from ▁the ▁Africa – S outh ▁America ▁land mass ▁around ▁ 1 3 5   mill ion ▁years ▁ago . ▁Mad agas car ▁later ▁split ▁from ▁India ▁about ▁ 8 8   mill ion ▁years ▁ago ▁during ▁the ▁late ▁C ret ace ous ▁period ▁allowing ▁plants ▁and ▁animals ▁on ▁the ▁island ▁to ▁evol ve ▁in ▁relative ▁isol ation . ▁Al ong ▁the ▁length ▁of ▁the ▁eastern ▁coast ▁runs ▁a ▁narrow ▁and ▁ste ep ▁esc arp ment ▁containing ▁much ▁of ▁the ▁island ' s ▁remaining ▁tropical ▁low land ▁forest . ▁ ▁To ▁the ▁west ▁of ▁this ▁r idge ▁lies ▁a ▁plate au ▁in ▁the ▁center ▁of ▁the ▁island ▁r anging ▁in ▁alt itude ▁from ▁ ▁above ▁sea ▁level . ▁These ▁central ▁high lands , ▁tradition ally ▁the ▁hom eland ▁of ▁the ▁Mer ina ▁people ▁and ▁the ▁location ▁of ▁their ▁historic ▁capital ▁at ▁Ant an an ar ivo , ▁are ▁the ▁most ▁dens ely ▁populated ▁part ▁of ▁the ▁island ▁and ▁are ▁character ized ▁by ▁ter rac ed , ▁rice - g row ing ▁valle ys ▁lying ▁between ▁grass y ▁hills ▁and ▁patch es ▁of ▁the ▁sub hum id ▁for ests ▁that ▁formerly ▁covered ▁the ▁high land ▁region . ▁To ▁the ▁west ▁of ▁the ▁high lands , ▁the ▁increasing ly ▁ar