The terpenoid composition of resins from the Miocene lignite horizons from the Kerala –Konkan Coast,western India was analyzed by Curie-point pyrolysis –gas chromatography –mass spectrometry (Cupy –GC –MS).The major pyrolysates were cadalene-based bicyclic sesquiterpenoids including some C₃₀-C₃₁ bicadinenes and bicadinanes typical of dammar resin from angiosperm plants of Dipterocarpaceae family.These plants are typically supported by tropical climates which the western Indian region was known to have experienced during early Tertiary period.The present study suggests that these palaeoclimatic conditions persisted until at least the Miocene epoch.These sesquiterpenoids which are commonly detected in many SE Asian crude oils may be utilised as useful biomarkers for petroleum exploration in the western Indian region.