
trikonamandalangal

englandile elii, comner ennividangalil avasanakaala jurassic kaalaghattatthile kimmeridge kaliman roopeekaranathinte puramthallalukalil ninnu kandethiya rando moonno enangalil ninnu ariyappedunna basel amonitinte vamshanasham sambhavicha oru janussaanu trigoneliteukal, koodaathe germmaniyile bindlackil perillaattha aadyakaala triasic kaalaghattatthile paara roopeekaranam koodiyaayirikkaam ithu. ithu aadyam oru bivalve aayi tharamthirichirunnuvenkilum pinneedu ithu oru amonite inamaayi tharamthirichu. orikkal eee janussil ulppeduthiya rund enangal maathrame innum saadhuvaayi kanakkaakkappedunnulla "tii. laattas "umm" tii. carvirostris, "samshayaaspadamaaya oru inathodoppam", tii. simplexes, orupakshe "lyrodon" enna inam aayirikkam.
cretatius oolittik paarakalil kaanapedunna chila kaalsya plettukalkkaanu "trigoneliteukal" enna januss namam aadyam nirddeshikkappettirum peru orikkalum prasidheekarikkappedaathi ivaye anischithamaaya amoniteukalaayi prakhyaapichu. athinusesham eee peru rund inam avasaanathe jurassic (c.156-151 Ma) amoniteukaleyum oru aadyakaala triasic (c.242.7 Ma) inatheyum prathinideekarikkaan upayogichu.