- Heterastridium
Heterastridium is a
genus of fossil marineHydrozoa n from the UpperTriassic . They are mostly discoid or spherical and some forms found in theKarakorum mountains are called Karakorum stones. [Erik Flügel (1960) Heterastridium conglobatum conglobatum Reuss, an Upper Triassic Hydrozoan from the Petra-Tou-Roumiou Limestone of Pendakomo, Cyprus. Journal of Paleontology 34(1):127-132] They vary in diameter from 1 to 35 cm and appear to followCope's rule for the prehistoric climate.References
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