Photos of Rhythmic Member of the Semanggol Formation.
This bed yields late Ladinian (Middle Triassic) ammonoids including Frankites apertus, Celtites epolensis, Anolcites sp. and Nathorstites? sp. and bivalve Daonella phcihleri. This fossil assemblage is indicative for Regoledanus Subzon of Protrachyceras Zon.