MORPHOMETRIC APPROACH TO DETERMINATION OF LOWER JURASSIC SIPHOVALVULINID FORAMINIFERA
Journal: Riviste UNIMI (Università degli studi di Milano)
Year: 2018

Siphovalvulina is among the first foraminifera that appear on carbonate platforms of the Lower Jurassic, forming a conspicuous element of low-diversity assemblages prior to recovery after the end-Triassic biotic crisis. The high morphologic variability of species of this genus is usually not documented, which makes the determination of species difficult and subjective. We demonstrate the variability in five morphotypes of Siphovalvulina in Sinemurian and Pliensbachian carbonate rocks from the Di