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Heterohelix Digitata
Heterohelix is an extinct genus of foraminifera belonging to the family Heterohelicidae of the superfamily Heterohelicoidea and the suborder Globigerinina.Heterohelix World Foraminifera Database, accessed 27 November 2018 Its type species is '''' (formerly ''Textilaria americana''). Species Species in ''Heterohelix'' include: * '''' * '' |
Santonian
The Santonian is an age in the geologic timescale or a chronostratigraphic stage. It is a subdivision of the Late Cretaceous Epoch or Upper Cretaceous Series. It spans the time between 86.3 ± 0.7 mya (million years ago) and 83.6 ± 0.7 mya. The Santonian is preceded by the Coniacian and is followed by the Campanian.Gradstein ''et al.'' (2004) Stratigraphic definition The Santonian Stage was established by French geologist Henri Coquand in 1857. It is named after the city of Saintes in the region of Saintonge, where the original type locality is located. The base of the Santonian Stage is defined by the appearance of the inoceramid bivalve '' Cladoceramus undulatoplicatus''. The GSSP (official reference profile) for the base of the Santonian Stage is located near Olazagutia, Spain; it was ratified by the Subcommission on Cretaceous Stratigraphy in 2012. The Santonian's top (the base of the Campanian Stage) is informally marked by the extinction of the crinoid '' Marsup ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heterohelix Digitata
Heterohelix is an extinct genus of foraminifera belonging to the family Heterohelicidae of the superfamily Heterohelicoidea and the suborder Globigerinina.Heterohelix World Foraminifera Database, accessed 27 November 2018 Its type species is '''' (formerly ''Textilaria americana''). Species Species in ''Heterohelix'' include: * '''' * '' |