Two major types of glycerol dialkyl glycerol tetraethers (GDGTs) are commonly
used in paleoecological and paleoclimatological reconstructions: isoprenoidal and
branched GDGTs. In aquatic environments, it was originally assumed that isoprenoidal
GDGTs, especially crenarchaeol, derive mainly from aquatic Thaumarchaeota, whilst
branched GDGTs are an allochthonous input derived from soil Bacteria. Recently,...