Identification of homoglycerol- and dihomoglycerol-containing isoprenoid tetraether lipid cores in aquatic sediments and a soil

•Homologues of isoprenoid GDGT lipid cores found in sediments and soil.•Each contains a homoglycerol or dihomoglycerol group plus glycerol.•Cyclopentyl ring-containing structures apparent, as are monoalkyl and trialkyl structures.•Lipids are most likely biosynthetic products of archaea.