title: The rise of the rhizosolenid diatoms.
abstract: The 18S ribosomal DNA molecular phylogeny and lipid composition of over 120 marine diatoms showed that the capability to biosynthesize highly branched isoprenoid (HBI) alkenes is restricted to two specific phylogenetic clusters, which independently evolved in centric and pennate diatoms. The molecular record of C25 HBI chemical fossils in a large suite of well-dated marine sediments and petroleum revealed that the older cluster, composed of rhizosolenid diatoms, evolved 91.5 +/- 1.5 million years ago (Upper Turonian), enabling an accurate dating of the pace of diatom evolution that is unprecedented. The rapid rise of the rhizosolenid diatoms probably resulted from a major reorganization of the nutrient budget in the mid-Cretaceous oceans, triggered by plate tectonics.
authors.affiliation: Department of Marine Biogeochemistry and Toxicology, Royal Netherlands Institute for Sea Research, Post Office Box 59, 1790 AB Den Burg, Texel, Netherlands. damste@nioz.nl
authors.forename: Jaap S Sinninghe
authors.initials: JS
authors.lastname: Damsté
authors.forename: Gerard
authors.initials: G
authors.lastname: Muyzer
authors.forename: Ben
authors.initials: B
authors.lastname: Abbas
authors.forename: Sebastiaan W
authors.initials: SW
authors.lastname: Rampen
authors.forename: Guillaume
authors.initials: G
authors.lastname: Massé
authors.forename: W Guy
authors.initials: WG
authors.lastname: Allard
authors.forename: Simon T
authors.initials: ST
authors.lastname: Belt
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Robert
authors.forename: Steven J
authors.initials: SJ
authors.lastname: Rowland
authors.forename: J Michael
authors.initials: JM
authors.lastname: Moldowan
authors.forename: Silvana M
authors.initials: SM
authors.lastname: Barbanti
authors.forename: Frederick J
authors.initials: FJ
authors.lastname: Fago
authors.forename: Peter
authors.initials: P
authors.lastname: Denisevich
authors.forename: Jeremy
authors.initials: J
authors.lastname: Dahl
authors.forename: Luiz A F
authors.initials: LA
authors.lastname: Trindade
authors.forename: Stefan
authors.initials: S
authors.lastname: Schouten
mesh_terms: D000475:Alkenes / Q000032:analysis* / Q000378:metabolism; D005075:Biological Evolution; D004275:DNA, Ribosomal / Q000235:genetics; D017377:Diatoms / Q000145:classification / Q000235:genetics / Q000378:metabolism; D005580:Fossils; D019015:Geologic Sediments; D008055:Lipids / Q000096:biosynthesis; D008969:Molecular Sequence Data; D010578:Petroleum; D010802:Phylogeny; D012337:RNA, Ribosomal, 18S / Q000235:genetics; D013729:Terpenes / Q000032:analysis* / Q000378:metabolism
chemical_list: D000475:Alkenes; D004275:DNA, Ribosomal; D008055:Lipids; D010578:Petroleum; D012337:RNA, Ribosomal, 18S; D013729:Terpenes