Lagourgue Laura auteur aut IRD Payri Claude auteur aut IRD text journalArticle eng text/pdf born digital access Udoteaceae is a morphologically diverse family of the order Bryopsidales. Despite being very widespread geographically, this family is little known as compared with the closely related Halimedaceae or Caulerpaceae. Using the most extensive Udoteaceae collection to date and a multilocus genetic data set (tufA, rbcL, and 18S rDNA), we reassessed the species diversity of the family, as well as the phylogenetic relationships, the diagnostic morphoanatomical characters, and evolutionary history of its genera, toward a proposed taxonomic revision. Our approach included a combination of molecular and morphological criteria, including species delimitation methods, phylogenetic reconstruction, and mapping of trait evolution. We successfully delimited 62 species hypotheses, of which 29 were assigned (existing) species names and 13 represent putative new species. Our results also led us to revise the genera Udotea s.s., Rhipidosiphon s.s., and Chlorodesmis s.s., to validate the genus Rhipidodesmis, and to propose three new genera: Glaukea gen. nov., Ventalia gen. nov., and Udoteopsis gen. nov. We also identified two large species complexes, which we refer to as the "Penicillus-Rhipidosiphon-Rhipocephalus-Udotea complex" and the "Poropsis-Penicillus-Rhipidodesmis complex". Using a time-calibrated phylogeny, we estimated the origin of the family Udoteaceae at Late Triassic (ca. 216 Ma), whereas most of the genera originated during Paleogene. Our morphological inference results indicated that the thallus of the Udoteaceae ancestor was likely entirely corticated and calcified, composed of a creeping axis with a multisiphonous stipe and a pluristromatic flabellate frond. The frond shape, cortication, and calcification are still symplesiomorphies for most extant Udoteaceae genera and represent useful diagnostic characters. specialized Chlorophyta macroalgae phylogeny species delimitation trait evolution MONDE 034 [Early access] [27 p.] 2021 1674-4918 https://www.documentation.ird.fr/hor/fdi:010081352 10.1111/jse.12716 1674-4918 [F B010081352] https://www.documentation.ird.fr/hor/fdi:010081352 https://www.documentation.ird.fr/intranet/publi/2021-06/010081352.pdf Accès réservé (Intranet de l'IRD) IRD - Base Horizon / Pleins textes 2021-06-15 2025-02-24 fdi:010081352 fre