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Lobophorais a common tropical to temperate genus of brown algae found in a plethora of habitats including shallow and deep‐water coral reefs, rocky shores, mangroves, seagrass beds, and rhodoliths beds. Recent molecular studies have revealed thatLobophoraspecies diversity has been severely underestimated. Current estimates of the species numbers range from 100 to 140 species with a suggested center of diversity in the Central Indo‐Pacific. This study used three molecular markers (cox3,rbcL,psbA), different single‐marker species delimitation methods (GMYC,ABGD,PTP), and morphological evidence to evaluateLobophoraspecies diversity in the Western Atlantic and the Eastern Pacific oceans.Cox3 provided the greatest number of primary species hypotheses(PSH), followed byrbcL and thenpsbA.GMYCspecies delimitation analysis was the most conservative across all three markers, followed byPTP, and then ABGD. The most informative diagnostic morphological characters were thallus thickness and number of cell layers in both the medulla and the dorsal/ventral cortices. Following a consensus approach, 14 distinctLobophoraspecies were identified in the Western Atlantic and five in the Eastern Pacific. Eight new species from these two oceans were herein described:L. adpressasp. nov.,L. cocoensissp. nov.,L. colombianasp. nov.,L. crispatasp. nov.,L. delicatasp. nov.,L. dispersasp. nov.,L. panamensissp. nov., andL. tortugensissp. nov. This study showed that the best approach to confidently identifyLobophoraspecies is to analyzeDNAsequences (preferablycox3 andrbcL) followed by comparative morphological and geographical assessment.
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Small shelly fossils and carbon isotopes from the early Cambrian (Stages 3–4) Mural Formation of western Laurentia
Abstract The extraordinary window of phosphatized and phosphatic small shelly fossils (SSF) during the early and middle Cambrian is an important testament to the radiation of biomineralizing metazoans. WhileSSFare well known from most Cambrian palaeocontinents during this time interval, western Laurentia has relatively fewSSFfaunas. Here we describe a diverseSSFfauna from the early Cambrian (Stages 3–4) Mural Formation at three localities in Alberta and British Columbia, Canada, complemented by carbon isotope measurements to aid in a potential future bio‐chemostratigraphic framework. The fauna expands the recordedSSFassemblage diversity in western Laurentia and includes several brachiopods, four bradoriids, three chancelloriids, two hyoliths, a tommotiid and a helcionellid mollusc as well as echinoderm ossicles and specimens ofMicrodictyon,VolborthellaandHyolithellus. New taxa include the tommotiid genusCanadiellagen. nov., the new bradoriid speciesHipponicharion perforatasp. nov. andPseudobeyrichona tauratasp. nov. Compared with contemporaneous faunas from western Laurentia, the fauna is relatively diverse, particularly in taxa with originally phosphatic shells, which appear to be associated with archaeocyathid build‐ups. This suggests that the generally low faunal diversity in western Laurentia may be at least partly a consequence of poor sampling of suitable archaeocyathan reef environments. In addition, the tommotiidCanadiella filigranaappears to be of biostratigraphical significance in Cambrian Stage 3 strata of western Laurentia, and the unexpected high diversity of bradoriid arthropods in the fauna also suggests that this group may prove useful for biostratigraphical resolution in the region.
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- Award ID(s):
- 1747731
- PAR ID:
- 10377561
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Papers in Palaeontology
- Volume:
- 7
- Issue:
- 2
- ISSN:
- 2056-2799
- Page Range / eLocation ID:
- p. 951-983
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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