The taxonomy and morphology of two taxa of the diatom genus Gomphonema with multiple stigmata from fossil localities in Africa are considered. Light and scanning electron microscopy as well as quantitative analysis of valve shape suggest two taxa are present in these collections. One of them, previously described as Gomphonema ventricosum var. africana, has 2-4 stigmata and conforms well with the original illustration of this taxon by Reichelt. However, this taxon does not appear to be closely related to G. ventricosum, and is a species in its own right, so a new name, G. kalahariense nom. nov., stat. nov. Jeff.R.Stone & Kociolek is proposed. This species is known from modern and fossil locations in Africa. A second species, Gomphonema chemeron Jeff.R.Stone, Westover & Kociolek sp. nov. is described from diatomite deposits of the Baringo Basin, Kenya, that are approximately 2.6 million years of age. This species, with 3-7 stigmata, has a distinctive shape and is easily distinguished from G. kalahariense. We compare these species with other multi-stigmate members of Gomphonema, including G. krammeri Reichardt, a fossil species described from Mexico and Cuba.
Bibliographical noteFunding Information:
Materials from the Baringo Basin were collected for HSPDP with funding support from the U.S. NSF Grants EAR#1123000, EAR#1338553 and BCS#1241859, and the International Continental Scientific Drilling Program (ICDP). Materials from Paleo-lake Mababe were collected with support from the U.S. NSF Grant OISE#021783. Additional support was provided by ISU Department of Earth & Environmental Systems, Oklahoma State University, and the Ministry of Minerals and the Energy and Water Resources (Botswana). This is publication #24 of the Hominin Sites and Paleolakes Drilling Project. We also thank two anonymous reviewers and Dr. Mark Edlund for comments that improved the manuscript.
© 2020 Magnolia Press.
Copyright 2020 Elsevier B.V., All rights reserved.
Continental Scientific Drilling Facility tags