Fottea

Fottea 2023, 23(2):164-176 | DOI: 10.5507/fot.2022.018

Tracing lineages of scale-bearing Chrysophyceae over geologic time

Peter A. Siver

Botany Department, Connecticut College, New London, CT. USA; e-mail: pasiv@conncoll.edu

Until the discovery of a massive number of fossil specimens in the early Eocene locality known as Giraffe Pipe, little was known about Chrysophyceae that bear siliceous scales from the geologic record. More recently, remains of chrysophyte scales have been reported from another Eocene site known as Horsefly, and uncovered from a Late Cretaceous site known as the Wombat locality. The aims of this investigation were to add the additional records from the Eocene and Cretaceous sites and to trace the known distributions of lineages, both with and without modern congeners, over the last 83 Ma. Twenty-nine scale types, referred to herein as lineages, have now been documented from the fossil record. Although the majority of the records document lineages within the order Synurales, specifically in the genera Mallomonas and Synura, species of the non-synurophyte genera Chrysosphaerella, Paraphysomonas, Lepidochromonas, and Spiniferomonas are also recorded, and the occurrences of stem lineages noted.

Keywords: Chrysophyceae, Cretaceous, Eocene, fossil, Giraffe Pipe, Horsefly, lineage, Synurales, Wombat

Received: August 24, 2022; Revised: October 31, 2022; Accepted: November 18, 2022; Prepublished online: July 31, 2023; Published: October 25, 2023  Show citation