Kalania pusilla, an exceptionally preserved non-calcified alga from the lower Silurian (Aeronian, Llandovery) of Estonia

A Silurian (Llandovery, Aeronian) Lagerstätte in Kalana, Estonia, has revealed exceptionally preserved noncalcified flora of algal fossils. A new dasycladacean algal species Kalania pusilla has been described. The paper describes the fossil specimens, which demonstrate well preserved fine internal anatomy of these siphonous unicellular algae, specifically anatomy of fertile specimens. K. pusilla is characterized by cylindrical uniaxial thallus, two orders of lateral segments — perpendicularly arranged whorls of short bulbous primary laterals, which bear clusters of gametophores in their mature stage and fine hairy secondary laterals.