Azolla primaeva

Azollophyllum primaevum

Azolla primaeva is an extinct species of "water fern" in the Azollaceae family known from Eocene fossils from the Ypresian stage (56 to 48 million years ago), found in southern British Columbia.

The species was first described from poorly preserved material collected in the Similkameen River area near Princeton, British Columbia and later noted from outcrops at Stump Lake northeast of Princeton. The fossils were described by David P. Penhallow in the 1890 volume On Fossil Plants from the Smilkameen Valley and Other Places in the Southern Interior of British Columbia. Though the volume only lists John William Dawson as author, Dawson notes that the A primaevum description had been written by Penhallow. Due to the poor nature of the type specimen the species was placed in the form genus Azollophyllum as Azollophyllum primaevum indicating its similarity to the modern genus, but at the same time acknowledging lack of detail needed to confirm its placement in the genus.

The species placement was formally changed with the publication of a paper written by Chester A. Arnold based on new fossil specimens collected near the former mining camp of Ashnola, British Columbia approximately 8 miles south of Princeton along the Similkimeen River. The fossils were produced from strata of the Allenby Formation, at the time considered Oligocene age, but now known to be of the Early Middle Eocene.