Azolla primaeva
Azolla primaeva is an extinct species of "water fern" in the family Salviniaceae known from Eocene fossils from the Ypresian stage (), 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.

Placement of the species 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 recovered from strata of the Allenby Formation, at the time considered Oligocene age, but now known to be of the Early Middle Eocene.

The specimens were studied by Arnold of the University of Michigan who published the 1955 type redescription for "A. primaeva" in the "Contributions from the Museum of. Paleontology, University of Michigan", Volume 12. Arnold noted the new specimens to consist of leafy vegetation and roots often forming mats in the rock. The plants are accompanied by microspore massulae and megasporangia.

At the time this paper was published, four species of "Azolla" had been described from the fossil record. The oldest species at that time was "A. intertrappea" from Eocene age strata in India and described in 1934 by Birbal Sahni and H. S. Rao. Also in 1934, Roland W. Brown described a similarly aged species, "A. berryi", from the Middle Eocene Green River Formation. An Oligocene species, "A. prisca", was published from the London Clays of England eight years earlier in 1926 by Marjorie E.J. Chandler and Eleanor M. Reid. The youngest of the fossil species was "A. tertiaria" described by Edward W. Berry in 1927 from Pliocene fossils found in the Esmeralda Formation of Nevada. Arnold notes that with the placement of "A. primaeva" into the genus "Azolla" means that its description in 1890 was actually the earliest species described from the fossil record.

After comparing the new fossil specimens to both modern and fossil species as much as he was able with the descriptions available, Arnold noted "A. primaeva" to be close in morphology to the living "A.filiculoides" and the Eocene "A. intertrappea" of India. Fossil specimens of "Azolla" have been recovered from the closely related strata of the Klondike Mountain Formation around Republic, Washington, but have not been described to species.
Q123509
extinct
Concept
Q7432
species
Concept
Q7175204
water fern
Concept
Q867194
Salviniaceae
Concept
Q76274
Eocene
TIME
Q40614
fossil
Concept
Q508691
Ypresian
TIME
Q1974
British Columbia
LOC
Q304833
Similkameen River
LOC
Q1020218
Princeton, British Columbia
LOC
Q7353891
Stump Lake
LOC
Q5238323
David P. Penhallow
PER
Q1702168
John William Dawson
PER
Q17105508
form genus
Concept
None
Azollophyllum
UNK
Q2962855
Chester A. Arnold
PER
Q16910317
Ashnola, British Columbia
LOC
Q14874560
Allenby Formation
LOC
Q101873
Oligocene
LOC
Q76274
Early Middle Eocene
TIME
Q230492
University of Michigan
ORG
Q3707858
type redescription
Concept
None
microspore massulae
UNK
Q4832012
megasporangia
Concept
None
A. intertrappea
UNK
Q2688170
Birbal Sahni
PER
Q7360478
Roland W. Brown
PER
None
A. berryi
UNK
Q76274
Middle Eocene
TIME
Q741367
Green River Formation
LOC
Q101873
Oligocene
LOC
None
A. prisca
UNK
Q2733342
London Clay
LOC
Q6455787
Marjorie E.J. Chandler
PER
Q6534142
Eleanor M. Reid
PER
None
A. tertiaria
UNK
Q3048727
Edward W. Berry
PER
Q18150498
Esmeralda Formation
LOC
Q2705087
A.filiculoides
Concept
Q6421276
Klondike Mountain Formation
LOC
Q1006641
Republic, Washington
LOC
Q4832823
Azolla primaeva
Concept
1890-01-01T00:00:00Z^^http://www.w3.org/2001/XMLSchema#dateTime
1890
DATE
1955-01-01T00:00:00Z^^http://www.w3.org/2001/XMLSchema#dateTime
1955
DATE
1934-01-01T00:00:00Z^^http://www.w3.org/2001/XMLSchema#dateTime
1934
DATE
1934-01-01T00:00:00Z^^http://www.w3.org/2001/XMLSchema#dateTime
1934
DATE
1926-01-01T00:00:00Z^^http://www.w3.org/2001/XMLSchema#dateTime
1926
DATE
1927-01-01T00:00:00Z^^http://www.w3.org/2001/XMLSchema#dateTime
1927
DATE
1890-01-01T00:00:00Z^^http://www.w3.org/2001/XMLSchema#dateTime
1890
DATE
+8^^http://www.w3.org/2001/XMLSchema#decimal
8
NUMBER
+12^^http://www.w3.org/2001/XMLSchema#decimal
12
NUMBER
taxon rank
parent taxon
follows
time period