Parakickxellomycetes Tedersoo, 2025

Tedersoo, Leho, Hosseyni Moghadam, Mahdieh S., Panksep, Kristel, Prins, Victoria, Anslan, Sten, Mikryukov, Vladimir, Bahram, Mohammad, Abarenkov, Kessy, Kõljalg, Urmas, Esmaeilzadeh-Salestani, Keyvan, Pawłowska, Julia, Wurzbacher, Christian, Ding, Yi, Alkahtani, Saad Hussin & Nilsson, R. Henrik, 2025, Thirty novel fungal lineages: formal description based on environmental samples and DNA, MycoKeys 124, pp. 1-121 : 1-121

Parakickxellomycetes Tedersoo class. nov.

Type order.

Parakickxellales Tedersoo .

Diagnosis.

Separation from other fungi based on diagnostic nucleotide signatures in SSU V 8 (positions 1476–1495 in S. cerevisiae ccaagkcaacgagtytacaa; two mismatches allowed) and LSU D 1 (positions 184–198 in type species and 180–194 in S. cerevisiae ggtataatttgcctg; two mismatches allowed). Forms a monophyletic, least inclusive clade in Kickxellomycota, covering sequences EUK 1189320 , EUK 1189314 , EUK 1100806 , EUK 1189309 , UDB 014747 , EUK 1107625 , EUK 1105293 , EUK 1189310 , EUK 1700155 , EUK 1189325 , EUK 1189316 , and EUK 1189321 (Fig. 1 ).

Notes.

Recognized based on eDNA sequences only. Encoded as clade GS 19 in EUKARYOME v 1.9. Currently harbors Parakickxellales. Comprises potentially 1150–1250 species. Detected in soil (98.6 % out of 1597 records), sediments (1.2 %), and water (0.2 %). Found in arctic tundra to tropical biomes across all continents except Antarctica, but present on Subantarctic islands. Relatively more common and diverse in the neotropics (37.3 % of records).

Figures

Figure 1. Maximum Likelihood SSU- 5.8 S-LSU phylogram indicating placement of novel lineages in the fungal kingdom as highlighted in a coloured shade and red font. Previously described taxonomic clades are collapsed. All branches of Sumavosporidiomycetes and Gelotisporidiomycetes are shortened two-fold. Poorly supported branches with bootstrap values below 95 % / 99 % are indicated in blue. The original tree with bootstrap values and uncollapsed branches is indicated in Suppl. material 1.