Cryptocalciella Mandolini, Szedlacsek & Peintner 2026, gen. nov.

Cryptocalciella Mandolini, Szedlacsek & Peintner gen. nov. Etymology. The name Cryptocalciella derives from Greek κρ ῠ πτός (hidden, concealed), and χάλιξ (pebble), later Latin calx (limestone). It refers to the concealed physiological abilities of the type species of this genus and to its ability to live hidden in calcareous sediments of the earliest soil developmental stages at glacier forefields. The ending “ - ella ” should provide a link to the family Mortierellaceae. Diagnosis. Phylogenomic (high coverage genome) and phylogenetic (rDNA) analyses clearly identify Cryptocalciella as a distinct lineage in the Mortierellaceae, with a sister-group relationship to Gamsiella (Fig. 1). Cryptocalciella pure cultures produce abundant mycelium on PDA and a large amount of intercalar and terminal swollen, bulbous gemmae. Sporulation occurs on minimal media (LCA or SEA) with large, unbranched sporangiophores resembling a crystal chandelier producing spherical sporangia with a columella. Smooth, ovoid to phaseoliform sporangiospores have a hyaline episporal layer. Type species. Cryptocalciella humilis Mandolini, Szedlacsek & Peintner. Generic description. Cryptocalciella species are characterized by fast-growing colonies and the formation of typical, bulbous gemmae formed in clusters in the mycelium (Fig. 3). They produce large, unbranched sporangiophores originating in bundles, thus resembling crystal chandeliers; at the sporangiophore tip, spherical sporangia with a columella are produced, which contain smooth, ovoid to phaseoliform sporangiospores surrounded by a hyaline, episporal layer (Fig. 4). The nutrient-poor habitat and the psychrotolerance discriminate it clearly from similar genera producing large amounts of gemmae, e. g., Benniella. Species belonging to the sister-group Gamsiella are easily distinguished based on sporangiophore morphology.