Rhizinigeritaceae

Name

Rhizinigeritaceae

Rank

Family

Authors (Name)

Ignatov M. S.  

Authors (Pub.)

Ignatov M. S. Voronkova T. V. Spirina U. N. Polevova S. V.  

Publication

How to recognize mosses from extant groups among Paleozoic and Mesozoic fossils [2024/10]

Journal

Diversity

Volume

16

Issue

10(622)

Page number

10

Year

2024

Parent Taxon

[Order] Protosphagnales

Type

[Genus] Rhizinigerites

Diagnosis

Stems sparsely branched, with three types of branches: (1) leafy branches similar to maternal stem, but with somewhat smaller leaves; (2) rhizoidophores, leafless axes with bundles of rhizoids; (3) prerhizoidophores, similar to rhizoidophores but lacking rhizoids. Foliose structures on stem around branch primordia absent. Rhizoids commonly present, some apparently arising from basal parts of stem with abundant rhizoids covering the stems, which generate them. Leaves erect-spreading to patent, ovate-lanceolate, gradually tapered to narrow linear-lanceolate upper part, at apex abruptly broadly acute and the leaf tip blunt, towards the base slightly rounded; margins plane, unbordered, bluntly serrulate due to some marginal cells slightly protruding beyond the leaf outline, maximally one cell wide; laminal cells short elongate or rectangular, with rounded ends, homogeneous or arranged in T-triads, and in some areas in leaf middle arranged in distinct oblique rows, where neighboring cell rows alternate in cell orientation: in one row elongate cells (1.5–2:1) are elongated in the oblique row direction, whereas in the next row, the cells have generally the same proportions (1.5–2:1), but are elongated in the direction parallel to the costa, thus forming areolation pattern similar to sphagnoid but without one cell of T-triads. Thus the leaves have numerous, more or less regularly arranged one-cell perforations; costa rather slender, disappearing shortly below leaf apex; moderately broad below but two cells wide above, looking unistratose in many places, with occasional presence of lateral branches formed by longer and darker cells, continued into lamina as unistratose, 1–2 seriate veins; the expression of veins varied, being apparent only in large, better developed specimens, especially near the leaf base. Brood bodies unknown.