Emphanisporites McGregor 1961
Creators: name: García Muro, Victoria J.
name: Rubinstein, Claudia V.
name: Steemans, Philippe
Publisher: name: Zenodo
Year: 2018
Subjects: Biodiversity
Taxonomy
Plantae
Bryophyta
Conjugatophyceae
Zygnematales
Zygnemataceae
Emphanisporites

description: Emphanisporites? tenuis sp. nov.
Fig. 11K–N.
1981 Emphanisporites sp. D; Richardson et al. 1981: 215, pl. 1.3.
2008 Emphanisporites sp. D Richardson, Rasul, and Al-Ameri, 1981; Steemans et al. 2008: 274, figs. 8–10.
2014 Emphanisporites sp. D Richardson et al. 1981; García Muro et al. 2014b: 485, fig. 8f.
2015 Emphanisporites sp. D Richardson et al. 1981; García Muro and Rubinstein 2015: 272, fig. 3.7.
Etymology: From Latin tenuis, tenuous; in references to the characteristic thin ribs.
Type material: Holotype: MPLP 13-60984 (N30 /2) (Fig. 11K). Paratype: MPLP 2-61065 (Q42) (Fig. 11L) from Cerro La Chilca section.
Type locality: Quebrada Ancha upper section, Los Espejos Formation, San Juan, Argentina (Fig. 1D, 4).
Type horizon: Storm-dominated inner shelf environment of the Los Espejos Formation, Přídolí.
Material.— Seven specimens measured. Samples MPLP 1-61065 (O28/3); MPLP 2-61057 (O47/1; Q42/1, U27); MPLP 2-60704 (K38/4), MPLP 9-60664 (S28), MPLP 10-60673 (J23/1). Wenlock?–Přídolí of Argentina, Cerro La Chilca and Quebrada Ancha localities, Los Espejos Formation.
Diagnosis.—Trilete patinate spore with numerous tenuous ribs on the proximal face.
Description.—Trilete patinate spore with subtriangular to subcircular amb. The thickness of the patina is variable. Laesure straight, extends to the equator, accompanied by labra about 2–4 μm in overall width. Equatorially thickened, 2–4 μm wide. Proximally, 18–26 ribs of less than 1μm of width per interradial area, extending to the patina.
Dimensions.—42–(50)–55μm (7 specimens measured).
Remarks.—Other species of Emphanisporites differ in presenting broader radial ridges and having no patina. Artemopyra inconspicua Breuer, Al-Ghazi, Al-Ruwaili, Higgs, Steemans, and Wellman, 2007 is ornamented by similar thin radial ribs in the hilum but lacks the trilete mark and the patina. According to the original diagnosis of McGregor (1961), the genus Emphanisporites does not comprise patinate forms. Possibly, a new genus should be considered for the specimens included in Emphanisporites? tenuis although the specimens are not enough to create it in the present contribution.
Stratigraphic and geographic range.— Richardson et al. (1981) recorded Emphanisporites sp. D from the late Ludlow of Libya and the early Přídolí of England and Wales but did not describe the species and the latter was not even illustrated. Lochkovian of the Amazon Basin, Brazil (Steemans et al. 2008). Wenlock? to Přídolí of the Precordillera, Argentina (García Muro et al. 2014b; García Muro and Rubinstein 2015).
description: Published as part of García Muro, Victoria J., Rubinstein, Claudia V. & Steemans, Philippe, 2018, Late Silurian palynomorphs from the Precordillera of San Juan, Argentina: Diversity, palaeoenvironmental and palaeogeographic significance, pp. 41-61 in Acta Palaeontologica Polonica 63 (1) on page 46, DOI: 10.4202/app.00400.2017, http://zenodo.org/record/10626537