Chara artesica Sanjuan & Martín-Closas 2014, n. sp.
Creators: name: Sanjuan, Josep
name: Martín-Closas, Carles
Publisher: name: Zenodo
Year: 2014
Subjects: Biodiversity
Taxonomy
Plantae
Charophyta
Charophyceae
Charales
Characeae
Chara
Chara artesica

description: Chara artesica n. sp.
(Fig. 4 I-L)
DIAGNOSIS. — Very small gyrogonites of genus Chara, 329-455 µm high and 232-368 µm, ellipsoidal elongate in shape, with a reduced number of convolutions (generally seven) and concave spiral cells.
HOLOTYPE. — Number 79907 of the Museu Geològic del Seminari Conciliar, Barcelona (Fig. 4 I-L).
PARATYPES. — Numbers 79908-79911 of the Museu Geològic del Seminari Conciliar, Barcelona.
TYPE LOCALITY. — Torre Casanova (Moià, Catalonia, NE Spain; 41°49’13, 6”N, 02°08’13, 2”E).
TYPE STRATUM. — Marls of the Artés Formation, in a bed 45 m above the base of the Torre Casanova stratigraphic section (Sanjuan & Martín-Closas 2012: sample TC-9, fig. 7).
AGE. — Middle Priabonian to Lower Rupelian according to its association with H. vasiformis form vasiformistuberculata and Harrisichara tuberculata.
DERIVATION OF NAME. — From the Artés Formation.
REPOSITORY. — Museu Geològic del Seminari Conciliar, Barcelona (MGSCB).
DESCRIPTION
Gyrogonites small, 329-455 µm high (mean 397 µm) and 232-368 µm wide (mean 304 µm), prolate and elongate in shape, with an isopolarity index ranging from 109-157 (mean 129). Spiral cells concave to almost flat (about 48 µm wide) and without ornamentation. Six to nine (frequently seven) convolutions are visible in lateral view (Fig. 5). Apex flat or slightly convex. Apical ends of cells unmodified or slightly widening in the centre. Base frequently pointed with a small pentagonal pore (about 45 µm in diameter). Wellcalcified gyrogonites show a rounded base.
AFFINITY
Ŋis new species belongs to genus Chara as shown by its ellipsoidal gyrogonite, the shape of the apical region, with slightly widening of spiral cell endings, and by the shape of the base, pointed to rounded with the spiral cell ends forming a superficial pentagonal pore. Ŋe combination of the very small size of the gyrogonites, a low number of convolutions and the concavity of the spiral cells allows the distinction of the new species from similar species. Chara artesica n. sp. shows strong similarities with Chara sp. 2 from the Ebro Basin described by Choi (1989), especially as regards their biometrical characters. However, Chara artesica n. sp. shows concave spiral cells and a flat to slightly convex apex, whereas Chara sp. 2 shows a convex shape in the apex and the spiral cells, probably related to the calcification degree.
Chara rhenana Schwarz & Griessemer, 1994 (Fig. 4 M-P)
Chara rhenana Schwarz & Griessemer, 1994: 148, pl. 1, figs 1-4.
DISTRIBUTION. — Previously, this species had only been reported in the Upper Eocene/Lower Oligocene from the Rhine Graben in Germany (Schwarz & Griessemer 1994; Schwarz 1997). Ŋe occurrence of this species in Sant Boi de Lluçanès provides the first occurrence of this species in southern Europe (Table 2).
DESCRIPTION
Medium-sized gyrogonites, 550-750 µm high (mean 640 µm) and 283-575 µm wide (mean 392 µm), very elongate, prolate to perprolate in shape, with a high isopolarity index ranging from 111-195 (mean 164). Concave to flat and nonornamented spiral cells (61 µm wide). Eight to eleven (frequently nine to ten) convolutions visible in lateral view. Apex flat. Apical ends of spiral cells distinctly widened. Base progressively tapering to pointed. Many specimens show a somewhat conical appearance. Basal pore mainly within a shallow pentagonal depression.
REMARKS
Most specimens of Chara rhenana from El Perers (Sant Boi de Lluçanès, NE Ebro Basin) are about 100 µm longer than the type population from the Rhine Graben (Schwarz & Griessemer 1994). Ŋe specimens studied are also similar to Chara vespiformis Groves, 1926 from the Bembridge flora (Isle of Wight, England). However, Chara vespiformis shows more convolutions in lateral view (twelve to thirteen) and the spiral cells are flat or convex.
Chara microcera Grambast & Paul, 1965 (Fig. 6 A-D)
Chara microcera Grambast & Paul, 1965: 244, pl. 2, figs 10-14.
DISTRIBUTION. — Chara microcera has been recorded from numerous localities in Europe ranging in age from the Lower Oligocene (Middle Rupelian) to Lower Miocene (Upper Aquitanian). In France, this species occurs in the Paris Basin (Grambast & Paul 1965; Riveline 1986), the Aquitaine Basin (Feist-Castel 1977a; Feist & Ringeade 1977) and the Provence Basin (Feist-Castel 1977a). In Switzerland, this species has been recorded in the western sector of the Swiss Molasse Basin (Kissling 1974). Ŋis species also occurs in many Oligocene localities from the Rhine Graben in Germany (Schwarz 1997). In Spain, this species has been reported in Lower Oligocene beds of the Ebro Basin (Feist et al. 1994), and in the Tajo Basin (Juliá de Agar 1991). In this study, Chara microcera is reported from lacustrine marls in the El Talladell and Vinaixa localities (NE Ebro Basin) (Table 4).
DESCRIPTION
Small-sized gyrogonites, 366-500 µm high (mean 440 µm) and 280-360 µm wide (mean 320 µm), elongate, prolate to perprolate in shape, with an isopolarity index ranging from 120-160 (mean 129). Concave spiral cells (42 µm wide) ornamented with characteristic isolated tubercles arranged along the spiral cells. Nine to eleven (frequently nine) convolutions visible in lateral view. Apex psilocharoid, flat and slightly prominent, ornamented with isolated small tubercles. Base rounded to slightly pointed showing a shallow pentagonal basal pore.
description: Published as part of Sanjuan, Josep & Martín-Closas, Carles, 2014, Taxonomy and palaeobiogeography of charophytes from the Upper Eocene- Lower Oligocene of the Eastern Ebro Basin (Catalonia, NE Spain), pp. 385-420 in Geodiversitas 36 (3) on pages 394-396, DOI: 10.5252/g2014n3a3, http://zenodo.org/record/4538531