Chara aff. antennata Grambast, 1958

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), Geodiversitas 36 (3), pp. 385-420 : 391-393

Chara aff. antennata Grambast, 1958 ( Fig. 4 E-H)

Chara antennata Grambast, 1958: 188 , fig. 79.

DISTRIBUTION. — Chara aff. antennata has previously been reported in Upper Eocene deposits from many European basins, i.e. Paris ( Grambast 1958; Riveline 1986), Languedoc (Feist-Castel 1971), Provence (Feist-Castel 1977a) and Hampshire Basins (Feist- Castel 1977b; Riveline 1986). In the Ebro Basin, gyrogonites of Chara aff. antennata do not show any

evidence of fragmentation or erosion, suggesting that they were buried in situ or after short transport from the original locality. Ŋe sample was collected within a plastic yellowish marl horizon with abundant marine fauna, i.e. foraminifers and ostracods.Taphonomic and sedimentologic evidence, together with the abundance of shallow marine fauna, suggests that Chara aff. antennata grew in brackish water lagoons close to the shoreline.

DESCRIPTION

Gyrogonites small to medium, 350-620 µm high (mean 506 µm) and 235-335 µm wide (mean 304 µm), very elongate in shape, with a high isopolarity index ranging from 117 to 202 (mean 154). Spiral cells concave (about 48 µm wide). Ornamentation consists of irregularly shaped and spaced tubercles (very variable in size, ranging from 15-40 µm in diameter) arranged along the spiral cells. Eight to twelve (frequently nine to ten) convolutions are visible in lateral view. Apex psilocharoid and slightly convex. Base pointed with small pentagonal pore (about 35 µm across).

DISCUSSION

Ŋe width of gyrogonites from La Portelleta section (Sant Boi de Lluçanès) was about 75 µm smaller than the type population of Verzenay ( France), resulting in a dominance of prolate to perprolate gyrogonite morphologies. Moreover, the specimens studied usually display smaller tubercles than the type population.

Figures

FIG. 4. — Charophytes from the Sant Boi and Artés Fms, Ebro Basin:A-D, Sphaerochara labellata Feist & Ringeade, 1977, Torre Casanova section; A, apical view, no. 80063 MGSCB, sample TC-28; B, lateral view, no. 80064 MGSCB, sample TC-28; C, lateral view, no. 80065 MGSCB, sample TC-28; D, basal view, no. 80066 MGSCB, sample TC-28; E-H, Chara aff. antennata Grambast, 1958, La Portelleta section; E, apical view, no. 80067 MGSCB, sample PO-2; F, lateral view, no. 80068 MGSCB, sample PO-2; G, lateral view, no. 80069 MGSCB, sample PO-2; H, basal view,no. 80070 MGSCB, sample PO-2; I-L, Chara artesica n. sp., Torre Casanova section; I, apical view, paratype no. 79908 MGSCB, sample TC-9; J, lateral view, holotype no. 79907 MGSCB sample TC-9; K, lateral view, paratype no. 79909 MGSCB, sample TC-9; L, basal view, paratype no. 79910 MGSCB,sample TC-9; M-P, Chara rhenana Schwarz & Griessemer,1994,El Perers-Serrat Rodó section;M, apical view, no. 80071 MGSCB,sample PE-1; N, lateral view,no. 80072 MGSCB, sample PE-1; O, lateral view, no. 80073 MGSCB, sample PE-1; P, basal view, no. 80074 MGSCB, sample PE-1. Scale bar: 500 µm.