Trinocladus sp.

Schlagintweit, Felix & Wilmsen, Markus, 2014, Calcareous Algae (Dasycladales, Udoteaceae) From The Cenomanian Altamira Formation Of Northern Cantabria, Spain, Acta Palaeontologica Romaniae 10 (1 - 2), pp. 1-2 : 19-21

Trinocladus sp.

Fig. 6v

Remarks: One transverse section, slightly larger than most specimens of T. tripolitanus and with a secondarily widened, undulating axial cavity is here treated as Trinocladus sp. Concerning the conspicuous dissolution features, we note similarities to both Trinocladus undulates (Raineri, 1922) (see Radoičić, Conrad &

Carras, 2005) from the Upper Cretaceous of Lybia and to specimens of Trinocladus divnae Radoičić illustrated by Bucur et al. (2010, e.g., pl. 1, fig. 7) from the Cenomanian of Egypt. T. divnae was described from the Cenomanian of Serbia ( Radoičić, 2006). On the other hand, comparable diagenetic alterations may also occur in T. tripolitanus ( Fig. 6u ).

?Family Polyphysaceae Kützing, 1843

Forma genus Frederica Barta-Calmus, 1967 , emend. Dieni et al., 1985

Frederica aff. coniconvexa Dieni, Massari & Radoičić, 1985

Figs. 7 a-d

*1985 Frederica coniconvexa n. sp. - Dieni et al., 9-10, fig. 4, pl. 2, figs. 47-54.

Remarks: The subconical to roughly triangular-rounded bodies (diameter: ~ 0.25-0.4 mm) exhibiting 11 to ~16 densely set peripheral pores (diameter: 0.03-0.05 mm) were observed in the near-reefal rudstones ( Fig. 3d ). Total number of pores cannot be evaluated due to the poor preservation. The triangular shape is often transformed into rounded shapes due to marginal erosion. The Cenomanian forms can be compared with those described by Dieni et al. (1985) from the Palaeocene of Sardinia. The genus Frederica Barta-Calmus was so far only known from Danian–Priabonian strata ( Barattolo, 2002, tab. 1). As for Acicularia and Terquemella , also Frederica represents a form genus as representing pluricystate fertile ampullae (see diagnosis of Dieni et al., 1985).

Forma genus Terquemella Munier-Chalmas ex. Morellet & Morellet, 1913

Terquemella div. sp.

Figs. 7 e-f

Remarks: Different morphotypes of Terquemella were rarely observed in the near-reefal rudstones ( Fig. 3d ). For a recent taxonomic summary, see Bucur et al. (2012).

Figures

Fig. 6 Dasycladalean algae from the Cenomanian of Cantabria, Spain. a-i Dissocladella bonardii Radoičić, Conrad & Carras, 2005. j-l Neomeris cf. mokragorensis Radoičić & Schlagintweit, 2007. m-u Trinocladus tripolitanus Raineri. v Trinocladus sp. ma = main axis, 1-3 = orders of laterals. Thin-sections: LR 198 (a), HG 5 (b), S 176 (c), S 178 (d-j), Co 41 (k, o, r, u), S 133 (l), LR 110 (m, t), Co 33 (n, q, s), Co 37 (p, v).

Fig. 7 Dasycladalean algae from the Cenomanian of Cantabria, Spain. a-d Frederica aff. coniconvexa Dieni, Massari & Radoičić, 1985. e-f Terquemella div. sp. Thin-sections AM 2 (a-d, f), S 135 (e).

Fig. 3 Microfacies of the Cenomanian algal-bearing carbonates (Altamira Formation) of Cantabria, Spain. a Packstone with benthic foraminifera, e.g., Lenticulina sp. (L), trocholinids (t), and calcareous algae Dissocladella? n. sp. 1 Conrad & Peybernès (D). b-c Wackestone with trocholinids, orbitolinids [Conicorbitolina (C) in c], Trinocladus tripolitanus Raineri (T), Neomeris cf. mokragorensis Radoičić & Schlagintweit (N). Note the oblique section of Coscinoconus indet. showing the complex canal system (arrow). d Reefal rudstone with Spirastrella (Acanthochaetetes) sp. and some trocholinids (circles). Thin-sections: S 180 (a), Co 35 (b), Co 41 (c), AM 2 (d). Scale bars 1.0 mm.