Rimocostatus

Name

Rimocostatus

Rank

Genus

Authors (Name)

Mašić E. Zaova D. Ognjanova-Rumenova N. G. Levkov Z.  

Authors (Pub.)

Mašić E. Zaova D. Barudanović S. Ognjanova-Rumenova N. G. Levkov Z.  

Publication

Rimocostatus bugojnicus gen.et. sp. nov. (Coscinodiscophyceae, Bacillariophyta) – a new fossil diatom genus from Gračanica, Bugojno palaeolake in Bosnia and Herzegovina [2022/11]

Journal

Diatom Research

Annee/Jahrgang

2022

Issue

10.1080/0269249X.2022.2130993

Page number

2

Year

2022

Parent Taxon

[Family] Heliopeltaceae

Fossil Status

valves

Type

Rimocostatus bugojnicus

Diagnosis

Frustules and valves circular in valve view, rectangular in girdle view. Valve face slightly convex or concave with radial pattern of short and strongly thickened ribs, interrupted close to the central area where irregularly arranged. Central area concentrically undulate to almost flat in smaller specimens. Marginal area with radiating striae becoming concentrically and/or irregularly organized in central area. Striae organized in fascicles. Fascicles uniseriate at valve centre, becoming biseriate to triseriate near valve mantle and multiseriate near valve mantle junction. Valve mantle with large number of fine areolae organized in 6–8 rows. Areolae with external cribrate occlusions, internally with domed cribra. Alveolar openings small round to elongated present at valve face mantle junction separated by strongly thickened costae. Valve face and marginal fultoportulae absent. Externally rimoportulae with simple, round openings positioned at interfascicles on valve mantle, internally stalked, with large and wide slit, centripetally oriented and situated on every costa. Spines small and conical, situated on valve face/mantle junction, continuing from ribs.