Probolocupsis sarmeikensis, Senowbari-Daryan, 2014

Senowbari-Daryan, Baba, 2014, Dasycladales Algae From The Norian-Rhaetian Reef Carbonates Of Argolis Peninsula, Greece, Acta Palaeontologica Romaniae 10 (1 - 2), pp. 1-2 : 40-42

Probolocupsis sarmeikensis nov. sp.

( Fig. 2 ; Fig. 4 a-n)

Derivatio nominis: Named from the town Sarmeika near the locality.

Holotype: Fig. 4l (magnification in Fig. 2 ).

Paratypes: Fig. 4 a-k, m-n.

Locus typicus: Norian-Rhaetian reef carbonates, north of the town of Sarmeika in the Mavrovouni Mountains ( Fig. 1 ).

Stratum typicum: Norian-Rhaetian reef carbonates.

Diagnosis: Cylindrical thallus with a narrow axial cavity. Trichophorous laterals of the first order are usually amalgamated at the base appearing as a thick wall around the axial cavity. Euspondyl arrangement of the laterals.

Differential diagnosis: See comparison after the description of the species.

Material: Numerous specimens in several thin sections.

Description: Almost all specimens of this cylindrical alga are cut in cross sections. Two specimens illustrated in Fig. 4c and the holotype Fig. 4l (H) exhibit the most characteristics of the alga in longitudinal section. The thallus of the holotype reaches a length of almost 10 mm with a diameter of 2.2 mm. The axial cavity of the holotype has a diameter of about 0.4 mm. Both longitudinal sections show that the laterals are arranged perpendicular to the axial cavity. The alga is characterized by a narrow axial cavity of 0.25-0.5 mm and a thick thallus wall. Ratio of axial cavity/thallus diameter varies between 11 % and 25% (see Tab. 1). Individual laterals appear spine-like on the thallus outside.

Marginal sections of the laterals may appear as points or small white circles ( Fig. 4e, g, k ). Because of the recrystallization of the majority of specimens the base of laterals is not well recognizable. The well preserved specimen illustrated in Fig. 4j exhibits that the laterals are arisen as single from the axial cavity, but others show two or three laterals arisen from the common base ( Fig. 4h ). Each spine-like lateral contains a very narrow tube ( Fig. 2 ; Fig. 4m : arrows). Length of laterals is usually 1 mm, their diameter about 0.08-0.15 mm, their number in each is 22-40. In the holotype as well as in the majority of specimens the recrystallization amalgamated the base of laterals, appearing as a thick wall around the axial cavity. Some biometrical data of Probolocupsis sarmeikensis nov. sp. are listed in Table 1.

Comparison: The distinctly narrow axial cavity of Probolocuspis sarmeikensis nov. sp. differs (without regard to the stratigraphic age) this species from the type species – Probolocupsis espahkensis Brönnimann et al. – and from P. aculeata Nittel clearly. Differences of the skeletal elements are additional criteria for distinguishing this species from the known species.

Schlagintweit et al. (2013) illustrated in Fig. 3a some dasycladalean specimens (maybe recrystallized) from the “Lower Gosau Subgroup of Austria ” as Milanovicella hammudai ( Radoičić 1975) , which are very similar to recrystallized specimens of P. sarmeikensis nov. sp. According to the diagnosis of Milanovicella, given by Granier & Berthou (1994) and compared with illustrations of the type material of Radoičić (1975), described as Likanella hammudai and revised by Schlagintweit (1990) the species of Sarmeika can not be attributed to this genus.

There are some morphological similarities between the species Neogyroporella ? gawliki described from the Upper Jurassic-Lower Cretaceous of the Northern Calcareous Alps by Schlagintweit (2005, compare also Schlagintweit 2011) and P. sarmeikensis .

The general appearance of P. sarmeikensis is similar to Teutloporella echinata , described by Ott (1975) from the Ladinian of the Lombardian Alps, northern Italy. The individual laterals in P. sarmeikensis are arranged perpendicular to the axial cavity, but they are orientated oblique in T. echinata . Laterals are risen as single from the axial cavity (later they can be branched: Fig. 4d, h ) in P. sarmeikensis , but they may be doubled? in T. echinata . In addition the shape of laterals in P. sarmeikensis is always spine-like and their cross sections are always circular or oval, but the shapes of laterals (see Ott 1975: fig. 3) and their cross sections in T. echinata are different. Advanced interpretations of these features deserve a comparing study of the material from Alps and Argolis.

Figures

Fig. 2 Probolocupsis sarmeikensis nov. sp. (Holotype). The magnification from Fig. 4l shows the spine-like extended individual laterals (some of the internal pores: see arrows). Laterals are perpendicular to the thallus axis.

Fig. 4 a to n Probolocupsis sarmeikensis nov. sp. from the reef carbonates near the town of Sarmeika, Peloponnes, Greece. a Cross section exhibiting the narrow axial cavity and the thick thallus wall. Laterals appear as white points in section through them. G058, x10. b Cross section through two poorly preserved specimens. G058, x8. c Oblique longitudinal section through an incomplete? specimen exhibits the laterals, which are oriented perpendicular to the axial cavity. G05C, x16. d Cross section of a specimen exhibiting the partly recrystallized laterals of the thallus. G05A, x16. e Cross section through an apparently poorly preserved specimen. Laterals appear as white points in section through them. G058, x16. f Cross section through an incomplete specimen. G050, x8. g Sections through a complete and an incomplete specimen. Laterals appear as white points around the incomplete specimen. G05B, x16. h Cross sections through two specimens. G05C, x12. i Cross section through a relatively well preserved specimen. G05C, x16. j Oblique section similar to Fig. i. G05C, x10. k Cross section exhibiting the pores (arrows) in the laterals. G05B, x16. l Longitudinal section through the holotype (for magnification see Fig. 2) and cross sections through two paratypes. G05C, x6. m Cross section through a recrystallized specimen. Arrows indicate the pores within the laterals. G05B, x16. n Cross section through a strongly recrystallized specimen causing the disappearance of the axial cavity. G025, x16.

Fig. 1 Geographic position of the Norian-Rhaetian reef locality north of the town of Sarmeika, Peloponnes, Greece.

Fig. 3 Diplopora obliqusipora nov. sp. (Holotype). The magnification from Fig. 5c shows the relics of metaspondyle arrangement of the tufts (large arrows, also the cross sections of the laterals at the base of the thallus indicate the metaspondyle arrangement of the laterals). Small arrows indicate the tufts arising from the common base. The thin wall around the axial cavity is clearly recognizable.