Two look-alike dasycladalean algae : Clypeina isabellae MASSE , BUCUR , VIRGONE & DELMASSO , 1999 from the Berriasian of Sardinia ( Italy ) and Clypeina loferensis sp . n . from the Upper Jurassic of the Northern Calcareous Alps ( Austria )

New material from the Berriasian of eastern Sardinia, Italy, and from the NW of Sardinia published by PECORINI in 1972 as “Clypeina sp. A”, allows a better characterization and an emended diagnosis of Clypeina isabellae MASSE et al., 1999 from the Berriasian of SW France. Another morphologically somehow similar Clypeina species from the Upper Jurassic of the Northern Calcareous Alps of Austria is described as Clypeina loferensis n. sp. Remarks on the genera Clypeina MICHELIN and Hamulusella ELLIOTT, a Clypeina-type dasycladalean alga with proximal bulged laterals, and Clypeina jurassica-sulcata are also provided.


Introduction
In 1999, MASSE et al. described the new dasycladalean alga Clypeina isabellae from the Middle-Upper Berriasian of southern France.As the description was based mainly on transverse and oblique sections, some biometric parameters (e.g.verticil spacing = h) and morphological details (e.g.connection of the laterals with the main axis) are unknown.Denoting that this species is only recorded from its type-locality, to the authors obviously escaped notice of the good illustration of the same taxon from the "Purbeckian" of NW Sardinia shown by PECORINI (1972, as Clypeina sp.A).Since its description, Clypeina isabellae was so far reported from the Upper Jurassic of Romania (BUCUR & SASARAN 2005, without illustration) the Northern Calcareous Alps of Austria (SCHLAGINTWEIT & EBLI 2000, without illustration;SCHLAGINTWEIT 2005, C. aff. isabellae).Well-preserved and abundant material from the Berriasian of Eastern Sardinia allows the redescription and emendation of Clypeina isabellae.Additional material from the Upper Jurassic of the Northern Calcareous Alps shows the distinctiveness of the Alpine specimens, here introduced as Clypeina loferensis sp.n.

Sardinia
Within the ambit of studies on the sedimentary cover of Eastern Sardinia, which have continuing for many decades at the Department of Geosciences of the University of Padova, detailed litho-and biostratigraphic analyses have been carried out on the carbonate platform deposits of Late Jurassic-Early Cretaceous age cropping out in the Oliena-Orgosolo-Urzulei massif (the so-called Supramonte).These researches have led to findings of abundant macro-and micropalaeontological associations.In particular, as regards calcareous algae, as well as spe-cies already quoted in the literature for Sardinia and other European regions, forms not referable to any known taxa were identified.Among these, Clypeina dragastani and Salpingoporella granieri were erected by DIENI & RADOI^I] (2000) for dasycladaleans occurring in beds of Early Berriasian age of the Sa Marghine Ruja section, in the Oliena territory (Fig. 2).This section represents the terminal part of the very thick Mt.Bardia Limestone formation, the age of which is Tithonian to Berriasian in most areas, but locally extending downwards into Kimmeridgian and Oxfordian.The Tithonian-Berriasian interval of the lithostratigraphic unit is characterized by a rather uniform facies association, corresponding to a generalized peritidal environment with well-developed microbial mats and fine-grained fenestral limestones.A regressive acme is reached in the upper part of this complex, which is marked by many horizons of black-pebble breccias, mud-cracked laminites and oligotypic assemblages consisting of charophytes, ostracods and small mollusks suggesting a scenario of wide supratidal flats disseminated with lagoonal to fresh-water ponds.The succession is commonly split into a number of highfrequency metre-scale cycles (DIENI & MASSARI 1985).
One of the best exposures illustrating the peritidal deposits is just that of Sa Marghine Ruja (Fig. 3), where the depositional pattern shows the characters of the wellknown "Purbeckian facies".This section (illustrated by DIENI & MASSARI 1985 under the name of "Sa Oche section") is located within the Lanaittu valley, which is a structural depression corresponding to an asymmetric syncline bounded by a NNE-trending fault system on the eastern side (Fig. 2).Within the mud-cracked almost barren laminated facies, volumetrically dominant, a number of packstone layers are intercalated, rich in microfossils of restricted environment, peloids and flat intra-clasts.These facies are thought to represent the record of storm flows intermittently encroaching on mud-cracked supratidal flats and depositing their load from suspension.A slight transgressive trend and increasing openmarine influence is suggested by the upward increment in number of these layers and appearance in the uppermost layer package of higher-diversity fauna and flora.
In the Sa Marghine Ruja section, the Tithonian-Berriasian boundary can be traced with sufficiently good approximation only by means of the content in plant remains, since foraminifers give no significant information from the bio-and chronostratigraphic viewpoint.The boundary may be located approximately between beds 848 and 851 (the sample numbers were marked with colored enamel paint on the beds cropping out along the studied succession).As regards Dasycladales, starting from bed 857, in addition to species already quoted in the Upper Jurassic, such as Actinoporella podolica (ALTH), Clypeina maslovi (PRATURLON), Clypeina solkani CONRAD & RADOI^I], Otternstella lemmensis (BERNIER) and Salpingoporella annulata CAROZ-ZI there are taxa which, at least until now, have only been recorded beginning from the Berriasian, such as
Diagnosis.Medium-sized dasycladalean alga with clearly spaced-out laterals inclined upwards 60°-80° in respect to the main stem, euspondyl in arrangement.Laterals elongate, fusiform, and connected to the small main stem starting from a comparatively narrow pore.Along their distal half the laterals are clearly separated from each others.Thin calcification covering main axis and laterals.
Description.Medium-sized representative of Clypeina with a small main axis amounting to less than 1/3 of the total diameter.Calcification of laterals and main axis is thin (thickness 0.02 to 0.04 mm).Due to the weak calcification of the main axis, longitudinal sections comprising two or more consecutive whorls are rare; in no case more than two verticils were observed (Pl. 1, fig. 4).Secondary non-fibrous calcifi-cation present at the base of the laterals.Most probably the distal parts of the laterals were poorly if at all calcified, open to its exterior.Laterals are elongatetubiform, inclined to the main axis (60°-80°), connected to the axis by a small pore (Pl. 1, figs. 1, 5).Due to their inclination, the laterals show a slight asymmetry in longitudinal sections (Fig. 5G).The upper side more or less directly stretches away from the axis, whereas the lower side of the lateral is a little bit more rounded, however, without forming a downward bulging.Transverse sections through the lower part of a verticil with less inclined laterals give rise to a more regular rosette (Pl. 1,figs. 2,11); in these cases laterals are circular to ovoid in longitudinal sections.The laterals stay in contact for 1/3 to 1/2 of their length before becoming untouching, individualized.Normally, the laterals are gradually widening, seemingly becoming narrower again toward their distal ends.The verticils are rather widely spaced-out.
Comparisons.Clypeina loferensis sp.n. is closely related to Clypeina isabellae MASSE et al. differing from this species above all by the lack of a bulge at the lower side of the lateral's proximal parts.Moreover, the observed intralateral fibrous calcification of C. isabellae and C. jurassica is missing in C. loferensis sp.n.Both species share similar dimensions also with a comparable variation grade of rare tiny and large specimens; the weak calcification of the membran of the laterals is present in both species.
In the description of their taxon, the authors furthermore added that the laterals are connected to the main axis by a short peduncle, poorly if at all recognizable in the original figurations.
Emended diagnosis.Tallus of elongate-cylindrical main axis bearing spaced-out fertile whorls of horizontal or slightly upward inclined (up to 16°) laterals.Relatively large tubular fertile laterals, containing ampulla, of slightly irregular shape with a small bulge on the lower side immediately near the main axis; in transverse section they are distally somewhat narrower.The skeleton prevailing consists of fibrous yellowish calcite, but also of colorless calcite.Individual calcification of laterals affects only their proximal and middle part, whereas the distal area is uncalcified.Main axis is feeble calcified.Very thin primary calcification characterizes also the wall of laterals, while yellowish calcite is intracellular deposition, usually united with wall skeleton by recrystallization.
Dimensions.The size of the Sardinian specimens varies more than 1: 3. D: 0.23-0.74mm, d: 0.081-0.31mm.The number of laterals per whorl is 6-15, generally varies between 10-12, rarely arrived to 14, exception-al are 6 or 15 laterals.Amongst the small-sized specimens, that one with an inner diameter of 0.123 mm and 10-11 laterals and another with 6 laterals and an inner diameter from 0.081 to 0.125 mm are worth noting (Pl. 2,Figs. 19,22).Distance between consecutive whorls 0.020-0.030mm.The main axis diameter is nearly of the same value as the length of the calcified part of the laterals, only sometimes larger and exceptionally smaller.Unique, extremement large specimen, here presented as Clypeina cf.isabellae (Fig. 6) derives from the Purbeckian of NW Sardinia (Nurra) illustrated by PE-CORINI (1972, Fig. 3d).The dimensions of this specimen (D: 1.15 mm, d: 0.48 mm) were obtained from the thin-section of the PECORINI collection.The similar example of an extreme large specimen in the population of Clypeina marginiporella MICHELIN was presented by GÉNOT (1987, pl. 26, fig. 1) as C. cf.marginiporella.
Description.As the main axis is weakly calcified, scattered individual whorls are prevailing, rarely two successive whorls, or, exceptionally four whorls as those in Pl. 2, Fig. 18, are preserved.Whorl rosette generally has very regular shape; in specimens with elevated number of lateral they are irregularly composed, somewhat overlapped (Pl. 2,Figs. 5,14).Adjacent laterals, depending of their number per whorl, may be more or less fused.In some very deep tangential section of specimens with elevated w number they occur, along fused portion, laterally congested having flattened shape (Pl.2, Fig. 10).The bulge in the initial portion of whorl is clearly visible in number of longitudinal and different tangential sections shown on Plates 3 and 4. In transverse sections through the lower part of the whorl, the bulges occur as small circles around the main axis (Pl. 2,Figs. 1,8), and this results also in some oblique sections (Pl.3, Fig. 16).Ampullae are rarely preserved, usually as remains of calcite filling (Pl. 2,Figs. 15,18,21).Only well preserved ampulla (Fig. 7; Pl. 2, Fig. 9) is enclosed in intracellular calcification (as in Clypeina jurassica, Figs.8A, B).
Relationships.Clypeina isabellae is related to the group of Clypeina species characterized by a more or less expressed bulge on the proximal lower side of lateral's wall (= small lower protuberance of DE CASTRO, 1997, pl. 20, fig. 1)  Species with larger bulges such as Cl.? sedalanensis and Cl.liburnica, according to BARATTOLO (1998, p. 84), belong to genus Hamulusella ELLIOTT as the "short proximal portion below the junction point" of the primary lateral "... is not visible or recorded in the typespecies of Clypeina".Consequently, the question is: which value of the bulge size can be taken as genus specific and is it an important character for distinguishing the two genera Clypeina and Hamulusella?Noteworthy, that the genus Hamulusella was considered a junior synonym of Actinoporella by GRANIER (1994), a view that is not followed here (see also BARATTOLO, 1998); other authors, though recognizing its affinities to Clypeina, maintained its validity (DELOFFRE & GÉNOT 1982;DELOFFRE 1988;DELOFFRE & GRANIER, 1992;GRANIER & DELOFFRE 1993).
The thin-sections with Clypeina isabellae MASSE et al. from the Berriasian of Sardinia are housed in the Museo di Geologia e Paleontologia, University of Padova.

Remarks on Clypeina jurassica FAVRE & RICHARD -Clypeina sulcata (ALTH) relationships
Actinoporella sulcata (ALTH) is known only as an imprint of transversal whorl's section from the Upper Jurassic Nizniów Limestone of the Ukraine illustrated by PIA (1920, Pl. 7, Fig. 8).Since that time, the species has not again been identified.RADOI^I] (1969) mentions that Actinoporella sulcata more appropriates to some Clypeina (cf.jurassica?).With respect to PIA's illustration, CONRAD et al. (1974) stated that undoubtedly there is a close resemblance to Clypeina jurassica or Clypeina inopinata, thus, necessitating the study  of further material from its type locality.In the monography of Jurassic-Cretaceous dasycladaleans provided by BASSOULLET et al. (1978, p. 32), Actinoporella sulcata (was regarded a synonym of Clypeina jurassica although the former was described prior to the latter. GRANIER & BRUN (1991) were considering Clypeina jurassica as a junior synonym of Clypeina sulcata without going further into discussion.Consequently, C. jurassica was not included in the "Critical Inventory" provided by GRANIER & DELOFFRE (1993).It is worth mentioning that no sulcata specimen or fragment was identified in 6 samples (8 thin slides, R.R.) from the type-locality which were kindly collected by S. PASTER-NAK (The National Academy of Sciences of Ukraine).Even in case where Clypeina jurassica (not inopinata) would be documented as junior synonym of Clypeina sulcata, there would be some solid arguments in favour of retaining the name jurassica as nomen conservandum.The present authors will refer to the General Committee of ICBN with an appropriate recomendation for a ruling this matter.
Transverse section of a whorl with 13 laterals which are not lying in the same plane, instead corresponding to tangential section of overlapping laterals (compare Fig. 14); sample 853/5.Fig. 6.
Transverse slightly oblique section cutting some bulges of laterals, note: thin primary calcification of the main axis; sample 853/4.Fig. 8.
Slightly oblique transverse section passing through the lower part of whorl -through bulges; sample 853/5.Fig. 9.
Transverse, slightly oblique section with, in the one lateral on right, clearly visible well preserved ampulla; sample 853/2.Figs.10-14.Different tangential sections; the section in Fig. 14 with overlapping laterals corresponds to specimen as that one shown in Fig. 5

FELIX
Fig. 1.Topographic sketch map of the type-locality of Clypeina loferensis n. sp.near the village of Lofer, Austria.