Lower Jurassic foraminiferal biostratigraphy of Podpeč Limestone (External Dinarides, Slovenia)

The “Podpe~ limestone” outcropping south of Ljubljana (Central Slovenia), deposited at the northern edge of the Dinaric Carbonate Platform, comprises mostly dark grey and black thick bedded oolitic limestone, and is renowned for several horizons of lithiotid bivalves. Foraminifera, especially Orbitopsella spp., are rather frequent, but no detailed distribution of foraminiferal taxa was given. Furthermore, documentation of foraminiferal species is scarce, with few photographs. In order to give a comprehensive picture of foraminiferal assemblage of the “Podpe~ limestone” and its distribution, three sections were measured in detail and sampled. The foraminiferal assemblage consists of 17 species, described in detail. On the basis of foraminifera, the investigated part of the “Podpe~ limestone” belongs to the Lituosepta recoarensis and Orbitopsella praecursor biozones of early Late Sinemurian and Early Pliensbachian age, respectively.

Biostratigraphic division of Jurassic shallow water carbonates of the central Dinaric Carbonate Platform has been given by raDoi^i] (1966) and recently by Veli] (2007). The key to a detailed subdivision of Lower Jurassic strata elsewhere in the Karst Dinarides is thus at hand.
The aim of this paper is to give a systematic account of foraminifera in the lithiotid bivalves-rich "Podpe~ limestone", an informal Pliensbachian stratigraphic unit of central Slovenia, and to present their distribution in three detailed sedimentological sections from the Mt. Krim area: the classical locality of the Podpe~ quarry, supplemented by data from Zalopate and Grad sections (Fig. 1).
Shallow-water carbonates with lithiotid bivalves can be followed over the area of Slovenia in an over 100 km long belt (BuSer & DeBeljak, 1996). Locally, Dozet and StroHmenger (2000) introduced a Lower Jurassic Podbukovje Formation, or Predole Beds with five members (Dozet, 2009). The correlation of the "Podpe~ limestone" with these units is unclear, due to the lack of definitions and biostratigraphic studies of the lower and upper boundaries of the "Podpe~ limestone". Furthermore, no type sections for the Podbukovje/ Predole Formations and their members were selected either, and a more detailed description and definitions of lithostratigraphic boundaries are missing as well. The "Podpe~ limestone" may thus correspond to one, two or all of the three successive middle members of the Podbukovje/ Predole Formations, i.e. Orbitopsella limestone, Lithiotis limestone and Oolitic limestone sensu Dozet (2009).
All these reports lack a detailed sedimentological section and the details of foraminiferal distribution.

Methods of study
In order to investigate foraminifera from the "Podpe~ limestone", three sedimentological sections were measured bed-by-bed in the wider Mt. Krim area (Fig. 1). Samples were collected from 55 beds, and 62 thin sections made, in which foraminifera were determined. Foraminiferal systematics follows BouDagHer-faDel (2008). Terminology follows  and BaSi et al. (2006). The positions of thin sections and the distribution of foraminifera are given in Figures 2-4.

Description of measured sections
The Zalopate section (see position on Fig. 1) is located at approximate coordinates 45°56´09´´ latitude and 14°27´21´´ longitude, a few meters above the road. The section starts with micritic limestone, which may be banded (straight dark and white, 5 mm thick lamina). Black finegrained oolite soon appears and then represents the dominant lithology. Accumulations of bivalves, brachiopods, intraclasts and oncoides are locally present at the base of oolite. Irregular reddish bedding planes are interpreted as shorttime emersion levels (see martinu{ et al., 2012). Grading, parallel lamination, occasional scour structures and ripples are present.
Description: Most of the material is identified as tests of megalospheric generation. The majority of specimens has only planispirally coiled part of the test. In a few cases the planispiral part is followed by uniserial part of the test. Protoconch is complex (bilocular cf. gu{i], 1977), 0.11-0.19 mm in diameter. It is followed by 1-2 planispiral coils, amounting to the outer test diameter of 0.56-1.00 mm. Chambers (3-5?) are hardly discernibly in the first coil. The second coil comprises 6-9 reniform chambers, separated by thick, short and obliquely positioned septa. The uniserial part of the test is 0.61-1.11 mm high, consisting of 3-8 chambers. The height of these chambers remains approximately constant (lumen height 0.13-0.14 mm), whereas the chamber width may stay unchanged or slightly increases (lumen width 0.42-0.61 mm). The aperture is initially simple basal, towards the end of the second coil becoming centrally situated, and in the uniserial part multiple/cribrate. Stolons are 0.04-0.07 mm in width, widely separated. The outer test wall and the septa near the outer wall (the gradual loss of perforations in septa was commented also in gu{i] & Veli], 1978) are agglutinated, riddled with large and densely packed pseudopores (alveoles in BouDagHer-faDel & BoSence, 2007), i.e., in the literature called a keriothecal wall (e.g. Septfontaine, 1988;BaSSoullet, 1994;taSli, 2001;ScHlagintweit & Veli], 2011). The outer wall and the septa are 0.06-0.08 mm thick. In the axial section the coiled part of the test appears biumbilical or with parallel, slightly compressed sides, 0.42 mm wide. The periphery of the test is widely rounded. The degree of chamber overlap is not distinctly visible.
The wall was originally described as having bifurcating alveoles (gu{i], 1977). It was later mostly described as keriothecal (BaSSoullet, 1994;fugagnoli, 1998;taSli, 2001;ScHlagintweit & Veli], 2011). The original distinction from Mesoendothyra Dain was based on the different wall texture (simple microgranular in Mesoendothyra vs. complex in Bosniella). However, Septfontaine (1988) considered Bosniella a junior synonym of Mesoendothyra. Because M. croatica differs from the type species of Mesoendothyra, BaSSoullet (1994) later considered Bosniella a valid Jurassic genus, comprising B. oenensis, B. fontainei and B. croatica. fugagnoli (1998) also considered both genera distinct, but due to the lack of revision of the type material of Mesoendothyra. taSli (2001) acknowledged both possibilities by considering Bosniella a junior synonym of Mesoendothyra or, alternatively, placing M. croatica into the valid genus Bosniella. I prefer the latter option, due to the presence of specimens referred to Mesoendothyra sp., which probably has a simple microgranular wall.
Bosniella fontainei Bassoullet from Middle Jurassic of Thailand has slighly smaller megalospheric tests, larger microspheric tests, less globular chambers and strongly inclined septa (BaSSoullet, 1994). It is safe to add that B. fontanei has more numerous chambers (9-10 or 10-11) in the last whorl of megalo-and microspheric tests, respectively.
Description: Specimens likely belong to a microspheric generation. The initial, irregularly coiled part consists of few chambers. It is followed by a planispiral part, approximately in two coils. The last whorl has 9-11 chambers, separated by obliquely set septa of thickness approximately equal to the wall. The total diameter of the coiled part is 0.40-0.54 mm. The uncoiled part of the test is short, not well developed, with only 1-2 free chambers. They are 0.04-0.05 mm high (lumen) and 0.2-0.26 mm wide, of boxwork shape. The aperture is at first a single opening, later becoming multiple (see Pl. 1, fig. 10). The outer test wall is coarsely alveolar, 0.04-0.08 mm thick.
Remarks: Lituolipora termieri was described from the Lower Jurassic of Morocco as Mayncina termieri with a simple finely agglutinated wall . gu{i] and Veli] (1978) later introduced a new genus and species, Lituolipora polymorpha, from the Lower Jurassic of Croatia. The new genus was established on the basis of coarsely perforated wall. gu{i] and Veli] (1978) were aware of the close similarity with M. termieri, but they came to a conclusion that the wall of M. termieri is not diagenetically altered. Septfontaine (1988) later decided for the contrary, and introduced a new genus Paleomayncina with the type species M. termieri. kaBal and taSli (2003) proposed to retain Lituolipora as a valid genus name for the sake of priority over Paleomayncina, and recognized L. polymorpha to be a junior synonym of L. termieri. Their opinion is followed in this paper. kaBal and taSli (2003) further documented the variability of the species and recognized three morphotypes, two corresponding to different onthogenetic stages of the megalospheric generation and one to microspheric tests (kaBal & taSli, 2003). Septfontaine (1988) and kaBal and taSli (2003) (Septfontaine, 1988).

Material:
Thin sections 333, 418, 533, 533b. Specimens are in basal sections (perpendicular to the coiling axis, one in slightly oblique section.

Description:
The test is free, roughly elliptical in outline. Test wall is dark, agglutinated and undifferentiated, simple. The outline of the test is continuous, without obvious sutures. Septa are of the same thickness as the outer test wall, and appear perpendicular or slighly oblique to the outer test wall. They divide the interior of the test in 5-10 chambers per whorl. A single solid micritic mass of circular outline (columella) occupies the center of the test. Columella is bordered by large, resorbed foramina (cf. BaSSi et al., 2006).
Test diameter ranges from 0.11 to 0.54, with larger tests having greater chamber number.
Remarks: According to literature descriptions (e.g.,  Pseudopfenderina has a high trochospiral form, which, however, cannot be visible in the observed material due to the lack of axial sections. The genus is distinguished from similar genera posessing axial columella in its lack of complicated wall structure (subepidermal reticular network in Kurnubia Henson; primitive hypodermal network in Praekurnubia Redmond) or in the absence of subcameral tunnel, which is present in Pfenderina Henson and Paleopfenderina Septfontaine Septfontaine, 1988;loeBlicH & tappan, 1987). The columella of Pseudopfenderina consists of pillars and secondary (?) carbonate deposits, forming a solid structure . As pillars are sometimes not visible, some authors prefer determination as Pseudopfenderina cf. butterlini (e.g., fugagnoli, 1998;BouDagHer-faDel & BoSence, 2007). Part of the material in BouDagHer-faDel and BoSence (2007) is attributed to Duotaxis metula Kristan in basal section, as no columella is visible and the umbilicus appears unfilled.
Hottinger (1967) distinguished two-times smaller specimens with fewer chambers per whorl (5-7 compared to 7-9 of P. butterlini) as an unnamed new species. His opinion was later followed by fugagnoli (1998), who counted 5-6 chambers per coil in material from the Southern Alps. However,  figures show 8-9 chambers per coil, and the size difference is here argued to derive from the different position of sections according to test's height (even though the test has fairly parallel sides in the later stage of growth). Larger equatorial sections have more chambers than smaller ones.  fig. 1; Pl. 11, Material: Thin sections 321, 322, 326, 329b, 333, 412, 418, 423, 428, 429a, ?335, 337, 513, 517, 523, 533, 535b, 536. Description: The test is trochospiral, with an apical angle 45-75° and up to 6 coils. Three chambers are visible in basal section of the last coil. The total test height is 0.25-0.77 mm, the width 0.20-0.51 mm. The twisted umbilical canal is clearly visible, indented on the inner side of the chambers. The chamber lumen is rounded to reniform. The wall is simple, microagglutinated.

Remarks:
The specimens ascribed here to S. variabilis differ from S. gibraltarensis in having a narrower apical angle. The holotype of S. variabilis was figured by Septfontaine (1980) and described in Septfontaine (1988)  Description: A high trochospiral test with remiform to rounded trapezoidal chambers in 6 coils measures 0.68 mm in height and 0.36 mm in width. The apical angle is 45°. The siphonal canal is relatively narrow.

Description:
The test is elongated, with pronounced dimorphism, expressed in the development of the planispiral part, followed by chambers in uniserial rectilinear or curvilinear arrangement. The aperture is not clearly visible; it could be multiple or circular. In some specimens, a single central opening is observed. The uniserial part of the test is circular in cross-section. Thick radial beams of the exoskeleton are pronounced, reaching far towards the centre of chamber. The wall is of variable thickness (0.04-0.06 mm).
Type 1: The test is uniserial throughout, or perhaps with a very small coiled initial part, which is not discernible. The number of chambers in uniserial part ranges from 4 to 8. They are fairly constant in height (lumen around 0.04-0.06 mm) and width, resulting in a test with roughly parallel sides, 0.65-1.00 mm long and 0.32-0.39 mm wide.
Type 2: The initial part of the test is planispiral, 0.19-0.34 mm in diameter. The number of coils is not clearly visible (2?). The coiled part is followed by 4 uniserial chambers in total length of 0.48 mm. Individual chambers are 0.05-0.06 mm high (lumen), maintaining approximately constant width.

Remarks:
A reconstruction of A. amiji is given by Baloge (1981). Radial partially developed beams (incipient septula?) are clearly visible in sections perpendicular to the axis of growth. Rafters are also depictured. BouDagHer-faDel and BoSence (2007) interpreted aperture as multiple, later reduced to a single central opening. loeBlicH and tappan (1987) and Septfontaine (1988) write about cribrate aperture. Smaller (1.2 mm) specimens with planispiral initial part were originally interpreted as microspheric tests, and the specimens lacking planispiral part as megalospheric. Hottinger (1967), however, could not confirm this. fugagnoli (1998) on the basis of the literature survey allowed for a possibility that both generations could possess a planispiral part.  (Banner et al., 1997); Late Sinemurian to Bathonian of Israel (pereliS groSSowicz et al., 2000); Early Bajocian of Quatar (al-SaaD, 2008). According to BaSSoullet (1997) and Banner et al. (1997) the species ranges from Late Sinemurian to end of Bathonian.

Description:
The test is mostly circular in equatorial section; planispiral coils are rarely followed by the uniserial part of the test. The outer test wall is microagglutinated. A keriothecal structure is suggested, but not clearly visible. The wall is 0.02-0.03 mm thick. Septa are approximately of the same thickness, situated slightly oblique. The aperture is simple basal, in the uncoiled part multiple.
Microspheric (?) test: The proloculus is not distinguishable. The planispiral part consists of (2?) 2.5-3 coils. Counting from the aperture backwards, the last coil comprises 7-10 chambers. The uniserial part is present in only one of the specimens, consisting of 4 chambers. Chambers are approximately as high as they are wide. The planispiral part of the test measures 0.22-0.43 mm in diameter. The total test length of the test with the uniserial part is 0.69 mm. The higher number of planispiral coils suggests these tests belong to the microsphaeric generation.

Megalospheric test:
The proloculus is circular, 0.03-0.04 mm in diameter. It is followed by 1.5-2.5 planispiral coils, with 9 chambers in total (6 are counted in the last whorl). The entire spiral part is 0.26-0.39 mm in diameter.

Remarks:
The shape of the test and the test size correspond to Mesoendothyra sp. described by fugagnoli (1998), pereliS groSSowicz et al. (2000), and Veli] (2007). The wall was determined by fugagnoli (1998) as simple, without exoskeletal structure. If this is the case, then it is appropriate to place this species into genus Mesoendothyra (although the stratigraphic gap between this and later species of this genus is not considered). However, the simple structure may be the product of diagenetic alteration of keriothecal wall, and the species should be assigned into genus Bosniella. The specimens presented here do not offer reliable evidence for this. The uniserial part in some specimens figured by Veli] (2007)

Description:
The total length of the test is 0.46-1.00 mm. A simple megalospheric proloculus measures 0.08-0.09 mm in diameter (the exception is specimen from thin section 333 with diameter of 0.07 mm). A planispiral part in 1.5 coils follows. Six to nine chambers are visible in the last coil, whereas the chambers are poorly visible in the initial part of the spire. The total diameter of the coiled part is 0.28-0.42 mm. In most of the specimens a uniserial part consisting of up to 12 chambers follows. Chambers are flat, 0.04-0.05 mm high (lumen) and separated by septa 0.03-0.05 mm thick (never thicker than the chamber lumen). Scattered endoskeletal pillars are visible crossing the chamber lumen. The wall appears undifferentiated, microagglutinated. The aperture is multiple in the uncoiled part, not visible in the planispiral one.

Remarks:
The specimens figured herein correspond best to Lituosepta recoarensis, originally described by cati (1959) from the Lower Jurassic of Southern Alps. Hottinger (1967) later refigured some of cati's (1959) specimens, adding some new specimens from High Atlas of Morocco, as well as a wealth of specimens, which he attributed to a new species, Lituosepta compressa. According to , the new species differs from L. recoarensis in having smaller test, a more pronounced flattening, a better developed pillars in the endoskeleton, a tighter coiling and a smaller proloculus in megalospheric forms (0.06-0.08 mm compared to 0.08-0.10 for L. recoarensis). In his opinion, transverse sections of L. recoarensis in cati (1959) possibly belong to Haurania. Both species of Lituosepta should thus be laterally compressed. In contrary to Hottinger, Septfontaine (1984) believed Cati was right about L. recoarensis having circular cross section, and he subsequently established a new genus, Planisepta, to comprise flattened ex L. compressa (Septfontaine, 1988). Furthermore, Septfontaine (1984) regarded specimens designated by Hottinger (1967) as L. recoarensis as belonging to P. compressa. fugagnoli (1998) and fugagnoli and loriga Broglio (1998) later accepted Hottinger's (1967) interpretation, disregarding validity of genus Planisepta. loeBlicH and tappan (1987) considered Lituosepta as a junior synonym of Labyrinthina Weynschenk. According to Septfontaine (1988), the initial coiled stage is more pronounced in the latter (3 coils compared to 1.5 coild in Lituosepta), whereas BouDagHer-faDel (2008) mentiones also a fan-shaped flabelliform test and a canalicular wall in Lituosepta.
In my opinion, the distinction between the two species is not well established. The size difference proves to be irrelevant (see specimens in fugagnoli, 1998, andBoSence, 2007). In fact, the only useful quantitative parameter seems to be the size of the proloculus, but the latter overlap at 0.08 mm. Based on the material figured by cati (1959) and Hottinger (1967), the difference may be in the tightness of coiling, i.e. the planispiral part of the megalospheric form opens after 1.5 coils in L. recoarensis and after 2 in L. compressa, and in the number of endoskeletal pillars, which are better developed (more numerous) in the latter species. It is also true, that Cati's microsphaeric specimen does not show a pronouncely fan-shaped uncoiled part. Thus, I agree with Septfontaine's opinion and regard Hottinger's specimens as belonging to L. compressa only. However, as the type material of L. recoarensis needs to be re-examined, I refrain from species designation. Regarding the genus name, I agree with fugagnoli (1998) and fugagnoli and loriga Broglio (1998) that the degree of flattening is not a generic criterion.
The name Planisepta is thus regarded as a junior synonym of Lituosepta, especially since there is no equivocal proof of the L. recoarensis cross section.
One of the specimens, figured by cHioccHini et al. (1994), does not show endoskeletal pillars. Its determination is thus considered doubtful.
Lituosepta differs from Orbitopsella Munier-Chalmas in having a simple megalospheric proloculus, and from Haurania Henson in a simple exoskeleton and in a laterally flattened test loeBlicH & tappan, 1987).
Geographic distribution and stratigraphic range: BaSSoullet (1997) regards L. recoarensis and L. compressa as stratigraphically very useful species, as the former is of Sinemurian and the latter of Pliensbachian age. However, due to taxonomic uncertainties regarding the distinction of both species, a careful re-examination of material is needed. The specimens from the synonymy list were collected in: middle Early Jurassic of Apennines, central Italy (cati, 1959;Sartoni & creScenti, 1962;cHioccHini et al., 1994); Late Sinemurian of Central Taurides, Turkey (kaBal & taSli, 2003); Late Sinemurian of Algarve Basin, Portugal (azerêDo et al., 2003); Late Sinemurian -Early Pliensbachian of Karst Dinarides (Veli] Description: A relatively small coiled (planispiral?) part of the test, 0.43 mm in diameter, is not clearly visible, so the number of coils (possibly 2) is poorly defined. In the outer part, however, more than 12 chambers can be counted, prior to the following uniserial part. In the latter, chambers, while retaining a constant height of 0.05 mm, become increasingly wider, producing a flaring test of total length of 2.07 mm. The uniserial part consists of 26 chambers. Septa and the outer test wall are 0.03 mm thick. Chamber lumen is crossed by numerous pillars. The wall is presumably simple in structure, microagglutinated. The aperture is multiple in the last part of the coiled and in the uniserial part at least.

Remarks:
Tests of distinct fan shaped planispiral part are here described separately from the rest of the Lituosepta material, as they better correspond to  specimens, which he regarded as belonging to L. recoarensis, but which, according to Septfontaine (1984), belong to L. compressa instead. raDoi^i] Pl. 144, fig. 2;Pl. 145, fig. 1) shows microspheric tests of supposedly L. recoarensis from middle Lower Jurassic of Karst Dinarides (Žumberak, Croatia), which have fewer chambers than specimens figured herein.

Megalospheric test:
In equatorial view the test appears fan shaped, semicircular, whereas in axial view the test is strongly elongated with parallel sides. Protoconch is complex, though the wall separating the proloculus from the deuteroloculus is usually not preserved. The size of the protoconch (lumen) is 0.18-0.31 mm. A short planispiral part follows with up to 12 chambers, and in the last stage of growth numerous uniserially arranged strongly arched chambers. These maintain constant height while gradually becoming wider. The total diameter of the test amounts to 2.14-2.35 mm.
The outer wall and the septa are 0.03 mm thick. A notable difference among specimens is in the size of agglutinated grains: while some specimens have uniformly thick wall, in others incorporated grain size exceeds the basic wall thickness by as much as 6.4-times. The exoskeleton is simple, with poorly visible beams. The endoskeleton consists of widely spaced and few pillars. Four to five stolon planes are visible.

Microspheric test:
The test is in »axial« section flat, with parallel sides, or with a gradually higher periphery, becoming biconcave. The total test diameter is 2.50-6.22 mm. The protoconch and the initial spiral part were not observed. The exoskeletal and endoskeletal features are as described above.

Remarks:
Despite the large number of specimens attributed to Orbitopsella only a few were determined to the species level. The criteria used in distinguishing O. primaeva from O. praecursor (Gümbel) and O. dubari Hottinger are: protoconch size and the test size (both smaller in O. primaeva) in megalospheric tests, and fewer stolon planes and much microspheric smaller test for O. primaeva (see . The number of spiral chambers could not be observed due to insuitable orientation of specimens. Compared to specimens in Hottinger (1967), the megalospheric specimens from the Krim area belong to A1 generation. The difference in coarseness of the wall is considered a phenotypic character (fugagnoli, 1998).
?Orbitopsella praecursor (Gümbel, 1872 , 333, 337, 413, 429B, 510, 513, 515, 517, 522, 524, 526, 530, 533, 535, 535b. Specimens of megalo-and microspheric generation. One specimen in axial section, 10 specimens in equatorial section. Description: Fairly large specimens have thick, finely agglutinated alveolar wall with widely spaced alveolae. Both generations (micro-and megalospheric) usually comprise well developed planispirally coiled initial part, followed by few uniserially arranged chambers. Chambers of the coiled part appear remiform, whereas chambers are triangular in shape in the uncoiled part of the test, tapering towards distal end. Aperture is a simple, large, centrally situated opening. Septa are of the same thickness (0.03 to 0.10 mm) as the outer test wall. The thickness of both, however, varies largely even in the same specimen.
Microspheric test: The coiled part of the test comprises 2-2.5 coils; the first is very small, with an indistinguishable number of chambers. The second coil consists of 3-4 chambers. The diameter of the coiled part is 0.16-0.41 mm. The rectilinear or curvilinear uniserial part, 0.5-0.67 mm long, consists of 2-5 chambers. The width of these in some sections appears equal to diameter of the initial coiled part. The maximum height of chambers (lumen, measured to the top of aperture, i.e. with septa thickness included) in the uncoiled part is 0.11-0.23 mm. A proloculus is too small to be measured.

Megalospheric test:
The initial part measures 0.26-0.48 mm in diameter and has 2 coils with 3 (?) and 5-7 chambers, respectively. The uncoiled part, 0.35-0.75 mm long, consists of 3-4 chambers, which are up to 0.11-0.28 mm high and 0.17-0.42 mm wide. A simple spheric proloculus measures 0.03-0.11 mm in diameter. In axial section, the initial coiled part appears biconcave, with chambers of the last whorl by 1/2 wider than the first whorl. The periphery is rounded, yet with box-like outline.

Remarks:
Meandrovoluta is among the most common benthic foraminifera in Early Jurassic carbonates, often described as Glomospira sp. The distinction from the latter, however, is in its wall structure, which is porcelaneous in Meandrovoluta and finely agglutinated in Glomospira Rzehak (fugagnoli et al., 2003). Its morphological variability, its presence in a variety of facies and assemblages, and a locally high abundance in low-diversity assemblages (personal observation in resediments of Perbla Formation, depositiory of B. Roži~, University of Ljubljana) suggest it is an opportunistic species (see DoDD & Stanton, 1990, p. 288). A somewhat similar Triassic genus Hoyenella Rettori has an initial mioliod coiling and a regularly developed last planispiral stage (rettori, 1994, 1995).
Finally, cai et al. (2005) described three new species from the Middle? Jurassic of Tibet: Glomospira wolongensis, Glomospira tingriensis and Glomospirella minuscula. The latter has a pronounced planispiral stage, and G. wolongensis appears smaller and with fewer coils, but G. tingriensis may prove to be a junior synonym of M. asiagoensis.
Remarks: Based on the original description, "Involutina farinacciae" differs from other species of this genus by its small size and the shape of the chamber lumen. However, rigauD et al. (in press) say there is no reliable criterion to separate "I. farinacciae" from Involutina liassica (Jones), due to the large variability of the species.

Geographic distribution and stratigraphic range:
The type material derives from early Early Jurassic of Monte Lacerone, Italy (Brönnimann & koeHn-zaninetti, 1969). raDoi^i] and joVanoVi] (2011) add numerous localities in Inner Dinarides, Karst Dinarides, Budva Basin and from Avroman Range area in Iraq, advocating "I. farinacciae" as a marker of middle Early Jurassic. The Podpe~ quarry is among the listed localities.
The wall is recrystallized into spar, originally aragonitic.

Remarks:
The determination of this species is problematic at the genus and species level.
kriStan (1957) introduced two new genera: Semiinvoluta and Coronella. Semiinvoluta was described as planispiral, evolute and with sutural canals on one side and coated with secondary material on the other side. Its type species, S. clari Kristan, has diameter of 0.62 mm and 5-9 coils. Some of the figures draw by hand, show a very low trochospiral coil. The description of Coronella is practically the same as of Semiinvoluta, except that the test is evolute on the coated side also. The type species, C. austriaca, measures 0.93 mm in diameter has 5 coils. Later, kriStan (1958) piller (1978) defined Coronipora as having one evolute side and the other coved by lamellae; the coiling is plani-to trochospiral. He hinted at the synonymy with Planispirillina Bermudez, but due to the lack of observation of the lamination in the latter, left both species valid. The distinction between Coronipora and Semiinvoluta was likevise questioned.
rigauD et al. (2013) greatly revised the Trocholinidae family. The genus Coronipora was redefined as having ridge-like lamellae and large perforations or short canals on the spiral side, and interfingering lamellae on the umbilical side, while Semiinvoluta possesses papillae on the umbilical side, shortened lamellae on the apical side and a depressed apical thickening. According to rigauD et al. (2013), "Coronipora" serraforma Senowbari-Daryan et al. is a junior synonym of S. clari.
According to the emendation of Coronipora and Semiinvoluta (rigauD et al., 2013), the specimens figured herein should belong to Coronipora, as no apical lamellae are visible. This distinction, however, is not obvious in the type material figured by kriStan (1957), and I consider this interpretation doubtful.
The species determination is likewise tentative. Considering a wide variety in size, Coronipora austriaca (Kristan), Semiinvoluta clari Kristan and Coronipora etrusca (Pirini) are likely candidates. The distinction from similar species is mostly lacking in the first description of these species, and the thorough revision seems necessary.
Geographic distribution and stratigraphic range: Poorly defined due to the unclarity of determination. The stratigraphic range is probably Rhaetian (?) -Early Jurassic.

Biostratigraphy
Several biostratigraphic schemes based on foraminifera exist for the Early Jurassic, and only a few more recent are discussed herein.
kaBal and taSli (2003) named three zones in the Early Jurassic of Central Taurides. Late Sinemurian Lituosepta recoarensis lineage zone (1) starts with the first occurence of L. recoarensis, and ends with the first occurence of Orbitopsella primaeva. Amijiella amiji is also present, and Lituolipora termieri and Lituosepta compressa occur for the first time. The latest Sinemurian -Early Pliensbachian Orbitopsella lineage zone (2) starts with the first occurence of O. primaeva and ends with the last occurence of O. praecursor. Algae Palaeodasycladus mediterraneous Pia is present. The Lituolipora termieri interval zone (3) begins with the last occurrence of Orbitopsella. This zone also represents the acme of L. termieri. The upper boundary is poorly defined and the zone may reach into the Toarcian, below the early Middle Jurassic Bosniella croatica zone.
From the Apennines, mancinelli et al. (2005) described three Early Jurassic zones. The Thaumatoporella parvovesiculifera (Reineri) interval zone (1) is Hettangian -Early Sinemurian in age. The lower boundary is the last occurrence of Triasina hantkeni Majzon, and the upper the first occurrence of P. mediterraneus. Duotaxis metula and Siphovalvulina variabilis first occur in the upper part of this zone. The Late Sinemurian P. mediterraneus local taxon range zone (2) starts with the first occurrence of its nominal species, and ends with its last occurrence. The Pliensbachian Orbitopsella local taxon range zone (3) follows.
According to biostratigraphic scheme of Veli] (2007), the Podpe~ and the Grad sections belong to Orbitopsella praecursor taxon range zone of the Early Pliensbachian. The highest occurrence of Orbitopsella is at the top of Podpe~ 1 section, or at the 2 nd metre of the lateral Podpe~ 2 section, so there is a possibility that the uppermost part of the measured PLATE 1 section reaches the early Late Pliensbachian (the start of P. liassica zone). However, no index taxa of P. liassica zone were found to support this possibility. The Pliensbachian age of these three sections is in agreement with the previous determination of age on the basis of lithiotid bivalves (e.g., BuSer & DeBeljak, 1996), although lithiotid bivalves are known also from Toarcian (DeBeljak & BuSer, 1998;SaBatino et al., 2013).
On the other hand, the Zalopate section, at least from the 6 th meter up, to the 34 th meter belongs to the early Late Sinemurian L. recoarensis zone sensu Veli} (2007), marked by the presence of L. recoarensis and absence of Orbitopsella. The section from the 34 th meter up could belong to the next, O. primaeva lineage zone of Late Sinemurian age. It has to be noted here, that no lithiotid bivalves were recorded in the Zalopate section and that the attribution to the "Podpe~ limestone" lies solely on lithological similarity and the geological map. The lack of a proper, lithostratigraphic definition of this unit is here obvious, and we would either have to correct the geological map, using a more strictly defined "Podpe~ limestone", or extend the stratigraphic span of the "Podpe~ limestone" to the Late Sinemurian. The Late Sinemurian -Pliensbachian age is also established for the Rotzo Member of the Calcari Grigi Formation of the Trento Plateau in Italy (fugagnoli & loriga Broglio 1998;maSetti et al., 1998;fugagnoli et al., 2003), which lithologically corresponds to the "Podpe~ limestone" (BuSer & DeBeljak, 1996).

Conclusions
The foraminiferal assemblage of the "Podpe~ limestone" was investigated in three sections located in the wider Mt. Krim area, south of Ljubljana.
The Zalopate section spans the lower part of the "Podpe~ limestone". No lithiotid bivalves were found. Orbitopsella first occurs 34 meters from the base of the section. Based on the presence of its nominal taxon, this part of the section belongs to the Lituosepta recoarensis zone of early Late Sinemurian age. The upper part of the section, marked by the presence of Orbitopsella primaeva, belongs to Late Sinemurian O. primaeva lineage zone. The Podpe~ 1 and Podpe~ 2 sections sample the classical locality of the "Podpe~ limestone". Numerous lithiotid bivalve coquinas are present. The presence of Orbitopsella praecursor and Bosniella oenensis indicate Early Pliensbachian Orbitopsella praecursor taxon range zone. The same zone was determined in the Grad section.