from the Rhaetian Dachstein Limestone of the Northern Calcareous Alps ( Germany , Austria )

During Late Triassic times, the Northern Calcareous Alps were part of a wide shelf exhibiting characteristic margin-parallel facies zonation located at the western end of the Tethyan Ocean (e.g. TOLLMANN, 1976, 1985; GAWLICK, 2000 with references; MANDL, 2000). The Norian–Rhaetian Dachstein Limestone is generally divided into the bedded lagoonal Dachstein Limestone and the Dachstein reefal limestone, i.e. protected internal lagoonal facies and typical outer platform settings with reefal and peri-reefal facies (e.g. ZANKL, 1971; LEIN, 1987; GAWLICK, 2000 – fig. 4). The Norian bedded Dachstein Limestone is typically represented by so-called Lofer cycles in the central platform area (FISCHER, 1964; ENOS & SAMANKASSOU, 1998). Within the “reef-limestones”, corals and calcarCoptocampylodon? rhaeticus n.sp., a New Problematic Microfossil (“incertae sedis”) from the Rhaetian Dachstein Limestone of the Northern Calcareous Alps (Germany, Austria)


INTRODUCTION
During Late Triassic times, the Northern Calcareous Alps were part of a wide shelf exhibiting characteristic margin-parallel facies zonation located at the western end of the Tethyan Ocean (e.g.TOLLMANN, 1976TOLLMANN, , 1985;;GAWLICK, 2000 with references;MANDL, 2000).
Besides several illustrations in the alpine literature, the material treated in the present paper comes from the Kehlstein near Berchtesgaden (Germany), the area west of Lofer (Austria) and the Rofan Mountains, Tyrol (Austria).The Rhaetian Dachstein limestone nearby and south of the Kehlstein house (samples Ber 101) has been chosen as the type-locality.

GEOLOGICAL SETTING
Mount Kehlstein in the Berchtesgaden Alps tectonically belongs to the higher Tirolic nappe (FRISCH & GAWLICK, 2001, in press) and was part of the Rhaetian lagoonal area south of the Kössen Basin (GOLEBIOWSKI, 1990(GOLEBIOWSKI, , 1991)).The sedimentary sequence consists of Norian lagoonal Dachstein limestone at the base, followed by marls and carbonates of the Kössen Formation (BRAUN, 1998 -cum lit.) and Rhaetian lagoonal Dachstein limestone.On the top of the sequence, Late Jurassic mass-flow deposits occur with components of Dachstein limestone, Late Jurassic shallow water limestones and carbonates of the Late Jurassic Oberalm Formation (LEBLING, 1935;PLÖCHINGER, 1955;BRAUN, 1998 -cum    -  LIER et al., 1969).DRAGASTAN (1989) provided the new combination Carpathoporella fontis (PATRULIUS) and chose a holotype from the authors material.
In all these taxa, the presence or absence of an axial hollow has been the reason for some of the discussion.Following PATRULIUS (1965) there are representatives of C. fontis some of which show an axial hollow and others that do not.For example, BASSON & EDG-ELL (1971) reported and figured both, Coptocampylodon lineolatus ELLIOTT and C. fontis from the Lower Cretaceous of Lebanon co-occuring in the same sample.The same observation can also be made with the new species Coptocampylodon?rhaeticus n.sp.with specimens with and without a central hollow.The latter are interpreted as sections through the closed distal parts.BASSON & EDGELL (1971, p. 420) discuss another interpretation, that "there have been varying degrees of calcification of the thallus and the central canal".
Coptocampylodon fontis PATRULIUS has been removed from the dasycladales by JAFFREZO (1974), followed by BASSOULLET et al. (1978).Some affinities with charophytes have been supposed by DRAGASTAN (1989), a view that we cannot follow for facies considerations since C. fontis is typical of well-agitated outer platform settings, for example in the Urgonian limestones of the Northern Calcareous Alps (SCHLAGINTWEIT, 1991)  As can be seen from the references cited, Coptocampylodon fontis PATRULIUS represents a widespread microfossil occurring within Upper Jurassic to Albian strata, with the greatest distribution in the Barremian Aptian interval ("Urgonian facies").For Coptocampylodon elliotti RADOIČIĆ, although also established in the sixties as C. fontis, we can only mention the occurrence in southern Italy (see synonymy) besides the type-locality in the Dinarides.

Origin of the name:
The species name refers to the stratigraphic occurrences in the Rhaetian stage.
Type-locality: Kehlstein area, ÖK 93 Bad Reichenhall, 1850 m AN, path from the Kehlstein house to the Hohe Göll at the base of late Jurassic mass-flow deposits (Fig. 1).
Type strata: Packstones and grainstones, gray to light brown limestones, m-thick bedded sequence of the lagoonal Rhaetian Dachstein limestone overlying the Kössen beds and the "Hauptlithodendronkalk".The latter was deposited in a transgressive-regressive cycle and approximates the Norian-Rhaetian boundary (GOLEBIOWSKI, 1991) consisting of massive coralline beds.Above the "Hauptlithodendronkalk" the lagoonal Rhaetian Dachstein limestone occurs forming an isolated platform between the Koessen basin to the north and the Hallstatt area to the south (GAWLICK, 2000).
Diagnosis: Small representative of the genus with a comparably long cylindrical part ("stalk") with a narrow axial hollow and without marginal outer grooves.Rounded part ("head") with or without an axial hollow and a low number of marginal grooves.

Description:
The new species is composed of a comparably long cylindrical ("stalk") (e.g.Pl. 1, Fig. 3) and an irregular rounded body ("head") (e.g.Pl. 1, Fig. 6), both showing a relatively narrow central or axial hollow.In the material studied, no specimens were found where both parts were in original mutual contact.That both parts belong to the same taxon, however, is obvious since these always occur in great abundance together (e.g.Pl. 2, Fig. 10).The solid cylindrical part up to 1.15 mm in length is often slightly curving and shows smooth outer and inner surfaces.In the cylindrical part, the central hollow comprises approximately 30% of the outer diameter.
The ball-shaped part shows marginal grooves (mostly 7) at the outer part (e.g.Pl. 2, Fig. 1).Since these do not transect the calcareous skeleton/wall, these cannot be termed pores.The relative diameter of the central hollow is very variable (mostly ~25%) with respect to the outer diameter.It is assumed that those sections, with a very small central hollow are cut more distally, near a closed end.The latter is evidenced by sections without any central hollow (Pl. 1, Fig. 6).These do not show the grooves, an effect that could be secondary in origin (e.g.abrasion in a high-energy environment).
Coptocampylodon? rhaeticus n.sp. is very close to C.? elliotti RADOIČIĆ from the Cenomanian of Montenegro.In fact, the biometric data of the specimens from the Rhaetian Dachstein Limestone are in the range of the Cenomanian species.The main difference is the absence of marginal grooves in the cylindrical part of C.? rhaeticus n.sp.showing a smooth outer surface.These grooves are well developed in C.? elliotti RADOIČIĆ (RADOIČIĆ, 1969: pl. 4, fig. 1, pl. 5, fig. 2, pl. 6, figs. 1-4).In C.? elliotti the marginal grooves often show a tendency to become externally closed as already remarked by DRAGASTAN (1989, p. 43).In C.? rhaeticus n.sp. the groves usually display a clear concave shape (e.g.Pl. 1, Fig. 5) and only occasionally become very narrow (e.g.Pl. 1, Fig. 6, left specimen).
-Packstones: the overall thin-section appearance clearly indicates that this microfacies is closely related to the described oolithic grainstones.Thus, components are directly comparable.There are some larger echinoid fragments irregularly distributed in the sediment resulting in a somewhat poorer grade of sorting.Samples: Ber 101/4A (locality Kehlstein near Berchtesgaden).
-Grainstones to packstone with a typical bimodal sorting: the fine-grained portion of this microfacies type is comparable to the above described oolitic grainstones.Within this, larger components consisting of intraclasts, bioclasts (echinoids, gastropods, corals) and the larger tests of the Concerning the occurrences at Grimming, BÖHM (1986) notes, that the oolitic facies only is reported from the Rhaetian "when no reef was present to shelter the lagoon and ooid bar could develop".The well-agitated facies types with remains of Coptocampylodon?rhaeticus n.sp.figured by MATZNER (1986) and BÖHM (1986) are directly comparable to the material presented here.
From the Upper Rhaetian "reef "-complex of the Steinplatte/Austria, STANTON & FLÜGEL (1989) were the first to recognize the specimens as "Dasycladacean algae characterized by small spiny thalli ".They are abundant in their "microfacies C 12 " that "comprises the strata overlying the relatively massive mound facies" (capping facies) ascribed to a platform margin environment (STANTON & FLÜGEL, 1989: p. 38).
In the western continuation, west of Lofer, the Rhaetian Dachstein limestone occurs over marls and coral limestones of the Koessen Formation (not proven by conodonts) in the same sedimentary position as at Mount Kehlstein.To the west, Coptocampylodon?rhaeticus n.sp.occurs in the Steinplatte area in the Rhaetian Dachstein limestone (STANTON & FLÜGEL, 1989).In the whole area some Rhaetian Dachstein limestones with Coptocampylodon?rhaeticus n.sp.occur as components within Late Jurassic mass-flow deposits (Kehlstein area, Schwarzbergklammbrekzie and Rofan mountains) eroded from nearby topographic rises (Trattberg Rise, e.g.Kehlstein) due to the closure of the Tethys Ocean in Jurassic times (GAWLICK et al., 1999 with references).

CONCLUSIONS
The calcitic "bodies" of the microfossil incertae sedis Coptocampylodon?rhaeticus n.sp.are very abundant and widespread in the Rhaetian Dachstein Limestone and the "Upper Rhaetian reef limestone" of the Northern Calcareous Alps characterizing high-energy outer platform to platform margin facies.Its systematic position so far remains uncertain.The interpretation as pos-sible secondary ramifications of Triploporella species such as T.? neocomiensis (RADOIČIĆ, 1969), assumed by previous workers for Cretaceous Coptocampylodons has to be rejected due to the findings in the Rhaetian.The calcareous remains obviously do not represent single individuals but parts representing an unknown function of a larger organism of unknown systematic position.
The determination of Coptocampylodon?rhaeticus n.sp.as a facies dependent fossil is a good aid for determining the palaeogeographic position of some outcrops in the Late Triassic of the Northern Calcareous Alps.This palaeogeography was destroyed by the later tectonic shortening (Jurassic to Eocene) with polyphase nappe formation and in later times by lateral tectonic extrusion.During these processes blocks moved towards the north and east out of their original palaeogeographic position.For reconstruction of the Late Triassic palaeogeography it is necessary to determine facies zones by clear stratigraphic data.Thus, the occurrence of Coptocampylodon?rhaeticus n.
lit., new unpublished results).Most of the samples derive from the Rhaetian Dachstein Limestone or from Dachstein limestones near the Norian/Rhaetian boundary (Ber 101-1, Ber 101-4) in the southern area of mount Kehlstein or near the top of Kehlstein (Fig. 1).The sample Ber 101-12 represents a clast in an upper Jurassic mass-flow deposit with allochthonous shallow water microfossils deposited on top of the Rhaetian Dachstein limestone in the northern part of the Kehlstein.Besides the type-locality, the new species has been detected from the following localities: -northern side of the Lofer Kalvarienberg at 960 m AN (forest road), in the westward continuation of the southern rim of the Kössen basin; sample KS 79a, d; Rhaetian backreef and lagoonal Dachstein limestone (GOLEBIOWSKI, 1991); -Rofan Mountains, Tyrol; sample RF 1-01; pebble in late Jurassic mass-flow deposits; -Unken valley; mass-flow deposits ("Schwarzbergklamm-Brekzie") of the

Fig. 1
Fig. 1 Tectonic map of the middle part of the Northern Calcareous Alps and sample locations of the complete sedimentary sequences of Rhaetian Dachstein limestone in the Kehlstein and Lofer area (after FRISCH & GAWLICK, 2001, in press).