Rivista Italiana di Paleontolo gia e Stratigrafia pagrne 391-398 Novembre 2002 MIDDLE TRIASSIC FORAMINIFERA FROM THE SECEDA CORE (DOLOMTTES, NORTHERN rTALY) FLORIAN MAURER' & ROBEMO RETTORI' Recei.cted. Marcb 26, 2002; accepted August 28, 2002 Key-oords: Foraminifera, Stratigraphy, Involutinidae, Middle Triassic, Dolomites, Southern Alps. Riassunto. Nel presente lavoro viene esaninata I'assoc.iazione a foraminiferi rinvenuti :n224 seziom sorrili efferîuare in sedimenti tor- biditici di una successione bacinale al limite Anìsico/Ladinico. La microfauna é costituita da forme di acqua bassa associate a foraminiferi caicareo-ialini (Lagenina) rilerìbili ad un ambiente di mare aperro. Lr definizione biostratìgrafica dell'intervallo mediotriassìco studiato per- mette la datazione di comparse e scomparse di alcuni foraminileri ben- tonici di mare basso. In particolare le specie Meanclrospira dinarica Kochansky-Devidè & Pantic e Areno.r,idalina cbialingchiangensis Ho sono lìmitate alla zona a Reitzi, mentre le specie Variostoma alta Krls- tan e Hoyenella gr. sinensís nella successione studiata non superano la zona a Curionil. L'er.ento biostratigrafico pìú significatir-o si rinviene alla base della zona a Gredleri dove si registra la comparsa della famiglia Involutìnidae Bùtschli, rappresentata dai generi Lamelliconus e Aulo tortus. La composizione microfaunistica é simile a quella conosciuta in aree paleogeograficamente circostanti, ma in generale si not;r una diversificazione generica e specifìca minore in confronto con le associ- azioni a foraminiferi dell'Anisico o del Carnico. Abstract. The assemblage of foraminifera in turbidite beds in Middle Triassic basinal deposits straddling the Anisian/Ladinian boundary interval r.as studied in 224 thtn secrions. The fauna consists mainly of shallow-r.ater inhabitants, associated with calcareous h1.a- line foraminifera (.Lagenina) of open-marine environment. Due to a well established biostratigraphy in the studied interval, the first and last appearance of some shallow-n'ater, benthic Ioraminifera can be assigned to the Mid Triassic ammonoid stratigraphy The species M e an dro sp ira d ín arica Kochansky-D evìdè & Pantic rnd Arenor ìd alina chialingchiangenszs Ho are limited to the Reitzi ammonoid zone. The species Varlostoma aba Krrstan and Hoyenella gr. sinensis both do not superate the Curionii zone in age in the studied succession. The bios- tratìgraphic most important e\rent occurs at the base of tbe Gredleri Zone nith the appearance of the family Involutìnidae Bútschli, repre- sented by the genera Lamelliconus andAuÌotortus. The faunal compo- sition is similar to those of neighbouring paleoprovinces, bur generaì- 11' a lower faunistical diversification compared to foraminiferal assem- blages in the Anisian or Carnian is observed. lntroduction Middle Triassic foraminifera are well studied with- in the Tethyan domain (Salaj et a1. 1983; Zanínetti 1,976; Oravecz-Schelfer 1987; Trifonova 1992, 1993, 1994; Rettori 1995). However, several case studies describe species of shallow-water habitats that lack age-diagnos- tic macrofaunas and thus in several cases the strati- graphic range of these forms is not very well defined. In this paper we describe foraminifera derived from a biostratigraphically well constrained interval straddling the Anisian /Ladinían boundary interval (Brack & Rieber 1993). Since the stratigraphic position of this stage boundary is still under discussion, only the names of the ammonoid zones are used in the text. The majority of the samples are taken from turbidite beds in a core drilled for scientific purposes at Seceda in the western Dolomites (Fig. 1; Brack et al. ZOOO) . In this respect, the here presented results are parf of the scien- tific investigations on the core. Geological setting. The Buchenstein beds, from which the samples were taken, are an up to ZO m thick succession of basinal limestones and marls with intercalations of debris from adjacent carbonate platforms and volcaniclastics (Viel 1979; Bosellini & Ferri 1980). They were deposited in small interplatform basins, which reached depths of up to 1000 m (Fig. 1; Bosellini 1984). During the deposi- tion of the Buchenstein beds oxygenation on the sea- bottom varied, leading to both laminated and bioturbat- ed facies types (Brack Ec Muttoni 2000). The biostrati- graphic range of this succession is well constrained by age-diagnostic macrofossils and encompasses five ammonoid zones (Reitzi, Secedensis, Cwrionii, Greclleri andArchelaws zones; Brack & Rieber 1993). AII224 studied samples are thin sections from tur- bidite beds, which mainly contain debris from the plat- I Free Universitv/Eerth Sciences, De Boelelaan 1085, 1081 HV Amsterdam, The Netherlands; emaìl: florian_maurer@yahoo.com 2 Dipartimento di Scienze della Terra, University of Perugia. Pjazza Universit.ì, 1, I-06100 Perugia, Italy; email: rrettori@unipg.it 392 F, Maurer & R. Rettort LADINIAN BASINS BOZEN/ BOLZANO carbonate platfoms basinal deposits Fig. 1 - A) Distribution of carbonate platforms and basinal sedi- ments in the Dolomites dur- itg the early Ladinian. Names of platformt are wrir- ten ìn italics, bold dark lines mark approximate position of pìarform basin trantitjon. B) Study area around Seceda indicating major outcrops of the Buchenstein beds, the well site (1) and additional sampling locations (2, 3, 10).w w-> | * -'.. -........... - 2200 re [:"ff:i:"J1"3::;") '- cablecar/chairrirt A KSÍX Ht"il"?"',;,$:,i# '",:::," f{| O-G) saîilirgto:eic.s --g-.- form top and slopes, and which are present throughout the studied succession (Maurer et aI. 2002). Most sam- ples derive from the Seceda core, which \il.as recovered in proximity to an age-equivalent carbonate platform (Fig. 1B). Additional samples were taken from outcrop sec- tions around the well site that cover a short stratigraph- ic interval missing in the core. Foraminiferal assemblage and diversification. In the analyzed thin sections foraminifera afe present as part of the debris shed from the adjoining car- bonate platforms and slopes by turbidity currents (Mau- rer et a1. 2OO2). Throughout the core we encountered platform-derived benthonic foraminifera in association with calcareous hyaiine (Lagenina) foraminifera of open-marine environment (Fig. 2). The assemblages attributed to a shallow-water environment are character- ized by the constant presence of unilocular, tubular foraminifera referable to the genus Earlandia Plummer, in association with microgranular multilocular foraminifera with elongated morphology belonging to the genera Endotebanella Yachard et aI. Endotriadella Vachard et al., and agglutinated foraminifera such as Ammobacwlites Cushman, Reo\Itax de Montfort and Palaeolituonella Bèrczi-Makk. Less frequent there occur trochospiral and streptospiral types of the genera Endoteba and Glomospira. Furthermore porcelaneous foraminifera are represented by Ophthalmidium sp., Arenovidalina chialingcbiangensis lHo, Hoyenella gr. sinensis (Ho) andAgathammina sp. Throughout the whole succession v/e noticed the presence of originally aragonitic foraminifera of the family Duostominidae Brotzen with the genera Varios- toma Kristan-Tollmann, D uo stomina Kristan-Tollmann and Krikoumbilica He. The sample 69.90 marks the appearance of the originally aragonitic family Involu- tinidae; upsection there follows a diversification of these types, represented by the lenticular genvs Aulotortus \feynschenk and the cone-shaped genvs Lamelliconus Piller (Fig. 2, 3, 4). Elongated calcareous hyaline foraminifera include the genera Nodosaria Lamarck, Pseudonodosaria Boomgaart, Frondicularia Defrance, Astacolws de Montfort and Lenticwlina Lamarck. The distribution of foraminifera along the studied section (Fig.2) shows phases of increase and decrease in the diversity (: richness) of the microfauna both at generic and specific levels. A general increase is given from the base of the section until sample 81.00. In the upper part of the Curionii zone follows a decrease in the Fig. 2 - Distribution of foraminifera found in 224 thin sections in the Seceda core along with a lithological log of the 20-103 m core interval. The range of ammonoid zones and current candidates 2 (sensu Krystyn 1983) and 3 (Sensu Brack & Rieber 1993) for the definition of the Anisian/Ladinian boundary are indicated on the left. Important macrofossils found in surrounding outcrop sections are indicated on the right (after Brack & Rieber 1993, Brack et al. 2OOO, Brack et al. 2OO1). The lithoiogy of the core is explained in inset on Fig. 3. important macrofossil occufrence 393Middle Triassic Foraminifera from Dolomìtes t. I al. a I t t, I I .t' t Daonella pichlei Protrachyceras sp . Daanella taramellii Daonella maussoni Eooptott achyceras d. recubariense Chiose,beras chleserse fuevadlfes secÉdensis, Daonella cl. golana Stap pa n i ce ra s evo I ut u m, ncinites dalamiticus Daonel{a elongata group Daonella cernercensis, Aplococeras sp. I rr .t Daanèlla lommeli group, Daanella tyralensis ì: ÈÈ ìì ff,I 2 I =Q J 394 presence of foraminifera and a total absence in the inter- val between samples 72.94 and 70.64. Above this level a new increase in diversification is present, dominated by the first appearance of the representatives of the family Involutinidae Bùtschli from sample 69.90 upwards. In the Gredleri and Arcbelaus zones the microfau- na does not show any major decrease in diversification. Only the interval 64-61m, which is characterized by very fine-grained (<1.77 micron) turbidite beds, lacks foraminifera (Fig. 2). Correlation of this interval with outcrop-equivaients revealed the Presence of foraminifera in coarser grained portions of turbidites closer to the platform (Fig.3). In the outcroP we also sampled the interval of section 10, illustrated in Fig. 3' and missing in the core due to local tectonic unconfor- mities. The outcrop samples show the same assemblages as the surrounding samples in the core close to this interval. In general v/e noticed a low faunistical diversi- fication compared to the foraminiferal assemblages in the Anisian or Carnian, although there is a good state of preservation in the analyzed samples. Stratigraphic implications. The well constrained biostratigraphic age of the section allows a more precise calibration of the first and last appearence of some of the described species. Due to an accurate core-to-outcrop correlation a direct compar- ison of the microfauna with the occurrence of age-diag- nostic macrofossils in the outcrop is possibie (Fig. 2). The sample 95.06 shows the presence of Mean- drospira dinarica Kochansky-Devidè & Pantic (Fig' 4)' a well known species in the Anisian of the Tethyan domain (Rettori 1995, cum bibl.). This species occurs in the Reitzi zone, but does not show up anymore further up in the section; it is therefore likely to have died out in the Reitzi zone. The species Arenooidalina cbial- ingchiangensls FIo, so far known as Middle Triassic in age (Rettori 1.995, cum bibl.) is limited to the Reitzi zone as weli and disappears above the sample 93.09. The species Variostoma aha Kristan and HoyeneÌla gr- sinensis are present in the Reitzi zone and both do not suPerate the Curionii zonein age in the studied succession. Palaeoli- tuonella meridionalis Bèrczi-Makk disappears at the base of the Gredleri Zone. The biostratigraphic most imPortant event occurs from leve1 69.90 m upwards with the appearance of the genera Larnelliconus and Aulotortus (Fig.2, 4). These Involutinidae are represented by the species L oentro- planus (Oberhauser), L. mwltispirws (Oberhauser), ,4. aff. A. friedli (Kristan-Tollmann) and A. gr. sinuosus \leynschenk. Based on ammonoid data their aPpearence can be pinpointed at a level slightly older than the base of the Gredleri zone (base late Ladinian sensu Krystyn 1983). In the Buchenstein beds in the Dolomites this level approximately matches the first occurrence of Budwror.,ignathus hwngaricus (Kozur & Vegh), a con- odont marker (Maurer 1999). Paleoecology From an ecological point of view some considera- tions can be made on the calcareous hyaline foraminifera (Lagenina) of open-sea environment' In particular we noticed that the elongated, cylindrical morphotypes (Ì)1odosaria, Frondicularia and Pseudonodosaria) are most frequent at the beginning or at the end of the anoxic intervals (e.g. levels 92.22 m and 64.49 m in Fig. 2, level 36 m in section 2 on Fig.3). This is in agreement with the fact that these morphotypes are adapted to dis- aerobic and low-energy environments (Murray 1'991; Tyszca 1993). The planispiral and biconvex strictly coiled forms such as biconvex Lenticwlina, are in con- trast more typical for better oxigenated substrates (Murray 1991.; Tyszca 1993). The fauna typical for restricted, low-energy shal- low-marine habitats (i.e. backreef and lagoon) is charac- terized by porcelaneous milioiid foraminifera (Haunold et a1.. 1997; Davaud & Septfontarne 1995; Travè et al. 1996; Fornos tt Ahr 1'997) and include the genera Oph- thalmidium Kubler & Zwingli, Arenooidalina Ho, Hoyenella Rettori and Agathammina Neumayr. In the studied section these types are more frequent than in older Anisian formations in the Dolomites, where only the genus Ophthalmidiwm is present (Senowbari-Daryan et a1. t993). In recent environments miliolid foraminifera are not limited to restricted shallow-marine areas, but occur also in forereef and slope settings (in the Bahamas, e.g. Rose & Lidz 1'977; in the Gulf of Aqaba, Reiss & Hottinger 198a). The here described genera may therefore have colonized the same range of environments in the Triassic. F. Maurer & R. Rettori Fìg. 3 - Correlation of rhe 52-66 m core interval (section 1) with equivalent portions in outcrop sections 2,3 and 10, where 10 is the most proximal and 1 the most distal section relative to the nearby carbonate platform. The foraminifera found in the outcrop samples are indicated. Note the occurrence of Nodosaria at the beginning and end of the anoxic facies intervals (e.g. 33.8 and 36 m in section 3)' The stratigraphic column in the core and the sections 2 and 3 is dìsturbed bv local tectonic unconformities. The 35-40 m interval shown in section 10 most probably represenrs the interual missing in the core. The occurrence of the macrofos srl DaonelLa rnoussoni Mérran, collected durirg this ,trd1,, i, indicated. The layer nith accretìonary lapilli represents a unique marker horizon that can be correlated over the entire Buchenstein basin within the Dolomites (Gianolla 1991, Maurer 1999). Due to the local unconformity at Seceda, the lapilli-la1,er disappears in section 3 and in the core. For general correlation of core and outcrop see Brack et al. (2000). i=, R@phaxsp i-= : :]-- l --:)- -F>:1 - '/ Lapilli layer -t=r iri::É:-;i#-*"componenls (oniy Frg.2) ì camonate tenses baf ma*;ng laminaled, anoxic facies a6relonary lapilli €oonale nocu€s with chefr | m cneÍ nodrlea sno palenes i:=- -:=_-:: : r=ri -=-l Middle hiassic Foraminifera from Dolomites \ 'ab I sEcEDA l : core-outcropcorrelation j:.r.3Èji: Earlandja g@cilis, E. amplr + Duastamina sp. + Eadandia gmcilis, E. ampli- Earlandía gftcilis, E. ampli- !' mumtis = Eadandzancils E amplr ? muahs Opntnatnidiumsp = G/orcspi€//a sp. ! Ealandîag6cìlís, E. afrpli- = nuÉlis, Qphthalnidium sp. = Ealandia oÈcilís E. am1l; = = = = = = = = = = = = = = = = = = = = = = = = = ? Eadandia_g?cilis .E ampl| muftxs, uuastomtna s0 , Aulototlus sp Eadandìa gftcilis, E ampli- + frurelis, Reophax 9p , Duostamina sp . Nodosara sp + Earlandta^g@cilts E ampli- mu@ils uuostomtna sp Auloto ft us gt. si t1 uosu6 + Ea.landia gftcilís. E ampli- muftlis. Duostóúina sp. 395 I Duostamina 9p., EaJo/ 2 leba all E. Dadau\) + Earlandia afrp1ímuElís Reophax sp. Lunucam- mtna sp. I Lunucak*ìre sp. =t muRts à = Duostamína sp- o, N] !l ol oì (rl ::) ? Earland;a ampl'mara, s -- Daonella moussoni iuff ayeÉ f"plei.a ve.de ì Ealandia /nplinunlis ReoplÈx,Ép. o (coreJ i___ì :=-=' :- key for sections dolom[ized _ /b.e,cia(ontyF,g 2....,..i]%-'ntonto'tnY -.:k r ^ r- ble@ia wilh car borale REophax sp 396 F. Mawrer & R. Rettori Fig. 4 - Illustration of some species of foraminifera found in the Seceda core. [ - Meandrospira dinarica Kochansky-Devidè & Pantic, level 95.06 m, magnification x66. 2 - Palaeolítuonella mínima He,level 95.06 m, magnification x106. 3 - Palaeolituonella meridionalis Bètczt- Makk, ler.el 68.92 m, magnification x8O. 4 - Lamelliconus mubispinzs (Oberhauser), level 69.22 m, magnification x50. 5 - Awlotortus ex gr. sinuosus.Weynschenk, level 6'1.83 m, magnification x,15. 6 - Aulotortus afl. A. friedli (Kristan-Tollmann), level 67.7a m, magnifica- tion x55. 7 - LameLliconus.oentoplanus (Oberhauser),level 69.90 m, magnification x58. The agglutinated and microgranular elongated genera Reophax, Endotriadella, Endotebanella and Ammobaculites are also paft of shallow-marine environ- ments; they are suggested to live infaunal with detrital- scavenger feeding habit (Jones Ec Charnock 1985). The elongated, unilocuiar genus Earlandia, whrch is quanti- tative the most abundant in the samples, and the origi- nally aragonitic genera Duostomina, Vnriostomd and Krihowmbilica of the family Duostomini dae are general- ly common in Triassic carbonate platforms. In the Gredleri and Arcbelau.s zones the lamellar, aragonitic foraminifera of the family Involutinidae appear as additional shallow-water inhabitants. These types, represented by the genera Lamelliconus andAwlo- tortus) live in various shallow-marine environments ranging from the reef to restricted lagoon (Piller 1928). Discussion and conclusions. A significant event in the faunal evolution of foraminifera recorded in the Buchenstein beds is the appearance of the family Involutinidae Bùtschli at the base of the Gredleri Zone (base late Ladinían sensu Krystyn 1983). Lenticular morphotypes are considered the ancestral forms of this family at the base of its evo- lution, followed by conical types (Salaj et al. 1983; Gazdzicki 1983; di Bari & Laghi 1994). For instance, Oravecz-Schef{er (1.987) describes the appearance of lenticular Involutinidae, assigned to the genera Aulotor- fas Weynschenk and Triadodiscus Pilier, followed by the conical genlrs Lamelliconws Piller, in the Carnian of the Transdanubian Central range. In contrast, we encoun- tered first the conical genus Lamelliconws (first appear- ance at level 69.90m) and then the lenticular morPho- type, representedby Awlotortus (fitst aPpearance at level 67.70m; Fig. 2). We attribute this phenomenon to a lack of lenticular morphotypes due to the general poor per- centage of foraminifera in the sampies, rather than to a different evolutionary trend of the family Involutinidae in the Buchenstein basin. The appearance of Involu- tinidae at the base of the late Ladinian as recorded here is in agreement with the general description of the evo- lution of this family in the late Ladinian/ early Carnian (e.g. Salaj et a1. tls:). Note, however, that the conicai morphotype Lamelliconws has been described already in the Anisian Eros Limestone of Hydra (Greece; Rettori et al. 1,994), which has been dated as Pelsonian in age based on conodonts (Angiolini et al.1.992). It is not clear what favourized the appearance of Involutinidae in the Gredleri Zone.In view of Mirquez Er Trifonova (2000), their occurrence depends on the relative percentage of aragonite solved in the sea water. In this respect, a rise in aragonite in the sea water could have favoured the evolution of Involutinidae in this part of the Tethys. In addition, it could have contributed to the rise in carbonate production on the adjoining plat- forms (e.g. Mmrer 1.999). The repeated alternation of oxic (:bioturbated) and anoxic (=laminated) facies in the Buchenstein beds of the Seceda core is a feature that is restricted to the area of the Dolomites and may have been caused by episodic closure of the seaways of the Buchenstein basin bordering the open ocean and related variations in oxy- genation of the sea floor. Equivalent basinal limestones in the Lombardian Alps (Bagolino, e.g. Brack Ec Rieber 1993) and Hungary (Oravecz-Scheffer 1987) show bio- turbated facies throughout their deposition. A compari- son of the foraminifera found in the iaminated facies of the Reitzi zone in the Seceda core with the equivalent bioturbated interval in the Transdanubian Central Range (Oravecz-Scheffer 1987) reveals no major differences in faunal composition. Lagenina are represented by similar genera in both areas, indicating that these foraminifera were probably not affected by oxygenation-variations Middle Triassic Foraminifera from Dolomites 397 on the sea bottom. The fauna described by Oravecz- Scheffer (1987) is poor in shallow-water foraminifera, probably related to a lack of turbidites in that succes- sion. The dataset presented here is limited to the source area oî the turbidite sediments, which may not cover the whole shallo.w-water habitat of the foraminifera. The Middie Triassic Buchenstein beds show a con- tinuous record of foraminifera in the late Anisian and early Ladinian over a time interval of five ammonoid zones. The presence of shallow-water, benthic foraminifera in turbidite deposits in this biostratigraph- ically well defined succession gives the opportunity to narrow down the biostratigraphic range of some species. This is a goal that can almost not be achieved when these species are found in place in their shallow-marine habi- tats, which normally lack age-diagnostic macrofossils. Overall, the fauna is characterizedby a lower diversifi- cation compared to older Anisian or Carnian foraminiferal assemblages. However, it has to be men- tioned that the presented dataset is limited to the tur- bidite source area, which might not have covered the whole foraminiferal habitat. Acb.notuled.gements. The authors appreciate useful comments by reviewer L. Zaniner.ti (Geneva) and the journal editor M. Gaetani (Mìlano). FM thanks the Austrian Academy of Sciences and the Vrije Universiteit Industrial Associates Program in Sedimentology for financial support. The preparation of thin-sections by Marco Stefani (Ferrara) and Felix Heller (Innsbruck) is acknowledged. Hans Rieber (Zurich) kindly provided the determination of the macrofossils. REFERENCES Angiolini L., Dragonetti L., Muttoni G. & Nicora L. (1992) - Triassic stratigraphy in the Island of Hydra (Greece). Rie. It. Paleont. Strat. 98: 137-180, Miiano Bosellini A. (1984) - Progradation geometries of carbonate platforms: examples from the Triassic of the Dolomites, northern kaly. Sedimentologt 31.: 1-24, Oxford. Bosellini A. Ec Ferri R. (1980) - La formazione di Livinallongo nella Va11e di S. Lucano (Ladinico inferiore, Dolomiti Bellunesi). Ann. Unio, Ferrara, N. S. Sez. X,6/5: 63-89, Ferrara. Brack P & Rieber H. (1993) - Towards a better definition of the Anisian/Ladinian boundary: new biostratigraphic data and correlation of boundary sections from the Southern AIps. Eclogae geol. Heb. 86/2: 415-527, Basel. Brack P & Muttoni G. (2000) - High-resolution magne- tostratigraphic and lithostratigraphic correlations in Middle Triassic pelagic carbonates from the Dolomites (northern kaly). Palaeogeogr, Palae oclim. Paleoecol. 1 67 : 361-380, Amsterdam. Brack P, Schlager'Wi, Stefani M., Maurer F. & Kenter J. (2000) - The Seceda drill hole in the Middle Triassic Buchen- stein beds (Livinallongo Formation, Dolomites, north- ern Italy) a progress report. Riot. It. Paleont. Strat. LA6: 283-292, Milano. Brack P, Muttoni G. & Rieber H. (2001) - Magnetostratigra- phy and biostratigraphy of the Middle Triassic Margon section (Southern Alps, Itaiy): comment. Earth and Planet. Sci. Lett., 193/l-2: 255-257, Amsterdam. Davaud E. Er Septfontaine M. (1995) - Post-mortem onshore transportation of epiophytic foraminifera: recent exam- ple from the Tunisian coast. /. Sed. Res. 65: 136-142, ruisa. Di Bari D. & Laghi G.F. (1994) - Involutinidae Bútschli lForaminiferida) in the Carnian of the Northeastern Dolomites (Italy). Mem. Scienze Geol. 46: 93-118, Padova. Fornos J.J. & Ahr \ilM. (1997) - Temperate carbonates on a modern, iow energy, isolated ramp: the Balearic plat- form platform, Spain. J, Sed. Researclt 67/2: 364-373, Tulsa. Gianolla, P (1991): Eruzione freatomagnetica a grande magni- tudo nel Ladinico delle Dolomiti (Nota preliminare). Rend. Soc. Geol. It. 14: 65-70, Roma. Jones \W & Charnock M.A. (i985) - Morphogroups of agglu- tinating foraminifera. Their life positions and feeding habits and potential appiicablility in paleoecological studies. Re,uue de Paléobiologie 42:311-320, Geneve. Gazdzicki A. (1933) - Foraminifers and biostratigraphy o{ 398 F. Maurer & R. Rettori Upper Triassic and Lower Jurassic of the Slovakian and Polish Carpathians. Palaeont. Polon. 14: \09-1'69, \farszawa. Haunold T.G., Baal C. & Piller \(E. (1997) - Benthic foraminiferal associations in the Northern Bay of Safa- ga, Red Sea, Egypt. Marine Micropal.2g Q-a):185-210, Amsterdam. Krystyn L. (1983) - Das Epidaurus-Profil (Griechenland) - ein Beitrag zLrr Conodonten-Standardzonierung des tethyzalen Ladin und ljnterkarn. In: Neue Beitrîge zur Biostratigrrphie der Tethys-Trias (ed. by ZapÍe H). \ehrrltpnr I-rrtzt t<<. Komm. ()sterr. Akad. Wiss, 5: 2ll- 258, Vienna. Mírquez, L. & Trifonova, E. (2000): Tasas evolutivas de algunos subórdenes de foraminíferos triísicos del írea occidental del Tethys. Rer,. Espan. Micropaleont. 32/1': 1'- le, Madrìd. Maurer F. (1,999) - 'Wachstumsanalyse einer mitteltriadischen Karbonatplattform in den westlichen Dolomiten (Sùdalpen). Eclogae geol. Hek;.,92 (3):361-378, Basel. Maurer F., Reijmer J.J.G. E Schlager, \( (2002) - Quantifica- tion of input and compositional variations of calcitur- bidites in a Middle Triassic basinal succession (Seceda, Dolomites, Southern Alps). Geol. Rund,schau, Berlin, in p res s. Murray J.\V (1991) - Ecology and distribution of living benth- ic Foraminiferids. Lee & Anderson Eds., London. Oravecz-Scheffer A. (1982) - Triassic foraminifers of the tansdanubian Central Range. Geoiogica Hwngarica, Ser. Palaeontologica 5A 1-331, Budapest. Piller \il (1978) - Involutinacea (Foraminifera) der Trias und des Lias. Beitr. Palàont. Òsterr.,5: 1-164, Vienna. Reiss, Z. & Hottinger, L. (1984) - The Gulf of Aqaba. Ecolog- ical Micropaleontology. Ecological studies 5A: 1-351, Snrinper-Verlrp. Berlin. Rettori R. (1995) - Foraminiferi de1 Trias inferiore e medio de1la Tetide: revisione tassonomica, stratigrafia ed inter- pretazione filogenetica. Publ. du Départm. de Géol. et Paléont. de Gene'oe 18.1-147, Geneve. Rettori R., Angiolini L. & Muttoni G. (1,994) - Lower and Middle Triassic Foraminifera from Eros Limestone, Hvdra island, Greece. Journ. of Micropal. 13/1: 25-46, London. Rose, PR. Er Lidz, B. (1977) - Diagnostic foraminiferal assem- blages of shallow-water modern environments: South Floriada and the Bahamas. Sedimenta, 6: 1-55,l'{iami. Salaj J., Borza K. Ec Samuel O. (19S3) - Triassic foraminifers of the \il/est Carpathians. Geolog. Ustat Dinyza Stwra, pp. .l 1-)l /. Drailslava. Senowbari-Daryan B., Zùh1ke R., Bechstàdt T. & Flúgel E. (1993) - Anisian (Middle Triassic) buildups of the Northern Dolomites (Italy): the recovery of reef com- munities after the Permian/Triassic crisis. Facies 28: 181-256, Erlangen. Tyszca I. 0993) - Response of Middle Jurassic benthic foraminiferal morphogroups to dysoxic/anoxic condi- tions in the Pieniny Klippen Basin, Polish Carpathians. Palaeogeogr., Palaeoclimatol, Palaeoecol. ll0/1: 55-81, Amsterdam. Travè A., Serra-Kiel J. &.Zamarreno I. (1996) - Palaeoecologi- cal interpretation of transitional environments in Eocene Carbonates (NE Spain). Palaios 11/2: 141-16A, Tulsa. Trifonova E. (1992) - Taxonomy of Bulgarian Triassic Foraminifera. I. Families Psammosphaeridae to Nodosinellidae. Geol. Balc. 22/ 1: 3-50. Sofia. Trifonova E. (1993) - Taxonomy of Bulgarian Triassic Foraminifera. IL Families Endothyridae to Oph- thalmidiidae. Geol. Balc. 23/2: 19-66,Sofia. Trifonova E. (1994) - Taxonomy of Bulgarian tiassic Foraminifera. III. Families Spiroloculinidae to Ober- hauserellidae. Geol. Balc. 24/2: 21-7A,Softa. Viel C. (o791 - Litostratigrafia Ladinica: una revi:ione. Ricostruzione paleogeografica e paleostrutturale del- l'area Dolomitico-Cadorina (Alpi Meridionali). Ri'0. It. Paleont. Strat. 85 (1), pp. 85-125, Milano. Zaninettt L. (1976) - Les Foraminifères du Trias. Riz,. It. Pale- ont. Strat.,82 (\): 1-258, Milano.