Bollettino Della Societi Paleontologica Italiana
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Bollettino della Societi Paleontologica Italiana Pubblicatosotto gli auspici del ConsiglioNazionale delle Ricerche Volume43, r. 1-2r2004 Proceedingof the ]" MEETITVGOF THE ITALIAIVOSTRACODOL( ,,IIVMEMORY OF GIULIAI{O RUGG Rimini,February I 2-I 4, 2003 Editors: Elsa Gliozzr Antonio Russo MUCCHI MODENA Bollenino delk Societh Paleontologica ltaliana 43 (r-2),2004rssN0375-7633 l8l-199 Modena,Novembre 2004 Taxonomic diversity of Late Cenozoic Cnheroide: from Cyprus Island SteliosGru-oures Dan L. Dnxlnl-oPol Geitonas School Institute of Limnology Yarl<tza Greece Austrian Academy of Sciences,Mondsee, Austria KEY WORDS - Osnacoda, Late Cenozoic, Cytheroidea, Thxonomic Diuersity Indices, ClP, ABSTRACT - Late Cenozoic osnacod assembhgesof south-western Cyprus offer a unique oP occurred at uarious marine sites during the Upper"Miicene-Lower Plioiine ariund the ishni Ostracodn obtained Kahuiso, and'Nicosia Formations pointed to enuironmen' "Missinianfauna fro* .strong called Salinity Crisis" evtent. This iffirmation is compared to those risnicted on I Polemi, and Mari and tli, ,harga in the Cytheroidea ttxocenosit ,Jotu*ent9d throygh a qyta.litqt time two indices of diuersity, the"Auerage Thloro*ic Distinctness (called Delta+ index) and the V index) are used foi the chaiacterisation" of"gtnut,Tnd changesin fossil osnacod assemblages.I"fo*ation on C. tWarwicl the LinnaeAn hierarchy fthe species,the the famifl, following thi Claike and the taxonomic diuersiiy. The results sug{est the occrotice of strissfal ecoTogicalconditions in the ct more Drecisely durini a lowering of1he"reuersal marine wAter leuel where the sampling areA nansfor-Clt tondiiions, fillowed kttr-o, by t"he to an eumarine situation. It is coicluded that the usefal desciiptors for palaeoecohgical changesand should. be more widely used. - RIASSUNTO - fDiversit) tassonomica dei Cytheroidea (Ostracoda) dell'isola di Cipro] in diuerse lncaliti aiU costa sud-occidentale dell'isola di Cipro si uerificArono importanii ca* "studiofossili ad ostracodi di queste localith ffie un'opportunith urita per stidiare le uariazioni palet detle osnacofauie delle l{akiatot e Nicosia hanno indicazioni di im, *Crisi"formaziini fornito collegate alh cosi/d.ena di saliniti del MessiniAno". Si i ttrcato di uertfcAre l'euento si ,onfigrnfrche: Amargeti, Polemi e Mari; i cambiamenti nelle associazioni titoro*iche a C7 ,r'aialiti qualitat;uZ delle ostracofaune stesse.Per la prima uolta uengono qui utiliz,zati, per ia ostracodi, hue indici di diuersiti' k Oittinzione Tiaionomica Media" (deni anche indici Deln (indice Lambdn+). Le informazioni sulle associazioni a Cytheroidea sono state utiliz,zate.per tre li (1998, e h famiglia), seguendogt; nlgor;nni di Ckrke e lVarwiik 2001) per calcolqo k diuersit, di condiiion'i ecilogiche=\ntiate" nell'Ambiente costierodurante un breui periodo di.tempo, Piil t del mare. L'AreA iampionata si sarebbe trasformata in un ambiente hgunare. salmastro,-suci marine. Si conclude ihe gli indici di diaersiih tassonomica di Ckrke e Varwick siano snumenl paleoambientali, e dourehbero essereusati piil ampiamente per le ricostuzioni paleoecologiche. INTRODUCTION confirmed Ruggieri's view. For instance evidence from the ostracod fluna, e.g. the occurrence of the Cyprideis^of Late Cenozoic (Upper Miocene-Lower Pliocene) torosaJones corrobotit.t the desiccation modei the ostracod assemblagesof Cyprus offbr a unique oppor- Palaeo-Mediterranean(Benson, 1976a, b) and the ex- tuniry to document the faunal changet occurred planation of this catastrophic event was further docu- yhi:h"Messinian at vanous marine sitesduring the so-called mented for the closure of the connections with the Saliniry Crisis" event. One should recall that the Mi- Atlantic (Hsi.iet al.,1973; Benson, 1976a).Short time ocene ended in the Mediterranean space,with the des- later, in Early Pliocene,the ongoing plate tectonic col- iccation of wide areas and the deposition of huge lision of Africa and Europe allowed the influx of oce- amount of salts (Duggen et al., 2003). A chain of anic water via Gibraltar in this desiccatedbasin, fill- "lago-mare", shallow lakes, so-called with diverse sa- irg it again. This lead to the formation of the present liniry conditions, from hypo- to hyper-saline ones, d{y Mediterranean (Hsi.i et al., 1978). A high number developed in many parts of the pre-existing sea. of publications appeared during the last 40-50 years Giuliano Ruggieri-Melanopsis recognised that the occurrence of in order to understand and bring closer to our eyes Congeria and molluscs during this period that unique phenomenon. Great attention has been .ouft be related to thd formation of shdlo; hypohaline paid to th. tf.t{y of fossil ostracods, among other or- lakes in the Palaeo-Mediterraneanspace at a sea-level ganisms in order to reconstruct the environmental niveau below thoseof the Atlantic (e.g.Ruggieri, 1958, -hanges and the evolutionary palaeobiogeographyof 1967; Ruggieri 6{ Sprovieri, 1976). More geological the Mediterranean realm (e.g. Russo, 1968; Benson and pdaeontological evidenceappeared later on which & Sylvester-Bradley,l97l; Benson, 1976b, 1984; r82 S. GALOUI(AS,D.L. DANIELOPOL Benson et al., l99l; Sissingh, 1972; Gliozzi et al., organismal and/or super-organismalentities, like the 2002). behaviour of individuals within popu.lationsand/or Authors like G. Ruggieri and R.H. Benson used specieswithin a given taxocenoslswrth clear selected ostracod species as markers for the phylogenetical relatedness.Continuing this line of "lago-m of the are" event (Ruggieri, thinking Benson (1976a, p. 6) proposed to approach characterisation (( 1967; Benson, 1976b). Others like Carbonnel (1978) the concept of crisis through biodynamic strategies or Gliozzi et al. (2002) used entire specieslists with from specificproblems". For this scientistthe study of "biodynamics" characteristicspecies, which could document through changesin living systemsis in the same their origin and palaeobiogeographythe transforma- way that a study of changesin geologicalstructures is "geodynamics". tion of an eumarine environment in different Biodynamics can be approachedat an perimarine environments. Moreover R.H. Benson re- organismal level by the examination of structural constructed historicd eventsin the Mediterranean from changes,which could occur during evolutionary time the examination of morphological changesof the os- or at the super-organismallevel, with changeswithin tracod carapacesof selectedspecies (Benson, 1977). animal assemblages.Both are related to the external In the present contribution, we propose another environmental evolution experiencedby the organisms. rype of information, the changeswithin the taxonomic Benson (1976b, p. 149), followitg Ruggieri'sviews, diversiry of a marine taxocenosis,the important ostra- formulated a precise diagnostic for the biodynamic "The cod group Cytheroidea, in time and space. Our ap- changeswhich reflect an environmental crisis: "classic" proach is a combination between occurrence of Cyprideisin the Messinian indicates a micropalaeontologicalstudies and a statisticalapproach strong departure from normal marine conditions, a 'Warwick recently by K.R. Clarke and R.M. very strong but not total dominance of continental developed 'Warwick, (Clarke & 1998, 2001). Below we review freshwaterconditions". Two other criteria were offered first, conceptual and methodological aspects related further in this publication (Benson, 1976b, p. 150): "If to the ostracod usage for the reconstruction of the the crisiswas real, there should have been an inter- "Messinian Saliniry Crisis"; we further present geo- ruption in the normal rate of evolution of ostracode logical and palaeontological information on Cyprus speciesand more important in the composition of material obtained and processedby one of us (SG) their faunal assemblages".For the former argument and presented in details in Galoukas (1995). The Benson published detailed studies.on speciesbelong- Cytheroidea data is then treated statistically for the irg to various phylogenetical lineages, e.g. the calculation and the representation of the data with Oblitacythereiscase (Benson, 1977). An interruption rwo diversiry indices, the Delta+ and the Lambda+ of in the morphological continuiry of theselineages dur- Clarke & \Warwick (1998, 2001) in order to check ilg ,f. Messinian as .9-pled to the previous time how well these indices can inform us about the envi- srtuauon or after the Messinian was evidenced.At the ronmental changesalready perceived by the paleonto- assembl$. level a strong reorganisationof the species logical information which already exist (Galoukas, composition was documented (review in Gliozzi et al., 1995) and here briefly exposed.Finally, we discussthe 2002). This is representedby the reduction in the "traditional" advantagesto combine techniques com- rypical marine ostracod lineag€s,which existedduring monly used by palaeontologistswith those developed the pre-Messinianin the Palaeo-Mediterraneansea and by neontologists for palaeoecologicaland palaeo- the arrival of caspi-brackishelements from the biogeographical reconstructions. Paratethyr. August Thienemann, one of the prominent lim- CONCEPTUALAND METHODOLOGICALISSUES nologists and biogeographersof the 20'h century, pro- "biozoenotische several ecological rules, called posed 'We The 1967 publication of Giuliano Ruggieri became Grundprinzipi.l', (Thienemann, 1954). will here a standard referencefor the idea that during the Up- mention rwo of them: ( 1) the speciesrichness is high-