, Rivista Italiana di Paleontologia e Stratigrafia March THE PLEISTOCENE BATHYAL TELEOSTEAN FAUNA OF ARCHI (SOUTHERN ITALY): PALAEOECOLOGICAL AND PALAEOBIOGEOGRAPHIC IMPLICATIONS. ANGELA GIRONE Receioed Januaty 31,2002; accEted, Nooember 18,2A02 Key Words: Otoliths, palaeoecology, palacoceanography, plei- recenrly, Di Geronimo er al. (1997) carried out a new stocene, southern ItalI study of the benthic faunas (foraminifers, molluscs, Ab*ract. The carly-middle Pleistocene releosrean fauna of the bryozoans, and serpulids) in light of the modern know- Archi section, cropping out along the Calabrian side of the Messìna ledge regarding the deep-sea Pleistocene Mediterranean Straits was studied. The ìntegrated approach, based on the palaeobathy- invertebrate faunas, bringing to attention the strong mone tdriece mp ectihrcoadl icttoourpalel da nwdi tehp tihbea tphaylaale oaessceomlobgliacgael sa, pwpraosa cahp, palilereda dfov ru sthced affinity of the benthic palaeocommuniries wirh the pre- palaeoenvironmenral reconstruction. The otolith benthic and ben- sent-day North Atlantic. thopelagic associations, strongly bathyal in their compositron, suggesr a In the presenr work, the otolith assemblages from deep bathyal palaeoenvironmenr, 5OO to lOOO m deep, which is in agrce- the Archi section were analysed to improve the know- manedn tt awxoitnho mthìeca iln vfeearttuerbersa toef btheen ttheilce ofsatuenaans .a sCsoemmbploagseitsio ninadl,i castteru cclteuararlyl, ledge of the Pleistocene deep-sea teleosrean fauna, focu- Atlantic or more generally oceanic affinitìes. The Archi releostean fauna sing mainly on their palaeoecology and palaeobiogeogra- indicates a palaeoceanographic pattern with deep-water and near-bot- phy. The integrated approach proposed by Girone tom temperature lower than 8-10'C, quite different from the Recent (2000b), based on the palaeobathymetric method akeady Mediterranean. well known in the literature (Nolf & Brzobohary 1994) Riassunto. E'stata studiata la fauna a teleostei della sezione pleis_ together with the palaeocological approach, was applied tocenica di Archi che affiora lungo il versante calabro deilo Stretto di for the palaeoenvironmental reconsrruction. Indeed this Messina. L'analìsi delle associazioni ad otolìti è stata condotta applican- integrated approach, already used on Pleistocene orolith do I'approccio inregraro, già utilizzato per associazioni del circalitorale assemblages (Girone 2000b), has provided a great profondo e dell'epibatiale, basato sul metodo paleobatimetrico e l,ap- proccio paleoecologico. Le associazioni bcntoniche e bentonectoniche improvement in the palaeoenvironmental reconstrucrion ad otoliti indicano un paleoambiente batiale presumìbilmelre compreso of deep circalittoral (sensu Pérès & Picard 1964; pérès tra 500 e 1000 m. 1967) and epibathyal deposits. The deep-sea assemblages Aspetti con-rposizionali, strutturali e tassonomici di queste asso- from the Archi site represent a good example to tesr rhe mciaenzitoen oi cienadnicicaan. oT alale loarffoin fitoàr ttee satfimfinointàia cuonn rlae gfaimuen ap aaltelaoncteicaan oog rgaefinccor icdae-l sensitiveness of the integrated approach in deeper set- tutto differente da quello dcl Mediterraneo attuale, con remperature al tings. fondo inferiori agli S-tO'C. The relationship between the teleostean fauna of the Archi section and the Atlantic fauna is discussed also in the conrext of an evolutionary model of the deep Introduction Mediterranean benthos based on the invertebrate faunas The Archi site is one the best known deep-sea (Benson 1972;Di Geronimo et aL. 1996; Di Geronimo & deposits cropping our in the Messina Straits area. It has La Perna 1.997; Corselli 2001). been studied several times with parricular arrenrion ro cnidarian faunas (Placella i928; Guadagno et al. 1979) and Geological setting molluscan faunas (Crovato & Thviani 1985; Taviani et al. 1990; Micali & Villari 1986; Rindone 1990). placella The Archi secrion crops out on the Calabrian side (1978) and Guadagno er a,I. (1979) also addressed the of the Messina Srrairs. The Messina Straits zone is cur- deep-sea Atlantic characrer of the Archi corals. More rently interprered as a basin belonging to the Calabrian- Dipartimento di Geologia e Geofisica, Università di Bari, via E. Orabona 4,70125 Bari, ltaly; e-mail: [email protected] 100 A. Girone PIio-Pleistocene sedimenlary units I ) Catona-Messina 2) Calanna 3) Reggio 4) Motta 5) Capo dell'Armi 6) Melitto 7) Castanea C A ftom Di Ce.onjmo el al., 1997r L Fig. 1 - A: Location of the studY LEGENDA B area; B: The tectono-sedi- |E ,b Il Srho"uetrnher,on ,gAh dr)r'niancr'i: chlo' ^nJ,raenr /I| -l' /'/ l sournec"l rar 'rcl"''ne tf_-- :_- : II t;1" '1"' RI Mmeesnstainrya Sfrtarmaitesw aorreka o (ffr othme l{1 .,,"0,,*o^ ffi fll .,', .' Di Geronimo et al., 1997, ^n-riunr,*,..o modified); C: The Archi . Sanple s e ctron. Peloritan Arc. It consists of tectonic crystalline-meta- Reggio Calabria (southern ltaly) (Fig. 1) and is well morphic units covered by the Capo d'Orlando Flysch exposed along an N-S abandoned quarry front. It consists (Late Aquitanian - Langhian) (Bonardi et al. 1980). This mainly of well-stratified pelitic sediments with beds ge- unit is tectonically overlain by the "argille varicolori", a nerally faintly sloping westward (Di Geronimo et al. chaotic mélange of pelitic matrix containing macrofossils 1997). Two bed-sets were recognised along the quarry as old as the Cenomanian and enclosing olistoliths of front: a lower one, whose beds are involved in a gentle Palaeogene calciturbidites and Chattian-Early Miocene flexure, and an upper one, showing paraliel bedding. qtr rtzareniric turbidites. The mélange is overlain by an Vithin the markedly homogeneous pelitic sequence' two unnamed sequence of Serravallian-Tortonian turbiditic thicker and coarser (silty-sandy) beds stand out at the deposits and rare Messinian evaporites. base of the upper bed-set (Di Geronimo et al. 1'997). A subsequent discordant Plio-Pleistocene sequence According to the calcareous nannofossiÌ assem- was recently recogn;sed (Barrier & Keraudren 1983; Bar- blages, the section ranges from the early Pleistocene rier et al. 1985; Barrier 1987; Arfa et aI. 1987 Montenat et (smal| Gepbyrocapsd nannofossil biozone) in its basal part al. tssz). It consists of diachronous facies whose age ge- (about the first three m), to the middle Pleistocene (Psea- neraily decreases from mainland to coastline and from doemiliania lacwnosa nannofossil biozone) in the middle- north to south. They were deposited within smali basins upper part (Di Geronimo et al. 1992) (Fig. 1). bounded by fauit escarpments, which sometimes crop out Previous studies of the benthic invertebrate fauna showing remains of sessile faunas (Barrier et al. 1989, (foraminifers, mol1uscs, bryozoans and serpulids) indi- 1996).The Plio-Pleistocene fault systems split the Messi- cate a bathyal palaeoenvironment, 5OO to 10OO m deep. na Straits area into several blocks that evolved as distinct According to the planktonic foraminifera assemblages, basins corresponding ro the "tectono-sedimentary enti- the deposition occurred during a cold phase (Di Geroni- ties" of Barrier (1.984, 1,987). The Archi section, 9 m thick, belongs to the Reggio mo et al. 1997). Moreover, the compositional, structural tectono-sedimentary entity (Fig. 1), which developed and taxonomical features of the palaeocommunities indi- during the upper part of the Early Pliocene up to the mid- cate a strong affinity with the present-day North Atlantic dle-late Pleistocene. The sedimentary sequence begins or oceanic conditions involving a psychrosphaeric palaeo- with transgressive shallow-water deposits, evolves to ceanographic model with bottom temperatures lower bathyal units, and ends with the "Messina Gravel". than 8"-10' C, which is very different from the Recent In particular, the section studied is located near Mediterranean model (Di Geronim o et aI. 1997). P /e istct cette te leo stean s of Ar ch t PLATL,1 All fossil otoliths_are.cleposited in the collcction of the Dip:irtimento di Geologia c Geofisic:, Unir,ersitr.of Bari In thc captions, thc abbreviation L st;rnds îor left otolith and the abbreviation R for right otolìth. Ftg. l-- Nans.enia groenlandica (Reìnhardt, 18a0) Lr samplc Archi 9. Iig. 2 - Micromesistius pailtdssou (Risso, 1826) I-; sample Archi 8. Fig. i - Chauliodus.sloarzl (Schncider, 1801) L; sample_Archi_10. Fig. a - Bathttlagus e uryops (Goodc & Bean, 1896) L; sarlple Archi S. irig. S - Coeloriicbus sreliarls Nolf & Girone, 2OO0 a: L; b: R; samplc Archi Z. Fig. 6 - Coryphaenoicle's cÍ. guentheri (Vaillant, 18S8) , r: L; b-c: R; sample Archi 8. Fig. 7_- Corypbrtenoides rupesrris (Gunners, 1265) R; a: sample Archi 8; b-c: Archi l. Fìg. S - Zoarcidae inci. L; :r: s:rrlplc Archi Zl b: Archi 4. Fìg. 9 - Bathypterois sp. R; sarlple Archi Z. 142 A. Girone T:h. | - Sv'remrric Ii'r of teleost raxa SYSTEMATIC I,IST OF THE TAXA FRONÍ ARCHI Sf,CTION ; ; from Archi section. Relative l'a x=a cixn lnbcotl dsp:e cRreescenl Atlantic taxa disappcared fron Mediterranean abundance of each species PELAGIC D% D% D% D% D% D% D% D% D% D% D.l, D% and total amount of speci- Bathylagus eurlops Goode & Bean, I 896 5.1 mens per sample. 'RCÈ!1]NIDAF 'lansenia grcenlandica (Reinhafdt, 1840) 1.4 03 0l IERNOFTHYCHIDAI vaurcli.us nuellerì (Cmelin, 1789) 3.2 0.6 Po\)ípilus àîf poilí Schultz, l96l ìl 2.6 ]ONOSîOMATIDAE Gonostona |nd. 04 Results ,HOTICH'IHYIDAE fincinguerria auetuafo (Coc.o, 1838) Ì yincingilerria po'|eriae (Cocco, I 838) t.l The twelve bulk samples :HA!LIODONTIDAE Chauliodus stoani Schneider, I E0l 0.4 Benthoserna glaciale (Reinhardt. I 83?) 9.6 8.9 22 545 20.6 117 5l 45 2.1 20.ó 9.5 collected along the Archi section Ceratoscopelus naderers6 (Lowe, 1939) 3ó 20.3 18,5 15.4 18.2 3 8.2 29.6 21 ì0.3 l6 40.5 l5 contain otoliths referable to Diaphus hohi Taaning, l9l8 1.7 ó Diaphus rafnesqui (Cocco, I 838) I 0l 0.5 t.l thirty eight teleost taxa (Tab. 1), EDlìedcpthrounsa t aisdsiloinig (i CNococmo,a 1[8 2l9g)30 1.2 t88 9 50.66 t6.2 4.7 thirty four of which can be clas- Htgaphun benaíti (Cocco. 1838) 23.2 183 l9 225 18.2 ll4 lÌó 5.2 ó.9 lóì 632 sified ar specific level. The Hr yHgyogpohptmh uhny sgpo. nIi (Lurken, I 892) 3.2 6.9 07..53 3 5132 8ó.51 68 preservation of the otoliths is " Lampadena bxicd Girone & Noll 2002 0.8 0l 1.1 generally good. In some cases, LMofb.tioanpchhrina dpou|nle.tiailib t(nZ ugRmafainyeesrq,u le9, l Il )El0 l2 8I' 96 78 E 52 1.4 24.6l E.ú ll though. the specimens of myc- Notascopel$ elangatus (CostÀ. I 844) 2.4 2 3.2 l.ó I0.5 ll t.1 2 21 tophids show soiution effects S*Svmcobpoelol opp sltìos rupsl ioveceranni(yùi sl MAorneta u&. MI 8o8s8n)a, 197ó 0.8 84 ì.I1 0t..57 8.I7 (especially on the inner faces, totaì oelaqlc sDeomenr 135 Ì42 i35 3l 306 188 29 230 131 l4J and in particuiar in the suicus IFNTHOPFT À(:TI D% D% D% Dr/. D% D% D% D% D% D% D% D% area, whereas the outer faces are ALEPdEPIIALIDAE 21.2 only slightly worn) or are Lampanyctus cracodilur (Risso, l8L0) 9l.l 84.ó 8ó 45.4 100 82.1 ó5.1 87.5 50 857 encrusted by bryozoans or Caaiculus orgentils Guichenot, I 850 E2 iíicromesistius poutasso! (Risso, 1826) l 18.2 il7 8.1 20 25 foraminifers indicaring long Phycìs blennoid* (Brunnich, 1768) 2 MACROIJRIDAE CoeLoùnchus caelorhtnces (Risso. l8 l0) l 3 exposure on the sea-bottom and * Cnelatínchus stellarìs Nolf& Gìrone 2000 ó.1 a slow sedimentation rate. The Corlphaenoides rupestru\ Gunners. 1765 2 2A 75 Coryphaenoi<les cÍ. guentheri (Vaillant. I 888) difference in preservation of the CAMNCIDAE ì2 5 inner and outer face of the }ENTHIC otoliths may be due to the struc- CHLOROPHTHÀLMIDAF 2 ìelloria cî. apoda Ciglìoli, I 883 i.6 3l ture of the sulcus area. The sur- ]ythitidae sp. ind. 1.6 3 0.5 t4.l face of the sulcus of several fish NCERTAE SEDIS loaecidae sD.ind. 9 2 is built of somewhat irregularly total benthìc and benthoDelaeìc specimenr 34 22 E 6 assembled carbonate particles which are loosely connected and Material and methods show a meshwork structure, while areas outside the sul- Twelve bulk-samples, each measuring about 1O dml, cus have a more compact structure (Martini 1974). Solu- were collected along the section (Fig.t). They were rou- tion will affect the sulcus area much more than the other tinely processed for macrofaunal studies, and the residues areas. The outer face of the sagittae will be more resistant sieved through a 250pm mesh. The coarser residues to solution processes, In sharp contrast to the other samples, samples Qa25'pm) contained the greatest number of specimens Archi 6 and Archi 7 are rich, both in species and speci- while the finer portions (>250 pm) were sorted in order mens. Sample Archi 5 contains the lowest number of to detect small-sized pelagic species. The abundance and specimens that are poorly significant palaeoecologically. dominance of each taxon for each sample were calculated The otolith assemblages include 22 species that still following the criterion proposed for the bivalve group by live in the Mediterranean Sea with two of them, Symbo- Di Geronimo & Robba (1976). The calculations were car- lophorws oeranyi and Chauliodus sloani (Pl. 1, fig. 3) iden- ried out separately for the pelagic and benthic - ben- tified as fossils for the first time. There are also five taxa, thopelagic groups (Tab. 1). referable to Atlantic species, which have long disappeared In the palaeoecological approach, only the ben- from the Recent Mediterranean. Among these, the bathy- thopelagic and benthic fishes were taken into account pelagic species Bathylagus euDtops (Pl. 1, fig. 4),Nansenia and, besides the taxonomic composition, other attributes groenlandica (P1. 1, fig. 1) and the benthopelagic of the associations were analysed (Girone 2000b). On the Coryphaenoides rwpestris (Pl. 1, fig. 7) are, for the first contrary, the entire assembiage (mesopelagic, ben- time, reported as fossil species whrle Polypnws cf. polli and thopelagic, and benthic fishes) was analysed using the Diaphus taaningi were already known in the Mediter- palaeobathymetric method proposed for this group by ranean area. P. cf. polli has been reported in the middle Nolf sc Brzobohaty (1994). Pleistocene of the Montalbano Jonico section (Girone Pleistocene teleosteans of Archi 103 pliocenicus and Coelorinchws stellaris (Pl. 1, fig. 5) are fos- trpelagic lbmthio-benthopelagic sil species; the first and the second are reported only in Pleistocene sediments of the Medirerranean (Girone Ec Nolf ZOOZ; Girone & Varola 2001). S. pliocenus is known as an endemic species of the Mediterraîean area from the Miocene (Tortonian) to the Pleistocene, while C. stellaris has been reported in the late Oligocene sediments of Aquitaine and in the Late Pliocene (Gelasian) and early- middle Pleistocene of the Medit err^nean (Nolf Sc Girone 2000). The assemblages recognised are composed of low percentages of benthic and benthopelagic componenrs that generally make up for less than 20% with respecr ro the pelagic group (Fig. 2), which is mostly represented by mesopelagic fishes (myctophids). Similar to the pelagic assemblages, the benthic and benthopelagic associations of Archi 6 and Archi 7 are the richest in specimens; the association of Archi Z is also the richest in species (Tab. 1). e È t È E i E E i Therefore, in the benthic-benthopelagic group ir is == possible to distinguish bottom-related taxa thar swim just above the sea bottom (benthopelagic) or that live in con- tact with it lbenthic). Fig.2 - Benthopelagic-benthic-mesopelagìc ratio in the otolith Benthic fishes (Tab. 1) are not common with only assemblages from the Archi section. two species, Bellotia cf. apoda found in three samples (Archi 2,7 and 11) and Bathypterois sp. (Pl. 1, fíg.9) 2000a; Girone & Varola 2001), and D. taaningi has been detected only in sample Archi 7. The Recent vertical dis- found from the Miocene (only Tortonian) to the middle tribution of B. apoda is poorly documented because this species is known only from a few specimens found off PleistoLcaemnep a(Bderznoab oiohnaictya ,& H Nygoolfp h2OwOmO ; sGpir.o ln,e S2c0o0p0elbo)p.sis Madeira and Portugai and in the Mediterranean. It has been caught in bottom trawls at depths from 3O to 5OO m (Whitehead et al. 1986). On the conrrary the genus E! III class (d>2mm) f II class (l mm<d<2mm) E I class (d<lmm) Bathypterois is circumglobal at tropical and temperate la- titudes and is typical at bathyal to abyssal depths (Vhite- loovo head et al. 1989).In the Recent Mediterranean and in the 90% Atlantic, five species belonging to this genus are reported. These, considered typical of deep bathyal environmenrs, 800/. are generally found exclusively at depths greater than ZOO m (Maurin 1968; Stefanescu et al. 1994). 100/" The abundance of benthic fishes in the Archi sec- 60% tion could increase if the specimens referred to Bythitidae sp. ind. andZoarcrdae sp. ind. (Pl. 1, fig.8) were inclu- 50% ded. These families are represented mostiy by benthic 40yo species living from a few merers to abyssal depths with only a few species being bathypelagic. In particular, the 30% specimens referred to the Bythitidae are very small in size 20% and are lacking diagnostic features for specific identifica- tion. Nevertheless, it is nor to be excluded that they could too/o belong to B. apoda. The specific attribution of the specimens referred o% ós€FoÈd _É ';F===- to the Family Zoarcidae was not possible due to the scarce vseeeg44+ Recent material available for comparison. The zoarcids sample are reported in cold and temperare waters of both hemi- spheres. Temperature and salinity are the main factors Fio ì Size distribution of otoliths in Lampanyctus crocodilws that influence their distribution. Several boreal species are populations from rhe Archi secrion. linked to water temperarures lower than O" C and a sali- 104 A. Girone 'c a ú9 I & E! I Sample cE tE! g-g 9{ "Íeo"Í- ! F, YE pP Sample €i!,69F éOO=ITeJllÈ .E 2ÈEea*ea: Archi 2 ;g €3 {;f<È;.: 9=0ó_t.:àÈ!?éo.Eè ;:* *.è9g -.E4É,!ì Èe Eb !?i ú!x Eî Archi 7 i00.. X8%,t* 100- lrl !l ?00 I I 200- 100 :: I 54.tq . 30ù l. 400 ti**|{l 859" 400 500 lr'ilìll]ilii:*lir.l:!irt;li-ll e2% 50ù : 600.. " Il77La 60c 700 70(! S-i$il 800 80ù I 900 ;i!ìillai:l 54% 90ù !1138% ".9i s: ;i3: É arî _F'bi" a - Recenr h:thvmetrìc disrribu- g Ei* îE +;e- ÉEÉ Eg ai 6 ÈÈ ;a E=ePÈ tsieonnte do fi nt eAlerocshti t2a,x Aa rcrehpìr e7-, 'E: ASracmhpi lle0 E ?i=é$î;zVzIut ASracmhip l1e1 Archi 10, and Archi 1 1 assemblages. For each 1OO m E. ÉEEÉgÉFEÉÉiÉiÈÉÉÈÉ itgÉÉÉÉttÉgÉti bathymetric interval, the graph shows the potential 100 lzzv, 100 presences, expressed as a 200 S]]ro* 200_ percentage of the total num- 300 : 300 ber of taxa utilised in the 400 __J/r"/o 400 analysis. The dotted lines 500 iilii*lllir:lil sr% 500 indicate nìghtly presence of 600 t*!t:;t5!tìlàil 88% 600 mesopelagic species at the 700 " I''''" 700. surface; see Nolf & Brzobo- 9E0000 $i{e$l:l,l 055r7"" 980000 hdeattayil e(d1 9d9is4c)u sf osiro na o mf othree I 000. 1000 methodology. nity of 34 "/"". Melanostigma atlanticwm is the only species blennoides and Gadicwlus argenteus were found only occa- reported in the western Mediterranean. It is bathypelagic sionally. The gadid species are represented mostly by over the continental slope mostly at 400 - 1000 m depth. medium-large specimens, though very large specimens of The benthopelagic group includes mostly gadids M. poutassou and P blennoides were found in samples and macrourids that represent the most abundant species. Archi 6 and Archi Z. Among the macrourids, the North On the conrrary, the myctophids, represented only by Atlantic Corypbaenoides rupestris is the most abundant. It one species, are the most abundant in specimens and was recognised in the samples from the middle-upper part occur widely throughout the section. However, the myc- of the section (samples Archi 7, Archi 8, and Archi 9; tophids show the highest diversity in the pelagic group (Tab. 1) where it is represented by very large specimens. (Tab. 1). Among the myctophids, L. crocodilus is a species In the sample Archi 8, it is associated with the congene- that can change life habits during growth and conse- ric species C. cf. guentheri whjch represents 60o/" of the quently may be considered a pelagic or benthopelagic associations. C. gwentheri, is the deepest species of this fish. In particular, the adults of this species dwell close to genus and, in particular, it has been found exclusively at the bottom changing their life habit from mesopelagic in depths greater than 800-1000 m (Stefanescu et al. 1994; the juvenile stage to benthopelagic in later stages (Ste- Morales-Nin 1990). fanescu Er Cartes 1992). The distribution of the three The macrourid group includes also the Recent class sizes recognised in the population of L. crocodilws Coelorincbws coelorincus found in samoles Archi 1 and from Archi (Fig. 3) suggests that the second and third Archi 6 and the fossil C. stellaris recognised in samples classes are the most abundant. Observations performed Archi Z and Archi 11 (Tab. 1). The former species is re- on the sizes of recent populations (Girone 2000b) indi- presented mostly by medium-iarge individuals whereas cate that the second and third ciasses are made of adult the sizes of the specimens referable to C. stellaris range specimens whereas the first is made of juveniles. Conse- from medium-large in Archi 11 to very large in Archi 7. quently, the populations of Z. crocodilws were included in Other species that occur occasionally tnclude Ale- the benthopelagic associarions. pocEhalus sp. and Trachwrus sp. whose taxonomic status Among the gadids, Micromesistiws powtassow (PL 1,, is not well defined because of their poor preservation. The fíg. 2) is the most common species whlle Phycis pelagic group includes mesopelagic and bathypelagic Pleistocene teleosteans of Archt 105 7* &aEE ÈÉóEdÈ(tr .Ò=63F:* I e ÌE:Igl Je2É.s0* àei*>É.Xed,o EEÉ,-: g EaAFE,."!o:'aÉz-'o:b5la s a._Es, có8gx>E-2è?9'_9úqz.:!É4.g >g "e:EÈ ASarcmhpil eI E óCg CÒEFp"Pú€AÈí ,':úÉTi -*àt-l-qÉe:g:E€È>fi!à;::9F:É,.. ASarcmhpi le3 oE €:<x2AFl2 î.ty!ccèli :Òó6:L f,é,Ò;úY1f gJ6>>. Fi!eE€;E3=;F-! >È;93L i,{EX2:8OàÌ! r>E9N SAarcmhpi le4 |il% 1 00- -lo:r" 100.- IIIilerv" I 00- Xiilsogt ?00- 200 20u '164-" -"..lttu" ;ilrìlilll 58% 100- T-ltto" 300 100- 400_ 400. "----l 100% 400- *ìJYl"/o 50ù -1i s6% 500 *'l*+-/ 50ù t:Jl#u;$-l ili-!,;ttl ó0G ffiff' 600., :''lae"/" 60ù .*----l- -]a:z" 7800{ùr ---:-1.-I8f-o/" 780000. T'"T:'l 7800&0 ,".' . .t,, II ." .ll rva 90ù lro1*64% 900 :1*È 90ù I 0ùù I 000 1 dtv" 100{r $lil{li$losx 3 i,l 2^a ooa 'È=i,=eÈ9É EóEd2o .Èl;tcEÉto ' ,giGsí{: -:'Eó21,É8- - .RÉ 3*2E. *.àóàE2*,Bl*.-È25 ,Éé- .gF36="P6$l o$oeF "EXb.E9óp A:E€U ASarcmhpi le6 Ia >9IEa 6éGhoÉÒ- 9ÉtldE_t tt.aJ>à-à. ->za a€Eé9li6 s sz:ÉE9o ASracmhip l1e2 100, il,,* r 00- ffiillssz 200- 200- r ", "188% 300- +'"^ 300- : *&.N 400_ fiaru" 400- ... 500 î--11 50{t =il:.T"::r;,*.:"i1l100% ó0ù -Trl,,* 60& É_+l 70& -::--::-1 700- 88% ;;+-J 80ù -=tj 800- :: ,.:"1zra 90& fr*rill ssx 900- '. xlì,* ''loox t000 I 000- F;- q - R.^.-t k".1".'-.'"ic distribution of teleost taxa represented in Archi 1, Archi 3, Archi 4, Archi 6, and Archi 12 assemblages; see Fig. 4 for the explanatìon. species. The mesopelagic species belong to the Family F eP,úE z2sf, Myctophidae, to the sternoptychids Mawrolicus mwelleri gri;g**i, I :ilHEseci and Polyipnus cf. polli, to the photichthyids Vincinguenia Sample I60 31si; Sarnple attenuata and V poweriae, and to the stomiatoid Chaulio- Archi 8 sE Archi 9 dus sloani. Bathylagus euTyops and Nansenia groenlandica, ÉiàAsÉEei é7, E'i8àÈ:È,:s iijiÉ occurring respectively in Archi 8 and Archi 9, are bathy- pelagic fishes. The myctophids are notably dominant 100 ltiit 100 ii, from 95"/" to 1OO%. Benthosema glaciale and Cerato- 200 Xaax 200 tl !lzs"z scopelus rnaderensis occur in all samples whereas Hygo' 110000 Ittnloov" 140@0_ i{lt:lltuìiìuliitl.tl:6t 3%75% phum benoiti, Myctophum punctatum, and llofoscopelus il*r*tlsgx elongatus are distributed widely throughout the section. 500 500 é00 600 ìtìiq:i:iì;ttìit The occurrence and abundance of Diaphus hohi and Elec- ---'1 700 **i#,t;{,{ roo% 700 t***!!llo0/o trona rissoi are occasional. The species recognised have a 980000 lllll -*---.l 980000. 1:t!:-11ì ìt11ìitiììi-i-:a lI w2OidOe m b taoth 1yOm0Oe tmric. Odtihsterrib supteiocnie sr aonf gai nmgo rfero dmef ianbedo ubta 1th0y0-- rli*llilrm ' I 000 1000. l88eo metric range, from 400 to 200 m, include Hygopbum bygo- mi, Diaphus rafinesqwi, and Symbolopborus oeranyl. Most of the myctophid species occurring in the assemblages Fig. 6 Recent bathymetric distribution ofteleost taxa represented in Archi 8 and Archi 9 assemblages; "c_"c'_ F -ìob 4 f'.^-'' t"h-"' "'""r.'ì_,- undergo size strati{ication with generally juveniles at shal- nation. lower depths of the bathymetric ranges and adults at 106 A. Girone greater depths. The populations of the myctophid species lmmobathyal Etbathyal 6eu from Archi are generally composed of individuals of he- r:mr terogeneous size except for NotoscopeLws elongatus and Archi 12 re Symbolopborus r;eranyi, which are represented entirely by ffi* very large individuals. Archi I I @ According to the palaeobathymetric method, the graphs reconsrructed for each assemblage indicate the Archi l0 f@fil highest peaks relative to bathymetric intervals at depths % greater than 300-4OO m and a rapid decline of percenrages Archi 9 corresponding to the shallower depths. The graphs of Archi 2, Archi 7, Archi 1O and Archi Archi 8 11 clearly position the lOOm-interval of maximum pre- k^ sence betrileen 400 and 5OO m for the assemblages Archi g ArchiT 2, Archi Z and Archi 11 and between 500 and 600 m for Archi 10 (Fig. a). In the other cases, the graphs shovr the Archi 6 200 m and 300 m-intervals of maximum presence ar depths between 4OO m and 600 m (Archi l),300 m and Archi 4 500 m (Archi 3, Archi 4, Archi 6) or 3OO and 600 m k (Archi 12) (Fig. 5). The graphs of the assemblages Archi Archi 3 8 and Archi 9 show wide but clear maximum peak IT between 500 and 9OO m with a rapid decline in the per- Archi 2 @- centages above 500 m (Fig. 6). VI Archi I l0 20 30 40 50 60 70 80 90 l00D% Discussion The otolith assemblages from the Archi section are Fig.7 - Distribution of benthic and benthopelagic fishes based on characterised by the dominance of meso-bathypelagic life environment in the Archi secrion. species over the benthic-benthopelagic species. The do- minance of meso-bathypelagic individuals may be related and are really indicative of the bottom depth. to their biologicai features and the heterogeneous nature Similarly to benthic invertebrate associations (Di &of tBheo sgeennecsei s1 o9f9 1fo)s. sCil oontosildithe riansgse bmiobllaoggeics a(sl ecnasuus eKsi,d wire ilsl Geronimo et al. 1,997), the increased richness of the teleostean benthic and benthopelagic associations in the s/orth noting that the pelagic species, in particular the middle part of the section (samples Archi 6 and Archi z) myctophids, form large shoals. On the contrary in the can be related to a positive ecological response of the deep-sea environments, the benthic and benthopelagic deep-sea communities ro rhe hydrodynamically active fishes are rarely represented by dense populations. More- phase. Field observarions and sedimentological and over the mesopelagic fishes are the main preys of larger palaeontological data suggest that the deposition of this predators, which may introduce the mesopelagic otoliths stratigraphic interval was affected by hydrodynamic into the sediment through their excrements (Nolf 1985). episodes, probably influenced by tectonics (Di Geronimo However, this hypothesis does not exclude all the et aI.1997). other factors that may have contributed to the origin of This kind of ecological response of the deep-sea the fossil otolith assemblages. The pelagic assemblages communities and of demersal fish associarions was contain otoliths from all fishes, distributed in the entire already highlighted by Gooday & Tirrley (1990 and refe- water column, that fall to the bottom. However, the rences) and Stefanescu et al. (1994) who showed the otoliths of benthic and benthopelagic species belong only to fishes that lived on the sea-bottom. Consequently, prominent role of near-bottom currents in increasing the organic inputs on the deep-sea bottom. populations of pelagic fishes recognised in the fossil assemblages are mixed populations, with specimens rhar lived in different strata of the water column and are not Palaeobathymetry necessarily indicative of the bottom depth. The wide size range observed in the fossil pelagic populations reflects The otolith assemblages from the Archi section are the size stratificarion that affects pelagic fishes during clearly bathyal in their composition. In fact assemblages their life. The populations of benthic and benthopelagic with macrourid otoliths, usually accompanied by great fishes occurring in the fossil assemblages and showing quantities of myctophid otoliths, are considered typical generally a single or similar dominant size range, are rhe of continental slope sediments deposited at depths of at genuine populations that inhabited the investigated area least 250 m (Nolf 1985; Nolf 8r Brozoboh aty 1994).They Pleistocene teleosteans of Archi 147 appear uncontaminated by reworked elements, except for In this framework, it is worth noting that the the specimen of a gobiid which records an environment gadids found along the Archi section are mostly referable quite different from the deep-sea. to large individuals. In particular the larger individuals of The benthic and benthopelagic associations include M. poutassou and G. argenteus were found in samples species typical of bathyal environments deeper than 4OO- Archi 6 and Archi Z. Similarly, the iiving macrourid C. 5OO m, such as the chloropthaimid Bathypterois, the ale- coelorinchws, characteristic in about 200 to 500 m (Cohen pocephaiid Alepocepbalws and the deeper bathyal et al. 1990), undergoes the larger-deeper phenomenon macrourids C, rupestris and C. cf. guentheri. The genera (Massutí et aI. 1995; D'Onghia et al. ZOOo) and conse- Bathypterois and C. cf. guentberi are generally reported as quently the occurrence of large individuals in deeper set- taxa closely associated with depths greater than 700-800 ting is frequent. According to palaeontological evidence, m (Stefanescu et al. 1994;Morales-Nin 1990). A similar the life habit of the fossil C. stellaris seems to be quite ecologic setting is indicated by the genus Alepocephalus, similar to the Recent congeneric and it also seems to have even though the living Mediterranean A. rostratus has been subjected to the larger-deeper phenomenon. Obser- been found occasionally at shaliower bathyal depths, vations carried out on the size of otoliths from different showing a wider bathymetric distribution from 300 to sites showed that the specimens of C. stellaris recognised 3600 m (Whitehead et al. t989). Flowever, according to in epibathyal associations are often smaller than the Maurin (1968), A. rostratus is related to a sea bottom otoliths occurring in middle bathyal associations (Girone deeper than 500 m often associated with Z. crocodilws. 2000b) in which the larger individuals are generally more C. rupestris shows a larger bathymetric distribution common. The specimens of C. stellaris from the Archi ranging from 400 m to over 1500 m even if it is more section, in particular those found in the sample Archi 7, abundant at depths deeper than 600-700 m (Hareide & are comparable in size to the otoliths from middle bathyal Garnes 2001; Lorance et al.2OO1) where it is the domi- associations. It is worth stressing again that in this sample nant species in the fish communities. It has been found in the fossil species is associated with deep-sea taxa such as Atlantic waters with temperatures of 8-10" C (Vhitehead C. rupestris, Batbypterois, and L. crocodilus. et al. 1986). This species undergoes seasonal vertical The benthic and benthopelagic associations, migrations, moving to deeper waters during the summer bathyal in their composition and structure, clearly indi- months and returning to shallowerwaters in the winter. cate a deep bathyal environment located in the mesoba- The common occurrence throughout the section of adult individuals of L. crocodilus should be also stressed. thyal interval. A palaeodepth between 4OO-5OO m and Maurin (1968) and Arena & Li Greci (1973) pointed out 1OO0 m can be tentatìve1y inferred in agreement with the the frequent occurrence of the adult individuals of this data from the analysis of the benthic invertebrate associ- myctophid at depths greater than 500 m on the sea floor ations (Di Geronimo et al. tSSlT . No notable evidence of of the central Mediterranean in association with the deep bathymetric changes can be identified even though the benthopelagic fishes. Therefore L. crocodilus, in its adult presence of deeper taxa such as C. cf. guentheri and stage, takes on a notable meaning in the deep ben- Batlrypterois in the middle part of the section could sug- thopelagic associations, in particular, in the Mediter- gest a somewhat deeper setting. ranean Sea and is reported as a characteristic species on The data obtained with the palaeobathymetric the middle slope 400-800 m deep (D'Onghia et a1. 1998; method are generaliy comparable with the data inferred Stefanescu et al. tvv+). by the palaeoecological approach based on benthic and In all benthic and benthopelagic associations from benthopelagic associations. According to the palaeoba- the Archi section, the dominance value of deep bathyal thymetric method, the assemblages recognised clearly species is over 7a"/" with the exception of the association indicate a bathyal environment but the palaeodepths from Archi 11 which represents only 50% (Fig. Z). inferred are generally shallower than those calculated with The group of epibathyal species, which are frequent the palaeoecological approach. The detailed analysis car- along the section but with dominance value varying from ried out on the benthic and benthopelagic associations l0o/o to 25% (Frg. Z), include the gadids G. argentews, M. suggests clearly that these are indicative of the mesoba- poutttssou and Plrycis blennoides and the shallorver bathyal thyal environment and consequently the deeper parts of macrourids C. coelorincbus and C. stellaris. the bathymetric range, indicated by the graphs, may be The gadids recognised, in subadult - adult stage, are more probable. In several cases, the shallower bathyme- considered as characteristic species of the upper conti- tric ranges are influenced by the presence of mesopelagic nental slope in the bathymetric range between 2OO and fishes whose bathymetric distribution does not exceed 4OO m (Maurin 1968; Arena & Li Greci 1,973;Cohenetal. 400 m in depth. It is obvious that their presence is not 1990) where they show their maximum abundance. How- excluded in bottom assemblages deeper than 400 m but ever, even if their abundance decreases sharply in the they are not representative of the real depth of the envi- deeper setting, the presence of larger individuals is rather ronment in which the assemblages were formed. On the other hand, the distribution of fish sizes and the larger- 108 A. Girone deeper phenomenon must be taken into account for a Because of these faunistic, ecoiogical, and biogeo- more precise reconstruction of the deep-sea environment. graphical features, a marked oceanic scene arises from the fish associations which differ from those of the Recent Mediterranean as already highlighted for other vertebrare Palaeobiogeography and palaeoceanography Pleistocene assemblages (Girone 2OOOb; Girone Er Varola 2001). This is in agreement with results from the inverte- The Archi benthopelagic and pelagic releostean fauna is characterised by a marked Atlantic affinity, brate communities in the examined site (Di Geronimo et already shown for the invertebrate benthic communities aI. 1997) and elsewhere (Benson 1972;Di Geronimo et al. (Di Geronimo er al. 1997). Several deep-sea Atlantic 1996; Di Geronimo & La Perna 1996, 1,997; Corselli 2001). A strongly different hydrological patrern is envi- species, no longer present in today's Mediterranean, were recognised and include the pelagic Bathylagus eulVops, saged with near-bottom temperatures lower than 8-10"C Nansenia groenlandica, Polyipnws cf. polli, and Diaphus as suggested by the North Atlantic living populations of aaningt. and the benthopelagic C. rupestris. benthopelagic fish C. rwpestris and of serpulids Neoaer- B. euryops and N. groenlandica occur only in the milia falcigera andVitreotubus digeronimol (Di Geronimo North Atlantic from off sourhern Iceland to about 35" N et al. 1997). A different palaeoceanographic setting is and 45" N respectively (Vhitehead et al. 1989). They are suggested also by the presence of the northern Atlantic meso-bathypelagic fishes caught at depths ranging from bathypelagic cold water dwellers Bathylagus euryops and 300 m to 1500 m in the northern areas and from 5OO m to Nansenia groenlandica and the presence of the eutrophic 1800 m in the southern areas. They are generally associa- mesopelagic fishes Diaphws taaningi and Polyipnus polli ted with water temperarures lower than 8-10"C; in diffe- (Girone & Varola 2001). rent localities they were caught in water between 3"C and 4-5'C (Bigelow et al. 1964). A similar meaning is shared also by the ben- Conclusion thopelagic C. rupestris. This species, associated with bot- tom temperatures lower than 10"C, has been reported The analysis of the twelve bulk samples collected only in the North Atlantic from about 37'N to Baffin along the Archi section resulted in the recognition of Island and Greenland, in the western Atlantic, and from thirty eight teleostean taxa, thirty four to the specific 45'N to off Iceland and Norway in the eastern Atlantic. level. Among these, twenty two species still live in the In the southern latitudes, C. rwpestris has been captured Mediterranean Sea and include Symbolopborus veranyi off Africa in the Mauritania upwelling area. and Cbauliodus sloani, identified as a fossil for the first Another faunal feature is represented by the occur- time, as well as Vincinguerria af[. attenuata and rence of extinct species, closely related to deep-sea Coryphaenoides aff. guentberi, whose raxonomic status is Atlantic or generally oceanic raxa, such as rhe pelagic not weli defined. The Archi assemblages include the Lampadena ionica and Scopelopsis pliocenicws and the ben- Atlantic bathypelagic species B atlty lagus eury op s, N ans e- nia groenlandica, and the benthop elagic Corypbaenoides thopelagic Coelorinchws stellaris. Based on presenr know- rupestris, ali reported for the first time as fossils and di- ledge, Lampadena ionica and S. pliocenicus can be consi- sappeared from the Recent Mediterranean. The Atlantic dered as palaeoendemic Mediterranean species. The gene- mesopelagic fishes D. taaningi and P. cf. polli, already ra Scopelopsis and Lampadena have disappeared from the reported in the Pliocene and Pleistocene sediments of the Recent Mediterranean; the living Atlantic species of Mediterranean (Nolf et al. 1998 Girone 2000b; Girone & Scopelopsis has been reported in the southern Atlantic Varola 2001), also occur. while Lampadena is presenr in both North and South In this work, the palaeobathymetric method was Atlantic (Nafpaktitis et aL. 1977; Nafpaktitis 8c Paxton integrated with the palaeoecological approach based on 1968; Nafpaktitis & Nafpaktitis 1969; HulIey 1981). A benthic and benthopelagrc taxa providing more precise significant geographic distribution is shown by S. multi- palaeoenvironment reconstructions. In particular, the punctatus, the unique Recent species belonging to this analysis of the structure of fish populations, besides ta- genus that is found in the Atlantic ocean. This species has xonomic composition, provided a good tool for the inter- often been included in the sourh subrropical region pretation of Pleistocene deep-sea benthic and ben- according to the zoogeographic distribution proposed by thopelagic associations as already demonstrared for the Backus et al. (1970) (fide Nafpaktitis et al. tlZZl in rela- deep-circalittoral and epibathyal associations (Girone tion to physical boundaries. Recently, Hulley (1981) 2000b). obser-ved that in the south subtropicai region S. mwlti- The benthic and benthopelagic associarions, srrong- punctatus is distributed only in the areas affected by the ly bathyal in their structure, are clearly indicative of a deep cold Benguela Current. Consequently, this geographic bathyal environment located in the middle bathyal interval. distribution suggests that this species cannot be consi- A palaeodepth comprising between 4OO-5OO m and lOOO m dered only as a warm species. can be inferred in asreement with the data from the ben-