the upper miocene fossil fish locality of pecetto di...

203Bollettino della Società Paleontologica Italiana, 49 (3), 2010, 203-225. Modena, 15 dicembre 2010

ISSN 0375-7633

IntroductIon

More than thirty years ago, carlo Sturani described a new fish fauna collected in the vicinity of Pecetto di Valenza (Fig. 1), after a landslide which had occurred near Cascina Valnera, in the Upper Miocene of the Eastern part of the Montferrato hills (Alessandria province) (Sturani & Sampò, 1973). According to Sampò, who had studied the foraminifera, the locality was supposed to be Messinian in age.

the material had been collected in diatomitic layers by Carlo Sturani and Mario Macagno who observed in the sediment the occurrence of pteropods: Cavolinia gypsorum Bellardi, 1873, heteropods: Atlanta or

Proatlanta sp., lepadids: Lepas sp., portunid crabs: Necronectes sp., as well as juvenile oysters (2 to 15 mm long): Ostrea cf. neglecta Michelotti, 1847, fixed on driftwood or, exceptionally, on a drifted shell of a cuttlefish (specimen MRSNP 35/140).

In his study of the fish fauna from Pecetto di Valenza - the material collected by him is kept in torino, in the palaeontological collection of the University (PU) - Sturani identified eleven (a number which is here reduced to ten) different species:- Family Clupeidae: Alosa elongata Agassiz, 1843;- Family Gonostomatidae [=Sternoptychidae]: Mauro-

licus gregarius Franceschi, 1922 [= M. muelleri (Gmelin, 1789)];

The Upper Miocene fossil fish locality of Pecetto di Valenza(Piedmont, Italy): a multidisciplinary approach

Jean Gaudant, Marie-denise Courme-rault, Eliana FornaCiari & Elisabeth Fourtanier

J. Gaudant, 17 rue du Docteur Magnan, F 75013 Paris, France (Muséum national d’Histoire de la Terre, USM 203, UMR 7207 CNRS); [email protected]

M.-D. Courme-Rault, 6 rue Porte vendomoise, F 45190 Beaugency, France; [email protected]. Fornaciari, Dipartimento di Geologia, Paleontologia e Geofisica, Università di Padova, via Giotto 1, I 35137 Padova, Italia; [email protected]. Fourtanier, Diatom Collection, California Academy of Sciences, Golden Gate Park, San Francisco, California 94118-4599 (USA); EFourtanier@

calacademy.org

Key wOrdS - Fishes, Micropalaeontology, Stratigraphy, Palaeoenvironment, Upper Miocene, Piedmont, Italy.

ABStrACt - Pecetto di Valenza is the first Upper Miocene fossil fish locality of Piedmont to have been studied and the only one in which fossils are embedded in a diatomitic sediment. Sturani & Sampò (1973) considered that it is Messinian in age. However, as a preliminary examination of the diatom flora from this locality by one of us (Elisabeth Fourtanier) suggested a late Tortonian age, it was decided to complete a more thorough micropalaeontological study in order to clarify the stratigraphical question. A comprehensive study of the diatom flora confirmed the preliminary results. Later, the study of the calcareous nannoplankton also concluded a late Tortonian age for the fossiliferous diatomaceous sediment. However, the examination of the planktonic foraminifera supports a Messinian correlation. Such a contradiction is puzzling and is hitherto not understood, even when making reference to a possible reworking.

The composition of the fish fauna from Pecetto di Valenza is very similar to that observed in the two other marine Upper Miocene fish faunas of Piedmont, as myctophids predominate in all of them with more than 50% of the total number of specimens, whereas clupeids belonging to the species Alosa elongata comprise about 20% of the fauna. Except for the two species of the genus Lepidopus which, together, reach almost 8%, each one of the other identified taxa is below 5% of the fish fauna. The occurrence of upwellings, which is indicated by the abundance of the diatom thalassionema nitzchioides in every diatomaceous sample, may have been responsible for the rather significant percentage of Lepidopus in the fish fauna. However, the upwelling environment did not exert any notable influence on the overall composition of the fish fauna from Pecetto di Valenza, relatively to those of the Tortonian of the Tanaro River and of the pre-evaporitic Messinian of Roddi, two localities in which diatoms are missing.

rIASSUNtO - [La località a pesci del Miocene Superiore di Pecetto di Valenza (Piemonte, Italia): uno studio multidisciplinare] - Pecetto di Valenza è il primo sito a pesci fossili del Miocene Superiore del Piemonte ad essere stato studiato. Inoltre è l’unico in cui i fossili sono inclusi in sedimenti diatomitici. Sturani & Sampò (1973) li hanno considerati di età messiniana. Tuttavia l’analisi preliminare dell’associazione a diatomee di questa località da parte di uno di noi (Elisabeth Fourtanier) suggeriva un’età tortoniana. Perciò, al fine di chiarire la posizione stratigrafica di questo sito, è stato condotto uno studio micropaleontologico con anche altri gruppi. Lo studio definitivo dell’associazione a diatomee ha confermato i risultati preliminari. In seguito anche lo studio dell’associazione a nannofossili calcarei ha permesso di concludere che i sedimenti diatomitici hanno un’età attribuibile alla parte alta del Tortoniano. Al contrario le analisi dell’associazione a foraminiferi planctonici supportano la correlazione con il Messiniano di Sturani & Sampò (1973). Questa contraddizione è inspiegabile e finora non è stata compresa.

La composizione della fauna di pesci di Pecetto di Valenza è molto simile a quella osservata nelle due altre faune a pesci del Miocene Superiore del Piemonte. In tutte i myctophidi predominano con più del 50% sul totale del numero di esemplari mentre i clupeidi appartenenti alla specie Alosa elongata sono circa il 20% della fauna. A Pecetto di Valenza, ad eccezione di due specie del genere Lepidopus che insieme raggiungono l’8%, ciascuno degli altri taxa identificati costituisce meno del 5% della fauna a pesci. La percentuale piuttosto significativa di Lepidopus nella fauna a pesci potrebbe essere imputabile alla presenza di upwelling indicata dall’abbondanza, in tutti campioni analizzati, della diatomea thalassionema nitzchioides. In ogni caso il confronto tra la composizione della fauna a pesci fossili del fiume Tanaro (Tortoniano) e di Roddi (Messiniano pre-evaporitico), due località in cui le diatomee sono assenti, con quella di Pecetto di Valenza indica che quest’ultima, globalmente, non è stata influenzata in maniera significativa dall’upwelling.

204 Bollettino della Società Paleontologica Italiana, 49 (3), 2010

- Family Myctophidae: Myctophum microsoma (Sauvage, 1870) [= M. licatae (Sauvage, 1870) plus, pro parte, M. dorsale (Sauvage, 1870)] and M. edwardsi (Sauvage, 1870) [= M. licatae (Sauvage, 1870)];

- Family Syngnathidae: Syngnathus albyi Sauvage, 1870;- Family Merluccidae: Merluccius merluccius (Linnaeus,

1758);- Family Caproidae: cf. Capros aper (Linnaeus, 1758) [=

Percoidei indet.];- Family Trichiuridae: Lepidopus proargenteus

Arambourg, 1927;- Family Carangidae: trachurus trachurus (Linnaeus,

1758);- Family Soleidae [= Bothidae]: Microchirus abropteryx

(Sauvage, 1870) [= Arnoglossus abropteryx (Sauvage, 1870)].

Additionally, Sturani noted that one species of myctophids, Myctophum microsoma (Sauvage, 1870), is the most frequent. He also noted that this fish community mainly includes nectonic fishes and considered that the lack of littoral species is indicative of a sedimentation taking place at some distance from the shore, in the upper part of the bathyal zone, at a depth comprised between 200 and 400 or 500 metres, under influence of upwellings which were producing waterblooms of diatoms.

New excavations were carried out in 1981 in the same area - more precisely near cascina Guarnera, at about 1 km S-SE of Pecetto di Valenza - by Giulio Pavia and Mario Macagno, assisted by Daniele Ormezzano. Consequently, a total amount of more than two hundred fishes specimens became available for study. The newly collected material is kept in torino, in the Museo regionale di Scienze naturali del Piemonte (MRSNP). Additionally, a section of about seven metres of sediment (Fig. 2) was sampled on this occasion (Pavia, 1989).

Fig. 1 - Map of the surroundings of Alessandria (Eastern Piedmont) showing the location of Pecetto di Valenza.

Fig. 2 - Lithostratigraphical section of the strata excavated in 1981 (from Pavia, 1989, modified). The numbers to the right indicate the position of the samples collected for micropalaeontological studies.

205J. Gaudant et al. - The Upper Miocene fossil fish locality of Pecetto di Valenza

Although it is impossible to know if Sturani’s and Pavia’s excavations were carried out, or not, exactly in the same part of the diatomitic sequence which is more or less exposed near Cascina Guarnera, the composition of the two fossil fish associations exhibit the same general composition. The main difference between them results from the occurrence of scombrids in the material collected during Pavia’s excavation.

The quantitative study of the composition of both fossil populations is completed by a comparison with those from the Tortonian of the Tanaro bed near Alba (Gaudant et al., 2007) and from the pre-evaporitic Messinian of Roddi (Gaudant et al., 2008).

The diatom flora was examined by Elisabeth Fourtanier who studied the samples collected during Pavia’s excavations. Additionally, Eliana Fornaciari examined the calcareous nannoplankton whereas Marie-denise Courme identified the foraminifera. A stratigraphical problem arose when Elisabeth Fourtanier studied for

comparison the diatoms of a fish specimen collected at Pecetto di Valenza by Oreste Cavallo, from the Museo civico “F. Eusebio” of Alba, during Sturani’s excavations: in fact, she unexpectedly concluded that the diatom flora of this sample is not Messinian but Tortonian (Fourtanier et al., 1991).

MICROPALAEONTOLOGICAL STUDy OFTHE SECTION SAMPLED IN 1981

diatoms (Fig. 3; Pl. 1)

Methods - Samples (ca. 1cc) were boiled in HCl and H2o2. the residues were rinsed by diluting them in distilled water and decanting off excess liquid after at least 12 hours of settling. This cycle was repeated 3 times. Strewn slides were prepared by sampling a fraction

Fig. 3 - Diatom occurrence chart at Pecetto di Valenza, and stratigraphical range of selected taxa. First and Last occurrence ages are based on data from the Pacific Ocean according to: 1: Barron (2003); 2: Barron (1976, updated). A= abundant, C= common, F= few, R= rare; LOD: Last occurrence datum; FOD: First occurrence datum; LCOD: Last common occurrence datum.


of the suspended residue with a pipette and spreading it on a cover slip that was air-dried and mounted on a slide with Hyrax.

For each sample an entire slide was scanned under the light microscope at 1000x power. Relative abundance of each taxa is reported (Fig. 3) as A (abundant), C (common), F (few) and R (rare).

results - Samples 1, 2 and 9 are devoid of diatoms. Samples 3-8 (55 cm-165 cm) yielded a well preserved and abundant diatom flora.

Palaeoecology - The diatom assemblages from Pecetto di Valenza are dominated by thalassionema nitzschioides, which is abundant in every sample. Chaetoceros resting spores are also frequent in levels 3 and 4. denticulopsis simonsenii (mostly in sample 3, 6, 7) and Coscinodiscus spp. are fairly common. The assemblages are typically oceanic with very few neritic species (e.g. Actinoptychus senarius).

thalassionema nitzschioides is a cosmopolitan planktonic species that is found in oceanic and coastal environments. The abundance of thalassionema nitzschioides seems to correspond to highly productive oceanic environments (Sancetta, 1992). Chaetoceros are abundant in areas of coastal upwelling (Schuette & Schrader, 1981).

The diatom flora at Pecetto is indicative of a highly productive oceanic environment. The influence of a coastal upwelling may be reflected in samples 3 and 4.

Age of the deposit - Stratigraphical markers (e.g. denticulopsis simonsenii, thalassiosira brunii, thalassiosira grunowii, Nitzschia porteri) occur in the section. The stratigraphical range of these markers have been well documented and directly correlated with the palaeomagnetic scale in the Pacific Ocean (Burckle, 1972; Barron, 1976, 2003; Shackleton et al., 1995). Previous studies in the Mediterranean neogene (e.g. Burckle, 1976, 1978; Gersonde, 1980; Gersonde & Schrader, 1984; Monjanel, 1987; Gaudant et al., 1996) demonstrate that the diatom zonation established in the Pacific Ocean is applicable in the Mediterranean area. We therefore accept

that the stratigraphical range of these stratigraphic markers is similar between the Mediterranean and the Pacific Ocean. The last occurrence datum (LOD) and the first occurrence datum (FOD) in the Pacific Ocean for selected species (Barron 1976, 2003) are indicated in Fig. 3.

The occurrence of denticulopsis simonsenii (Last common occurrence - Lco - around 8.6 Ma in all areas except Antarctica) and the occurrence of thalassiosira brunii (Lo 9.0 Ma) suggest an age older than 9.0 Ma. the occurrence of Actinocyclus ellipticus f. lanceolata (Fo 10.5 Ma) and the absence of Actinocyclus moronensis (Lo 9.8 Ma) suggest an age younger than 9.8 Ma. the other stratigraphic markers present in the section are supporting an age of about 9.0-9.8 Ma (Tortonian) for the section of Pecetto di Valenza.

In addition, we note that the diatom flora is characteristically lacking definitive Messinian diatoms such as those recorded at Masseria il Salto (Gaudant et al., 1996) or Capo Rossello (Schrader & Gersonde, 1978). Messinian diatoms absent at Pecetto include Nitzschia miocenica (Fo 7.3 Ma), thalassiosira praeconvexa (Fo 6.7 Ma) and thalassiosira convexa var. aspinosa (Fo 6.6 Ma). Furthermore, we note the absence of species that could be characteristic of the uppermost Tortonian, such as thalassiosira burckliana (Fo 9.0 Ma), Nitzschia fossilis (Fo 8.9 Ma), Alveus marina (Fo 7.9 Ma) and Nitzschia reinholdii (FO 7.6 Ma) (Barron, 2003). The base of the Messinian has been astronomically dated at 7.251 Ma (Hilgen et al., 2000).

The assemblage from Pecetto di Valenza resembles that described by Schrader (in Berggren et al., 1976) at El Cuervo (Andalusia, Spain) and that of the upper diatom sedimentation episode studied by Bustillo and López Garcia (1997) in the Guadalquivir Basin of Spain, suggesting that diatom deposition occurred between ca. 9.0 to 9.8 Ma in at least parts of the Mediterranean.

Calcareous nannofossils (Fig. 4)

Methods - Nine samples were prepared from unprocessed material as smear slides and examined

EXPLANATION OF PLATE 1

Selected diatoms from Pecetto di Valenza.

Figs. 1-3 - denticulopsis simonsenii (sample 6).Figs. 4-5 - Nitzschia porteri (sample 6).Fig. 6 - Rouxia californica (sample 6).Fig. 7 - Thalassiosira flexosa (sample 8).Fig. 8 - rhizosolenia miocenica (sample 6).Fig. 9 - Thalassiosira flexosa (sample 6).Fig. 10 - thalassiosira cf. gersondei (sample 6).Fig. 11 - dimmerogramma sp. 1 of Schrader & Gersonde, 1978 (sample 7).Fig. 12 - Nitzschia praereinholdii (sample 6).Fig. 13 - Thalassiosira grunowii (sample 6).

207Pl. 1J. Gaudant et al. - The Upper Miocene fossil fish locality of Pecetto di Valenza


using a light microscope at 1250x magnification. After a preliminary qualitative analysis to evaluate the abundance and the state of preservation of calcareous nannofossil assemblages, the following quantitative and semiquantitative counting methods (Backman & Shackleton, 1983; Rio et al., 1990) have been applied in order to check the presence or absence of index species:

1) Counting the number of biostratigraphically useful species in an area of about 1 mm2 (Reticulofenestra pseudoumbilicus, Minylitha convallis);

2) Counting a prefixed number of taxonomically related forms, i.e., 100 helicoliths (Rio et al., 1990);

3) Counting the number of rare but biostratigraphically useful species in an area of about 6-7 mm2 (2-3 vertical traverses), i.e. discoasterids.

results - With the exception of sample 9, all the other ones contain common calcareous nannofossils, having a rather good state of preservation. The results are shown in Fig. 4. Reworked Cretaceous and Palaeogene taxa are present in almost every sample, and are fairly common in the sample 4. The other samples exhibit similar associations in which dominate placoliths and helicoliths.

the genus discoaster is generally poorly represented and the marker species (e.g. discoaster hamatus and d. pentaradiatus) are virtually absent (Fig. 4). Minylitha convallis is present (from rare to scarce) in samples 1, 2, 6, 8 and 9. Helicoliths are common. Especially, Helicosphaera stalis is present in all samples (Fig. 4). Among placoliths, Reticulofenestra pseudoumbilicus is always common.

Age of the sediments - Helicosphaera stalis is widely distributed throughout the Tortonian (from zone MNN8b to zone MNN11a of Fornaciari et al., 1996 and Raffi et al., 2003) while Reticulofenestra pseudoumbilicus ranges from the Middle Miocene to the Early Pliocene, although

it displays an interval of reduced presence or virtual absence (Paracme) starting from the base of MNN10a (Raffi et al., 2003) at ca. 8.8 Ma (Raffi et al., 2006). Therefore, the concomitant occurrence of common r. pseudoumbilicus and H. stalis allows an assignment of the Pecetto di Valenza section to the calcareous nannofossil zones MNN8b-MNN10. Additionally, the presence of Minylitha convallis makes possible a correlation of the strata with an interval ranging from the upper part of zone MNN9 to the top of MNN10 (cf. Raffi et al., 2003, fig. 1). Hence, on the basis of the stratigraphical distribution of r. pseudoumbilicus, M. convalllis and H. stalis the age of the Pecetto section is Tortonian and ranges from the upper part of zone MNN9 to the top of MNN10 of Raffi et al. (2003) (Fig. 4).

Foraminifera(Figs. 5-6)

Methods - All the samples being more or less marly, they were washed with water to which hydrogen peroxide had been added. Then the sediment was sifted with three sifters having meshes of 0.500, 0.250 and 0.125 mm. Finally, the foraminifera were examined under a binocular microscope.

results - According to the composition of the foraminiferal associations, the Pecetto section can be subdivided into four members.

1) The sample Pecetto 1 can be distinguished from the following ones by the abundance of the foraminifera. Although no planktonic marker was found in this level, this planktic foraminifera association points toward a Tortonian age. Benthic foraminifera, very diverse in species and numerous in samples, indicate an environment which was favorable for their growth. Most species

Fig . 4 - Dis t r ibut ion of selected calcareous nannofossil taxa at Pecetto di Valenza. Countings: relative abundance of helicoliths species on 100 counted helicoliths. number of discoasterids on 6-7 mm2. Number of Reticulofenestra pseudoumbilicus and Minylitha conval l i s on 1 mm 2. A: Abundant; C: Common; D: Dominant; P: Present; cf.: compare to.

Helicosphaera% N/mm2

Sam

ple

H. c

arte

ri

H. p

acifi

ca/o

rient

alis

H. s

talis

H. e

uphr

atis

H. r

ecta

Dis

coas

ter b

rouw

eri

Dis

coas

ter h

amat

us

Dis

coas

ter

varia

bilis

Min

ylith

a c

onva

llis

R. p

seud

oum

bilic

us >

7μm

Cre

tace

ous

taxa

rew

orke

d

Pal

eoge

ne ta

xa re

wor

ked

Dia

tom

s

9 84 10 6 0 0 0 0 2 4 35 P P

8 47.17 14.15 37.73 0 0.94 0 0 2 1 37 P A

7 66 4.8 29.26 0 0 1 0 0 0 16 P P

6 56.2 6.6 37.14 0 0 0 0 0 2 9 A

5 81 3.8 13.5 0.96 0 5 0 10 0 7 P

4 94.4 0.9 4.7 0 0 0 0 30 0 10 C C A

3 91 2 5 2 0 0 0 1 0 10 A

2 83 4 13 0 0 6 0 24 5 4

1 80 6 14 0 0 5 1cf. 25 7 8 P P

REWORKED

209

characterize an open sea oxygenated environment, normal salinity waters, and circalittoral to infralittoral conditions, on a muddy bottom. Bulimina, Brizalina, Bolivina and Uvigerina proliferated in an environment rich in organic matter. The existence of surface currents can explain the presence of genera living in water plant communities (Biasterigerina or elphidium), which are very scarce, and probably carried away from their habitat by down slope transport.

2) The appearance of the planktonic taxa Globorotalia humerosa and Globigerinoides eamesi in samples Pecetto 2 and 3, followed by that of Globorotalia suterae in the sample Pecetto 4, argue for a Messinian age. The large variety of planktonic species is remarkable in these three levels; however, this does not apply to benthic foraminifera. It seems that depositional conditions changed and were no longer as favorable for benthic foraminifera as in Pecetto 1. Species of open sea and normal salinity waters are scarce or absent (such as Uvigerina for example). Genera living in water plant communities are more frequent (Biasterigerina, Cibicides, elphidium). Species supporting dysoxic and salinity increases (Bolivina, Brizalina, Rectuvigerina, Hopkinsina) are predominant and associated to species supporting suboxic conditions (Cancris, Gyroidina, Cassidulina). the bottom remains muddy.

Fig. 5 - Distribution of the planktic foraminifera throughout the section of Pecetto di Valenza sampled by Pavia (1981).

J. Gaudant et al. - The Upper Miocene fossil fish locality of Pecetto di Valenza

Fig. 6 - Distribution of the benthic foraminifera throughout the section of Pecetto di Valenza sampled by Pavia (1981).


3) From Pecetto 5 to 8, planktonic foraminifera remained diverse and well represented. The Globorotalia humerosa-Globigerinoides eamesi association, along with Globorotalia suterae and additionally with G. conomiozea (Pecetto 7) is always present and therefore indicates a Messinian age. Benthic foraminifera show few variations in their contents in comparison with Pecetto 2 to 4; however, intervals which are poor in benthic foraminifera (Pecetto 6 and 8) alternate with levels where they are still rather well represented (Pecetto 5 and 7). Genera living in sea plant communities are present, such as forms supporting suboxic conditions (Cancris, Pullenia) or dysoxy and salinity increases (Rectuvigerina, Hopkinsina, Hanzawaia). the bottom remained muddy. the presence of Uvigerina may suggest sporadic incursions of waters having a normal salinity.

4) Depositional conditions observed in the sample Pecetto 9 are similar to those of Pecetto 1. The planktic foraminifera belong to the association Globorotalia humerosa - G. praemargaritae (the second one scarce) and include Globigerinoides eamesi, indicating a Messinian age. Among benthic foraminifera, genera living in sea plant communities are less numerous at the species level, as well as those supporting dysoxy and salinity increases (Hopkinsina). On the other hand, the abundance of the four species of Uvigerina, indicates a close relation to an open sea environment. Associated to Bulimina, Brizalina and Bolivina, they characterize again an environment rich in organic matter. the bottom remained muddy.

Interpretation - The associations of planktic foraminifera observed in the samples 2 to 9 are indicative of a Messinian age. Moreover, they look rather similar to those described by Wernli (1980) from the Messinian of the Mediterranean coast of Morocco. However, although Globorotalia humerosa and Globigerinoides eamesi are frequent at Pecetto di Valenza, Globorotalia suterae, G. conomiozea and G. praemargaritae are less common.

From a palaeoenvironmental point of view, the fossiliferous layers correspond to a sedimentation taking place in a quiet area of the circalittoral zone which was disturbed from time to time by surface currents, as shown by the important number of foraminifera normally living in sea plant communities. Additionally, the fact that, except in the sample Pecetto 1, the benthic foraminifera are unfrequent, may be related to the occurrence of dysoxic

conditions on the bottom, as suggested by Van Hinsbergen et al. (2005).

Note - During this study, we have mainly used the data published by Berggren et al. (1995), Bolli, Saunders & Perch-Nielsen (1985), Betzler et al. (2006) and Hüsing et al. (2009) for determining the stratigraphical distribution of the planktic foraminifera, whereas we have taken into consideration the publications by AGIP (1982), Murray (1973, 1991), Van der Zwaan (1979) and Zachariasse & Spaak (1983) for interpreting the environmental significance of the benthic fauna.

The fish fauna (Figs. 7-10; Pls. 2-6; Tab. 1)

The present description of the Upper Miocene fish fauna from Pecetto di Valenza relies on the bulk of material collected, first by Carlo Sturani, Giulio Pavia and Mario Macagno and, later, by a team composed of Giulio Pavia, Mario Macagno and daniele ormezzano (table 1).

Family Clupeidae Cuvier, 1817Genus Alosa Linck, 1790

Alosa elongata Agassiz, 1843(Pl. 2, figs. 1-2)

discussion - this species is represented by 18 specimens (15.3%) in the material collected by Sturani, and by 31 (25%) in the newly collected material. It is rather well known from an anatomical point of view since its description by Arambourg (1927), which was completed more recently for fishes from the Upper Miocene of the surroundings of Alba (Gaudant et al., 2007, 2008). The characteristic shape of the preoperculum and the operculum is shown in Pl. 2, fig. 1. Additionally, the ventral surface of an isolated neurocranium exhibiting the two pterotic bullae and the left prootic one is also figured (Pl. 2, fig. 2).

The standard lengths of the examined specimens range from 107 to 175 mm in Sturani’s collection (with the exception of a larger fish reaching 280 mm), whereas it ranges from 69 to 215 mm in the material collected in 1981, except for a larger fish reaching 284 mm.


Fossil fishes from the Upper Miocene of Pecetto di Valenza.

Fig. 1 - Alosa elongata (Agassiz). Head. Specimen MRSNP 35/08.Fig. 2 - Alosa elongata (Agassiz). Neurocranium. Specimen MRSNP 35/30.Fig. 3 - Maurolicus muelleri (Gmelin). Specimen MRSNP 35/32b.Fig. 4 - “Myctophum” licatae (Sauvage). Specimen MRSNP 35/58b.Fig. 5 - “Myctophum” licatae (Sauvage). Specimen PU 12 463 (Sturani’s collection).

211J. Gaudant et al. - The Upper Miocene fossil fish locality of Pecetto di Valenza Pl. 2


Family SternoptyChidae Duméril, 1806Genus Maurolicus cocco, 1838

Maurolicus muelleri (Gmelin, 1789)(Pl. 2, fig. 3)

discussion - Maurolicus muelleri is a species which is well known in the Messinian of the Mediterranean basin. It was first described as Clupea gregaria and then as Sahelinia gregaria by Arambourg (1925, 1927) in the Messinian of Licata (Sicily) and later of Oran and Sidi Brahim (Algeria). Additionally, a detailed description of this species was published by Landini & Menesini (1980). Ten specimens were collected at Pecetto di Valenza. Four belong to Sturani’s collection (3.4% of the collected material), whereas six were found in 1981 (they constitute 4.8% of the material found at that time).

As shown by Fig. 14, their standard lengths range from 10.5 to 35.5 mm. It may be noted that the specimens having a standard length exceeding 30 mm were collected in 1981.

Family myCtophidae Gill, 1893Genus “Myctophum” Rafinesque, 1810 (s.l.)

“Myctophum” licatae (Sauvage, 1870)(Pl. 2, figs. 4-5)

discussion - Myctophum licatae is a species which is already well known as it was widespread during the

Tab. 1 - Composition of the Upper Miocene fish fauna from Pecetto di Valenza. the study was managed separately for the Sturani’s collection belonging to the Torino University and for the material collected in 1981 under the leadership of Pavia for the Museo regionale di Scienze naturali del Piemonte.Note: The specimen of Solea cf. solea was kept in the private collection of the late Mario Macagno.

Messinian throughout the Mediterranean basin in which it was dominant in many localities. It is also the case at Pecetto di Valenza as 103 specimens were collected: 61 by Sturani (51.7% of the collected material) and 42 in 1981 (33.9% of this material). These percentages can be compared to those observed in the Tortonian of the Tanaro River (43.4%) and in the Lower Messinian of Roddi (40%) (Gaudant et al., 2007, 2008).

this species is well known through its description by Arambourg (1925, 1927) who distinguished two other species that we consider as synonyms of Myctophum licatae: Myctophum microsoma (Sauvage, 1870) and Myctophum edwardsi (Sauvage, 1870) (Gaudant & Ambroise, 1999).

The standard lengths of the specimens range from 10.5 to 61.5 mm, whereas the maximum frequency is observed between 10 and 50 mm (Fig. 14), to be compared with a maximum frequency between 30 and 55 mm in the Tortonian of the Tanaro River and 40 and 65 mm in the pre-evaporitic Messinian of Roddi. This indicates that young specimens were rather more abundant at Pecetto di Valenza.

“Myctophum” dorsale (Sauvage, 1870)(Pl. 3, figs. 1-3)

discussion - The second species of myctophids identified at Pecetto di Valenza is quite less abundant than



Fig. 1 - “Myctophum” dorsale (Sauvage). Specimen MRSNP 35/80.Fig. 2 - “Myctophum” dorsale (Sauvage). Specimen MRSNP 35/87.Fig. 3 - “Myctophum” dorsale (Sauvage). Same specimen: enlargement showing the photophores (arrows).


Myctophum licatae. Only six specimens were found by Sturani (5.1% of the collected material) and 11 in 1981 (8.9% of the fish number). This species differs from Myctophum licatae (Sauvage) by their thicker scales and the possession of rather large light organs. Their standard lengths range from 15.5 to 40 mm. The percentage of representatives of this species at Pecetto di Valenza is similar to what is known in the Tortonian of the Tanaro River and in the Messinian of Roddi (Gaudant et al., 2007, 2008), but the size of the specimens is slightly smaller at Pecetto di Valenza.

Family merluCiidae Adams, 1864Genus Merluccius Rafinesque, 1810

Merluccius merluccius (Linnaeus, 1758)

discussion - Sturani & Sampò (1973, pl. I, fig. 1) described and figured a well preserved specimen of Merluccius merluccius. This specimen (PU 12373/1 and /2) has a standard length of 155 mm and a maximum height of body measuring 30 mm. The dorso-ventrally crushed head of another fish (PU 12349) can be assigned to the same species. Additionally, the caudal region of a larger fish (MRSNP 35/99), which is covered by small cycloid scales ornamented with ovoid circuli, was found in 1981.

As already emphasized by Sturani & Sampò (1973), it was the first time that the genus Merluccius was recorded from the diatomitic Upper Miocene of the Mediterranean basin.

Family SynGnathidae Bonaparte, 1832Genus Syngnathus Linnaeus, 1758

Syngnathus albyi Sauvage, 1870(Pl. 4, fig. 1; Pl. 6, fig. 1)

discussion - This species is represented by fifteen specimens in the studied material. Six were found by Sturani (5.1% of his collection) against nine collected in 1981 (7.3%). Their standard length (measured or estimated) ranges from about 260 to 500 mm. This species, which is widely distributed in the upper Miocene of the Mediterranean basin, was already described by Arambourg (1925, 1927). In Piedmont, it is also present in the Tortonian of the Tanaro River and in the Lower Messinian of Roddi (Gaudant et al., 2007, 2008). An

isolated operculum was found at Pecetto di Valenza in 1981 (Pl. 4, fig. 1). It is an ovoid bone bearing a reticulate ornamentation. Its length equals about 1.5 time its height.

Suborder Percoidei Bleeker, 1859Percoidei indet.(Pl. 5, figs. 1-3)

discussion - At least five indetermined small percoids were collected at Pecetto di Valenza. Three were found by Sturani. One of them (PU 12355/1 and /2; Pl. 5, fig. 1) was tentatively determined by him as “cf. Capros aper (L.)”. However, this juvenile fish is indicated as being only 9 mm long, against 14 mm for the specimen here figured which is labelled in this collection “cf. Capros aper (L.)” (Pl. 5, fig. 1). It has a height of body which is almost half of its standard length. This specimen differs from Capros aper (Linnaeus, 1758) in having both shorter spines in the first dorsal fin and longer ones in the anal fin. Additionallly, its operculum is wider when compared to the narrow operculum of Capros aper so that this specimen cannot be assigned to the genus Capros Lacepède, 1803.

A second juvenile percoid fish was collected by Sturani (PU 12473; Pl. 5, fig. 2). It has also a rather thick-set body as its body height reaches 4 mm for a standard length of 10 mm. It is mainly characterized by its convex skull roof outline. The length of the spines of its dorsal fin is clearly shorter than that which can be expected for the genus Capros.

A third specimen (PU 12474; Pl. 5, fig. 3) strikingly differs from the preceding ones. It has a standard length of 9 mm. This juvenile fish cannot be assigned to the genus Capros as it has an elongate body, which has a maximum height included four times in standard length, and also dorsal fin spines which are quite shorter, as well as an anal spine which is quite smaller than those of Capros aper.

Family CaranGidae Rafinesque, 1815Genus trachurus Rafinesque, 1810

trachurus trachurus (Linnaeus, 1758)

discussion - this species is only represented by a small specimen which is preserved in part and counterpart (PU 124471/1 and /2). It was described and figured by Sturani & Sampò (1973, pl. II, fig. 1). Its standard length does not exceed 40.5 mm for a maximum depth of body of 11.5



Fig. 1 - Syngnathus albyi Sauvage. Left operculum. Specimen MRSNP 35/107b.Fig. 2 - Lepidopus sp. Right premaxillary deprived of its long fangs. Specimen PU 17808 (Sturani’s collection).Fig. 3 - Lepidopus proargenteus Arambourg. Head of specimen MRSNP 35/109.Fig. 4 - Lepidopus proargenteus Arambourg. Caudal fin of specimen MRSNP 35/109.


mm. Although this specimen is still rather juvenile, a series of characteristic scutes is present along the anterior part of the lateral sensory line in the upper part of the abdominal region.

Family SCombridae Rafinesque, 1815Genus Sarda Cuvier, 1829

Sarda sp.(Pl. 5, fig. 4)

discussion - Two small specimens collected in 1981: MRSNP 35/119a+b (Pl. 5, fig. 4) and 35/120 a+b, the standard length of which is only 42 and 44 mm, bear witness of the occurrence of this species at Pecetto di Valenza. Their body is elongate, the maximum height of which is included five to six times in standard length. The vertebral column comprises at least 36 vertebrae, 19 of which are postabdominal. The vertebral centra bear long neurapophyses and haemapophyses. the thin pleural ribs are about 15 pairs; the posterior ones articulate with vertebral parapophyses, the length of which increases backwards.

The caudal fin is deeply forked; it is supported by three vertebral centra which are quite shorter than the preceding ones. the posterior triangular centrum supports two triangular hypural plates which are not yet fused together as in adults.

Genus Sarda Cuvier, 1829?

Sarda? sp.(Pl. 5, fig. 5)

discussion - The posterior part of a rather large fish indicates the occurrence of another scombrid fish (MRSNP 35/12; Pl. 5, fig. 5) at Pecetto di Valenza. It shows the posterior part of the abdominal region, especially the posterior pleural ribs and a rather well preserved postabdominal region which is composed of 19 vertebrae. Among them, 16 have elongate centra which are bearing long arched neural and haemal apophyses. Posteriorly, the caudal axial skeleton includes two shortened centra bearing rather strong neural and haemal apophyses and a triangular terminal centrum which is fused with a very wide triangular hypural plate in front of which the

parhypural articulates with the terminal centrum, whereas, dorsally, one long epural is present. The caudal fin is not preserved.

The first dorsal fin is missing, except for its posterior pterygiophores. The posterior dorsal fin is imperfectly preserved: two unbranched rays are present in front of the fin; behind them, the number of branched rays was of about six. The endoskeleton was apparently composed of seven pterygiophores. At least five or six - and possibly up to eight - pinnules were present behind the posterior dorsal fin; they articulate with rather strong pterygiophores.

The anal fin, which was rather small, begins behind the posterior dorsal fin. Although it is poorly preserved, it seems to have been supported by at least six pterygiophores. At least five or six - and possibly up to seven - pinnules were present behind it. they are supported by robust pterygiophores similar to those supporting the dorsal pinnules.

taxonomical interpretation - The lack of the anterior part of the body, especially of the head and of the first dorsal fin makes difficult a precise taxonomical assessment of this fossil. However, the relative position of the second dorsal fin and of the anal fin and the probable number of pinnules behind them (higher than five) show that it does not belong to the genus Scomber Linnaeus. on the contrary, both characters agree with those of the genus Sarda Cuvier.

Family triChiuridae Rafinesque, 1810Genus Lepidopus Gouan, 1870

Lepidopus proargenteus Arambourg, 1927(Fig. 7; Pl. 4, figs. 2-4; Pl. 6, fig. 2)

discussion - Sturani & Sampò (1973) noted that eight specimens of Lepidopus had been first collected at Pecetto di Valenza: six were assigned to the species L. proargenteus and two to L. albyi. In fact, Sturani’s collection really includes 11 more or less incomplete specimens and three isolated premaxillaries. Additionally, six specimens were found in 1981 during the excavations carried out by Giulio Pavia and Mario Macagno.

Although no diagnostic character is visible on it, except its size, as its height of body measures 38 mm, a body fragment was figured by Sturani & Sampò (1973, Tav. II, fig. 4) as L. proargenteus (PU 12356). One of the



Fig. 1 - Percoidei indet. Specimen PU 12355/1 (Sturani’s collection). This specimen was wrongly considered by Sturani as belonging to the genus Capros).

Fig. 2 - Percoidei indet. Specimen PU 12473 (Sturani’s collection).Fig. 3 - Percoidei indet. Specimen PU 12474 (Sturani’s collection).Fig. 4 - Sarda sp. Specimen MRSNP 25/119a.Fig. 5 - Sarda? sp. Specimen MRSNP 35/123.


premaxillaries (PU 17808) was figured later by Landini & Sorbini (1980). This premaxillary (Pl. 4, fig. 2), which is lacking its two long fangs, is exposed by its lateral surface. Its oral edge was bearing about thirty acute teeth of moderate size.

Among the material excavated in 1981, only three (out of eight) specimens can be determined at the species level. All belong to the species Lepidopus proargenteus.

One of them (MRSNP 109; Pl. 4, figs. 3-4; Pl. 6, fig. 2) is a complete specimen reaching 695 mm in standard length with a height of body measuring 30 mm. Its vertebral column consists of 145 vertebrae: 45 abdominal - against 35-36 in Lepidopus albyi according to Arambourg (1925) - and 100 postabdominal. The head shows the premaxillary which is provided with two strong fangs (Fig. 7), the dentary, the oral edge of which bears a series of sharp teeth of moderate size. The operculum has undergone a 90° rotation. Its posterior outline is lacerated. the small caudal fin (Pl. 4, fig. 4) seems to have consisted of about six rays and was apparently paddle shaped. This unusual morphology of the caudal fin suggests that this species was possibly intermediate between the other species of Lepidopus which have a forked caudal fin composed of 15 furcated principal rays and the recent apodous genus trichiurus Linnaeus. Although the dorsal fin is not totally preserved, it seems to have been composed of about 138 rays, as indicated by the pterygiophores supporting the missing rays. The composition of the anal fin is unknown as it is partly destroyed.

The second incomplete large specimen (MPSNP 114/1 and /2) lacks the caudal region. According to the size of its head, its estimated standard length reached about 880 mm.

the third specimen corresponds to the head and the forepart of the abdominal region of a very large fish. According to the size of its head which is 150 mm long, its standard length may be estimated about 1250 mm. Its premaxillary bears a very large fang having a small notch on its posterior edge (Fig. 7).

Lepidopus albyi (Sauvage, 1870)

discussion - The occurrence at Pecetto di Valenza of a second species of the genus Lepidopus is indicated by specimen PU 12366, in which are preserved the remains of a rather small head with a premaxillary bearing a fang, the posterior edge of which is smooth, without notch.

Lepidopus sp.

discussion - Except for the five specimens described above, all the other specimens of Lepidopus found at

Pecetto di Valenza cannot be determined at the species level. The fact that many of them are rather small or moderate in size may suggest that they generally belong to Lepidopus albyi, although there are necessarily among them young representatives of Lepidopus proargenteus.

Family bothidae regan, 1910Genus Arnoglossus Bleeker, 1862

Arnoglossus sauvagei (capellini, 1878)

discussion - The unique specimen of Heterosomata (PU 12374) found by Sturani at Pecetto di Valenza is a juvenile (18.5 mm in standard length) which was wrongly described and figured by Sturani & Sampò (1973, Tav. II, fig. 6) as Microchirus abropteryx (Sauvage). In fact, this specimen has a vertebral column which is composed of about 36 vertebrae, 27 or 28 of which are postabdominal, whereas Microchirus abropteryx has only 27 vertebrae: 9 abdominal and 18 postabdominal.

Family Soleidae norman, 1931Genus Solea Quensel, 1806

Solea cf. solea (Linnaeus, 1758)

discussion - Landini (1982) described as Solea cf. vulgaris (Quensel) a specimen having a standard length of 73 mm, which had been collected at Pecetto di Valenza by the late Mario Macagno. It is an elongate fish bearing the eyes on the right side, having a standard length of 73

Fig. 7 - Lepidopus proargenteus Arambourg. Fang borne by the premaxillary of specimen MRSNP 35/113.



Fig. 1 - Syngnathus albyi Sauvage. Specimen MRSNP 35/102.Fig. 2 - Lepidopus proargenteus Arambourg. Specimen MRSNP 35/109.Fig. 3 - Archaeotetraodon bannikovi Carnevale & Tyler. Specimen MRSNP 35/125.


mm. Its maximum height of body is included three times in the standard length. The vertebral column includes 42 vertebrae: 8 abdominal and 34 postabdominal. There are about 70 rays in the dorsal fin and 62 in the anal fin.

The composition of the vertebral column and of the dorsal and anal fins of this specimen support its attribution to the genus Solea and the existence of a direct relationship with the recent species Solea solea, from which it differs only by the composition of its dorsal fin which seems to have several rays less than the recent species.

Family tetraodontidae Bonaparte, 1832Genus Archaeotetraodon Tyler & Bannikov, 1994

Archaeotetraodon bannikovi Carnevale & Tyler, 2010(Figs. 8-10; Pl. 6, fig. 3)

discussion - The family Tetraodontidae is represented at Pecetto di Valenza by a unique rather large specimen (MRSNP 35/125), the standard length of which reaches about 345 mm. This specimen has recently been described by Carnevale & Tyler (2010) who designated it as the holotype of a new species: Archaeotetraodon bannikovi. For this reason, we give only here a short description of this specimen (MRSNP 35/125) which was collected in 1981.

the head, which is partly disarticulated, shows the ventral surface of the neurocranium on which the parasphenoid is preserved. The premaxillary is present in front of the neurocranium. It bears about ten teeth which are distributed in two main rows whereas one additional tooth is present ventrally (Fig. 8). The symphysal edge of

the premaxillary is indented for allowing the articulation with the symmetrical premaxillary. About six compressed, leaf-like teeth are present on the dentary. A triangular operculum is fossilized at some distance above the neurocranium.

The vertebral column is composed of about 20 vertebrae having rather robust and elongated centra. The third and the fourth centra bear triangular neurapophyses which are flattened, whereas the following neurapophyses are not.

Fig. 8 - Archaeotetraodon bannikovi Carnevale & Tyler. Toothed premaxillary of specimen MRSNP 35/125.

Fig. 9 - Archaeotetraodon bannikovi Carnevale & Tyler. Caudal axial skeleton of specimen MRSNP 35/125. Hy 3+4: upper hypural plate; PU 1+U 1+Hy 1+2: uro-terminal complex fused with the lower hypural plate; PU 2: first free preural centrum.

Fig. 10 - Archaeotetraodon bannikovi Carnevale & Tyler. Bifurcated spinules borne by the scales of specimen MRSNP 35/125.

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Fig. 11 - Stratigraphical interpretation of the diatomitic sediments of Pecetto di Valenza taking into account the ages provided by three different micropalaeontological studies.

The caudal fin, which is paddle shaped, is composed of about 11 main rays, nine of which are furcated. Its length equals about one quarter of standard length. It is supported by a remarkably specialized posterior centrum (PU 1+U 1) which is fused with the lower hypural plate (Hy 1+2), whereas an upper hypural plate (Hy 3+4) articulates with it (Fig. 9).

The dorsal and anal fins, which are more or less opposed, are situated near the middle of the body. Their composition is unknown. The first pterygiophore of the dorsal fin points horizontally forwards.

The body is covered with many bifurcated spinules which are well preserved in front of the dorsal (Fig. 10) and anal fins.

concLuSIon

The micropalaeontological study of the fossiliferous sediments from Pecetto di Valenza has shown that no

real agreement exists between the results obtained with diatoms and calcareous nannoplankton which clearly indicate a Tortonian age, and those deduced from the foraminifera which suggest a Lower Messinian age (Fig. 11). This discrepancy cannot hitherto be explained.

The separate study of the two collections made first by Sturani and then, in 1981, by Pavia has evidenced small differences in the composition of the collected material (Tab. 1; Fig. 12).

The most important difference concerns the percentage of myctophids: 61.0%, including 51.7% of Myctophum licatae in the first one, against 46.8% and only 33.8% of Myctophum licatae in the second one. on the contrary, Alosa elongata is less abundant (15.3%) in Sturani’s collection than in the material collected in 1981 (25.0%). It should also be noted that Lepidopus remains are more abundant in Sturani’s collection (9.3%) than in the newer material (6.5%) (Fig. 12).

These small differences suggest that the excavations did not take place exactly in the same part of the diatomitic series outcropping near Pecetto di Valenza (as suggested by the fact that, according to Sturani, at the place first excavated, the fossiliferous level was only three metres

Fig. 12 - Comparison of the fish associations from Pecetto di Valenza successively collected by Sturani and Pavia. a: Sturani’s excavations; b: Pavia’s excavations (1981).



thick, although the diatomitic series is obviously quite thicker).

Considering the bulk of material collected during both excavations, it is possible to compare the fish fauna from Pecetto di Valenza with those which were recently described in the Upper Miocene of the vicinity of Alba (Gaudant et al., 2007, 2008). A great similarity exists between these three fish faunas (Fig. 13), as the myctophids and especially those belonging to the species

Myctophum licatae are predominant in them: 42.6% of the collected material at Pecetto di Valenza, 43.4% in the Tortonian of the Tanaro River and 40.0% in the pre-evaporitic Messinian of Roddi, while the percentage of myctophids reaches 53.7% at Pecetto di Valenza, against 51.8% in the Tanaro River and 45.0% at Roddi. Additionally, the second most abundant species is Alosa elongata, with more than 20.0% in these three localities: 20.2% at Pecetto di Valenza, 22.9% in the Tortonian of

Fig. 13 - Comparison of the global fish fauna from Pecetto di Valenza with those from the Tortonian of the Tanaro River and the pre-evaporitic Messinian of Roddi. a: Tanaro River (Tortonian); b: Pecetto di Valenza; c: Roddi (Messinian).

223

the Tanaro River and 20.7% at Roddi. The third most important component of the fish fauna from Pecetto di Valenza is the genus Lepidopus, represented by two species which, together, reach 7.9% of the collected material, to be compared with 6.0% observed in the Tortonian of the Tanaro River.

If we consider now the standard length of the fishes, another striking similarity also exists between the three localities (Fig. 14). At Pecetto di Valenza, the species

Alosa elongata ranges from 69.5 to 284 mm, with a majority of specimens between 100 and 165 mm. this may be compared to the situation known in the Tortonian of the Tanaro River in which we have observed specimens ranging from 125 to 260, and even 282 mm and in the pre-evaporitic of Roddi: specimens having a standard length ranging from 105 to 135 mm, a majority of specimens being included between 105 and 135 mm. taking into consideration the Myctophum licatae from

Fig. 14 - Histogram of measured or estimated standard lengths of the teleostean fishes collected at Pecetto di Valenza.



Pecetto di Valenza, their standard length ranges from 10.5 to 61.5 mm, the majority of them being situated between 10 and 50 mm. This situation is to be compared with those observed in the Tortonian of the Tanaro River: standard length ranging from 34.5 to 118 mm and highest frequence between 30 and 55 mm, and in the pre-evaporitic Messinian of Roddi: standard length from 21 to 72 mm, with the highest frequence between 40 and 65 mm. Consequently, the main difference between these three populations of Myctophum licatae is the slightly smaller size observed at Pecetto di Valenza in which the very young specimens are more abundant.

To conclude, as already emphasized by Gaudant & Cavallo (2008), the main difference existing between the fish fauna from Pecetto di Valenza and the two other ones from the marine Upper Miocene of Piedmont depends mainly on the nature of the fossiliferous sediments as, at Pecetto di Valenza, the fish fauna is preserved in a diatomitic sediment including upwelling markers instead of being preserved in more or less marly sediments totally devoid of diatoms which have yielded the fish fauna from the Tortonian of the Tanaro River and from the pre-evaporitic Messinian of Roddi.

ACkNOWLEDGEMENTS

The first author is greatly indebted to Franca Campanino Sturani and daniele ormezzano (Museo regionale di Storia naturale del Piemonte, Torino) for assistance during the preparation of the present study and for the loan of the figured specimens. He also does not forget that a first attempt to solve the stratigraphical question had already been made, more than ten years ago, in collaboration with Maria romeo and Agata Di Stefano (Università di Catania). John Barron (US Geological Survey) is warmly acknowledged for providing precise information concerning the stratigraphical distribution of diatom species identified at Pecetto di Valenza, and Jim Tyler (National Museum of Natural History, Washington) for his help in determining the tetraodontid fish.

Joël Dyon and Denis Serrette (Paris) respectively prepared the figures and photographed the fossils.

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Manuscript received 4 March 2010Revised manuscript accepted 18 October 2010


the upper miocene fossil fish locality of pecetto di...

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