The Vallès-Penedès Miocene mammal record comprises more than 300 sites ranging from the Late Ramblian to the Middle Turolian, that is from about 19.6 Ma (Larrasoaña et al., 2006) to 7.4/6.8 Ma (Agustí et al., 2001 and Hilgen et al., 2012). However, sampling is uneven and most of the sites correspond to the late Aragonian and early Vallesian. Regarding the localities, approximately two thirds of them have only small mammal remains, but a remarkable number has provided both small and large mammals. A list of the main sites and fossiliferous sections is given in Table 1. Finally, there are a few localities from which mostly large mammal remains have been recovered. Most of the old collections were assembled by the means of surface collecting as a result of quarrying activity at brickyards, where the workers often found mammal fossils during manual digging. The use of systematic collecting techniques increased since the late 1950s and early 1960s. These include planned excavations as well as systematic screen-washing of sediment samples of the major sites. During the early 1980s screen-washing techniques were improved, with the introduction of sieving equipment capable of processing huge sediment samples (Daams and Freudenthal, 1988). Therefore, larger micromammal samples, comprising between fifty to a few hundreds of individuals, could be gathered for many known sites. During the 1990s and the 2000s, most of the mammal sites known to date were discovered as a result of emergency campaigns coinciding with major construction porjects. Macrommamal remains were mostly collected after systematic excavation, whereas screen-washing was used for the micromammals. Thus, most of the material has been obtained using standardized collecting methods. The material is kept in the collections of the Institut Català de Paleontologia Miquel Crusafont (ICP) at Sabadell, except for part of the old collections, which are curated in the Geology Museum of the Barcelona Seminary and in the Museum of Natural Sciences of Barcelona.

Magnetostratigraphic sampling in the Vallès-Penedès Basin started during the mid 1990s (Garcés et al., 1996) and focused on the Vallesian successions. More recent studies have complemented these data with those from long sections covering the Late Aragonian and its transition to the Vallesian (Alba et al., 2012a and Moyà-Solà et al., 2009). The sequences studied for magnetostratigraphy include four main sections: Abocador de Can Mata, Les Fonts, Montagut and Viladecavalls, plus a few shorter ones (Fig. 4). These sequences contain abundant mudstone beds, which allowed a tight sampling resolution of 1–2 m/site. Routine stepwise demagnetization of the natural remanence magnetization revealed the presence of a stable magnetization carried by iron oxides such as magnetite and hematite. Since magnetostratigraphy relies on the demonstrably primary character of the rock magnetization, a number of stability tests (Opdyke and Channel, 1996) were performed. In the Vallès-Penedès sequences, the relative uniformity of bedding dip attitudes made the fold test insignificant, but a northerly directed mean direction after tilt correction suggests a pre-folding magnetization. A positive conglomerate test further supported a primary, synsedimentary origin. More significantly, magnetostratigraphic results could be cross-checked with biostratigraphy along multiple composite sections of Montagut, Les Fonts, Terrassa and Viladecavalls (Fig. 4), thus indicating that the retrieved magnetic zonation bears chronostratigraphic significance.

Time series diversity analyses require a great accuracy in the dating of individual sites as well as a well-resolved taxonomy (see Badgley et al., this issue). Considering the quality of our data, diversity analyses can only be performed for the late Aragonian and early Vallesian, for which most of the sites have associated bio- and magnetostratigraphical data of high quality. Regarding the taxonomic data, the quality of the record is not the same for all mammal groups. Small mammals, and in particular the orders Rodentia and Eulipotyphla, are more abundant and have a more continuous record than large mammals. Furthermore, they have been thoroughly reviewed and genus-level identifications are available (Casanovas-Vilar et al., research in progress). Between the late Aragonian (12.6 Ma) and the end of the Vallesian (9.0 Ma) these orders are represented by more than 20,000 specimens from nearly 200 different sites. Our calculations are carried out at the genus level, excluding all the material that could not be identified to this taxonomic rank.

The calculation of sampling probability and generic richness requires the use of quantitative data. In this regard, we used the maximum number of individuals of each taxon, since this information is routinely written down in our collection inventories. Sampling probability was calculated using the method devised by Barry et al. (2002) (see also Badgley et al. and Flynn et al., this issue) as modified by Van der Meulen et al. (2005) and Van Dam et al. (2006). This method considers the probability of finding a given taxon based on its abundance and sample size: p = 1 − 1 − q r \[ p=1-{\left(1-q\right)}^{r} \] where q is the relative abundance of the taxon in the interval where it was first (or last) recorded and r is the additional number of specimens sampled. A genus is considered to be absent when the cumulative probability of finding it over preceding or succeeding time intervals is greater than 0.9. Not surprisingly, the inferred range for a given taxon may extend beyond its last observed record and earlier than its first observed record. This is ultimately related to its abundance, so that rare taxa tend to have long inferred ranges unless sample size is large enough to reject that they were present. We used a range-through assumption, so we consider a genus to be continuously present between its first and last appearances. This assumption is in contrast with Van der Meulen et al. (2005) who interpreted discontinuous ranges as local extinctions followed by subsequent migrations. In our case only a few very rare taxa show discontinuous ranges, so we rather attribute their absence to sampling biases. The studied time span (12.6–9.0 Ma) was divided into 0.1 Myr bins, and observed and inferred genera ranges were used to calculate generic richness for each bin (Fig. 7). Considering that the typical extent of time-averaging for terrestrial vertebrate assemblages in fluvial systems and surface accumulations oscillates between 100 and 100,000 years (Behrensmeyer, 1982 and Behrensmeyer et al., 2000), shorter time bins are not recommended. Finally, we have evaluated the effects of sample size in the calculation of these richness measures using the Spearman's rank order correlation test.

The early Miocene successions of the Vallès-Penedès Basin have produced relatively few sites, and many of them, particularly the older ones, are very poor. Crusafont et al. (1955) systematically surveyed this part of the record and found about fifteen mammal-bearing sites, although many of them have since been destroyed (Casanovas-Vilar et al., 2011b). In recent years, some classical sites (such as Costablanca or Molí Calopa) have been surveyed again in order sample microvertebrates, which had been overlooked by earlier researchers. The correlation of these localities is entirely based on biostratigraphy. Magnetostratigraphical studies are now in progress.

The oldest site in the Vallès-Penedès Basin is Turó de les Forques (TFR, Fig. 1 and Fig. 2), which is located in a small outcrop of the Basal Breccia Unit. This site contains scarce macromammal remains and a richer rodent assemblage that includes the cricetid Melissiodon, the eomyid Ligerimys cf. fahlbuschi, the glirid Pseudodryomys ibericus, and scarce remains of the cricetodontine Democricetodon. The first common occurrence of Democricetodon marks the beginning of the Aragonian, but this genus is already recorded in the latest Ramblian, though it is very rare (García-Paredes et al., this issue and Van der Meulen et al., 2012). Therefore, this site is correlated with the late Ramblian zone A, which according to the latest data from the Ebro Basin would range between 19.6 and 16.8–17 Ma (Larrasoaña et al., 2006). The Ramblian is chronologically equivalent to zone MN3 and its upper part corresponds to the so-called “cricetid vacuum” (Daams and Freudenthal, 1989), that is, the time interval between the last occurrence of the old Oligocene cricetids of the genus Eucricetodon and the earliest cricetodontines of the genus Democricetodon. During this time Melissiodon, a peculiar genus showing a unique “honeycomb” molar morphology, is the only cricetid present in western Europe.

The remaining Ramblian sites of the Vallès-Penedès show a similar rodent fauna dominated by the glirid genera Pseudodryomys and Simplomys, as well as eomyids of the genus Ligerimys. Relatively rich Ramblian macromammal faunas are known from Molí Calopa, Costablanca and Sant Andreu de la Barca (MC, CBL and SAB in Fig. 1 and Fig. 2). These include abundant remains of the minute artiodactyl Cainotherium miocaenicum, although the cervid Procervulus dichotomus is also common (Casanovas-Vilar et al., 2011a and Casanovas-Vilar et al., 2011b). The equid Anchitherium and the felid Styriofelis are present at various sites, whereas the first gomphotheres (Gomphotherium) are recorded at Sant Andreu de la Barca (Agustí and Galobart, 1997). Mein (1975a) used the earliest record of proboscideans in Europe to characterize the MN4 zone (16.8/17–16/16.4 Ma), but for Western Europe the first common occurrence of Democricetodon is now used as diagnostic criterium for the base of this zone and the beginning of the Aragonian (Hilgen et al., 2012, Van der Meulen et al., 2011 and Van der Meulen et al., 2012). In the Vallès-Penedès (Sant Andreu de la Barca) and France (Navère; Bulot and Ginsburg, 1993) the record of proboscideans precedes that of Democricetodon, and is therefore placed in the late MN3, with an age ranging from 19.6 to 16.8/17 Ma. This age is congruent with recent dating of the proboscidean dispersal event in Central Europe at ca. 17.5 Ma (Pálfy et al., 2007). However, the appearance of this order in other areas of Eurasia is substantially older, with deinotheres present at the Pakistan Siwaliks at around 23 Ma (Flynn et al., 2013) and an unidentified elephantoid having been reported from the Latest Oligocene of the Bugti Hills (Antoine et al., 2003 and Antoine et al., 2013).

Macroplant remains are abundantly reported from the shallow lacustrine levels of the Costablanca series and offer a detailed picture of the local paleoenvironment surrounding the humid areas (Sanz de Siria Catalán, 1993 and Sanz de Siria Catalán, 2001). The recovered flora points to a tropical to subtropical climate with rainfall seasonality (Sanz de Siria Catalán, 1993 and Sanz de Siria Catalán, 2001). This reconstruction is congruent with the small mammal fauna, which is dominated by glirids with a simple dental pattern that purportedly preferred more arid environments than most of their relatives (Van der Meulen and De Bruijn, 1982). However, the large mammal fauna, which includes basal pecorans (Amphitragulus), cervids (Procervulus) and small browsing equids (Anchitherium), is more consistent with forested environments (Casanovas-Vilar et al., 2011a).

The early Aragonian is chronologically equivalent to the MN4. The sites are located in facies of small lacustrine systems or in distal facies of alluvial fans (Fig. 1 and Fig. 2). Most of the known localities were first reported by Crusafont et al. (1955). The richest sites belong to the Subirats unit, in the Penedès sector, which is defined by an alternation of lutites and carbonates that correspond to shallow lakes and the distal facies of alluvial fans (Agustí and Cabrera, 1980, Cabrera, 1981a and Cabrera, 1981b). These include les Cases de la Valenciana, Can Martí Vell, and more importantly els Casots (LV, CMV and CS, Fig. 1). Els Casots was excavated during the 1990s and has produced a rich collection of micro- and macromammals in a remarkable state of preservation (Casanovas-Vilar et al., 2011c). In the Vallès sector, the early Aragonian sites are located in red lutites corresponding to the distal facies of major fan systems. Some sites, such as les Escletxes del Papiol or Sant Mamet (PA and SM, Fig. 2) are just a few meters below the Langhian marine units. The Vallès sites have mostly micromammals.

The beginning of the Aragonian is marked by the first abundant occurrence of the cricetodontines Democricetodon and, slightly later, Megacricetodon (Daams and Freudenthal, 1988, Daams and Freudenthal, 1989, Daams et al., 1999, García-Paredes et al., this issue and Van der Meulen et al., 2012). These cricetids originated in Asia (Flynn and Wessels, 2013 and Maridet et al., 2011) and soon after their earliest record in Western Europe they became major components of the Aragonian and earliest Vallesian faunas (e.g., Daams et al., 1988). In the Aragonian type area, the Calatayud-Montalbán Basin, the presence of Megacricetodon distinguishes local zones B and C, both covering the early Aragonian (Daams and Freudenthal, 1988, Daams et al., 1999, García-Paredes et al., this issue and Van der Meulen et al., 2012). In the Vallès-Penedès, Democricetodon (D. hispanicus) and Megacricetodon (M. primitivus) coexist in all the studied localities but in Sant Mamet. However, the absence of Megacricetodon may be due to insufficient sampling. Furthermore, the paracricetodontine Eumyarion (E. weinfurteri) is also present in this site (Agustí, 1981), and its first appearance in other Spanish basins is in zone C (Daams and Freudenthal, 1974, García-Paredes et al., this issue, Ruiz-Sánchez et al., 2003 and Van der Meulen et al., 2012). Even though D. hispanicus and M. primitivus dominate the rodent assemblages in most sites, the eomyid Ligerimys ellipticus and the glirids Pseudodryomys ibericus and Simplomys simplicidens are common components as well (Agustí, 1981, Agustí, 1983, Agustí and Llenas, 1993 and Casanovas-Vilar et al., 2011c). None of the known sites in the Vallès-Penedès could be correlated to the lowermost Aragonian (zone B), where characteristically Democricetodon is the only cricetid genus present. Interestingly, the Calatayud-Montalbán local zones could be extended to the Ramblian and Early Aragonian record of the Vallès-Penedès (Casanovas-Vilar et al., 2011a and Casanovas-Vilar et al., 2011b), a situation contrasting with that of the late Aragonian and especially the Vallesian, when the rodent succession shows marked differences between these areas.

Most of our data on the Early Aragonian large mammal faunas of the Vallès-Penedès come from the site of els Casots (Casanovas-Vilar et al., 2011c and references therein). The suid Eurolistriodon, the early bovid Eotragus and the tragulid Dorcatherium appear for the first time (Agustí et al., 1985, Casanovas-Vilar et al., 2011a and Casanovas-Vilar et al., 2011c). At this time, deinotheres are first recorded, being scarcely represented at els Casots and les Escletxes del Papiol. Cainotherium persists, but is rarer than in earlier sites. The suoids (Eurolistriodon, Taucanamo), paleomerycids (Ampelomeryx) and some rhinoceroses (Plesiaceratherium) are common among the large mammal faunas. The most abundant carnivores are the amphicyonids (Amphicyon) and ursids (Hemicyon, Plithocyon).

During the Langhian (15.97–13.65 Ma), great parts of the basin were covered by a shallow sea embayment, so it is not surprising that no mammal sites are correlated to the approximately time-equivalent middle Aragonian, which equals to MN5. However, some portions of the Vallès sector were exposed at that time, so they might potentially yield sites of this age. On the other hand, there are numerous paleobotanical sites around the towns of Martorell and Sant Sadurní d’Anoia. These have produced a rich collection of macroflora, indicating that the environment was slightly more arid than during the Ramblian (Sanz de Siria Catalán, 1993 and Sanz de Siria Catalán, 2001). In addition, palynological samples have been collected from marine sediments close to the small reef systems of Sant Pau d’Ordal, located just a few kilometers to the south of Sant Sadurní d’Anoia (Bessedik and Cabrera, 1985). The pollen assemblage indicates the presence of Avicennia mangroves in the coastline.

The late Aragonian is one of the best represented time intervals in the Vallès-Penedès Basin. Most of our knowledge of this period derives from the study of the intensively-sampled Can Mata composite series at els Hostalets de Pierola (Penedès sector; Fig. 1). This series (Fig. 4) comprises the sections of the Abocador de Can Mata landfill (ACM), the Ecoparc de Can Mata (ECM), and a few nearby classical sites (Can Mata 1 and 3), which together include more than 200 mammal sites that have produced tens of thousands of specimens (Alba et al., 2011). The Can Mata composite series ranges from about 12.5 Ma to 10.6 Ma, the age of the sites being well constrained thanks to a combination of detailed litho-, bio- and magnetostratigraphical data (Fig. 4; Alba et al., 2011, Casanovas-Vilar et al., 2011d and Moyà-Solà et al., 2009). In addition to the Can Mata series, there are a number of other sites that have been correlated to the Late Aragonian. These include the classical Sant Quirze sites (SQ, Fig. 2), Ca n’Almirall and les Conilleres (CAL and CO, Fig. 1; Agustí et al., 1985). The latter two are placed in the upper transitional facies of the Marine and Transitional Unit and in palustrine facies related to fluvial sequences in the Penedès sector. Agustí et al. (1985) reported the presence of the cricetids Cricetodon aff. jotae, Eumyarion medium and Megacricetodon crusafonti, which would indicate a correlation to MN6. However, the fauna has not been studied in detail, so other correlations cannot be ruled out. On the other hand, certain sites that had been traditionally placed in the Late Aragonian, namely Can Missert and Castell de Barberà (CM and CB, Fig. 2), are here correlated to the Early Vallesian because scarce hipparionin remains were identified during a recent review of the collections (Robles et al., 2011 and Rotgers and Alba, 2011).

A high-resolution biozonation for the late Aragonian and Vallesian has been devised on the basis of the rodent fauna (Casanovas-Vilar et al., 2011d and research in progress). The late Aragonian rodent assemblages are characterized by the dominance of the cricetids Hispanomys, Democricetodon and Megacricetodon. Usually, Hispanomys is the most abundant taxon, being represented by several different species during this time interval. This allows defining a long Hispanomys Assemblage Zone that covers the late Aragonian and earliest Vallesian (c. 12.5–10.3 Ma, Fig. 5). The coexistence of different species of Megacricetodon and Democricetodon, as well as the first record of the equid Hippotherium, allow the subdivision of the Hispanomys zone into four subzones (Fig. 5): M. crusafonti + D. larteti Concurrent Range Subzone (?–12.4 Ma); M. crusafonti–D. crusafonti Interval Subzone (12.4–11.9 Ma); D. crusafonti–Hippotherium Interval Subzone (11.9–11.2 Ma); Hippotherium–Cricetulodon hartenbergeri Interval Subzone (11.2–10.3 Ma). The last corresponds to the earliest Vallesian, whereas the previous three correlate to the late Aragonian. Even though the faunal succession is not the same, these subzones can be correlated with the local zones of the Calatayud-Montalbán Basin (Daams et al., 1999). Subzone G2 from Calatayud-Montalbán would be approximately equivalent to the M. crusafonti + D. larteti subzone, whereas the subzone G3 would be equivalent to the M. crusafonti–D. crusafonti and the D. crusafonti–Hippotherium interval subzones in the Vallès-Penedès. Similarly, our zones can be correlated to the MN units, with the three Late Aragonian subzones being equivalent to the MN 7 + 8 (Hilgen et al., 2012). Nevertheless, if one follows the definition of the MN zones of Agustí et al. (2001) or Mein (1999), the older subzone (M. crusafonti + D. larteti) would be equivalent to uppermost part of the MN6.

As explained above, the late Aragonian small mammal faunas are dominated by Hispanomys, Democricetodon and Megacricetodon. The paracricetodontine Eumyarion may be very common at certain sites, such as ACM/BCV1 (see Fig. 4). The glirids are diverse though not abundant and include mostly purported forest-dwelling genera (Bransatoglis, Muscardinus, Glirudinus, Myoglis). The small eomyids Keramidomys and Eomyops as well as the flying squirrels (Albanensia, Miopetaurista) are first recorded in the M. crusafonti + D. larteti subzone, ca. 12.5 Ma. Castorids (Chalicomys) are first recorded ca. 11.9 Ma, but are very rare. The hypsodont cricetid Anomalomys, appears for the first time at ca. 11.8 Ma. The eulipotyphlan faunas are diverse (e.g., Furió et al., 2011 and Furió et al., 2015) and include talpids (Desmanella, Talpa), dimylids (Plesiodimylus), heterosoricids (Dinosorex), abundant erinaceids (Galerix, Parasorex) and crocidosoricine soricids.

The large mammal faunas are also diverse (Alba et al., 2011). The megaherbivores include two different genera of proboscideans (Gomphotherium, Deinotherium), rare chalicotheres (Anisodon) and diverse rhinos (Alicornops, Hoploaceratherium, Lartetotherium). The suoids (Albanohyus, Conohyus, Listriodon, Propotamochoerus) are also diverse and common, whereas the cervid Euprox may be common at some sites. There is a remarkable diversity of carnivorans, including mustelids, hyaenids, felids (Pseudaelurus, Styriofelis) and false sabertooths (the barbourofelid Albanosmilus). The suid Listriodon splendens, the small and short-legged rhino Alicornops and specially the moschid Micromeryx are the most abundant large mammals in the Can Mata composite series. Hominoids (Anoiapithecus brevirostris) are first recorded at around 12.3–12.4 Ma (Alba et al., 2013). This group shows a remarkable diversity around 11.9–12 Ma (M. crusafonti–D. crusafonti Interval Subzone), being represented by the genera Dryopithecus, Anoiapithecus and Pierolapithecus (Casanovas-Vilar et al., 2011d). Pliopithecoids first occur slightly later, at around 12 Ma (Alba et al., 2012b), but are mostly recorded between 11.8–11.7 Ma (D. crusafonti–Hippotherium Interval Subzone), being represented by the genus Pliopithecus. The cervid Euprox furcatus, a common component of the fauna, is first recorded during the M. crusafonti + D. larteti subzone. Other ruminant groups, such as the bovids and the tragulids, are generally rare. Amongst the bovids, Miotragocerus and Tethytragus first occur during the D. crusafonti–Hippotherium Interval Subzone. Tethytragus, an abundant genus in the inner Iberian basins, is restricted to this zone, being represented by scarce remains only.

Overall, the late Aragonian faunas of the Vallès-Penedès Basin stand out by their high diversity due to the presence of a number of taxa that are extremely rare or not recorded at all in other Iberian Basins (Agustí, 1989, Casanovas-Vilar and Agustí, 2007, Casanovas-Vilar et al., 2008 and DeMiguel et al., 2011). These taxa are traditionally recognized as forest dwellers, shared by the Vallès-Penedès and other European regions such as France and Germany, but absent from inner Spain. Amongst the small mammals these include certain eulipotyphlans (dimylids, talpids), arboreal glirids, pteromyinins, eomyids, and certain cricetids such as Eumyarion and Anomalomys. The large mammal faunas are congruent with the occurrence of more forested environments, since certain taxa such as hominoids, pliopithecoids or chalicotheres are not recorded from elsewhere in the Iberian Peninsula. Others, such as suoids and rhinocerotids, are more abundant and usually more diverse in the Catalan basins. Unfortunately, there are no time-equivalent paleobotanical data that could provide a more complete picture of the Late Aragonian paleoenvironments in the basin.

The Vallesian mammal successions have been the subject of multiple reviews, given that the Vallès-Penedès is the type area for this mammal age (Agustí and Moyà-Solà, 1990, Agustí et al., 1985, Agustí et al., 1997, Casanovas-Vilar et al., 2011a, Casanovas-Vilar et al., 2011d, Moyà-Solà and Agustí, 1987 and Moyà-Solà and Agustí, 1989). Most of the Vallesian sites are placed near the towns of Sabadell and Terrassa, in the Vallès sector of the basin (Fig. 2), and have associated magnetostratigraphical data (Fig. 4; Agustí et al., 1997 and Garcés et al., 1996).

Crusafont Pairó (1950) defined the Vallesian on the basis of the coexistence of the first hipparionin horses with faunal elements that were characteristic of the forest faunas of the Middle Miocene, such as certain rhinos, cervids, suoids and chalicotheres. Previously, hipparionins were thought to be characteristic of the so-called Pikermian faunas, after the Turolian site of Pikermi, near Athens (Greece). The Pikermian faunas are dominated by open country herbivores, such as antelopes, giraffes and horses, whereas forest elements, such as deer, are rare (Bernor et al., 1996, Eronen et al., 2009 and Solounias et al., 1999). Such faunas represent a rather uniform mammal community from the standpoint of their ecological characteristics, not necessaritly at the taxonomic level of genera and species. The Pikermian fauna expanded its range into Western Europe during the Turolian (Bernor, 1983, Bernor, 1984 and Eronen et al., 2009). However, Crusafont Pairó (1950) showed that some ‘Pikermian’ taxa such as the earliest hipparionins dispersed earlier. Currently this dispersal is placed within chron C5r.1n in the Vallès-Penedès Basin, with an estimated age of 11.2 Ma (Garcés et al., 1996 and Garcés et al., 1997; dates recalculated taking into account the latest version of the GPTS after Ogg, 2012). This age is not inconsistent with the record of the Calatayud-Montalbán Basin, where the entry could be placed between 11.2 and 10.8 Ma (Garcés et al., 2003, García-Paredes et al., this issue and Van Dam et al., 2014). It is also congruent with the data from Central Europe (Bernor et al., 1988, Daxner-Höck et al., 2015 and Woodburne, 2009), but it is somewhat older than age estimates for this event in other areas (Sinap Formation, Siwaliks), which range from 10.8 to 10.3 Ma (Barry and Flynn, 1989, Barry et al., 1982, Barry et al., 1985, Barry et al., 2002, Flynn et al., 2013 and Kappelman et al., 2003). The oldest occurrence of hipparionins (Hippotherium) is recorded at the lowermost part of the Montagut composite section (Fig. 4). However, the Aragonian/Vallesian transition is documented in the Can Mata composite series, the sites belonging to the ECM section and the classical locality of Can Mata 3 (CM3) being correlated to the Vallesian (Fig. 4). CM3 has numerous hipparionin remains, which would be slightly younger than the ones of the Montagut section. On the other hand, these equids are not recorded in any of the ECM sites. The earliest Vallesian rodent faunas cannot be distinguished from those of the Latest Aragonian and are placed within the Hispanomys Assemblage Zone (Fig. 5). Only the presence of the equid Hippotherium confirms their Vallesian age. The Hippotherium–Cricetulodon hartenbergeri Interval Subzone defines the Earliest Vallesian. In some rodent faunas, the cricetodontine Megacricetodon ibericus may be extremely abundant, such as Creu Conill 22 or Can Feliu (CCN22, CF, Fig. 2).

The rest of the Vallesian subzones are defined on the basis of the evolution of the cricetine genera Cricetulodon and Rotundomys. The species present are members of a well-known anagenetic lineage (C. hartenbergeri–C. sabadellensis–R. montisrotundi–R. bressanus), characterized by its increasing hypsodonty coupled with a simplification of the molar pattern into a continuous sigmoidal crest (Freudenthal, 1967, Freudenthal et al., 1998 and Mein, 1975b). The Cricetulodon Range Zone (Fig. 5) covers most of the early Vallesian (MN9) and the beginning of the late Vallesian (MN10). This zone is divided into three subzones depending on the Cricetulodon species present: C. hartenbergeri Range Subzone (10.3–10 Ma); C. hartenbergeri–Progonomys hispanicus Interval Subzone (10–9.7 Ma); and the short-lasting C. sabadellensis + P. hispanicus Concurrent Range Subzone (9.7–9.6 Ma). Cricetulodon is the most common element in these subzones and it may define up to 70% of the recovered remains. The genera Democricetodon and Megacricetodon are rare and only represented by the small-sized species. The castorids (Chalicomys, Euroxenomys) and the paracricetodontine Eumyarion are common at certain sites such as Can Llobateres 1 (CL1, Fig. 2). The micromammal faunas of this subzone are diverse in forest elements, particularly glirids. Eulipotyphlans reach their highest diversity, with at least three genera of erinaceids, two genera of dimylids and talpids, and four of soricids (Van den Hoek Ostende and Furió, 2005). The hitherto persisting heterosoricid Dinosorex is still a common element, but suddenly disappears from the micromammal assemblage at the very beginning of the Vallesian (Furió et al., 2015). The first occurrence of murids in Western Europe defines the boundary between Early and Late Vallesian, or between MN9 and MN10 (Agustí et al., 1997, Agustí et al., 2001 and Hilgen et al., 2012). Progonomys hispanicus is the earliest murid in the Vallès-Penedès, being recorded at several sites in the uppermost part of chron C4Ar.3r (Fig. 4 and Fig. 5), with an estimated age of 9.7 Ma. This rodent family evolved in the Middle Miocene in Pakistan (Jacobs, 1977), while the genus Progonomys first appeared in that area around 12 Ma (Barry and Flynn, 1989, Barry et al., 1982, Barry et al., 2002, Flynn et al., 1995, Flynn et al., 2013 and Wessels, 2009). Updated stratigraphic correlations attained in the Calatayud-Montalbán Basin (García-Paredes et al., this issue and Van Dam et al., 2014) show a very rare presence of Progonomys during the Early Vallesian, at 10.4 Ma, and a common occurrence of this form after 10.0–9.9 Ma. In Turkey, its first record is slightly older, at 10.1 Ma (Kappelman et al., 2003). In our study area, the dispersal of Progonomys coincides with the first appearance of Rotundomys (R. freirensis), although C. sabadellensis is still the dominant rodent in most assemblages. At the same time, a number of taxa are no longer recorded, including the cricetids Democricetodon, Megacricetodon, Eumyarion and the glirids Microdyromys, Glirudinus, Bransatoglis and Muscardinus vallesiensis. Castorids and pteromyines become rarer. This set of local extinctions is part of the Vallesian Crisis (see below).

Regarding the large mammals, the early Vallesian faunas retain large numbers of Late Aragonian components, so that the immigration of Hippotherium did not coincide with any noticeable extinction event (Agustí et al., 1997). Giraffids, the felid Machairodus and the bovid Austroportax immigrated at the same time (Casanovas-Vilar et al., 2011a; Fig. 5). The long-ranging felid Pseudaelurus is last recorded within the C. hartenbergeri subzone. The hominoid Hispanopithecus is recorded at several sites from the Cricetulodon zone (Casanovas-Vilar et al., 2011d). Overall, the Early Vallesian faunas are extremely diverse, including a high diversity of medium to large-sized herbivores and carnivoran species (Agustí et al., 1997, Agustí et al., 2001 and Casanovas-Vilar et al., 2011a). Bovids became more diverse and abundant. This assemblage is very similar to that of contemporaneous sites from Central Europe (Casanovas-Vilar et al., 2008 and Casanovas-Vilar et al., 2010), such as Rudabánya in Hungary (Bernor et al., 2005), which on the other hand has also produced great ape remains. Finally, the Early/Late Vallesian transition witnessed the extinction of several large mammal taxa of Middle Miocene origin in the context of the Vallesian Crisis (see below). These include the barbourofelid and amphycionid carnivorans, the suids Listriodon and Parachleuastochoerus, and the bovid Miotragocerus.

Even though the murids are continuously present in the Vallès-Penedès Basin, they remain usually rare components of the mammal faunas. This contrasts with the late Vallesian assemblages of other Iberian basins, such as the Teruel Basin, where murids are dominant and define the basis for local biostratigraphy (Van Dam, 1997 and Van Dam et al., 2001). By contrast, the genus Rotundomys is the most abundant component of the faunas in the Vallès-Penedès, defining the Rotundomys Abundance Zone that covers most of the late Vallesian (Fig. 5). This is divided into two subzones according to the member of the anagenetic lineage present: R. montisrotundi Lineage Subzone (9.6–9.4 Ma) and the R. bressanus Lineage Subzone (9.4–8.9 Ma). As the upper boundary for this zone we take the Vallesian/Turolian age boundary in the Teruel Basin (Krijgsman et al., 1996 and Van Dam et al., 2001), since it is not recorded in any of the magnetostratigraphical sections of the Vallès-Penedès. The rodent faunas are less diverse than during the early Vallesian, although a number of forest elements are present in low numbers (Agustí et al., 1997, Agustí et al., 1999, Casanovas-Vilar et al., 2011a and Casanovas-Vilar et al., 2014). In the R. montisrotundi subzone, Progonomys hispanicus is the only murid species present, whereas in the R. bressanus subzone the murid assemblage is enriched with the appearance of P. cathalai and P. woelferi as well as the genera Parapodemus and Huerzelerimys. Rotundomys montisrotundi coexists for some time with its putative descendant, R. bressanus. The large mammal faunas record a number of new eastern immigrants, particularly during the R. bressanus subzone (Agustí et al., 1997, Casanovas-Vilar et al., 2011a and Casanovas-Vilar et al., 2011d). These include the suids Schizoporcus and Microstonyx, the equid Cremohipparion and the bovid Tragoportax, which will later become major components of the Turolian faunas. Amongst the carnivorans, the hyaenid Adcrocuta is first recorded within the R. montisrotundi subzone, whereas the ursid Indarctos is last recorded at the same time. Finally, hominoid primates (Hispanopithecus) are last recorded within this subzone, at the site of La Tarumba 1 (LTR1, Fig. 2), which has an estimated age of about 9.6 Ma (Casanovas-Vilar et al., 2011d). Pliopithecoids survived into the R. bressanus subzone, being last recorded at 9.1 Ma at Torrent de Febulines (TF, Fig. 2; Moyà-Solà et al., 2001).

The Vallesian biozonation of the Vallès-Penedès can be recognized in other Catalan basins, such as La Seu d’Urgell or the Empordà basins (Casanovas-Vilar et al., 2011b). However, it is different from that in other areas of Spain, such as the Calatayud-Montalbán Basin (Daams and Freudenthal, 1988 and Daams et al., 1999) or the Teruel basins (Van Dam et al., 2001 and Van de Weerd, 1976). While the order and timing of the main bioevents, such as the first record of Cricetulodon and Progonomys, are roughly the same, the major components of the faunas that are the basis for the local biozonations differ. For example, Rotundomys is not recorded in Teruel, and in the Vallès-Penedès the murids are too rare to be considered for the definition of local biozones. Casanovas-Vilar and Agustí (2007) emphasized these differences and related them to the occurrence of more humid and forested environments in the Vallès-Penedès, particularly during the Late Vallesian. Such an interpretation is supported by the distribution of other mammal taxa such as certain glirids, the flying squirrels, chalicotheres and hominoid primates, to name just a few examples.

Regarding the Vallesian paleoenvironment, the diverse mammal fauna, rich in forest elements, has been interpreted as indicative of subtropical to warm-temperate humid forest environments (Agustí and Moyà-Solà, 1990, Agustí et al., 1984, Agustí et al., 1999, Casanovas-Vilar and Agustí, 2007 and Morales et al., 1999). Unfortunately, the paleobotanical information of this period is very scarce, and has to be complemented with data from other Catalan basins (Empordà, Cerdanya). These show that the zonal vegetation consisted of a warm-temperate mixed forest defined by evergreen laurels, together with leguminous trees and shrubs as well as a significant proportion of deciduous elements (Sanz de Siria Catalán, 1993 and Sanz de Siria Catalán, 1994). The subtropical taxa would have been mostly restricted to the humid areas in the lowlands (Marmi et al., 2012). The rich Late Vallesian macroflora from Trinxera Sud Autopista 2 near Terrassa (TSA2, Fig. 2) indicates the presence of a warm-temperate mixed forest with up to 40% of deciduous taxa (Agustí et al., 2003).

Only two Turolian sites are well known from the Vallès-Penedès: Ronda Oest de Sabadell A1 in Sabadell and Torrentet de Traginers in Piera (ROS-A1 and TT, Fig. 1 and Fig. 2). However, some fossiliferous areas, particularly around Viladecavalls and Piera, might potentially yield new Turolian sites. Furthermore, the Vallesian/Turolian transition could be recorded at the Ronda Oest de Sabadell succession (Fig. 2), although these faunas and their stratigraphical context have not been studied in detail yet. ROS-A1 has a relatively rich small mammal sample dominated by the murid Huerzelerimys vireti, which would indicate an early Turolian (MN11 or zone K) age (Agustí et al., 2001, Van Dam et al., 2001 and Van Dam et al., 2006). The large mammals are insufficiently known, but the faunas are significantly impoverished with bovids and Hippotherium dominating the assemblage. In contrast, Torrentet de Traginers (also known in the literature as Piera) has produced a rich large mammal fauna that includes more than 2700 specimens. Its diversity is remarkably low, far below that of the Vallesian assemblages. The fauna is overwhelmingly dominated by the bovid Tragoportax gaudryi, with the equid Cremohipparion mediterraneum and the giraffid Birgerbohlinia schaubi as major components (Fig. 6). The remaining taxa include the suid Microstonyx and the hyaenid Adcrocuta, amongst others. Forest elements are extremely rare, but chalicotheres (Anisodon) and rhinoceroses (Aceratherium, Dihoplus) are still present. Intensive screen-washing has not been carried out at this site, so the small mammal sample size is very limited, consisting of just twenty molars belonging to the murid Occitanomys adroveri, which indicates a Middle Turolian (MN12 or zone L) age (Agustí et al., 2001, Van Dam et al., 2001 and Van Dam et al., 2006). This contrasts with previous correlations, which mostly on the basis of the large mammal fauna had correlated this site to MN11 (Agustí et al., 1985, Agustí et al., 1997 and Casanovas-Vilar et al., 2011a). The composition and structure of the mammal fauna are very similar to those of contemporaneous sites of the Teruel Basin (Alcalá, 1994 and Alcalá et al., 2000), pointing to a similar arid and warm environment in both regions. This is in sharp contrast with the situation seen during the Vallesian, when the environment was clearly more humid and forested in the Vallès-Penedès Basin. Furthermore, although biostratigraphical data are preliminary, the Teruel rodent-based local zonation can apparently be extended to the Vallès-Penedès Basin.