THE PIG CONOHYUS SIMORRENSIS FROM THE UPPER ARAGONIAN OF ALHAMBRA , MADRID , AND A REVIEW OF THE DISTRIBUTION OF EUROPEAN CONOHYUS

The suid remains from Alhambra (Madrid, late Aragonian, Middle Miocene; MN6, zone F) are described and assigned to Conohyus simorrensis. Conohyus is well known in Spain from late MN5, or zone E, MN7+8, or zone G, and MN9. The material from Alhambra fills the gap in the Iberian record. The Iberian record shows that Cononhyus became larger, with relatively larger posterior molars and with reduced premolars. This evolution occurred in a large area that extends from western Europe to Anatolia. We present an overview of the European and Anatolian localities with Conohyus.


Introduction
The locality of Alhambra was discovered in 1991 by the geologist Javier González when a new street was constructed near to the banks of the Manzanares river in the La Latina quarter in the center of Madrid.The locality was excavated during two campagns, the first one in november 1991 was directed by Laureano Merino and Susana Consuegra and the second one in november 1994 was directed by Esther Herráez and Susana Consuegra (Herráez et al., 2000).
The fossils were found arcosic sandy clays, corresponding to the middle: levels of the Unidad Superior (upper unit) of the Madrid basin (Peláez- Campomanes et al., 2000).
The faunal association is typical of the earlier part of the Upper Aragonian, biozone F (Soria et al., 2000)  Conohyus is a suid with enlarged premolars, which is typical for the Tetraconodotinae, to which it belongs.It is assumed to have evolved fram the Indian form Sivachoerus sindiense when it spread into Europe (Van der Made, 1999).In west and central Europe, it appeared late in MN5 or zone E and is becoming known from an increasing number of localities of this age.Conohyus became larger, increased the size of its pos- terior molars and reduced the size of its premolars (Van der Made, 1989Made, , 1998Made, , 1999; Van der Made & Ribot, 1999;Mazo et al., 1998).During the Vallesian, the genus spread fram Europe to the Indian Subcontinent and Africa and went extinct in Europe.Conohyus is becoming known fram an increasing number of European localities, especially from late MN5, or zone E and fram MN7+8, or zone G.There are relatively few MN6, or zone F, localities.The locality of Alhambra is of this age and thus increases our know ledge of a less well known section of this lineage.

Methods and material
Here we use the MN units (Mein, 1975;De Bruijn et al., 1992) and the zonation of the Aragonian (zones B-G; Daams et al., 1999).
(The prefix Tu stands for Túneles, a name initially applied for the locality.)Ba.la

Description and comparison
The P3 (PIate 1, fig. 3) is a massive tooth with a high pratoconid and pratopre-and pratopostcristids that end very low.There are two posterior roots, which is common in the Tetraconodontinae, but not in other Suidae.Teeth of this size and morphology are typical ol' the Tetraconodotinae.In Europe, Conohyus and Parachleuastochoerus steinheimensis have P 3 of about this size.The P 3 of P. steinheimensis tends to be smaller than that of Conohyus, but in the sample fram La Grive there is one abnormal!ylarge specimen (fig.1).The specimen fram Alhambra is even larger than this largest specimen fram La Grive and is wel! within the ranges of Conohyus.Within this genus there is a tendency to reduce this tooth (fig.2).This reduction seems to be clearest in the width.The variation in the length is bigger, but also seems to reduce.However, not al! specimens fit this tendency wel! and apparently, reduction is accompanied by an increase in variability.If there is a tendency in the length-width index, the tooth becomes more elongate.None of the values of the Alhambra specimen is indicative for a very old, nor for a very young age.
Both M 2 (Plate 1, figs.molars, and decrease in size of the premolars, and the large size of the P 3 from Alhambra, it is more likely, that the molars are Mz than MI' The Mz tend to have relatively thicker enamel than MI> and absolutely much thicker enamel (Van der Made, 1996).However, in the specimens from Alhambra, enamel thickness could not be measured in the standard way, since the teeth are not worn.It is possible that there are differences in crown height between MI and Mz, but this character has not yet been studied in a detailed way.In Conohyus, the molars increased in size (Van der Made, 1989Made, , 1998Made, , fig. 9, 1999, figs. 12-14;, figs. 12-14;Van der Made & Ribot, 1999, fig. 6;Mazo el al., 1998, figs. 10-11).The molars from Alhambra fit well with the M 2 of Conohyus simorrensis (fig.3).

Discussion
As appears from the description, the material from Alhambra fits best Conohyus simorrensis and in particular the early, but not very early stages.Alhambra is placed in MN6, or zone F, what is consistent with the aparent stage of evolution indicated by the fossils.The area with the most "complete" record of Conohyus is the Iberian Peninsula, where the genus is known from MN5, or zone E, MN7+8,
Though the Tetraconodontinae have a long range from the earliest Middle Miocene to the end of the Pliocene, their presence in Europe is restricted to the Middle and earliest Late Miocene (late MN5 -MN9).They are represented with by two genera, Conohyus, with one lineage and two species, and Parachleuastochoerus, with two lineages and three species (Van der Made, 1990bMade, , 1999)).The Conohyus lineage starts with C. simorrensis, which evolved into the larger C. giganteus (= C. ebroensis).Parachleuastochoerus has one lineage of sma11 size (P.huenermanni -P.crusafonti) and one of larger size (P.steinheimensis).Conohyus simorrensis and Parachleuas-tochoerus steinheimensis are of similar size, differing mainly in the relative size of their premolars, those of Parachleuastochoerus being sma11er.Till relatively recently, P. steinheimensis was not considered to be a different species, or a subspecies of C. simorrensis (eg.Hünermann, 1968;Thenius, 1952Thenius, , 1956;;Ginsburg, 1980), but Chen (1984) proved them to be different species, and Fortelius et al. (1996) transferred "Conohyus" steinheimensis to Parachleuastochoerus. The separation of the two species (and genera) is sometimes difficult and there are localities for which there is no recently published opinion as to which of the two is present.
In Table 1 we list the localities where we believe the presence of Conohyus reasonably sure and in Figure 4 we give their approximate geographic positions.The first co11umn in Table 1 gives the name of the locality, occasional1y with a question mark, when there is doubt as to the correct name of the locality or presence of Conohyus.The second co11umn gives the age of the locality, in terms of MN units or zonations of the Aragonian.The third co11umn gives a reference for the age; sometimes the age (in MN units) is plainly given, but sometimes the age had to be interpreted on the basis of information in that paper, in that case the reference is between brackets.The fourth column indicates the place where we studied or consulted the fossils or casts.The fifth co11umn gives a reference for a paper that describes or figures the material or gives measurements, or a recent paper that indicates the material to be Conohyus (and not P. steinheimensis).
A cast of a mandible with P 3 -M 2 in the MGPUSB is of a large Conohyus and is indicated to be from "Haute Garonne".Stehlin (1899Stehlin ( -1900, p. 140, p. 140) mentions this cast and states that the original is in Toulouse and is from Le Fousseret.However, the specimen is very muc:h larger than a specimen from Le Fousseret in the MNHN.Its size suggests that it is late MN7+8 or MN9.Richard (1946) gave an overview of the faunas, and cited Conohyus from SI. Gaudens.We do not know on what material this citation is based.The cast in the MGPUSB should be from one of these localities.A sku11 from SI. Gaudens-Valentine is the type of "Sus valentini" and is placed by Stehlin (1899Stehlin ( -1900, p. 139) , p. 139) Ginsburg, 1987Ginsburg, 1977, 1987?Channay MN9 Ginsburg, 1987Ginsburg, 1977, 1987?Lublé MN9 Ginsburg, 1987Ginsburg, 1977, 1987 Ginsburg (1977) described teeth from three 10ca1ities in the Fa1uns de Touraine and assigned them to Conohyus simorrensis, and believed them to be of a "fa1un" that is older than Sansan.The teeth would be MN5 in age.However, Ginsburg (1989) described sorne more material and now thought them to be of the younger "fa1un aArca" (MN9).The P 3 fram Hommes is much larger than that of P. steinheimensis and is even large for Conohyus (Fig. 1).The P 4 fram Fonte do Pinheira (MN9) are small (Van de Made, 1989), suggesting a size decrease in this tooth (which would imp1y that the large specimen from Hommes is not that young), but then the cast fram "Haute Garanne" discussed aboye has also very large premolars.The p3 from Lublé is narrow, is out of the known range for Conohyus and within that of Parach-leuastochoerus steinheimensis (Fig. 5) A partial p3 fram Channay (DTp = 14,4) is also narraw for Conohyus.A p 4 from Channay is within the ranges for early Conohyus but prabably not of the later Conohyus, since the genus seems to aquire wider p4 in evolution (Fig. 6).Two P4 from Channay are large compared to P. steinheimensis and are in the lower range of Conohyus (Fig. 7).The specimen fram Hommes and sorne of the specimens from Channay certainly belong to Conohyus, while part of the material fram Channay and the specimen from Lublé might represent P. steinheimensis, or alternatively reduced premolars of late Conohyus.This latter option would fit well the mandible fram Fonte do Pinheira.However, no upper tooth row of Conohyus of this age is known from Europe.Parachleuastochoerus steinheimensis is from La Grive (old collections in MGL).Data from Channay from Ginsburg (1987).Thenius (1952) assigned two fragmentary teeth from Neudorf Sandberg to Conohyus simorrensis simorrensis and a complete molar to Hyotherium soemmeringi, but did not give any measurements.There is probably only one species, either belonging to Conohyus or to Parachleuastochoerus, but with the data available, it is not possible to decide.
Van der Made (1990aMade ( , 1997) ) listed four localities as possibly having Conohyus.These localities remain problematic.In one of them, Can Ponsic 11, there are two M3 that are too large for most of the suids that are known from MN9 and too small for Hippopotamodon antiquus, but might fit the large MN9 Conohyus.However no Conohyus M3 are known from MN9, so this possibility cannot be confirmed.The citation from La Ciesma is based on a single molar.

Conclusions
The suid material from Alhambra is assigned to Conohyus simorrensis.This new record from MN6 fills a gap in the Spanish record of the genus, where it is now known from late MN5 (or zone E) to MN9.The Spanish record shows that Conohyus became larger, with relatively larger posterior molars and with reduced premolars.This evolution must have occurred in a large area that extends from western Europe to Anatolia, because the lineage is also recorded with different ages and evolutionary levels from France, Austria and Anatolia.
. • in "Hyotherium" simorrense.We do not know this material; it might belong to Conohyus or to Parachleuastochoerus steinheimensis.A specimen from Nuri Yamut might represent Conohyus or Sivachoerus (Van der Made & Tuna, 1999).
Tabla l.-European and Anatolian localities with Conohus.