N. Jb. Geel. Palaont. Mh. Stuttgart.Januar 1991

A new Haplobunodontidae (Mammalia, Artiodactyla) from the Eocene of Turkey

By Stcphanc Ducrocq, Montpellier, and Scvket Sen. Paris

Wi th 2 figures in the text

DUCRocQ,S. &SEN, S. ( 199 1): A new Haplebullodontidae (Mammalia, Artiodactyla) from the Eocene of Turkey. - N. jb. Geo!. Palaont. Mh. , 1991 (l): 12-20; Stuttgart.

Abstract: This paper provides the description of a new Haplobunodontidae, PambmlOtioIJ allatoliwm n. g. 11. sp. from middle Eocene deposits of Eski Celtek, Turkey. The toOth mor­pholog)' of thi s taxon di sp lays rather primitive characters when compared wi th other gen· en of the family. The H:aplobunodontidae being hitht'rto conside red as stri ctly European, the occurrence of this new animal in Turkey supports the h)'pothesis that faunal exchanges between western Europe and western Asia were possible during th e Eocene.

Zusarnmcnfassung: Aus dcm Miueleozan von Eski Cel tek, Turkei, wird Ptlrllb/tIUJodon lIfllltoliCllm n. g. n. sp. beschrieben. Der Vergleich III it den anderen Gattungen cler Familie weis! darauf hin, dan die turkisc he Form primi!iver ist. Die Haplobunodontidat' waren bis zu diesem Fund nur aus Europa bekannt. Das Vorkommen dieser Spezies in der Turkei un­terstutzt die These von f:H1nistischem Austausch zwischen \X'est-Europa und \'\'cst-Asien wahrend des Mittclcozans.

In troduction

The Eski Celtek mine was not the specific subject of researches to discover remains of Vertebrates. Specimens were found by miners and commiued to the care of geologis ts from the Mineral Research and Exploration Institute of Turkey (M. T. A.) by its director; [he same applies to the specimen described in this paper which was en trusted to one of us (5. SEN) when he visited the mine in 1969.

The main mammal remains found at Eski Celtck belong to PalaeoamtlSia kall­

Slti OZANSOY 1966. referred to the Embrithopods by SEN & HEI NTZ in 1979. The geographic location of this mine, [he stratigraphic data and [he age of the beds are indicated in that paper. This mine is situated North of Amasya, and its age would be Lutetian on the basis of [he occurence of Nummulitcs uroniensis in ma­rine beds overlying the lignites (OZ.'\NSOY 1966). SIN & HEINTZ mentioned "un palais d'un grand Condylarthre" as representing a second species of mammal froJ11lhe site. It is this specimen that forms the subjectof this paper. The original foss il is in the collections of the Natural History Museum of Egee University in Izmir. The descr iption that follows and the measurements have therefore been made 011 the bJsis of pbs[cr caSlS made by onc of us (5. SEN).

A new Haplobunodont idae from the Eocene of Turkey

Systematic study

Order Artiodactyla OWEN, 1849 Sub-Order Ancodonta MATTHEW, 1929

Super-Family Anthracotherioidea G ILL, 1872 Family Haplobunodontidae PILGRIM, 1941

ParabWlOdoll anatolicum n. g. n. sp.

13

H olotype : A palate with right P4/ -M3f and left M If -MJ/ . Collecti ons of the Natu ­ral History rvluseum o f Eg~e Uni versity. Izmir, n" EC 15.

T y pe-Ioca 1 i t )': Mine of Eski Cehek, Dept . of Amas),a, Turkey.

D e ri .... atio n omi nis: Partlblt1lodoll because Turkey is situated outs ide the known distributional range of the Haplobunodontidae;anatoliw1t/ in reference to Anatol ia where the local ity is.

o i ag nos is : Medi um sized; MJ/ smaller than M2/; trape7.0idally shaped molars with a crescentiform metaconule; mesostyle rather internally situated; parastyle weak; no inter­nal cingulum; metacone with flauened externa l wall; external wa ll of the labial cusps strongly canted inward; rather strong P4/ with elonga ted ex ternal cusp and vertically notched on its labial side; crenulated enameL

The material consists of a palate with ri ght P4/ -M3/ and Idt MI / -M3/ (Fig. t )j all the teeth except for the left M 1/, which lacks the paracone and the meta­cone, are quite well preserved. The most deeply worn tooth is the M1/, the others being bare ly worn at the apex of the main cusps.

This palate was crushed during foss ilization: even though the palatal bones are completely broken, and the right dentary row displaced and rotated towards the lingual side, the teeth are very well preserved. A canine is stuck to the pos­terior part of the palate, but whether it belongs to the foss il palate or not cannot be determined. \'Ve therefore take no further account of the canine in our de­scriptions and comparisons.

The P4/ is nearly triangular, and is aboU[ as large as the M 1/ ; it has two con­ical tubercles of which the external one is the largest. This one is mesio-distally elongated and its external wa ll is rather canted towards the centre of the tomh. The lingual cusp is smaller and si tuated mesially, and is bordered on the disto­lingual side by a broad cingulum. The two tubercles are relatively dis ti nct, the internal one connecting with the external one by a ve ry slight crest half the height of [he cusp. The cingulum is present only on the distal side with a weak style just behind the lingual cusp. There may be an incipien t style in front of the ex ternal cusp, but because the tooth is broken at this place, it is not poss ible to be precise. The external wall is crenulated. As in the molars, the P4/ seems to have two external roots (Fig. 2).

The molars are rather trapezoidal in shape, particularly the M2/ and the M3/ . The mesial lobe is broader than the disral one and the teeth are bunodonr. The tubercles are conical and on ly the metaconule has a crescentiform aspect, con-

14 Stephane Ducrocq and Sevket Sen

Fig. I. PaY(lbmlOtioll (/1lt1toiimnl n. g. n. sp. from the Middle Eocene of Eski Cehek, Turkey; ventral view of the palate wi th left NII / -M3/ and right P4/ -M3/ (holotype, EC IS); scale

bar: I cm.

cave towards the metacone (at least on the left M2/). The paracone and [he meta­cone show two crests descending from their apex and joining the mesio- and dis­to-vestibular corners of the rooth. In addition, a rather well-marked mesostyle is connected to the disral crest of the paracone and to the mesial crest of the meta­cone. The metaconule has two arms contributing a slight inflation in the centre of the valley (particula rl y perceptible on the M2/). Only the metacone presents a flattened external wall, due to the presence of mesial and distal crests on the cusp. The paraconule is of modes t size) being smaller than the other CUSPSl but it is nevenheless clearly discernible, is closer to the protocone than to the para­cone, and is slightly concave towards the latter cusp. The external wall of the pa­racone shows fine vertical wrinkles as in the P4/.

A cingulum is present on the vestibular and distal sides of the molars. A weak parastyle in front of the paracone comprises a thickening of the cingulum. From this point, a cingulum of roughly constant thickness surrounds the vest ibular side and joins the posterior crest of the metaconule (pos t metaconule crista of GENTRY & H OOKER 1988). The crests that descend from the apex of the para­cone and metacone join the external cingulum. Despite the overlap of rhe mes ial

A new Haplobunodontidae from the Eocene of Turkey 15

B

Fig. 2. P"rablllloc/oll (f1ltlfolicllm n. g. n. sp. from the Middle Eocene of Eski Cehek, Turkey; right upper tooth row, P4/ ·M3/ (holotype, EC 15): A and B - occlusal view; C -labial view;

scale bar: 1 cm.

and distal edges of adjoining tecth , the molars have a sl ight mesial ci ngulum that is particularly visible in front of the protocone and the paraconule. Finally, there is marked labial flare of the external cusps resembling the condition in the Cebo­choeridae.

The M3/ possesses a peculiar aspec t: its trapezoidal occlusal oudine is morc marked than it is in M2/; its anterior len gth and width approximate to the di­mensions of the M 1/ . Because the metacone is reduced and is close to the meta·

16 Stephane Oucrocq and Sevket Sen

conule. the width of the posterior lobe is reduced. The cusps of this molar are more slender and more sharply-pointed than are those of the preceding molars. The medial'! valley is comparatively wider than it is in the anterior teeth . Finally, the crests of the tubercles are similar to those of the M1 I and M2/, but are less clearly visible because the tooth is mOTC slender.

Measurements (in mm): Right P4/: L - 9.8; \'V - 11 .1 Right M 1/ : L - 9.9; \VI - 11.7 Length of the right row N I-NUl : 37.0

Left MU: L - 10.5; \VI - 14.6 Left MJ/: L - 9.0; IV - 11.8 Le ngth of the left row M I /- M3/ : 27.0

Comparisons with other taxa and discussion

This specimen shows striking affinities with representatives of the family Anthracotheriidae. The teeth are brachybunodont, the quadrangular molars (es­pecially M t/ and MU) have four main cusps and a we ll developed paraconule. Some of these cusps have well-marked crests. Finally, one can observe a slight molarization of P4/.

Comparison with the Burmese anthracotheres which it most closely resem­bles (PILGR IM 1928) y ields the fo llowing s imilarities:

- AlIthracothema PILGR IM, 1928: P. anatolicum shares with Anthracothema the absence of a lingual cingulum, the rather weak mesostyle, and crescentiform metaconule. On the other hand, it diffe rs from this genus by its more trapezo i­dal molars, by the slight expansion of the anterior cingulum, by the less salient cusps at the bases of the crowns and the weak flare of their lingual walls. Fi­nally, the dimensions of the Turkish specimen are smaller than those of the smallest representative of A11thraCOlhema.

- AlIlhracokeyyx PILGRIM & COTTER, 191 6: It differs from it by more wea kly developed sty les and cingulum, the less pyramidal and erect cusps, the median va lley which is not interrupted by a mesio-distally directed central crest, and by the shape of the ex ternal tubercle of P4/ which is not crescentiform.

- AuthracohyllS PILGR ll-ol & COTTER, 191 6: It is more like AnthracohYIH because of its rather slight mesostyle, bunodont tubercles and the absence of an inter­nal cingulum. On the other hand, it differs from AnthrllcohY1f5 by its metacon­ule with V-shaped crests and its poorly developed paraconule.

Finally, the Turkish fossil closely resembles Siamotherium krabieme SUTEE­THORN et al., 1988 from the Eocene of Thailand by the general structure of the teeth, the flattened external wall of the metacone, and the tendency to seleno­donty of the metaconule (SlITEETHORN et al. 1988). It differs from this species in its more developed mcsostyle, in its possession of a stronger cingulum on the ex­ternal side of the molars, but absent on the internal side, in its more molarized P4/ and above all by the spectacular size reduction of the M3/, contrast ing strongly to the general pattern of molar size gradients in the Anthracotheriidae.

A new Haplobunodontidae from the Eocene of Turkey 17

This characte r seems to us to be important enough to prevent the inclusion of p, (1Il1llOlicum whithin the AnthracOlheriidae,

When we studied the plaste r cast, we no ted a cenain likeness with the genus Pbenacotiw COPE, 1873 (Condylanhra, Mammalia), The two taxa show strong

reduc tion of the NB / , an increase in molarization of P4/ , a bunodont appear­

ance, the presence of a mesos tyle and the size of the molar. H owever, Pbenacotius has a hypocone and nOt a metaconule, and the external cusp of the P4/ is practi­

ca lly di vided into two pans (L OVOCAT 1958), It is the refore clear that no close re­lationsh ip exists between these two laxa,

On the contrary, we notice some affinities with o ther Aniodactyls such as

Haplobunodontidae, characterized by increases molarization of the P4/ . mobrs wh ich are quite bunodont [ 0 bunoselenodont. and sometimes a reduced MJ/ (VIRET 1961, SUDRE 1977), \,(le have therefore compared our sample with the

genera Antbracobunodoll, Rbagatherittm, Haploblfllodon, Lopbiobttnodon and Ma­sillabttllc, The size difference is strong, since the molars of the Turkish specimen

are practically twice the size of those of the above genera,

- AlItbracobmlOdon HELLER, 1934, and [he Turkish specimen have :tn anterior

lobe broader than the posterior one, a crescellliform metaconule and a rather

strong mesostyle . We note meanwh ile in the species A, weigelti, from Geiscl­tal, an additional style situated on the lingual side between the protocone and

rhe met:tconule. :tn uninterrupted cingulum, a stronger paraconule, 3n M3/

larger than MU and a P4/ with two external cusps, The P4/ of A, louisi from Grisolles is triangular but is distinguishable from that of our fossil in having a well differentiated paracone and metacone, an incipient metaconule and a

marked labial cingulum, Concerning the molars, the cusps of A. IOllisi are more crescen tiform (especially the intern:tl ones), and the crests of the ex ter­

nal tubercles are more pinched and more salient than in our sample (SUDRE

1977).

- The genus Rbagatberium PICTET & HUMBERT, 1855-57. possesses molars that

are rather like those of our specimen , a slightly reduced M3; however, the P4 / is strongly molarized :tnd the tubercles have :t more se lenodont appeara nce.

- With Haplobllllotlol1 DEPERET, 1908, the Turkish specimen sha res a mesia l

lobe of the molars which is broader th:tn the di stal one and a crescentiform

metaconule. But it d iffers frol11 the European form in having a less well devel­oped parastyle. the absence of labial crests on the external cusps, the absence

of a distal cingulum and of a lingual one at [he level of the metaconule and the

protocone, a more internally placed mesostyle and the external w:tll of the labial cusps more canted inwards. Finally, the P41 is longer and broader than

in Hllplobll1lOdon. - The Turkish fossil shares with LophiobulIodoll DEPERET 1908 a bro:td mes ial

lobe, the absence of a lin gual cingulum (a t least in the species L. dJodllnicum). a

crescentiform metaconule, a paraconule close re the protocone and a reduced

N.Jb. G("ol. PJ,bom, .\Ih. ]991

18 Stephane Ducrocq ::md Sevke t Sen

M)/. On the other hand, it differs by the absence of a distal cingulum, the s lighter cam of the internal wall of the molars, and the more inwardl y canted

external wall of the labial cusps in the cast, whereas LophiobwlOdon has a strong parasty le, col umns on the external cusps and a less massive P4/. MasiJ/ablllle TOBIE N, 1980 and the Turkish speci men share the broader mesial

lobe, a marked mesostyle .:md a crescentiform metaconule; but Masillabune differs in having a complete cingulum, cusps closer to each mher, a stronger pnrastyle and nn M3/ larger than the M2/ (TOB IEN 1980),

Finally, we compared o ur cast with Choeropotamus CUVI ER, 1821 in which

the mo lar structure is rather close to thal of the Turkish animal although the form er is a Choeropotamidae. In fact, both show brachybunodont teeth wi th

small and low cusps, an ante rior lo be broader than the posterior o ne , a relatively

strong P41 and si milar dimensions. Nevertheless , Choeropotamllsdoes not have a

reduced MJ /, it has a nearly continuous cingu lum. the ex ternal cusps of its mo­lars form columns on the ir labial side, and the P41 has a we ll-formed crescenti ­

form protOcone that partly su rrou nds the paracone.

r n summary. we see that the structure of the tee th in the Turkish sample exhi ­

bits an o rganization ve ry close to that of different mem bers of the family HapJo­

bunodontidae. The main difference is the larger size of the Turkish form. The

morphological differences noticed above can be considered as being a va ri ation of characters between different genera of the same famil y. It seems that Anthra­cobltllodoJl is the closest to the Turkish specimen although it is more deri ved (mo re molarifo rm P4 / , sty les o f the molars stronger, internal cusps more buno­

selenodont). We propose therefo re to include this new taxon whithin the Haplo­bunodontidae. In a gene ra l way, our specimen shows a more primi tive den tal

structure than that of the other representatives of the famil y. T his peculiar struc­

lUre is charac te ri zed by a less mobriform P4 /, more bunodont tubercles, rhe ab­sence of well-marked cres ts on the cusps, an inte rru pted cingulum, a mesostyle

which is not salient labially, and a weak paraconule. The rather bunodont cha­

racter o f the cusps and the mo re inwardly located mesostyle are also present in Masillabrme. T he Turkish animal shows however incipient selenodonty o f the

metaconule and of the paraconule, a ra the r strong inward cant of the external wa lls of the labial cusps and tubercles generally localed more towards rhe centre

of the tooth. The reduced MJI is not a character typical to all the H aplobullo­

dontidae: illdeed, AnthracobmlOdoll does no t have thi s morphological fea ture. It is the refore probably an occas ional character of this fami Iy. Does the Turk ish an­

imal represent a form related to Masil/abrme because of the two fea lUres ci ted

above. or should it be included in a distinct branc h? \Vhatever the case, it seems to be necessary to attribute this specimen to a new taxon, Pm-abmwdol1 ana/o­

tiC/1nl n. g. n. sp.

A new Haplobunodontidae from the Eocene of Turkey 19

Conclusions

Until now, the famil y Haplobunodolllidae has been found in western and central Europe. The Anato lian species represent s its most o riental occurrenct> and considerably en larges the area of distribution of this group during the Eocene. H owever, as was discussed above, this species possesses several derived charac ters which obscure its phylogenetic relationships with other haplobuno­dontids.

The Eski Celtek mine is the only Eocene local ilY in Turkey which has yielded more than one species of mammals: Palaeoanltlsia kmlSu; OZANSOY and Parabtt­

nor/on anatoliclIm n. g. n. sp. O ther localities have yielded only P. ka1lSui (SEN & HEI NTZ 1979). Both species present close European affinilies. The largest Mam­mal known from Eski Cehek, Palaeoamasia kansui. has a tooth morphology sim­ilar to that of Crivadiatben'mn from the Eocene of Rumania which belongs to the subfamily Palaeoamasinae (SEN & HEINTZ 1979, RAOULESCO & SUORE 1985) and differing from {he Arsinoitheriinae from Fayum in its more primitive denti­tion. It is thus probable that some mammalian exchanges between Anatolia and wes tern Europe occurred during the Eocene,

Acknowledgments

We would like 10 thank Dr. B.LANGE-BADRE and Prof.J. -J. ]AEGER foc theu advice at the beginning of this study, and to Or. O. E. RUSSELl who gave us access (0 his collections in the l\ luseum National d'Histoire Naturelle in Paris.

We thank particularly Dr.]' SUDRE for having read the manuscript on se\'eral occasions and fo r his advice and const ructive remarks, and finally for having lent us casts and origi­nlls of some taxa.

" le are very grateful to Dr. r-. 1. PICKFORD and N. COU RT who corrected Lh e English text.

Finally, we thank C. ABRIAL for the photographics, and D. VISSET for [he drawings.

References

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20 S. Ducrocq and S. Sen, A new Haplobunodonlidac

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TOBIEN, H. (1980): Ein 3nthracoth erioider Paarhufcr (A rti odac tyla, J\ lammalia) aus dcm Eoz3n van Mcssel bei Darmstadt (Hessen). - GeoL Jb. Hcsscn. 108: 11 -22; \'<fiesha­den.

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Bei der Tiibingcr Schriftleitung cingegangen am 26. Marz 1990.

Anschrift der Verfasser:

ST~PHANE DUC ROCQ, Laboratoi re de Paleontoiogie des Vertebres, Univcrsitc des Sciences et Tech niques du Languedoc, Place Eugene Bataill on, F-340f,O, Montpdlier Cedex; SEVKET

SEN, Laboratoire de Paleontologie des Venebres, Un i ve rsi tl~ Pierre et Marie C urie, 4, Place Ju ssieu, F-75252 Paris Cedex os.