ANTHRACOBUNE AIJIENSIS NOV. SP. . (MAMMAIJA: PROBOSCIDEA) FROM ' THE SUBATHU FORMATION, ! tlll EOCENE FROM NW HIMALAYA, INDIA KIStIOR KUMAR WadiaInstitute of Himalayan aeology, 33, General Mahadeo Singh Road, Dehradun 248 001 INDIA ABSTRACT A. aifiensis nov. sp., a new smaller species of Anthracobune PILGRIM, 1940 is reported from the Middle Eocene transitional part of the Subathu Formation of Kalakot, Jammu • Ka~hmlr) India. It is closely related to other Indo-Pakistan anthracobunids but differs in possessing certain derived characters like nonmoladsed premolars, reduced first premolars and lower canines (? or absent) and strong diastema between first lower premolar and anterior teeth. The new material supports Wells & Gingerich's (1983) proposal of a separate Family Anthracobuni- dae for Anthracobune and its allies and suggests its close alliance with moeritheriids. Ishatherium subathuensis SAHNI • KUMAR, 1980 is very similar to anthracobunids but it is retained in Sirenia on the basis of morphology of its molars and incisor tusk and its occurrence in marine Ypresian sediments. Thus the Family Anthracobunidae now includes Anthracobune aijiensis nov. sp., A. pinfoldi PILGRIM, 1940, dozaria palustris WELLS & GINGERICH, 1983, Lammidhania wardi PILGRIM, 1940 and Pilgdmellapilgrimi DEHM & OEITINGEN-SPIELBERG,1958. Pilgdmel- la is generically distinct and represents the most primitive anthracobunid. A. aifiensis nov. sp. appears to be the most advanced taxon among known anthracobunids. The amphibious nature and marshy habitat of anthracobunids as suggested by their dental morphology, host rock lithology, and the accompanying fauna indicate that the deposi- tion of transitional part of the Subathu Formation may have taken place in coastal environment. This implies that the shoreline of rapidly contracting Tethys was close by, as is also evident from mixing of marine and terrestrial elements. The age of the land mammal yielding transitional part of Subathu sequence is considered as Lutetian on the basis of foraminiferal biostratigraphy and its correlationship with standard sections in Pakistan. ANTHRACOBUNE AIJIENSIS NOV.SP. (MAMMALIA, PROBOSCIDEA) DE LAFORMATION DE SUBATHU, EOCENE DU NW DE L'HIMALAYA, INDE. R~.SUMI~ Anthracobune aifiensis nov. sp., petite esptce du genre Anthracobune lalLGRIM, 1940, est d6crite des couches de transition d'~ge 6octne moyen de la Formation de Subathu dans la r6gion de Kalakot) Jammu et Kaehmlre, Inde. La nouveUe esptce est 6troitement apparent6e aux autres Anthracobunid6s indo-pakistanais mais eUe en difftre par certains caracttres dtriv6s tels : des prtmolaires non molaris6es ; des premitres pr6molaires et des canines inf6rieures rtduites (ou absentes ?) ; un fort diasttme entre la premitre pr6molaire inftrieure et les dents ant& rieures. Le nouveau mattriel conforte la proposition de Wells & Gingerich (1983) d'une famille d'Anthracobunidae distincte pour regrouperAnthracobune et les formes qui lui sont proches ; il suggtre 6galement line relation 6troite avec les Moeritheriid6s. Ishatherium subathusensis SAHNI & KUMAR, 1980 est tr~s semblable aux Anthracobunidts mais il est maintenu darts les Sirtniens d'aprts la morphologie des molaires et de l'incisive-dtfense, ainsi que par sa prtsence dans des d6p6ts matins ypr6siens. Ainsi la famille des Anthracobunidae comprend Anthracobune aifiensis nov. sp., A. pinfoldi PILGRIM, 1940, Jozada palustris WELLS & GINGERICH, 1983, Lamrnidhania wardi PILGRIM, 1940 et Pilgrimella pilgrimi DEI-IM & OETHNGEN=SPIELBERG, 1958. Pilgrimella se distingue nettement au plan g6n6- rique et repr6sente la forme la plus primitive des Anthracobunidts. A. aifiensis nov. Sp. parait &re le taxon le plus 6volu6 des Anthracobunidts connus. La morphologie dentaire des Anthracobunid6s suggtre un comportement amphibie et tin habitat mar6cageux. La lithologie et la faune associte indiquent que les couches de transition de la Formation de Subathu ont pu se dtposer darts un environnement c6tier. Cela implique que le rivage de la T6thys 6tait proche comme l'atteste le mtlange d'616ments matins et terrestres. L'~ge des couches de transition de la s6quence de Subathu qui ont livr6 les mammlftres est consid6r6 comme Lutttien d'aprts les donntes biostratigra- phiques des Foraminiftres et les corrtlations 6tablies avec les coupes standard du Pakistan. KEY-WORDS: EOCENE, TEWHYTHERIA, PROBOSCIDEA; ANTHRACOBUNIDAE, SUBATHU FORMATION, INDIA, PAKISTAN. MOTS-CL~ : EOCt~NE, TErHYIItERIA, PROBOSCIDEA, ANTHRACOBUNIDAE, FORMATION DE SUBATHU, INDE, PAKISTAN. (Geobios, 1991"~ In ° 24, fasc. 2 | Manuscrit accept6 dgfinitivement le 17.08.90 k, lg. 221-239 ./)
Transcript
ANTHRACOBUNE AIJIENSIS NOV. SP. . (MAMMAIJA: PROBOSCIDEA) FROM
' THE SUBATHU FORMATION, ! tlll EOCENE FROM NW HIMALAYA, INDIA KIStIOR K U M A R Wadia Institute of Himalayan aeology, 33, General Mahadeo Singh Road, Dehradun 248 001 INDIA
ABSTRACT
A. aifiensis nov. sp., a new smaller species of Anthracobune PILGRIM, 1940 is reported from the Middle Eocene transitional part of the Subathu Formation of Kalakot, Jammu • Ka~hmlr) India. It is closely related to other Indo-Pakistan anthracobunids but differs in possessing certain derived characters like nonmoladsed premolars, reduced first premolars and lower canines (? or absent) and strong diastema between first lower premolar and anterior teeth. The new material supports Wells & Gingerich's (1983) proposal of a separate Family Anthracobuni- dae for Anthracobune and its allies and suggests its close alliance with moeritheriids. Ishatherium subathuensis SAHNI • KUMAR, 1980 is very similar to anthracobunids but it is retained in Sirenia on the basis of morphology of its molars and incisor tusk and its occurrence in marine Ypresian sediments. Thus the Family Anthracobunidae now includes Anthracobune aijiensis nov. sp., A. pinfoldi PILGRIM, 1940, dozaria palustris WELLS & GINGERICH, 1983, Lammidhania wardi PILGRIM, 1940 and Pilgdmellapilgrimi DEHM & OEITINGEN-SPIELBERG, 1958. Pilgdmel- la is generically distinct and represents the most primitive anthracobunid. A. aifiensis nov. sp. appears to be the most advanced taxon among known anthracobunids. The amphibious nature and marshy habitat of anthracobunids as suggested by their dental morphology, host rock lithology, and the accompanying fauna indicate that the deposi- tion of transitional part of the Subathu Formation may have taken place in coastal environment. This implies that the shoreline of rapidly contracting Tethys was close by, as is also evident from mixing of marine and terrestrial elements. The age of the land mammal yielding transitional part of Subathu sequence is considered as Lutetian on the basis of foraminiferal biostratigraphy and its correlationship with standard sections in Pakistan.
ANTHRACOBUNE AIJIENSIS NOV. SP. (MAMMALIA, PROBOSCIDEA) DE LA FORMATION DE SUBATHU, EOCENE DU NW DE L'HIMALAYA, INDE.
R~.SUMI~
Anthracobune aifiensis nov. sp., petite esptce du genre Anthracobune lalLGRIM, 1940, est d6crite des couches de transition d'~ge 6octne moyen de la Formation de Subathu dans la r6gion de Kalakot) Jammu et Kaehmlre, Inde. La nouveUe esptce est 6troitement apparent6e aux autres Anthracobunid6s indo-pakistanais mais eUe en difftre par certains caracttres dtriv6s tels : des prtmolaires non molaris6es ; des premitres pr6molaires et des canines inf6rieures rtduites (ou absentes ?) ; un fort diasttme entre la premitre pr6molaire inftrieure et les dents ant& rieures. Le nouveau mattriel conforte la proposition de Wells & Gingerich (1983) d'une famille d'Anthracobunidae distincte pour regrouperAnthracobune et les formes qui lui sont proches ; il suggtre 6galement line relation 6troite avec les Moeritheriid6s. Ishatherium subathusensis SAHNI & KUMAR, 1980 est tr~s semblable aux Anthracobunidts mais il est maintenu darts les Sirtniens d'aprts la morphologie des molaires et de l'incisive-dtfense, ainsi que par sa prtsence dans des d6p6ts matins ypr6siens. Ainsi la famille des Anthracobunidae comprend Anthracobune aifiensis nov. sp., A. pinfoldi PILGRIM, 1940, Jozada palustris WELLS & GINGERICH, 1983, Lamrnidhania wardi PILGRIM, 1940 et Pilgrimella pilgrimi DEI-IM & OETHNGEN=SPIELBERG, 1958. Pilgrimella se distingue nettement au plan g6n6- rique et repr6sente la forme la plus primitive des Anthracobunidts. A. aifiensis nov. Sp. parait &re le taxon le plus 6volu6 des Anthracobunidts connus. La morphologie dentaire des Anthracobunid6s suggtre un comportement amphibie et tin habitat mar6cageux. La lithologie et la faune associte indiquent que les couches de transition de la Formation de Subathu ont pu se dtposer darts un environnement c6tier. Cela implique que le rivage de la T6thys 6tait proche comme l'atteste le mtlange d'616ments matins et terrestres. L'~ge des couches de transition de la s6quence de Subathu qui ont livr6 les mammlftres est consid6r6 comme Lutttien d'aprts les donntes biostratigra- phiques des Foraminiftres et les corrtlations 6tablies avec les coupes standard du Pakistan.
KEY-WORDS: EOCENE, TEWHYTHERIA, PROBOSCIDEA; ANTHRACOBUNIDAE, SUBATHU FORMATION, INDIA, PAKISTAN. MOTS-CL~ : EOCt~NE, TErHYIItERIA, PROBOSCIDEA, ANTHRACOBUNIDAE, FORMATION DE SUBATHU, INDE, PAKISTAN.
(Geobios, 1991"~ In ° 24, fasc. 2 |
Manuscrit accept6 dgfinitivement le 17.08.90 k, lg. 221-239 ./)
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I N T R O D U C T I O N
Recent reviews with descriptions of important additio- nal material of Anthracobunidae from Eocene Kulda- na Formation of Pakistan by West (1983), and Wells & Gingerich (1983) have well illustrated this enigmatic family of Moefithedum - like mammals represented by at least four very similar taxa that had been referred to various families and orders by different workers in the past. Since all the taxa of this family are more or less of the same size, have a very similar dental morpholo- gy, and have been found in contemporaneous strata within 275 km distance, their diversity has been hard to understand and explain and has compelled us to conti- nuously reevaluate their taxonomic affinities (DeEm & Oettingen-Spielberg 1958, Gingerich 1977, West 1980, 1983, Wells & Gingerich 1983, Doming et aL 1986, Tassy & Shoshani 1988). The taxonomic history of the Family Anthracobunidae is abstracted in figure 1.
The present find of well preserved dental material refe- rable to another new species, Anthracobune aijiensis has not only added a new member to the fnmily bot has also necessitated a fresh commentary on Anthracobunidae from India and Pakistan. It is this new material that forms the subject matter of the present paper.
The fossils ofA. aifiensis comprising a nearly complete mandible and a left maxillary fragment were recovered
from the purplish grey siltstone horizon of tbe upper- most transitional part of the Subathu Formation (the Upper part of the Subathu Formation consisting main- ly of purple/red shales and siltstones represents the transition between marine and truely continental fa- cies) exposed near the Village Aiji on Metka-Mohgala Road, Rajauri District, Jammu & Kashmir (fig. 2). A mandible containing p0st canine dentition of both sides was found appressed to the skull (mainly denti- tion) of a small carnivore and the two were later sepa- rated with great difficulty. The carnivore dentition will be described elsewhere. The close association of carni- vore and A. aifiensis dentitions is not of much signifi- cance (except for the simple fact that the two coexis- ted), as the carnivore is less than half the size of truely herbivorous anthracobunid. A left maxillary fragment with partially damaged premolars was found within a meters distance from the mandible in exactly the same stratigraphic level and possibly represents the same in- dividual.
The horizon that yielded A. aijiensis material lies in the transitional part of Subathu (fig. 3). Although al- most all of the transitional sequence is fossiliferous, with varying concentrations at various levels, the oldest and youngest levels (that show concentration) are loca- ted roughly 3 m below and 1.5 m above the A. aijiensis horizon respectively. The lowest level (Pink claystone)
Pilgrirn~ 1940
Dehm ~ Oettingen- Spielberg~ 1958
Gingerich~ 1977
Westj 1980
West, 1983
Wells and Gingerich, 198:$
Kumor ( th is paper )
Anthracobune
, ] I _A. pinfoldi ? A. daviesi 7. A.wardi
(~nthrocofheriidae : Ar t iodaety la)
. . . . / I I . . . . . .
A_.. pinfoldi ? A. daviesi Pilg.rimella wardi P. p_.]grimi
:-" ~--='--='=-: Pristichampsine Crocodiles :<------'--"-:'" "- also Cetaceans & Artiodactyls)
ii , rn. "x: :<. 'x'.'x'.'.~" Anthraeobune eijiensis
Greyish Purple Shaly Siltstone
Sc al..__ee Pink Cloystone
=-O Greenish Grey Claystone
Figure 3 - Lithology of A. atflensts-yielding section exposed near the Village Aiji on Metka-Mohgala Road, Rajauri District, Jammu & Kashmir, showing positions of ossiferous horizons.
Succession litbologique de la coupe de la route Metka-Mobgala, pros du vil- lage d'A#'i, District de Rajauri et position des horizons ayant h'vrds los restes squelettiques.
had earlier produced Metkatius kashmiriensis KUMAR & SAHNI 1985 (Raoellidae : Artiodactyla) at West Babbian Gala locality, about 1,2 km west of the pre- sent locality (Kumar & Sahni 1985). This horizon
223
contains rare but well preserved specimens which are usually very difficult to prepare due to hardness and compact nature of the dpystone. The youngest ossife- rous level which is also exposed at Aiji, produces abundant rodent teeth associated with crocodiles and fish and scanty material of other mammals including archaeocete cetaceans and dichobunid artiodactyls (Kumar & Jolly 1986). The A . aijiensis - yielding hori- zon is, however, least productive and mostly yields scanty bone pieces or enamel fragments ; other pos- tcranial elements occurring in this horizon are usually compressed and distorted. The mandible ofA. aifiensis which got buried with symphyseal joint and most teeth intact has also suffered some degree of post burial de- formation which caused fractures and displacement along the symphyseal joint and has considerably distur- bed the disposition and orientation of teeth. However, the morphology of teeth has remained largely unaffec- ted by the deformation.
The ever increasing number of identical or very closely related micro and mega vertebrate species occurring in the Subathu Formation of India and in Kuldana For- mation of Pakistan suggests an undoubtable identical age for the two formations. The land mammal produ- cing parts of Subathu and Kuldana formations are considered as of late Ypresian and Lutetian (late early Eocene or early middle Eocene) age on the basis of fornminiferal biostratigraphy (Nagappa 1959, Meissner et aL 1974, Mathur 1978, Bhatia 1982).
Institutional Abbreviations - BMNH = British Mu- seum of Natural History (London, UK) ; GSP-UM = Geological Survey of Pakistan (Quetta, Pakistan) - University of Michigan (Ann Arbor, USA) ; H-GSP = Howard University (Washington D.C., USA) - Geolo- gical Survey of Pakistan (Quetta and Islamabad, Pa- kistan) ; LUVP = Lucknow University, Vertebrate Paleontology Collection, Departement of Geology (Lu- cknow University, India) ; IPHG (Munich) = Institut fiir Palfiontologie and historische Geologic, Munich (Federal Republic of Germany) ; WIF/A = Wadia Institute Fossil Collection, Wadia Institute of Hima- layan Geology (Dehradun, India).
Repository - The fossils described in this paper are ca- talogued and stored in Museum repository of Wadia Institute of Himalayan Geology, Dehradun, India.
S Y S T E M A T I C P A L E O N T O L O G Y
Class MAMMALIA Order PROBOSCIDEA IUiger, 1811 Family ANTHRACOBUNIDAE Wells & Gingerich, 1983
Emended diagnosis - Medium-sized animals closely related to but considerably smaller than Moeff therium
224
/72 ° /74° [
* ~ " ~ . / - ' , ( ( ! -"--- / WoLA. N ' I
~ MURREE II • / / (" ArT/fSliC_''" . . . . OSLAMABAD/"ll '~ ........ INDIA ~-~
HANGU - 5 / ,.:'CAMPBEL'LPUR • * I'. PUNCH . . . . . . I I I .... ~ K O H A T _/_ (I LAMMIDHAN "., , / )) /-~-¢~,,-~-... I I , , ~ o z ~ - - - , j~s~q l . . . . . . . -"-..~ ~ . , ,
-" ....... -r-.---'- m. \, - t'" ' - - -~ . . . - - f ...... ,~w~L~,,o, ~ ,' ~ ' - - - " I I [ ( ; PAKISTAN ~, ( , / LJ O., I I / . . . . . . . . . . ' ,
---] ,.~1~' O 50 IOOkm ~, .~ s ~ , e "~"°~ I I 351 ~ l I I "K ~AOSHERA.' 2(q( RIASI H / / = - -R ,~ , ~.~,o;~N-"\.~[:::.:?_,, ¶, LI / ~ - =- LR:::i'lies f°r E°cene Anfhr°e°bu3nddpum f a " / " N" "'LH'::~'~ ~" "l~ i / [ d ~ u n d a r y ~ I n f e r n a l i o n a l Boundary ~ )d~i JA~MU 1 I
172° 174 ° ]
Figure 4 - Map showing Eocene an- thracobunid localities of India and Pakistan.
Carte des localitds ~ Antbracobunidds do- cones de l'Inde et du Pakistan.
ANDREWS, 1901. Most forms retain primitive eutherian dental formula but some have much reduced lower ca- nines and first premolars. Lower jaw symphysis short. Lower teeth distinctly lophodont (M/l-M/2 bilopho- dont, M/3 trilophodont) with high conical cusps, me- dium to deep valleys, and smooth to finely rugose or erenulated enamel. Anterior and lingual cusps higher than posterior and buccal cusps respectively. Twinning of cusps is very common. Posterior premolars molari- sed in certain taxa but in others they are semimolari- form to nonmolariform. Lower molars have well defi- ned cristid obliqua and posterior cingular cusps which are paired in last molars ; they lack independent para- conids. Upper molars have characteristic shape (L/W ratios) ; they are usually transverse with length more than posterior width but less than anterior width ; they lack ectoloph. Differs from Moeritheriidae in retaining reduced lower canines and first premolars and in pos- sessing less massive and broad ascending rami.
Included genera -Anthracobune PILGRIM, 1940 ;3"oza- r/a WELLS & GINGERICH, 1983, Pilgrimella DEHM & OETrINGEN-SPIELBERG, 1958 and Lammidhania GIN- GERICH, 1977.
Age and distribution - Early Eocene to middle Eo- cene, northwestern part of the Indian subcontinent (northern South Asia).
GENUS ANTHRACOBUNE PILGRIM, 1940
Emended diagnosis - Large anthracobunids, one-half to two-third the size of Moeritherium. Lower jaws anteriorly shallow with short symphyses terminating near P/2 ; lo- wer canines and first premolars reduced ; P/3 and P/4 nonmolarised ; transversely lophodont lower molars have paraconid connate with metaconid and fairly high crlstid obliqua ; M/3 with prominent subequal hypoconulids.
Upper canines present ; upper premolars with single or double labial cusps ; P3/-P4/possess both lingual and la- bial cusps but only the anterior transverse crest (prepro- tocrista), upper molars lophodont with four major cusps and two well developed conules.
Anthracobune differs from Pilgrimella and Jozaria in high L/W ratio of lower molars, from Pilgrimella in sin- gle talonid cusps on P/3-P/4, high cristid obliqua in lo- wer molars, and in presence of only the anterior trans- verse crest on P3/-P4/, from Jozaria in having normal sized P/3, from Jozaria and Larnmidhania in subequal hypoconulids on M/3, and from Lammidhania in large size, possessing a P/I, P/4 with a paraconid and in hi- gher cristid obliqua.
Included species - Anthracobune pinfoldi PILGRIM, 1940 and A. aijiensis nov. sp.
Age and distribution - As for the family.
ANTHRACOBUNE AIJIENSIS NOV. SP. : pl. 1, figs. 1-4 ; pl. 2, figs. 1-7 ; pl. 3, figs. 1-3.
Origin of name - Named after the Village Aiji where the type locality is situated.
Holotype - WIF/A 1101, left and right dentaries of mandible with partial symphysis, LP/1 to LM/3, RP/2 to RM/3 and an isolated RI/2-3.
Paratype - WIF/A 616, left maxillary fragment with al- veoli for canine, and M3/, roots for P1/, M1/and M2/, a well preserved P2/and lingually damaged P3/-P4/.
Hypodigm - WIF/A 1176 an isolated left DP/3.
Horizon and type locality - Grey siltstone, transitional part of upper Subathu exposed near the Village Aiji
* Measurements from Wells & Gingerich, 1983; ** Measurements from casks.
T a b l e 1 - Comparative m e a s u r e m e n t s ( in mm) o f l o w e r c h e e k t ee th o f E o c e n e a n t h r a e o b u n i d s f r o m Ind ia a n d Pak i s t an .
Dimensions compardes des dentsjugales infdrieures des Anthraaobunidds docdnes de l'lnde at du Pakistan.
on Metka-Mohgala Road (about 200 meters towards Mohgala from kilometer stone showing Metka 3 km, Mohgala 5 km), Rajauri District, Jammu & Kashmir.
Age and distribution - Early middle Eocene, nor- thwestern India.
Specific diagnosis - Medium-sized anthracobunid more than 50 % smaller than A, pinfoldi (calculated on the basis of crown area of lower molars). Symphysis extends to the level of anterior part of P/2 ; lower ca- nine either absent or much reduced (uncertain at this stage due to inadequate data) with more than 15 mm diastema between it and P/1 ; P/1 very reduced and linear (150 % smaller than P/2) with very high L/W ratio (as high as of M/3) ; P/2-P/4 with distinct paraco- nids. P/3-P/4 with single talonid cusps. Lower molars have the highest L/W ratio (average for M/l-M/3 = 1.61, for M/3 = 1.92) than other anthracobunids ; M/1 with double paraconid-metaconid ridge ; upper canine large ; P1/reduced ; P2/-P4/with double labial cusps ; P2/with a much reduced lingual cusp ; upper molars not known.
A. aijiensis differs from A. pinfoldi in smaller size, hi- gher L/W ratio of M/1 and M/3, lower L/W ratio of M/2, double protoconid-metaconid crest, higher cristid obliqua and in upper premolars with double labial cusps.
Description - Upper Dentition - WIF/A 616 is a left maxillary fragment with alveoli for canine and M3/, roots of P1/, M1/ and M2/, a complete P2/, and lin- gually damaged P3/and P4/. Above M2/a major por- tion of the jugal bone which constitutes the lower rim
of the orbit is preserved. Anteriorly, it reaches to the level of M1/and posteriorly it extends beyond the last molar diverging from the maxillary bone above it. Ca- nine is represented by a large, laterally compressed al- veolus approximately 80 and 6 % larger than those for P1/and P2/respectively. The shape and alignment of the alveolus suggests that the tooth was laterally compressed and forwardly directed. The upper canine or its alveolus is not preserved in any on the known anthracobunids hence comparisons with present mate- rial are not possible.
P1/was very reduced (70 % smaller than P2/) and li- near and possibly single-cusped situated close to P2/ but separated from canine by a 5.5 mm long diastema. The corresponding lower tooth is also remarkably re- duced.
P2/is simple, triple-rooted and triangular with a nar- row anterior and a broad posterior portion. A massive paracone and a smaller metacone are separated from each other only near their apices by a distinct notch. On the labial side, a distinct furrow extending between the apical notch and the cingulum delineates the para- cone and metacone. On the lingual side, a similar fur- row is present only in the upper portion of the two cusps. A distinct parastyle is situated along the ante- rior ridge of the paracone slightly below its mid-height. A small ?protocone is present on the lingual side in the posterior haft of the tooth ; its height is one fourth that of the paracone. The protocone and a small pro- toconule are joined by an incipient ridge. From the protoconule a short inflated ridge extends anterola- bially and terminates against the massive lingual face of paracone at about the level of its one-eighth height.
226
Anthracobune aijiemis Anthracobune pinfoldi Pilgrimella pilgrimi Jozaria palustris Lammidhania wardi Tooth L x W L/W L x W L/W L x W L/W L x W L/W L x W L/W
Tab l e 2 - Crown surface a reas ( length X width, expressed in square mil l imeters) and crown sh ap e ( length/width) indices for the lower cheek tee th of E o c e n e an th racobun ids f r o m India and Pakistan.
Indices des surfaces des couronnes (longueur x largeur en mm2) et du contour des couronnes (longueur/largeur) des dentsjugales infdrieures des Anthracobu- nidds.docdnes de l'lnde et du Pakistan.
A strong cingulum encircles the entire tooth excepting a small lingual portion near the protocone ; posterior cingulum is the strongest and forms a distinct shelf.
P3/ is squarish and slightly larger than P/2 and P4/. The morphology of lingual cusps is nearly the same as in P2/. A distinct parastyle is present slightly lingual to the anterior descending ridge of paracone ; it is sepa- rated from a well developed protoconule by a deep notch. A large central protocone is completely dama- ged. The presence of a metaconule is uncertain. A strong cingulum encircles the entire tooth.
P4/ is very similar to P3! but is 22 % smaller with a poorly developed parastyle and a defmite metaconule behind the larger protoconule. The lingual and poste- rior slopes of metacone are not as broad as in P3/. The protocone is heavily damaged but its preserved portion clearly shows that it was robust and situated anteriorly from the centre. A metaconule is distinctly inde- pendent of the metacone.
Mandible - The mandible consists of well preserved dentaries containing complete post canine dentition. Although a part of the symphysis is preserved in WIF/A 1101, none of the incisors and canine or their alveoli are in place. However, an isolated incisor (most
probably an I/2) was found in the matrix attached to left dentary. In all probabilities this incisor belongs to the same individual as WIF/A 1101. Posteriorly, the symphysis extends to the level of anterior part of P/2. In front of first premolar, up to a distance of 15 mm, no evidence of a canine or incisor is present indicating a long diastema. P/3 to M/3 form a close series while P/l, P/2 and P/3 are separated by small (2 mm and 1.5 mm respectively) diastemata. It is not certain as to whether this is a specific character or an individual va- riation.
The depth of dentaries is more or less constant from M/3 to P/3, anterior to which it gets shallower in the symphyseal area suggest'rag a procumbent incisor dis- position as inferred for P. pilgrirni. The posterior por- tion of the mandible containing condyle, coronoid pro- cess and the angular process is damaged. The gradual ascent of ramus starts about one centimeter behind the posterior extremity of the last molar (in P. pilgrimi it rises steeply at the posterior end of M/3). This one centimeter area behind the M/3 is longitudinally divi- ded, into an outer excavated furrow for the attachment of muscle and an inner raised area. The maximum thi- ckness of the dentary in this region is 15 ram.
P L A T E 1
Anthracobune aijiensis sp. nov., WIF/A 1101, holotype. (All views are in stereo pairs). Fig. 1 - Left dentary with P/1 - M/3 in lingual view. Fig. 2 - Left dentary with P/1 - M/3 in labial view. Fig. 3 - Right dentary with P/2 - M/3 in lingual view. Fig. 4 - Right dentary with P/2 - M/3 in labial view. (In all figures scale bar equals 1 cm).
Geobios n o 24,fasc. 2
PI. 1 K. K u m a r
228
Genus & species P1/ P2/ P3/ P4/ M 1/ M2/ M3/ and catalogue nos. L W L W L W L W L W L W L W
Anthracobune aijiensis WIF/A 616
Anthracobune pinfoldi BMNH M 15795
H-GSP 82-31P
Pilgrimella pilgrimi IPHG 1956 II 20
IlPHG 1956 I121
H-GSP 538
LUVP15006
?Lammidhania wardi GSP-UM 549 Note: In the columns showir
11.0? 6.8? 16.8 13.3 16.3 15.5 15.0 15.7
15.5? 18.7 19.0 23.1
19.1 23+ 20.3 26+ 25.0 26+ 26.3" 30+ 27+ 27.6
22.5 25+ 18+
18.2 19.6
18.4
21.0
21.0
18.0 12.0 16.5 17.4 I5.4 18.0 15.8 17.0 18.4
14.4
19.4
14.5
22.0
17.5
20.7
16.7
16.5 17.7 width of molars, the upper figures represent the anterior (maximum) width and the lower figures equal posterior width.
T a b l e 3 - C o m p a r a t i v e m e a s u r e m e n t s (in m m ) of u p p e r c h e e k t ee th o f E o c e n e a n t h r a c o b u n i d s f r o m Ind ia a n d Pak i s t an .
Dimensions compardes des dents jugales supdrieures des Anthracobunidds docdnes de l'Inde et du Pakistan.
Lower Dentition - A small I/2-3 has a transverse main cusp flanked on either side by small accessory cusps, and a deep and straight slender root. The apex of the main cusp is linear and posteriorly sloping. A small an- terior accessory cusp is placed high adjacent to the main cusp ; a slightly larger but lower accessory cusp is positioned similarly on the posterior side. Anterior and posterior descending ridges of the main cusp are thick and extend to the respective accessory cusp, of the two sides. Of these, the anterior ridge is short and gently sloping while the posterior ridge is long and steep. A dissected cingulum is present only on the lingual side. A contact facet is seen on the anterior side of the tooth indicating its close contact with 1/1 or I/2 ; no such facet is present on the posterior side suggesting that it is the last incisor.
P/1 is very small, elongated and double-rooted with a prominent and high protoconid flanked on either side by smaller and much lower cuspids. Of these, the pos- terior cuspid is lower than the anterior which is infla- ted at the base. The cingula are present only on the anterior and posterior borders of the tooth with slight extentions on lingual and labial sides.
P/2 is 61 percent larger than P/1 with anterior portion 25 percent narrower than the posterior. The protoco- nid is the highest cusp extended posterolingually into an incipient metaconid. Along the anterior descending ridge of the protoconid, a small paraconid emerges from above the anterior cingulum and reaches up to two-third height of the protoconid. Its apex is clearly separated from the protoconid by a small notch. In the talonid a central hypoconid orginates slightly above the
posterior cingulum and extends to mid-height of proto- conid. It is also delineated from the protoconid by a notch. The posterior cingulum stretches to two-third length of the tooth on lingual and labial sides while the anterior cingulum covers only one fourth length of the tooth on both sides. On the posterior side, two ridges descend from the apex of the protoconld. Of these, the more pronounced lingual ridge incorporates into it an incipient metaconid and comes down to a notch which separates it from the hypoconid. The outer ridge is strong in the apical part but faints downwards termina- ting near the mid-height of hypoconid on the labial side. An elongated area between the two ridges forms a depression.
A simple nonmolariform P/3 is similar to P/2 but it is 17 % larger. The paraconld is low (1/2 the height of protoconid). A metaconid is much better developed than in P/2 ; it is placed lingual to the protoconid at a lower height with a slight shift towards the posterior side. A strong cingfilum is present all along the poste- rior border of tooth extending on labial and lingual sides up to more than one-third length of tooth. A not so strong cingulum marks the anterior border.
P/4 also has a single-cusped talonid. It is rectangular with a large protoconid and a well separated subequal metaconid. A much reduced paraconid is centrally lo- cated just above the anterior cingulum. The protoco- nid has a ridge which runs down anteriorly and then as it becomes stronger, turns lingually to end up with the anterior cingulum. This ridge passes from above the paraconid. Another relatively steep but poorly defi- ned ridge descends posteriorly from the apex of pro-
229
AnthracobuneaOiensis Anthracobunepi~ldi Pilgri~llapilgrimi ~mmid~niawardi T ~ t h L x W L ~ L x W L ~ L x W L ~ L x W L/W
PI/
P2/
P3/
P4/
PI/- P4/
(Average)
M1/
M2/ M3/
M1/- M3]
(Average)
PI/- M3/
(Average)
74 1.62
223 1.27 290 0.83 216 1.5
253 1.05 458 0.83 287 0.95
235.5 0.95 528 0.78 277 0.85
196 1.22 425? 0.81? 260 1.1
605 0.96 294 0.93
720 0.86 406 0.97
606 0.98
644 0.93 350? 0.95
534 0.87 296? 1.04
292 0.93
Note: Upper teeth of Jozafia palusms are not known.
Table 4 - Crown surface areas (length X width, expressed in square millimeters) and crown shape (length/width) indices for the upper cheek teeth of Eocene anthracobunids from India and Pakistan.
Indices des surfaces des couronnes (longueur x largeur en ram2) et du contour des couronnes (Tongueur/lar- geur) des dentsjugales supdrieures des Anthracobunidds docdnes de l'Inde et du Pakistan.
toconid and merges into the talonid. The protoconld and metaconid are anteriorly separated from each other by a deep furrow which runs vertically almost all along their height. The metaconid also has a ridge running down posteriorly into the talonid. The hypo- conid located in the centre of talonid is half an high as the protoconid. A distinct cristid obliqua emerges from the apex of the hypoconid and runs obliquely to join the posterior face of metaconid, a little below its summit. The cingula are well developed and entire except on the lingual side.
M/1 is 12 and 54 % smaller than P/4 and M/2 respecti- vely. The trigonid and lingual cusps are slightly higher than the talonid and labial cusps respectively. The tri- gonid lacks a paraconid, though there is a well marked "garland" like anterior ridge in the form of a ledge with a parallel furrow descending from the protoconid to a little above the base of metaconid. A protoconid is placed more anteriorly than the metaconid ; the two are joined by a double ridge that encloses a small transverse basin. A fairly high and labially concave cristid obliqua extends from hypoconid to median base of metaconid..The hypoconid is located slightly ante- riorly from the line of entoconid and the two cusps are joined by a distinct transverse crest (hypolophid). The posterior portion of the talonid has a wide shelf with a prominent hypoconulid which is free of the hypolo- phi& A cingulum is very poorly developed except on the posterior border.
M/2 is more robust than M/1 with 35 % greater crown surface area. The anterior part of the cristid obliqua is slightly expanded. In the valley between the hypoconid and protoconid two conspicuous cuspids (mesoconids) are present : the lingual cuspid is globular while the labial one is transversely oblong extending down to the labial cingulum. The anterior, posterior and labial cin- gula are better developed while a lingual cingulum is absent.
M/3 is 17 % longer than M/2 with about 20 % greater crown surface area. It differs from M/2 in that the an- terior of the double protoconid-metaconid crest is poorly developed is the middle where a notch is pre- sent between them. Also the transverse basin between these two cusps is not as well defined. Anterior to the double crest, a distinct ledge - like ridge descends from the protoconid (from below its apex) r , nning pa- rallel to the anterior cingulum and finally mingling into it near the anterolingual corner of the tooth. The verti- cal level of this ledge drops successively from M/1 to M/3. A relatively low cristid obliqua is nearly straight and not labially concave as in anterior molars. In a val- ley between the hypoconid and the protoconid, labial to the cristid obliqua, only one transverse cuspid (me- soconld) is present ; labially it terminates well above the cingulum. A twinned hypoconulid has subequal cusps/lobes. The lingual lobe extends more posteriorly than the labial lobe. From its apex two ridges descend
one runs posteriorly behind the labial lobe and merges into the labial cingulum which, traversing the entire length (labial) of the tooth blends into another ridge that comes down posteriorly from the apex of the protoconid ; the other ridge runs anteriorly ending abruptly near the base of entoconid. The labial lobe also has a ridge that runs anteriorly parallel to the cris- tid obliqua and joins the hypolophid. The two lobes of hypoconulid are independent of each other, but toge- ther they give an appearence of a third lophid. The hypoconulid and hypoconid are separated by a deep but narrow valley which extends to the labial border of the tooth. An anterior cingulum is stronger than in M/1 and M/2.
WIF/A 1176, an isolated DP/3 is elongated and about 88 % longer than wide. The corresponding tooth of Lammidhania (H-GSP 1000) is 100 % longer than wide. A protoconid is much larger than closely placed slightly lower metaconid. The apices of the two cusps are distinctly separated and their posterior slopes are
230
gentler than the anterior. On the anterior side the pro- toconid and metaconid are separated by a deep groove but on the posterior side, they are joined by ridges descending from their apices. A low and conical (25 % lower than protoconld) central paraconid is joined to the protoconid by a faint ridge on the labial side, and is separated from the metaconid by a distinct groove. In H-GSP 1000, a paraconid is very poorly developed. A hypoconid is robust than the equally high, conical entoconid. It is situated slightly posteriorly than the entoeonid. The ectonophid runs obliquely from a point in between the hypoconid and the metaconld and reaches to the apex of the latter cusp.
The posterior cingulum is strong and raised medially in the form of a small swelling which probably repre- sents a hypoconulid. This hypoconulid is joined to the hypoconid by a ridge and is separated from the ento- conid by a valley. The anterior cingulum is not as well developed as the posterior. A lingual cingulum is ab- sent. The labial cingulum is indistinct. The enamel sur- face is nearly smooth and the roots are fairly long.
Holotype - BM(NI-I) M15792, right and left mandibu- lar fragments with parts of M/2 and M/3 plus BM(NH) M15794, an isolated molar trigonid fitted on to the left M/2 of M15792 by Gingerich (1977).
Hypodigm - BM(NH) M15795, left P2/-P3/; M15793, left M/3 ; M32169, right lVi/2 ; H-GSP 82-31 P, left maxillary fragment with P3/-M3/.
Type locality - Lammidhan, north-west of Basal, At- tock District, Punjab Province, Pakistan.
Age and distribution - Middle Eocene, Upper Knlda- na Formation, Attock District, Punjab Province, Pa- ldstan.
Emended diagnosis - Largest species of Anthracobune about 33 % larger than A. aijiensis ; lower molars much broad with anteroposteriorly shortened trigonld portion, fairly high cusps, single metaconld-protoconid crest, low cristid obliqua originating from metaconld ; M/2 with a relatively large hypoconulid, M/3 with in- distinct cristid obliqua and a hypoconufid connected to entoconid by a low ridge. Upper premolars possess single labial cusps, P3/-M3/length = 118 mm ; in up- per molars the length is less than anterior width but greater than posterior width, M3/is more or less trian- gular.
Remarks A. pinfoldi, so far known only from Pakistan, represents the largest anthracobunid. Its dia- gnosis has been emended in this paper in the light of new material from Kalakot and to clear the confusion caused by West's (1983) erroneous synonymy of Pilgri- mella with Anthracobune. West's attribution of maxilla- ry fragment H-GSP 82-31P to A. pinfoldi is correct as indicated by the relative size of corresponding upper and lower teeth an by its distinctness from upper teeth of P. pilgrimi and A. aijiensis. This specimen obviously cannot be associated with Lammidhania because of its much larger size. Similarly it cannot be compared with Jozaria as the size of teeth in H-GSP 82-31P gradually increases posteriorly while in Yozaria the P/3 is much larger than adjacent anterior and posterior teeth. The specimen BM(NH) 32169 was discovered by Gingerich (1977) in the collection from Lammidhan lying in the British Museum, and was referred to RM/1 of P. pin- foldi. The dimensions of this tooth, however, suggest that it is a M/2, hence in the table of measurements in this paper it has been referred as M/2.
Synonymy Pilgrirhella pilgrimi DEHM & OETIINGEN-SPIELBERG, 1958 P. pilgrimi SAHNI & KHARE, 1973. ?P. pilgdmi GINGERICH, 1977. P. pilgrimi COOMBS & COOMBS, 1979. Anthracobune pinfoldi (in part) WEST, 1980. A. pilgrimi WEST, 1983.
P L A T E 2
Anthracobune aijiensis sp. nov., WIF/A 1101, holotype. (All views are in stereo pairs). Fig. 1 - Left dentary with P/1 - M/3 in occlusal view. Fig. 2 - Right dentary with P/2 - M/3 in occlusal view. Fig. 3 - Right 1/2-3 in lingual view. Fig. 4 - Right 1/2-3 in labial view.
A. aijiensis sp. nov., WIF/A 1176. (All views are in stereo pairs). Fig. 5 - Left deciduous P/3 in occlusal view. Fig. 6 - Left deciduous P/3 in labial view. Fig. 7 - Left deciduous P/3 in lingual view. (In all figures scale bar equals 1 cm).
Geobios n ° 24,fasc. 2
H . 2 K. K u m a r
Holotype - IPHG (Munich) 1956 II 20, an isolated right M1/.
HypodigIn - LUVP 15006, right P2/-M2/ ; GSP-UM 687, right M3/ ; H-GSP 1981, left P/l-M/3 and right P/4-M/3.
Type locality - Lammidhan, north of Basal, Attock Di- strict, Punjab Province, Pakistan (Dehm and Oettin- gen-Spielberg's (1958) locality n ° 24 and West and Lu- kacs locality n ° H-GSP 677.
Age and distribution - Late early to Middle Eocene Kuldana Formation, North-west Frontier Province and Punjab Province, Pakistan ; Subathu Formation, Kala- kot, Jammu and Kashmir, India.
Emended diagnosis - Medium -sized anthracobunld, dental formula = 13/3. C1/1. P4/4. M3/3 ; average L/W ratio of lower molars is 1.23 in comparison to 1.6 in Anthracobune, 1.4 in Jozaria and 1.5 in Larnmidha- nia ; M/1 smaller than P/4, M/2 squarish, cristid obli- qua poorly developed ; P/3-P/4 with double talonid cusps. Upper premolars have two labial cusps with both pre and postprotocrista present.
Differs from Anthracobune, Jozaria and Lammidhania in low cristid obliqua and single metaconld-protoconid crest (double in A. aijiensis), from A. aifiensis and J. palustris in P/3 - P/4 with double talonid cusps, fromA. pinfoldi in P3/-P4/with double labial cusps and shape of upper molars, and from A. aifiensis and A. pinfoldi in ouble transverse crests on upper premolars.
Remarks - P. pilgrimi is known from India and Paki- stan by well preserved material. West's (1983) recent synonymy of Pilgrimella with Anthracobune and the proposal of new combination, A. pilgrirni is undoubte- dly erroneous. Pilgtirnella is generically distinct and represents the most primitive anthracobunid. Its diffe- rential characters are discussed under the headings "comparisons" and "discussion" in the following pages of this article. The genus and species P. pilgrimi is, the- refore, retained here on the basis of its original holo- type material and later additions oy upper (LUVP 15006) and lower (H-GSP 1981) dentitions by Sahni and Khare (1973) and West (1980) from India and Pa- kistan respectively.
As pointed out by Wells & Gingerich (1983) the speci- men n ° IPHG (Munich) 1956 II 21 originally described by Dehm & Oettingen-Spielberg (1958) as a left M/2 of Pilgrimella and later included in the hypodigm of the same taxon by West (1983) does not belong in P. pilgrimi. It differs from P. pilgrimi in being substantially smaller, having distinct shape and in possessing a straighter central transverse valley. It could possibly represent an upper molar of Lamrnidhania.
232
COMPARISONS
The lower teeth of Anthracobune aijiensis are most si- milar to those of A. pinfoldi but differ in being sub- stantially smaller ; the M/2 and M/3 have 58 and 54% smaller crown surface area respectively. The respective linear measurments (length and width) of M/2 and M/3 are 27 and 16% and 24 and 33% smaller. Mor- phologically, the lower molars of A. pinfoldi differ from those of A. aijiensis in anteroposteriorly shorte- ned trigonid, single metaconid-protoconid crest and in low cristid obliqua. It may be mentioned here that ho- lotype mandible ofA. aijicnsis belonged to an adult in- dividual. Although a M/1 (BM(NH) 32169) of P. pin- foldi has also been described, its dimensions indicate that it is M/2 ; hence it is not being compared with M/1 of the new species. The L/W ratio of M/3 of A. aifiensis is 1.91 in comparison to 1.67 in A. pinfoldi, since M/1 and lower premolars of the latter species are not known, further comparisons are not possible.
Considering the close similarity in lower teeth, the up- per teeth of A. pinfoldi are surprisingly much distinct from the new species. They are not only larger but also have disproportionate L/W ratios (tabl. 4). The most remarkable distinguishing feature is in P3/ and P4/ which have single labial cusps in contrast to paired ones in the new species. The triangular P2/of the new species is very characteristic and possesses a small in- dependant cingular lingual cusp and paired labial cusps.
The close similarity in lower teeth and marked diffe- rences in upper teeth ofA. pinfoldi and A. aifiensis can by thought to indicate that the upper teeth of these species might belone in some other taxa and not in them, but the present study dearly discards this thought on the basis of various evidences. The upper teeth ofA. pinfoldi are so large sized that on this para- meter they are comparable only with J. palustris among known anthracobunlds. Now if it is presumed that the relative size of lower teeth also reflects on the size of upper teeth, i.e., if a lower tooth is much enlarged, the corresponding upper tooth will also be enlarged, then the affinity of A. pinfoldi with J. palustris is ruled out straight away on the basis of the fact that in J. palustris P/3 is largest among the premolars and is even larger (nearly 12%) than M/l, while in A. pinfoldi the P3/is of normal size being smaller than P4/and M1/and lar- ger than P2/.
The upper teeth of A. panfoldi cannot be compared with P. pilgrimi as this taxon has its own well estab- lished upper dentition which cannot be doubted. Al- though the complete upper dentition of P. pilgrimi is not known from Pakistan where this taxon was first reported on the basis of isolated upper molars and later substantiated by nearly complete lower teeth, its
233
lower dentition has so far not been found in India where welI preserved P2/-M2/ are known, but still it is undoubtedly clear that the ~aterial reported from the two countries belong to single species, P. pilgrimi. The maxillary fragment LUVP 15006 occludes excel- lently well with the dentary H-GSP 1981. In both up- per and lower teeth the first molar is remarkably smaller than preceding and succeeding teeth. Lam- midhania wardi is also not comparable with A. p[nfol- di because of its much smaller size. The Length from P/2 to M/1 in L. wardi is 66.4 mm ; the length of P2/ to M1/ of P. pinfoldi is 80ram, The new species, A. aijiensis has its own upper dentition (described in this article) which occludes pe!:fectly well with its lo- wer teeth, was found within a meters distance from the lower teeth at exactly the same stratigraphic level and is markedly different from the upper teeth of A. pinfoldi. So far the upper dentition of only A. pinfol- di, A. aijiensis and P. pilgrimi are known. They are all closely related but can be distinguisbed specifically. It is thus evident that upper and lower teeth of A. ai]iensis, A. pinfoldi and P. pilgrimi have rightly been identified and associated.
Pilgrimella pilgrimi is of nearly the same size as A. aijiensis but had a closely related yet distinct dental morphology. Its lower dentition differs from the new species in possessing a definite canine ; short or no diastema between P/1 and canine ; a fairly large P/1 ; P/2 with much better developed metaconid ; P/2-P/4 with much better developed paraconid ; P/3-P/4 with better developed and high trigonid cusps and double talonid cusps ; M/1 much smaller than posterior' mo- lars ; almost square M/2, and low cristid obliqua in molars. In P. pilgrimi M/3, the two hypoconulids are posteriorly joined by a low ridge and there are no accessory cuspids lateral to cristid obliqua in molars. The length/width ratio of teeth is much less in P. pil- grimi, the average for premolars and molars combi- ned being 1.32 in comparison to 1.57 in the new spe- cies. In A. aijiensis, the ascending ramus gradually from about one centimeter behind the M/3 while in P. pilgrimi it rises steeply at the posterior and of the M/3.
The upper teeth of A. aifiensis are very similar to those of P. pilgrimi but differ in less overall robus- tness and slightly low-crowned nature. P1/of the new species is very reduced and P2/is simple and triangu- lar with single lingual cusp located free from the la- bial cusps. In P. pilgrimi P2/is complex with a lingual cusp joined to the labial cusps by ridges. P3/and P4/ ofA. aijiensis have only anterior transverse crests (as in A. pinfoldi) which join paracone, protoconule and the protocone (preprotocrista) ; in P. pilgrimi both anterior and posterior crests are present. In P3/of P. pilgrimi a much lower parastyle is more anteriorly lo- cated, a metaconule is very distinct and joined to me-
tacone, the lingual slope of metacone is very steep, the anterior cingulum is not confluent with the poste- rior cingulum and the labial cingulum is strong and entire even in the central portion. In P4 /o f the same species, the cingular shelf on the anterolabial corner of the tooth is not as well delineated from the para- cone as in WIF/A 616. The upper molars of the new species are not known but they can be expected to be morphologically close to P. pilgrimi and A. pin- fotai.
A. aijiensis can be easily distinguished from Z palustn's which possesses 28 to 42% larger lower molars with much less L/W ratio and without metoconids. Y. palus- tr/s is diagnosed by higher and wrinkled cristid obliqua, a very large (larger than M/I) rectangular P/3, P/3-P/4 with well separated trigollid cusps and M/3 with an in- cipient cristid obliqua and unequal (nearly 1 to 5) hypoconulid cusps. The upper dentition of J. palustris is not known.
A. aijiensis has 6 to 20% larger teeth with slightly hi- gher average L/W ratio than Lamrnidhania wardi which most probably lacked the first lower premolar (West 1980). The P/2 of L. wardi is prominently tape- red at both the ends and has a very high L/W ratio (1.0 in comparison to 1.6 in the new species). In L. wardi P/3 is anteriorly very narrow and wedge-shaped with subequal protoeonld and metaconid, an elonga- ted central hypoconid, and a paraconid one-third as high as the protoconid ; in A. aijiensis it has a broad front, a metaconid smaller than protoconid and a pa- raconid half as high as the protoconid. The former species has P/3 and P/4 with distinct and well separa- ted trigonid cusps, higher hypoconid and twinned protoconids in contrast to poorly defined trigonid areas, low hypoconid and single protoconid in the latter taxon. The P/4 ofA. aijiensis has a distinct cris- tid obliqua, a small paraconid, and a metaconid with a strong anterior descending ridge which joins a simi- lar ridge from protoconid and a posterior descending ridge that joins the labial cingulum ; in comparison, the P/4 of L. wardi lacks a paraconid and an anterior descending ridge of metaconid, has a posterior des- tending ridge of metaeonid which does not join the labial cingulum and instead merges into the talonid, and bears a poorly defined cristid obfiqua. In L. war- di, the cingular shelves on the anterolabial borders of P/3 - P/4 are absent and the edges of premolar cusps bear distinct crenulations. The molars of L. wardi have lower cristid obliqua ; its M/3 possesses twinned metaconids and single or unequal hypoconulids, the lingual being exceedingly small (relative size approxi- mately 1 to 15). The only known upper tooth of L. wardi is an isolated P'3] (GSP - UM 549). It is nearly of the same size as P3 /of the new species but differs in being more transverse. It resembles A. pinfoldi in that it has only the anterior tranverse crest and dif-
234
fers in much smaller size and in having paired labial cusps.
DISCUSSION
The peculiar dental morphology of Anthracobune, Jo- zaria, Lamrnidhania and Pilgrimella which in the past had been referred to groups as divergent as Artiodac- tyla, Perissodactyla, Condylarthra and Proboscidea formed the basis for their classification in a separate Family Anthracobunidae (Wells & Gingerich 1983). The new material of Anthracobune from Kalakot not only supports the erection of separate family for these very similar taxa from Indo-Paekistan region but also strengthens their alliance with Moeritheriidae as envi- saged earlier by West (1983) and Wells & Gingerich (1983).
A. ai]iensis shows a few characters which bring the Fa- mily Anthracobunidae closer to the Family Moerithe- riidae in certain respects. These characters are (1) ve- ry reduced first premolars, (II) a long diastema be- tween the first lower premolar and the anterior tooth (canine or an incisor), (III) the complete loss or pre- sence of a much reduced lower canine, (IV) more pro- minent lophodonty, (V) paired subequal hypoconulids and (VI) procumbent symphyseal area. Since anterior part of the symphysis is not preserved in the mandible ofA. aijiensis, the number of incisors and the presence or absence of a lower canine could not be ascertained. The preserved part of the symphysis, however, does show a strong diastema between a very small P/1 and the anterior tooth which could have been either the ca- nine or an incisor. The very reduced nature of first premolar and a fairly long dii~stema clearly suggest that the lower canine was either absent or exceedingly reduced. While these characters indicate close link be- tween Anthracobunidae and Moeritheriidae there are certain other characters which suggest otherwise. The most significant among these are - the ascending rami of Anthracobunids in general and A. aijiensis in parti- cular do not rise abruptly behind the last molar as they do in moeritheriids, instead they rise gradually about one centimeter bebind the M/3 ; also the rami are
much less massive and dense than in moeritheriids. Other notable differences with moeritheriids have been listed and discussed at length by Wells & Ginge- rich (1983).
In the light of present data it is obvious that West's (1983) inclusion of "anthracobunids" in the Family Moeritherhiidae is not appropriate because anthraco- bunids are a distinct group with many primitive characters. The disparities in characters are significant and do not even support their inclusion in moeritheroi- dea. However, with the addition of A. aijiensis in the family the ancestral relationship between Anthracobu- nidae and Moeritheriidae seems to be established beyond suspicion.
Among the known anthracobunids, A. aijiensis appears to be most advance. About Lamrnidhania it is still not sure whether it possessed the first premolar and lower canines or lacked them mad it cannot be confirmed un- til more complete material is found. Similarly the evo- lutionary status of]ozaria andA. pinfoldi cannot be in- terpreted because of tho lack of relevant data. I t is however certain that P. pilgrimi was the most primitive anthracobunid because it not only possessed molari- form premolars but also well developed first premo- lars, lower canines and all the three incisors, and lacked all but rudimentary diastemata. Thus in the cur- rent scenario A. ai]iensis emerges as the most derived anthracobunid in northern South Asia. But still it is clear that no presently known anthracobunid is close enough to Moeritherium to be considered as directly ancestral to it and the existence of an intermediate form between A. aijiensis ond Moeritherium seems ine- vitable.
As regards to ordinal status ot the Family Anthracobu- nidae the available data suggests its closest relations- hip with Proboscidea artd to a lesser degree also with Sirenia and Desmostylia. Its parities and disparities with the aforementioned orders have been dealt with in some detail by wells & Gingerich (1983) and Tassy & Shoshani (1988). Antlgacobunids can be readily dis- tinguished from sirenians on the basis of lesser premo- lar count, double hypoconulids on last lower molars,
PLATE 3
Anthracobune ai]iensis sp. nov., WIF/A 616, paratype. (All views are in stereo pairs). Fig. 1 - Left maxillary fragment with P2/-P4/in labial view. Fig. 2 - Left maxillary fragment with P2/-P4/in occlusal view. Fig. 3 - Left maxillary fragment with P2/-P4/in lingual view.
Ishatherium subathuensis~ holotype. (All views are in stereo pairs). Fig. 4 - Right M2/in lingual view. Fig. 5 - Right M2/in occlusal view.
L subathuensis, paratype. (All views are in stereo pairs). Fig. 6 - Trigonid of left M/1-2 in occlusal view. Fig. 7 - Trigonid of left M/1-2 in anterior view. (In all figures scale bar equals 1 cm).
Geobios n ° 24,fasc. 2
P1.3 K. Kumar
236
almost entire cingula (sirenians usually lack labial and lingual cingula), shorter rostra and symphysis and wea- ker diastemata. Desmostylians, in general, differ from anthracobunids in possessing down turned jaws with upper and lower incisor tusks, M/2 with six cusps as on M/3 of anthracobunids, M/3 with seven cusps (an extra cusp is positioned behind the heel) and upper molars with eight cusps arranged in a unique pattern some- what similar to mastodons. However, some of these characters, viz., M/2 with six and M/3 with seven cusps are not known in Behemotops DOMNING et al. 1986, a recently reported Ollgocene desmostyllan from Pacific Northwest (Domning et al. 1986). While Wells & Gin- gerich (1983) attributed their new family to Probosci- dea, West (1983) who grouped the "anthracobunids" with moeritheriid preferred to be open in deciding on its higher rank and wrote "order uncertain or Probos- cidea". West, however, was certain on the superordinal rank Tethytheria (a term coined by McKenna 1975 to include coordinate orders Proboscidea, Sirenla and Desmostylia) in which he placed Moeritheriidae inclu- ding the "anthracobunlds". The present study supports the inclusion of Anthracobunidae in Proboscidea but still with some reservations.
Regarding the habitat of anthracobunlds their dental morphology suggests that they were purely herbivo- rous feeding probably on soft aquatic vegetation. This is also corroborated by West (1983) and Wells & Gingerich's (1983) interpretation of an amphibious nature and marshy habitat for anthracobunlds. The lithology of sediments which have yielded anthraco- bunids in India and Pakistan consists mainly of marls, siltstone and fine sandstone representing the trans- ition between marine and continental facies and pro- ducing mixed fauna dominated by terrestrial mam- mals. The associated marine mammals include very primitive archaeocete whales, and fish comprise mainly pycnodonts and rare rays. Nearly similar si- tuation prevailed in Moeri thedum - yielding beds of Fayum which also produce archaeocetes in company with moeritheriids. A coastal environment for the de- position of transitional part of the Subathu Forma- tion therefore has the support of paleontological as well as lithological data. And that the shoreline of continuously contracting Tethys was closeby is indi- cated by mixing of marine and land vertebrates. In the field season of 1988, an altogether new vertebrate level, again in the transitional sequence and about 20 km E. of present locality was delineated by this au- thor. This further indicates rapid withdrawl of main Tethys from the area and existence of its remnant in the form of an epicontinental arm which not only supported marine life but also terrestrial life of am- phibious nature. The paleoenvironmental analysis of the coeval Paleogene strata just across the Pakistan border, near Kotli, has recently been done in fair de- tall by Wells & Gingerich (1987). They envisage a
single complete transgressive-regressive cycle for the diposition of the Subuthu Formation during the early Eocene.
COMMENTS ON ISHATHERIUM SUBATHUENSIS
Ishatherium subathuensis based on a nearly complete second upper molar (initiatly identified as a lower mo- lar), an incisor tusk and some post cranial elements was described by S~hni & Kumar (1980) as a dugongid sirenlan from shallow marine lower part of the Suba- thu Formation of Type Area, Subathu, H.P. which is considered as of definito Ypresian age on the basis of foraminiferal biostratigraphy. The material was later substantiated with the fmd of trigonid portion of a left lower molar, probably second (Kumar 1982). Since then a diverse assemblage of sharks, rays and other marine fish has been reported from Ishatheriurn - yiel- ding beds (Kumar & Loyal 1987).
In recent years the validity of I. subathuensis as a sire- nian has been doubted because of its resemblance with Pilgrimella pi lgdmi (Savage, pers. comm, 1981, Ginge- rich & Russell 1981, D0mning et al. 1982, West 1983, and Wells & Gingerich 1983). Domning et al. (1982) while commenting on earliest old world records of Si- rinia quoted Gingerich et aL 1979 : 113) and West (1980 : 509) and noted that the mnmmal-bearing part of the Subathu Formation is generally regarded as late Middle Eocene and that Ishathedurn may not be a si- renian. It is clarified her~ that lshatherium came from lower/middle part of Subathu Formation which is shal- low marine and of Ypresian age. The "late Middle Eo- cene" horizon with which Domning et al. mixed up the Ishatherium horizon lies in the upper transitional part of Subathu Formation and yields terrestrial mammals (the material described in this paper came from this horizon). So the two horizons are stratigraphically wide part and should not be mixed up.
Wells & Gingerich (1983) removed I. subathuensis from Sirenla and grouped it with Pilgrimella in the Fa- mily Anthracobunidae under Proboscidea. Although the molar morphology of Ishathetiurn is very similar to anthracobunlds and to some extent explains its listing with them, the associated incisor tusk with some post cranial material and their occurrence in truely marine Ypresian beds have no resolve.
The RM2/ of I. subathuensis (pl. 3, figs. 4,5) is 15 to 20% larger than most anthracobunids including Pilgri- mella but is of more or less the same size as A. pinfol- di. However, the size of the trigonid of a lower molar (LM/1 or LM/2) which was recovered from approxi- mately the same stratigraphie level as holotype and wi- thin distance of 200 meters is comparable with all
237
known anthracobunids except Lammidhania which is roughly 20% smaller. An intimate study of lshatherium molars indicates that although they have a remarkable parity with anthracobunid teeth they are distinct from all the known taxa of that family. The RM2/(holotype) of disputed sirenian differs from P. pilgrimi mainly in being low-crowned and in possessing more robust wi- dely separated lingual cusps of which the hypocone is slightly higher and placed more lingually than the pro- tocone. The last mentioned character is very striking and is not seen in any of the anthracobunids in which the protocone usually occupies a more lingual position than hypocon e. Another characteristic feature of RM2/is the anterior slope of trigon which is very pro- longed and shelf like ; in anthracobunids this is gene- rally steep. The metacone has an almost vertical lin- gual slope ; a large metaconule is separated from the metacone by a very narrow valley and from the hypo- cone by an open valley. A very distinct metastyle ap- proximately one-third as high as metacone is conspi- cuously present alongside the metacone ; seemingly it originated from the posterolabial cingnlum. None of the anthracobunids possess a metastyle. The protoco- uule is quite distinct and is joined to the paracone by a high sinuous ridge and to the protocone by a much lo- wer ridge. The posterior slope of talon is also prolon- ged as is the anterior slope of trigon ; this feature is not seen in anthracobunids. The posterior cingnlum is strong and raised.
The R M 2 / o f I. subathuensis is of the same size as A. pinfoldi but morphologically just as distinct from it as from P. pilgrimi. The upper molars of A. pinfoldi have even more lingually shifted protocone. The lingual cin- gulum which is very well developed in A. pinfoldi and P. pilgrimi is absent in Ishatherium. Also the upper mo- lar of Ishatherium is longer than broad unlike the si- tuation in A. pinfoldi in which upper molars particular- ly M1/-M2/are squarish to broader than long, the up- per molars of Jozaria, A. aifiensis and Lammidhania are not known hence comparisons with them are not possible.
The trigonid of LM/1-2 of Ishatherium (pl. 3, figs. 6,7) is also distinct from those of anthracobunids. It is rela- tively low-crowned with a robust protoconid and a twinned metaconid. The cristid obliqua is very charac- teristic ; it extends to the apex of metaconid (posterior cusp of the twinned metaconld). The protoconi d and metaconid are joined by a transverse ridge. Another ridge from the metaconid, runs down anteriorly and joins a thick descending ridge from protoconid near its base. A triangular depression is present between the last mentioned ridges and the transverse ridge. The posterior slope of trigonid is relatively prolonged and has rugose enamel. Anterior cingnlum which is usually present in anthracobunids is lacking here. Thus the lo- wer molars of Ishatherium differ from anthracobunid
molar mainly in their low-crowned nature, more robust cusps, origin of cristid obliqua from the apex of meta- conid and in prolongation of the anterior slope of tri- gould.
The association of the incisor tusk (figured and descri- bed as L subathuensis in Szhni & Kumar (1980) with molars cnnnot still be confirmed but possibly it belon- ged in L subathuensis. B~sides the incisor certain post cranial elements, viz., a dorsal vertebra, the distal part of femur and a pelvis (the last element remains undes- cribed) were also tentatively included in L subathuen- sis (S~hni et al: 1980). The above discussion resolves that (I) L subathuensis is distinct from all the known anthracobunids, (II) it already had developed enlarged incisor tusks characteristic for sirenlans, (III) it thrived in shallow marine waters of Ypresian age in associa- tion with sharks, rays and other exclusively marine fish (IV) it is very unlikely that a Ypresian species will per- sist till Lutetian without any significant change. It is thus rather apparent that lshatherium has been erro- neously transferred from Dugongidae (Sirenia) to An- thracobunidae (Proboscidea). In view of the available data the author's present preference is to retain lsha- therium in Sirenia and to regard it a close relative of anthracobunlds and moeritheriids. It is likely that Su- bathu Sirenia and the anthracobunlds descended from a common ancestor and that the former diverged from the anthracobunids in an early stage and evolved sepa- rately.
C O N C L U S I O N S
Anthracobune aijiensis, a new herbivorous land mam- mal is recorded from the early Middle Eocene transitional part of the Subathu Formation, Kalakot, Jammu & Kashmir, India. The new taxon appears to be the most derived anthracobunid and suggests closer affinities between anthracobunids and proboscideans. It possibly lacked a lower canine, and among the an- thracobunids it had closest link with moeritheriids.
Anthracobune is now known by two species, viz., A. ai- fiensis and A. pinfoldi, the latter species representing the largest known anthracobunid.
Ishatherium subathuensis (Sahni & Kumar 1980) is not an anthracobunid. Its very similar, yet distinct dental morphology, enlarged incisor tusks plus its occurrence in shallow marine sediments of Ypresian age in asso- ciation of sharks, rays and other marine fish suggest that it is best placed in Sirenia and that it should be retained in this order until more diagnostic material is forthcoming.
The genus and species Pilgrimella pilgrimi is a valid taxon ; its synonymy withAnthracobune and the propo-
238
sal of new combination, A. pilgrimi by West (1983) is fallacious. P. pilgrimi is the most primitive anthracobu- nid, known from India and Pakistan.
The Family Anthracobunidae thus includes only four genera and five species, viz., Anthracobune pinfoldi, A. aijiensis, Yozaria palustris, Pilgriraella pilgrimi and Lam- midhania wardi.
Among the Tethytheres, anthracobuuids are most simi- lar to proboscideans and it is very likely that they were ancestors of moeritheriids.
The dental morphology of anthracobunids dearly shows their suitability for an aquatic food habit which in turn indicates their adaptability also for an amphi- bious mode and thus a marshy habitat.
The mixing of marine and nonmarine faunal elements in the transitional part of Subathu Formation indicates a coastal depositional environment. It also suggests that the shoreline of rapidly receding Tethys was close- by at the time of deposition of transitional sediments.
Acknowledgements - The author is highly thankful to Drs. Ashok Sahni, Department of Geology, Punjab University, Chandigarh (In- dia), P.D. Gingerich, Department of Paleontology, Michigan Uni- versity Ann Arbor (USA), and Pascal Tassy, Laboratory of Paleon- tology, University of Paris VI (France) for reviewing the manuscript and suggesting many improvements. Thanks are also due to my col- leagues Drs. A.C. Nanda and B.N. Tiwari for going through the ma- nuscript and offering useful suggestions, to Dr. Trilochan Singh for his all round help in preparation of this ms. and to Drs. N.S. Ma- thur and K.P. Juyal for accompanying me in the field. Drs. P.D. Gingerich, Michigan University (USA) and R.M. West, Carnegie Museum, Pittsburgh (USA) provided casts of anthracobunid mate- rial in their care. Various facilities for this research were extended by the Director, Wadia Institute of Himalayan Geology, Dehradun and are gratefully acknowledged. A large part of this ms. was writ- ten at home and my wife Ms. Nishi Kumar's close cooperation in this regard deserves special mention.
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