In the Indus Suture zone, the lower Paleogene sediments are represented by the Indus 
Formation (Danian - Ypresian) and the succeeding Hemis Conglomerate (Mid. - Late Eocene).  The study of biostratigraphic succession of the Indus Formation suggests that marine conditions continued uptil early late Ypresian  in this zone.  The following foraminiferal taxa, indicative of shallow marine conditions, have been recovered from this unit : Alveolina ellipsoidalis, A. ilerdensis, A. trempina, A. schwageri, Glomalv-  
eolina lepidula, Miscellanea miscella, Nummulites minervensis, N. increscens, N. burd. kuepperi, N. burd., N. partchi, Assilina pustulosa, A. pomeroli, A. laminosa, placentula, A. plana, Discocyclina sp., Nodiscocyclina barkeri and Lockhartia hunti.  This was followed by a regressive phase due to upheaval of the region and the upper part of this unit was deposited under brackish to fresh water conditions.  This is evidenced by the occurrence of a zone of Seila, thin shelled oysters and other molluscs overlain by a zone of plant fossils.  It is attributed to the collision between the Indian and Eurasian plates 
leading to closing of the sea from this zone.  It was followed by upheaval along this zone 
with attendant upliftment. The red beds of the youngest fluvio-deltaic Gongmaru  La 
Member of the Indus Formation and the succeeding fluvial Hemis Conglomerate were 
deposited during this phase. 

In the Zanskar Tethyan zone, the uppermost Cretaceous - lower Palaeogene sediments 
comprise the Marpo (Maastrichtian - earliest Thanetian) - Stumpata (early Thanetian) - 
Dibling (early Thanetian - late early Ypresian) - Kong (late early Ypresian - late Ypre- 
sian- Chulung La (latest Ypresian - Lutetian) succession in the South Zanskar belt (SZB) 
and the Goma (Maastrichtian - Danian) -  Lingshet (Thanetian - late early Ypresian) - 
Kong (late early Ypresian - late Ypresian) succession in the North Zanskar belt (NZB). 

In the Himalayan foothills belt, during the deposition of the Subathu sediments there was 
a minor regression of the sea in the early late Ypresian times.  However the final regres- 
sion of the sea from this zone took place in the early Lutetian times.  The two regressive 
phases are evidenced by biozones containing fresh to brackish water taxa, namely Seila,  
Physa, Aplexa and thin-shelled oystes (molluscs); Neocyprideis and Ilyocypris (ostraco- 
des); and chara fruits.  The first regression is related to the collision between the two pla- 
tes resulting in uplift of the region in the early-late Ypresian times.  The final regression in 
the early Lutetian times is attributed to the second uplift of the region due to continued 
collision between the two plates.  However, in certain sections, marine conditions contin- 
ued till the end of Subathu sedimentation as indicated by the occurrence of Nautilus and 
Venericardia (molluscs), as well as Hermanites, Alcopocythere and several other ostrac- 
odes in the youngest zone of the Subathu Formation. 

Fossil assemblages from NW Himalaya indicate progressive southerward withdrawal of 
the Tethys due to upheaval of the regions, i.e. from the Indus Suture zone in the beginning 
of late Ypresian (52 Ma), from the Zanskar Tethyan zone towards the end of Ypresian 
(50 Ma) and from the Himalayan foothills belt in early Lutetian (48 Ma) times. 

Charophytes from the Type Section of Upper Dharmsala Formation were found associt- 
ed with microfish remains and ostracods in large numbers (B.N.Tiwari). Representative 
specimens of the species present in the assemblage were studied and are found to indic- 
ate an age range of late Eocene to early Olgocene. Previous studies on the palaeobiolo- 
gical samples of long ranging forms from the same locality suggested Oligocene/Miocene 
age. 

 Assignment of late Eocene - early Oligocene age to the assemblage from Upper Dhara- 
msala Formation indicates a rather continuous sedimentation in Sirmur Basin following the 
deposition of Marine horizons of Subathu. It can be postulated that a major break in sedi- 
mentation exists between Murree/Dharamsala/Dagshai-Kassauli and Siwalik during south- 
wrd shift of depo-centre from Sirmur Basin to Siwalik Basin. 

Rodentia from Siwalik continue to be useful in further refining temporal aspect of the seq- 
uence in general and of location in particular. Assemblage of rodent molars currently under 
study is from a locality near Trilokpur, near Kotla in Himachal Pradesh and the sample size 
is still being increased. Isolated rodent molars along with associated microfaunal compon- 
ents from the locality  are recovered.  Recently a ctenodactylid rodent molar was added to 
the Progonomys and associated murid rodents from locality. With discovery of this cteno- 
dactylid element the whole assemblage assumes palaeobiogeographical signifiance. Cteno- 
dactylids are essentially Eastern and Central Asian Group of rodents and immigrated to 
Southern Asia during a spell of drier and cooler climate in this region. 

Kishor Kumar studied vertebrate remains associated with molluscs and plant remains 
have been recovered from the the Ladakh Molasse Group.   In the western  Ladakh 
(Kargil  region), the basal part of the  group, i.e., the Kargil Formation has yielded 
diverse material represented by artiodactyls,  rodents, snakes, testudines, crocodilians 
 and fish.  The vertebrates from the overlying Tarumsa and Pashkyum formations are 
dominated by fish, though other lower vertebrates are also present. From the Pashkyum 
Formation a few rodent incisorteeth were also recovered.  Their preliminary study sugg- 
ests that these incisors may belong to some very primitive cricetids.  In the Nyoma region, 
eastern Ladakh  the  Kuksho Formation has  yielded  fish remains associated with moll- 
uscs, ostracodes and plants. From the overlying Karit Formation only bone fragments 
of unknown affinity  have been  recovered so far. 
 
Additional vertebrates from the Kargil Formation include a few upper molars of traguloid 
artiodactyls and some rodents and the fish are represented by   fresh water families, Cyprinidae, Siluridae and Channidae. On the basis of rodent and artiodactyl fauna, the lower part of  the Ladakh Molasse Group is considered as of Oligo-Miocene age.  No age diagnostic fossils have so far been found in the Tarumsa and Pashkyum formations but, being stratigraphically younger, they are obviously of Miocene age. The Pashkyum Formation, however,  may also extend into Pliocene as indicated by the  molluscan fauna.  From the Kuksho and Karit formations, the faunal evidence is inadequate for chronological interpretations. Lithostratigraphically , however, they appear to be coevals of Tarumsa and Pashkyum formations of western Ladakh. 

The fairly diverse nature of the lower vertebrate community from the Ladakh Molasse Group suggests a moderately evolved food web cycle.  The majority of the vertebrate elements from the Ladakh Molasse Group  were of  small size  which implies that the habitat was not rich enough to support the larger animals and land  dwelling  predators. 
 
A restudy of the 'diacodexine' material from the Subathu sediments of Kalakot area (Kumar and Jolly, 1987) in the light of recently published literature has indicated that the material does show some primitive primate characters, and there is a possibility that it actually belongs to a primitive primate. Further study of this material is presently on and exciting results are expected.