Record of Additional Middle Eocene Vertebrate Remains from the Mikir Hills, NE India: Implications on Paleoenvironment and Paleobiogeography

The fossiliferous middle Eocene deposits of Sylhet Limestone of Mikir Hills have yielded vertebrate and invertebrate faunas. The fossil assemblages recorded in this contribution consist of shark, ray, crocodile, conical tooth, broken fragments and echinoderm spines. Ray and crocodile tooth are reporting for the first time from the Mikir Hills. Paleoenvironmental analysis based on the fossil fish assemblage in association with invertebrate (foraminifera) remains and sedimentogical observations suggest a shallow marine environment ranging from open marine, inner neritic to more proximal coastal settings. Also, the presence of common marine elements (similar faunas) from Kutch, Rajasthan, Himachal Pradesh, Assam (India), New Hampshire, Libya, Iraq, Iran, North Western Sahara (Algeria), Tanzania (East Africa), Italy, Germany, Southern North Sea basin (Europe) based on previous published works and the present finding testifies to the connection of the Tethys Sea during Lutetian-Bartonian of middle Eocene.

Early Cambrian Ichnofossils from the Mussoorie Syncline and revision of Trace Fossil Biozonation of the Lesser Himalaya, India

A new locality bearing ichnofossils of the Cruziana Assemblage Zone-Ⅲ from the Mussoorie syncline,Lesser Himalaya,is located in rocks of Member-B of the Dhaulagiri Formation,Tal Group,exposed along the Maldewta-Chhimoli fresh road cut section.The site yielded ichnofossils Bergaueria perata,Cochlichnus anguineus,？Diplocraterion isp.,Dimorphichnus obliquus,diplichnitiform Cruziana bonariensis,Diplichnites gouldi,Glockeria isp.,Helminthopsis isp.,Monomorphichnus lineatus,Phycodes palmatum,Palaeophycus striatus,Planolites beverleyensis,Planolites montanus,Treptichnus cf.T.pedum,scratch marks and an undetermined worm impression.An Early Cambrian age （Cambrian Series 2） is assigned to the ichnofossil-bearing strata based on the stratigraphic position between the Drepanuroides and Palaeoolenus trilobite zones.A revised Cambrian ichnofossil zonation is presented for the Tal Group of the Mussoorie syncline.Together with their occurrence on rippled surfaces,and the lateral displacement of some trackways （due to current action）,a sub-aqueous shallow-marine depositional setting is proposed for the rocks of Member-B.

Ichnofossils from the Miocene Middle Bhuban Formation, Mizoram, Northeast India and their Paleoenvironmental Significance

An ichnofossil assemblage is preserved in sediments of the Middle Bhuban Formation, Surma Group, of Miocene age from the Durtlang and Chanmari sections, Aizawl district, Mizoram, northeastern India. The studied sections comprise a thick, bioturbated and thinly bedded sandstone-silty shale facies. The preserved ichnofossils show high density and low diversity with the assemblage represented by feeding and resting traces, i.e., Psilonichnus upsilon Frey et al., 1984, Ophiomorpha isp., Teichichnus spiralis Mikulas. 1990, Skolithos isp., Palaeophycus isp., and other horizontal burrows. Sedimentary structures associated with these traces are mainly cross bedding, flaser bedding and slump structures. Considering the distribution of the Psilonichnus ichnogenus across an integrated ichnological-sedimentological framework, the stratigraphic interval of the Middle Bhuban Formation, in which they occur, are interpreted to have been deposited under a shallow, marginal-marine channel complex dominated by tidal channels developed in quiet, brackish-water portions of a delta plain.