The Lameta Formation, also known as the Infratrappean Beds (not to be confused with the contemporaneous Intertrappean Beds), is a sedimentary geological formation found in Madhya Pradesh, Gujarat, Maharashtra, Telangana, and Andhra Pradesh, India, associated with the Deccan Traps. It is of the Maastrichtian age (Late Cretaceous), and is notable for its dinosaur fossils.
History
The first fossils found in the Lameta Formation were discovered between 1917 and 1919.F. v. Huene and C. A. Matley, (1933), "The Cretaceous Saurischia and Ornithischia of the Central Provinces of India", Palaeontologica Indica (New Series), Memoirs of the Geological Survey of India 21(1): 1-74
The Lameta Formation was first identified in 1981 by geologists working for the Geological Survey of India (GSI), G. N. Dwivedi and Dhananjay Mahendrakumar Mohabey, after being given limestone structures–later recognised as dinosaur eggs–by workers of the ACC Cement Quarry in the village of Rahioli near the city Balasinor in the Gujarat state of western India.
Lithology
The formation is underlain by the Lower Cretaceous sedimentary "Upper Gondwana Sequence" also known as the Jabalpur Formation, and is overlain by the Deccan Traps basalt. The Lameta Formation is only exposed at the surface as small isolated outcrops associated with the Satpura Fault. The lithology of the formation, depending on the outcrop, consists of alternating clay, siltstone and sandstone facies, deposited in fluvial and lacustrine conditions. The environment at the time of deposition has alternatively been considered semi-arid, or tropical humid.
Fossil content Many dubious names have been created for isolated bones, but several genera of dinosaurs from these rocks are well-supported, including the titanosaur sauropods Isisaurus and Jainosaurus and the Abelisaurs Indosaurus, Indosuchus, and Rajasaurus and the Noasaurids Laevisuchus and ‘’Jubbulpuria’’.Weishampel et al., 2004, pp.517-606 Synapsids are also known form the formation, such as the possibly late surviving Avashishta, possibly the last known non- mammalian synapsid the possibly youngest known stegosaurian ichnogenus Deltapodus, madtsoiid snakes and other fossils.
Dinosaurs
Ornithischians Genus Species Location Stratigraphic position Material Notes Images Ankylosauria? Indet.IndeterminateRahioliIsolated vertebrae, scapulocoracoid, humerus, femur, and several armor fragments such as hollow lateral spikes and solid dorsal scutes.Described as a nodosaurid, but the limb bones are titanosaurian. Brachypodosaurus B. gravis Chota Simla Hill "Humerus.""Table 17.1," in Weishampel, et al. (2004). Page 367. May not be dinosaurian Ceratopsia? Indet.IndeterminateKheda Horncore base.Originally described as a ceratopsian horncore, but likely represents a theropod limb element or a dorsal rib of a theropod or a titanosauriform. Deltapodussp.JetholiSolitary footprint.A Possible Late Cretaceous Stegosaur, Like Dravidosaurus. Hypsilophodontidae? Indet. Indeterminate. Marepalli, Jabalpur Teeth and other materials. Hypsilophodontidae is not a natural grouping. Ornithischia? Indet.D. M. Mohabey. 1989. The braincase of a dinosaur from the Late Cretaceous Lameta Formation, Kheda District, Gujarat, western India. Indian Journal of Earth Sciences 16(2):132-135.IndeterminateKhedaGSI/GC/2905 Originally identified as an indeterminate ornithischian braincase. Later found out to be a Titanosaur dorsal vertebra.Wilson, J.A.; Malkani, M. S.; Gingerich, P. D. 2004. A Sauropod Braincase from the Pab Formation (Upper Cretaceous, Maastrichtian) of Balochistan, Pakistan. Gondwana Geological Magazine, Special Volume 8:101-109. Parankylosauria Indet. Indeterminate Rahioli A parankylosaurSpheroolithus?sp.Polgaon, TidkeparEgg fossils.Questionably assigned to this genus
Sauropods Genus Species Location Stratigraphic position Material Notes Images Isisaurus I. colbertiDongargaon Hill Taunri Holotype skeleton consists of cervical, dorsal, sacral, caudal vertebrae, ribs, pelvis, scapula, coracoid, left forelimb, and other bones. Other specimens, such as the skull, hindlimb, and foot bones, are unknown. A lithostrotian titanosaur.Jainosaurus J. septentrionalisBara Simla Taunri "Basicranium and partial postcranial skeleton.""Table 13.1," in Weishampel, et al. (2004). Page 269. "Humerus and Femur". A colossosaurian titanosaur. J. cf. septentrionalis Chhota SimlaPartial skeleton including a rib fragrement, caudal centrum, humeri, radius and an articulated left limb. Titanosaurus T. blanfordiBara Simla Panchgaon Pisdura Hill Caudal vertebrae."Table 13.1," in Weishampel, et al. (2004). Page 270. A dubious genus of titanosaur. T. indicusBara Simla Pisdura Hill Caudal Vertebrae, two partial rami of haemapophysis, partial left tibia, partial right fibula, and a partial referred femur. T.? rahioliensis Rahioli Village About 34 teeth in total. Might not belong to this genus.Megaloolithus M. cylindricusChui Hill, Bara Simla, Nand region, Pavan, Ghorpend, Bagh Caves, Dhar, Indwan, Kadwal, Dholiya Raipuriya village, Akhada village, Jhaba village, Padlya village, Jhabua, Dohad, Jhalod, Garadi, Kheda, Rahioli, Dholi Dungri. Multiple specimens consist of fossilized egg shells that are covered in volcanic sediments Sauropod egg fossilsM. dhoridungriensisM. jabalpurensisM. khempurensisM. megadermusM. problematicaM. walpurensisM. sp. Titanosauriformes Indet. Indeterminate Ukala. Dorsal vertebrae, parts of the ilia and pelvis, and limb bones. A titanosauriform sauropod.Sauropoda Indet.indeterminateRahioliSeveral HumeriThe humeri ranges from 70 to 85 cm in length, they have gracility index that ranges from 73 to 78.Titanosauria Indet.Wilson, J. A., P. C. Sereno, S. Srivastava, D. K. Bhatt, A. Khosla, and A. Sahni. 2003. "A new abelisaurid (Dinosauria, Theropoda) from the Lameta Formation (Cretaceous, Maastrichtian) of India", Contributions from the Museum of Paleontology of the University of Michigan, 31:6Chatterjee, S. & D.K. Rudra (1996). "KT events in India: impact, rifting, volcanism and dinosaur extinction". Memoir of the Queensland Museum 39(3): 513indeterminateTemple Hill, Rahiolidisarticulated remains.Discovered alongside the Rajasaurus holotype.Bara Simlapartial skeleton, consisting of limb bones(including a femur), girdles, vertebrae(including cervical and caudal vertebrae) and a braincase.An indeterminate Titanosaur.Rajulwari villagePRASAD, K.N. & VERMA, K.K. (1967) "Occurrence of dinosaurian remains from the Lameta beds of Umrer, Nagpur district, Maharashtra". Current Science 36(2): 547-548.9 to 10th caudal vertebrae and a nearly complete hindlimb(with femur, tibia, fibula and phalanges) that measures 2.1 metres.Orignally referred to Titanosaurus indicus.TaunriPost Cranial material.Indeterminate titanosaurs.
Theropods
Abelisaurids Genus Species Location Stratigraphic position Material Notes Images Abelisauroidea Indet.IndeterminateMultiple specimens.Could be referred to Abelisauridae or Noasauridae.AbelisauridaeIndeterminateMultiple specimens.Include form similar to Majungasaurus and forms similar to Carnotaurus.CompsosuchusC. solusBara Simla"Vertebrae"Previously considered a Noasaurid now considered an indeterminate Abelisaurid Indosaurus I. matleyi Bara Simla Partial skeleton, including a partial skull. A majungasaurine abelisaurid Dryptosauroides D. grandis Bara Simla "Vertebrae." A abelisaurd theropodEllipsoolithusD. M. Mohabey. 1998. Systematics of Indian Upper Cretaceous dinosaur and chelonian eggshells. Journal of Vertebrate Paleontology 18(2):348-362E. khedaensisKhedaEggsTheropod egg fossils. Indosuchus I. raptorius Bara Simla Cranial remains, including two braincases, as well as a nearly complete skeleton. A abelisaurid theropod Ornithomimoides O. barasimlensis Bara Simla "Vertebrae."A abelisaurid theropod O. mobilis Bara Simla "Vertebrae" Orthogoniosaurus O. matleyi Bara Simla "Tooth" A abelisaurid theropod Rahiolisaurus R. gujaratensis Rahioli Village Cervical, dorsal, sacral, and caudal vertebrae, portions of pectoral and pelvic girdles, and several hind limb bones of different individuals. A brachyrostran abelisaurid Rajasaurus R. narmadensis Temple Hill, Rahioli A partial skeleton consists of maxillae, premaxillae, braincase, and quadrate bone on the skull; and spine, hip bone, legs, and tail in post-cranial remains. A majungasaurine abelisaurid
Noasaurids Genus Species Location Stratigraphic position Material Notes Images Laevisuchus L. indicus Bara Simla Only vertebrae."Table 3.1," in Weishampel, et al. (2004). Page 49. A noasaurine noasaurid. Noasaurinae Indet.IndeterminatePisdura Hill A partial dentary.A noasaurine noasaurid.Noasauridae Indet.IndeterminateMultiple specimens.May include femora from very large individuals.
Other Theropods Genus Species Location Stratigraphic position Material Notes Images Coeluroides C. largus Bara Simla "Isolated vertebrae.""Table 3.1," in Weishampel, et al. (2004). Page 50. A Indeterminate theropod also known from Dabrazhin Formation of Kazakhstan JubbulpuriaJ. tenuisBara Simla"Vertebrae."Likely junior synonym of Laevisuchus?MegalosaurusType A-ERahioliSeveral teeth The overall length of the teeths ranges from 0.7 to 6 cm, all were originally identified as belonging to Megalosaurus,(beside GSI Type No. 19988 as it was identified as a Majungasaurus tooth). However a specimen(GSI Type No. 19996) may instead represent a troodontid. Ornithomimidae? Indet.Weishampel, et al. (2004). "Dinosaur distribution." Pp. 517-607. IndeterminateBara SimlaCeratosaurian taxa from the Lameta Formation have been erroneously referred to ornithomimdae.Theropoda Indet.IndeterminateGSI K27/572, fragmentary cervical vertebra.Initially described as allosauroid. But the researchers didn't classify it as an abelisaurid, possibly representing a member of a clade outside of abelisauroidea, the preserved height of the vertebra is 16 cm.TrachoolithusTrachoolithus in the Paleobiology DatabaseT. faticanus Bara SimlaEggs.Theropod egg fossils.
Indeterminate or chimaeric taxa Genus Species Location Stratigraphic position Material Notes Images "Dubeynarainsaurus" "D. sahni"Sirolkhal"Partial dentary with associated teeth."May instead be a pterosaur, proposed to be either belonging to the Infratrappean or Intertrappean beds, although if it were a pterosaur it would not be Maastrichtian. Lametasaurus L. indicus Bara Simla "Sacrum, ilia, tibia." "Sacrum, ilia, tibia, spines, armor.""Table 17.1," in Weishampel, et al. (2004). Page 368. Includes crocodylomorph, titanosaur scutes and possibly ankylosaurian osteoderms. Also includes abelisaurid material now removed from the type and is being assigned to the Rajasaurus.
Reptiles
Snakes Genus Species Location Stratigraphic position Material Notes Images Madtsoia M. pisdurensis Pidura Hill Upper A madtsoiid snake. Sanajeh S. indicus Dholi Dungri A skull, precloaca vertebrae and ribs. A madtsoiid snake.
Crocodylomorphs Genus Species Location Stratigraphic position Material Notes Images Dyrosauridae Indet.Rana, R. S. 1987. Dyrosaurid crocodile (Mesosuchia) from the infratrap pean beds of Vikarabad, Hyderabad District, Andhra-Pradesh. Cur rent Science 56:532-534 Indeterminate. Kisalpuri and Vikarabad. Vertebrae, eggs and teeth. A non-phosphatosaurinae dyrosaurid neosuchian.
Turtles Genus Species Location Stratigraphic position Material Notes Images Jainemys J. pisdurensis Pisdura hill A kurmademydin kurmademydine.Pelomedusidae Indet.D. M. Mohabey. 1990. Discovery of dinosaur nesting site in Maharashtra. Gondwana Geological Magazine 3:32-34.S. L. Jain and A. Sahni. 1983. Some Upper Cretaceous vertebrates from central India and their palaeogeographic implications. In H. K. Maheshwari (ed.), Proceedings of the Symposium on "Cretaceous of India: Palaeoecology, Palaeogeography and Time Boundaries", Lucknow. Indian Association of Palynostratigraphers 66-83.IndeterminateA turtle.
Mammals