Wikipedia
Lameta Formation
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.[1] It is of the Maastrichtian age (Late Cretaceous), and is notable for its dinosaur fossils
| Lameta Formation | |
|---|---|
| Stratigraphic range: Maastrichtian ~ | |
Exposure of the Lameta Formation at its type locality of Lameta | |
| Type | Geological formation |
| Underlies | Intertrappean Beds, Deccan Traps deposits |
| Overlies | Jabalpur Group or Precambrian Basement |
| Area | 5,000 km2 (1,900 sq mi) |
| Thickness | Variable, typically 18–45 m (59–148 ft) |
| Lithology | |
| Primary | Claystone, sandstone limestone |
| Other | Conglomerate |
| Location | |
| Coordinates | 23°12′N 80°00′E / 23.2°N 80.0°E |
| Approximate paleocoordinates | 24°42′S 63°12′E / 24.7°S 63.2°E |
| Region | Western India |
| Country | India |
| Extent | Madhya Pradesh, Gujarat, Maharashtra, Andhra Pradesh, Telangana |
| Type section | |
| Named for | Lameta Ghat |
Lameta Formation (India) | |
History edit
The first fossils found in the Lameta Formation were discovered between 1917 and 1919.[2]
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.[3]
Lithology edit
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.[4][5]
Fossil content edit
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 Noasaurids Laevisuchus.[6] Mammals are also known form the formation, such as the possibly late surviving Avashishta, the possibly youngest know stegosaurian Deltapodus, madtsoiid snakes and other fossils.
Dinosaurs edit
Color key
| Notes Uncertain or tentative taxa are in small text; |
- Sauropods
| Genus | Species | Location | Stratigraphic position | Material | Notes | Images |
|---|---|---|---|---|---|---|
| Isisaurus | I. colberti | Dongargaon Hill | Holotype skeleton consists of cervical, dorsal, sacral, caudal vertebrae, ribs, pelvis, scapula, coracoid, left forelimb, and other bones. Other specimens such as skull, hindlimb, and foot bones are unknown. | A titanosaur. | ||
| Jainosaurus | J. septentrionalis | Bara Simla | "Basicranium and partial postcranial skeleton."[7] | A titanosaur. | ||
| Titanosaurus | T. blanfordi | "Caudal vertebrae."[8] | A titanosaur. | |||
| T. indicus | "Teeth"[9] | |||||
| Megaloolithus[10] | M. cylindricus | Sauropod egg fossils | ||||
| M. dhoridungriensis | ||||||
| M. jabalpurensis | ||||||
| M. khempurensis | ||||||
| M. megadermus | ||||||
| M. problematica | ||||||
| M. walpurensis | ||||||
| M. sp. |
- Theropods
| Genus | Species | Location | Stratigraphic position | Material | Notes | Images |
|---|---|---|---|---|---|---|
| Compsosuchus | C. solus | "Vertebrae" | Previously considered a Noasaurid now considered an indeterminate Abelisaurid[11] | |||
| Coeluroides | C. largus | Bara Simla | "Isolated vertebrae."[12] | A Indeterminate theropod also known from Dabrazhin Formation of Kazakhstan | ||
| Dryptosauroides | D. grandis | Bara Simla | "Vertebrae."[12] | |||
| Indosaurus | I. matleyi | Bara Simla | Partial skeleton, including a partial skull.[13] | |||
| Indosuchus | I. raptorius | Bara Simla | Cranial remains, including two braincases, as well as a nearly complete skeleton.[13] | An abelisaurid theropod. | ||
| Jubbulpuria | J. tenuis | "Vertebrae."[12] | Likely junior synonym of Laevisuchus[14] | |||
| Lametasaurus | L. indicus | Bara Simla | "Sacrum, ilia, tibia."[12] "Sacrum, ilia, tibia, spines, armor."[15] | |||
| Laevisuchus | L. indicus | Bara Simla | Only vertebrae.[13] | A noasaurid | ||
| Ornithomimoides | O. barasimlensis | Bara Simla | "Vertebrae."[12] | An abelisaurid[14] | ||
| O. mobilis | Bara Simla | "Vertebrae"[12] | ||||
| Orthogoniosaurus | O. matleyi | Bara Simla | "Tooth"[12] | |||
| 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. | An 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. | An abelisaurid. | ||
| Noasauridae | Indeterminate | A partial dentary[14] | A noasaurid. |
- Ornithischian
| Genus | Species | Location | Stratigraphic position | Material | Notes | Images |
|---|---|---|---|---|---|---|
| Brachypodosaurus | B. gravis | "Humerus."[16] | May not be dinosaurian | |||
| Spheroolithus? | Sp. | Polgaon, Tidkepar | Egg fossils | Questionably assigned to this genus[17] | ||
| Deltapodus[18] | Solitary footprint | Possibly a Late Cretaceous Stegosaur, Like Dravidosaurus | ||||
| Ankylosauria | Indeterminate | Rahioli | Isolated vertebrae, scapulocoracoid, humerus, femur, and several armor fragments such as hollow lateral spikes and solid dorsal scutes.[19] | Possibly a nodosaurid. |
Reptile edit
Snakes edit
| Genus | Species | Location | Stratigraphic position | Material | Notes | Images |
|---|---|---|---|---|---|---|
| Sanajeh | S. indicus | A skull, precloaca vertebrae and ribs. | A madtsoiid snake | |||
| Madtsoia | M. pisdurensis[20] | A madtsoiid snake |
Turtles edit
| Genus | Species | Location | Stratigraphic position | Material | Notes | Images |
|---|---|---|---|---|---|---|
| Jainemys | J. pisdurensis | A bothremydid side-necked turtle |
Mammals edit
| Genus | Species | Location | Stratigraphic position | Material | Notes | Images |
|---|---|---|---|---|---|---|
| Avashishta | A. bacharamensis | A Haramiyida Mammal |
Mollusca edit
See also edit
- List of dinosaur-bearing rock formations
- Geology of India
- Deccan Traps
- Maevarano Formation, contemporaneous fossiliferous formation of Madagascar
- Intertrappean Beds contemporaneous formation in India, also known for its fossils
References edit
- ^ Wilson Mantilla, Gregory P.; Renne, Paul R.; Samant, Bandana; Mohabey, Dhananjay M.; Dhobale, Anup; Tholt, Andrew J.; Tobin, Thomas S.; Widdowson, Mike; Anantharaman, S.; Dassarma, Dilip Chandra; Wilson Mantilla, Jeffrey A. (2022-04-01). "New mammals from the Naskal intertrappean site and the age of India's earliest eutherians". Palaeogeography, Palaeoclimatology, Palaeoecology. 591: 110857. Bibcode:2022PPP...59110857W. doi:10.1016/j.palaeo.2022.110857. ISSN 0031-0182.
- ^ 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
- ^ Wilson, J. A.; Sereno, P. C.; Srivastava, S.; Bhatt, D. K.; Khosla, A.; Sahni, A. (2003). "A new abelisaurid (Dinosauria, Theropoda) from the Lameta Formation (Cretaceous, Maastrichtian) of India" (PDF). Contributions from the Museum of Paleontology University of Michigan. 31 (1): 1–42.
- ^ Srivastava, Ashok K.; Mankar, Rupesh S. (January 2015). "Lithofacies architecture and depositional environment of Late Cretaceous Lameta Formation, central India". Arabian Journal of Geosciences. 8 (1): 207–226. Bibcode:2015ArJG....8..207S. doi:10.1007/s12517-013-1192-y. ISSN 1866-7511. S2CID 67851941.
- ^ Kumari, Anjali; Singh, Seema; Khosla, Ashu (January 2021). "Palaeosols and palaeoclimate reconstruction of the Maastrichtian Lameta Formation, Central India". Cretaceous Research. 117: 104632. Bibcode:2021CrRes.11704632K. doi:10.1016/j.cretres.2020.104632. S2CID 224946979.
- ^ Weishampel et al., 2004, pp.517-606
- ^ "Table 13.1," in Weishampel, et al. (2004). Page 269.
- ^ "Table 13.1," in Weishampel, et al. (2004). Page 270.
- ^ "Table 13.1," in Weishampel, et al. (2004). Page 271.
- ^ Khosla, Ashu; Lucas, Spencer G. (2020), "Discussion: Oospecies Diversity, Biomineralization Aspects, Taphonomical, Biostratigraphical, Palaeoenvironmental, Palaeoecological and Palaeobiogeographical Inferences of the Dinosaur-Bearing Lameta Formation of Peninsular India", Late Cretaceous Dinosaur Eggs and Eggshells of Peninsular India, vol. 51, Cham: Springer International Publishing, pp. 207–271, doi:10.1007/978-3-030-56454-4_5, ISBN 978-3-030-56453-7, retrieved 2024-01-21
- ^ Mohabey, D. M.; Samant, B.; Vélez-Rosado, K. I.; Wilson Mantilla, J. A. (2024). "A review of small-bodied theropod dinosaurs from the Upper Cretaceous of India, with description of new cranial remains of a noasaurid (Theropoda: Abelisauria)". Journal of Vertebrate Paleontology. e2288088. doi:10.1080/02724634.2023.2288088.
- ^ a b c d e f g "Table 3.1," in Weishampel, et al. (2004). Page 50.
- ^ a b c "Table 3.1," in Weishampel, et al. (2004). Page 49.
- ^ a b c Mohabey, Dhananjay M.; Samant, Bandana; Vélez-Rosado, Kevin I.; Wilson Mantilla, Jeffrey A. (2024-02-07). "A review of small-bodied theropod dinosaurs from the Upper Cretaceous of India, with description of new cranial remains of a noasaurid (Theropoda: Abelisauria)". Journal of Vertebrate Paleontology. doi:10.1080/02724634.2023.2288088. ISSN 0272-4634.
- ^ "Table 17.1," in Weishampel, et al. (2004). Page 368.
- ^ "Table 17.1," in Weishampel, et al. (2004). Page 367.
- ^ Khosla, Ashu; Lucas, Spencer G. (2020), "Indian Late Cretaceous Dinosaur Nesting Sites and Their Systematic Studies", Late Cretaceous Dinosaur Eggs and Eggshells of Peninsular India, vol. 51, Cham: Springer International Publishing, pp. 117–205, doi:10.1007/978-3-030-56454-4_4, ISBN 978-3-030-56453-7, retrieved 2024-02-13
- ^ Galton, Peter M.; Ayyasami, Krishnan (2017-07-01). "Purported latest bone of a plated dinosaur (Ornithischia: Stegosauria), a "dermal plate" from the Maastrichtian (Upper Cretaceous) of southern India". Neues Jahrbuch für Geologie und Paläontologie - Abhandlungen. 285 (1): 91–96. doi:10.1127/njgpa/2017/0671. ISSN 0077-7749.
- ^ Chatterjee, Sankar (2020), Prasad, Guntupalli V.R.; Patnaik, Rajeev (eds.), "The Age of Dinosaurs in the Land of Gonds", Biological Consequences of Plate Tectonics: New Perspectives on Post-Gondwana Break-up–A Tribute to Ashok Sahni, Vertebrate Paleobiology and Paleoanthropology, Cham: Springer International Publishing, pp. 181–226, doi:10.1007/978-3-030-49753-8_8, ISBN 978-3-030-49753-8, retrieved 2024-03-29
- ^ Mohabey, D.M.; Head, J.J.; Wilson, J.A. (2011). "A new species of the snake Madtsoia from the Upper Cretaceous of India and its paleobiogeographic implications". Journal of Vertebrate Paleontology. 31 (3): 588–595. Bibcode:2011JVPal..31..588M. doi:10.1080/02724634.2011.560220. S2CID 129792355.
Bibliography edit
- Weishampel, David B.; Peter Dodson, and Halszka Osmólska (eds.). 2004. The Dinosauria, 2nd edition, 1–880. Berkeley: University of California Press. Accessed 2019-02-21. ISBN 0-520-24209-2