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Kallamedu Formation | |
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Stratigraphic range: Maastrichtian to Danian ~ | |
Type | Geological formation |
Unit of | Ariyalur Group |
Underlies | Niniyur Formation |
Overlies | Archean Basement |
Thickness | Variable, typically 5–5,000 km (3.1–3,106.9 mi) |
Lithology | |
Primary | Claystone, siltstone limestone |
Other | Conglomerate |
Location | |
Coordinates | 11°41′46″N79°24′46″E / 11.6962°N 79.4127°E |
Country | India |
Extent | Kallamedu |
Type section | |
Named for | Kallamedu village |
The Kallamedu Formation is a Late Cretaceous (Maastrichtian) geologic formation located in the Ariyalur district of Tamil Nadu, India that forms part of the Ariyalur Group. [1] It dates to the Maastrichtian of the Late Cretaceous. Dinosaur remains and petrified wood samples are among the known fossils recovered from this formation. [2]
The Kallamedu Formation likely represented a fluvial environment. It is composed of siltstones, clays and sandstones. The high organic carbon content of some of the rocks are consistent with a swamp. [3]
Color key
| Notes Uncertain or tentative taxa are in small text; |
Dinosaurs from the Kallamedu Formation | ||||||
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Genus | Species | Material | Notes | |||
Abelisauridae indet. [4] | "Disassociated remains" and teeth. | |||||
Carnosauria indet.? [5] | "Fragmentary remains" | Carnosauria was often used as a wastebasket taxon. | ||||
Troodontidae indet. [4] | One isolated tooth (DUGF/52). | |||||
Bruhathkayosaurus [5] [6] | B. matleyi | ilium and ischium, femur, tibia, radius and part of a vertebra (specifically a platycoelous caudal centrum). Remains no longer exist | Initially described as a Theropod, it was reclassified as a Titanosaur. | |||
Sauropoda | Indeterminate. [7] [8] | "Fragmentary remains." | ||||
Titanosauria | Indeterminate. [9] | Solitary egg. | ||||
Titanosauria | Indeterminate. [10] | Ten large sauropod bones, some of which could be identified as a humerus or femur, proximal end of a femur and scapula. All the bones pertain to the limbs. | Similar in size to Bruhathkayosaurus. [6] | |||
Fusioolithus [9] | F. baghensis | Dinosaur eggs. | ||||
?Camarasauridae [11] | Indeterminate. | Vertebrae. | Camarasaurids are not known from the cretaceous. | |||
?Stegosauria [12] | Indeterminate. | Misinterpreted sauropod bone. | Other more plausible Stegosaur material is known from Cretaceous India. |
Crocodylomorphs from the Kallamedu Formation | ||||||
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Genus | Species | Material | Notes | |||
Crocodilia [13] | Indeterminate | Teeth. | ||||
Simosuchus [13] | cf. Simosuchus sp. | Teeth. | Notosuchian Related to Simosuchus . | |||
Turtle from the Kallamedu Formation | ||||||
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Genus | Species | Material | Notes | |||
Kurmademys [14] | K. kallamedensis | Nearly complete skull. | A Side-necked Turtle. | |||
Testudines [13] | Indeterminate | Several fragmentary pieces of carapace and one vetebral element. | Too fragmentary to compare with Kurmademys. |
Fish from the Kallamedu Formation | ||||||
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Genus | Species | Material | Notes | |||
Lepisosteidae [13] | Indeterminate. | Scales. | Similar scales are known from the Intertrappean Beds. | |||
Amphibians from the Kallamedu Formation | ||||||
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Genus | Species | Material | Notes | |||
Anura [13] | Indeterminate. | Fragmentary ilium. | ||||