Kallamedu Formation

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]

Kallamedu Formation
Stratigraphic range: Maastrichtian to Danian ~70.6–65.5 Ma PreꞒ Ꞓ O S D C P T J K Pg N
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	11.6962°N 79.4127°E / 11.6962; 79.4127
Country	India
Extent	Kallamedu
Type section
Named for	Kallamedu village

Lithology

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]

Paleofauna

Color key Taxon Reclassified taxon Taxon falsely reported as present Dubious taxon or junior synonym Ichnotaxon Ootaxon Morphotaxon		Notes Uncertain or tentative taxa are in small text; crossed out taxa are discredited.

Dinosaurs

Dinosaurs from the Kallamedu Formation
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

Crocodylomorphs from the Kallamedu Formation
Genus	Species	Material	Notes
Crocodilia[13]	Indeterminate	Teeth.
Simosuchus [13]	cf. Simosuchus sp.	Teeth.	Notosuchian Related to Simosuchus.

Turtles

Turtle from the Kallamedu Formation
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

Fish from the Kallamedu Formation
Genus	Species	Material	Notes
Lepisosteidae[13]	Indeterminate.	Scales.	Similar scales are known from the Intertrappean Beds.

Amphibians

Amphibians from the Kallamedu Formation
Genus	Species	Material	Notes
Anura[13]	Indeterminate.	Fragmentary ilium.