Intertrappean Beds

The Intertrappean Beds are a Late Cretaceous and early Paleogene geologic unit in India. These beds are found as interbeds between Deccan Traps layers, including the slightly older Lameta Formation. They consist a number of different subgroups and formations, and span the Cretaceous–Paleogene boundary.^[2][1]

Intertrappean Beds
Stratigraphic range: Maastrichtian-Ypresian, 67.7–56 Ma PreꞒ Ꞓ O S D C P T J K Pg N
Type	Unit
Unit of	Deccan Traps
Overlies	Infratrappean Beds
Location
Coordinates	17.2°N 77.9°E / 17.2; 77.9
Approximate paleocoordinates	28.0°S 59.0°E / -28.0; 59.0
Region	Madhya Pradesh, Maharashtra, Telangana, Gujarat, Uttar Pradesh, Andhra Pradesh, Karnataka[1]
Country	India
Intertrappean Beds (India)

Many mostly fragmentary fossils, especially of small vertebrates, are known from the formation.^[3] Indeterminate theropod and pterosaur remains have been recovered from the formation, as well as dinosaur eggs.^[4][5] The mammal genera Deccanolestes, Sahnitherium, Bharattherium, Indoclemensia, Indotriconodon and Kharmerungulatum have been recovered from several localities.^[6] The Early Eocene-aged^[7] Bamanbor locality in Gujarat preserves articulated freshwater fish specimens.^[8][9] A rich plant flora is known from the formation.

Stratigraphy

Although often thought of as a contemporaneous unit that was formed in a single rapid eruption event, more studies that date the age of the volcanic beds indicate that the Deccan Traps did not erupt all at once. Instead, different portions appear to have erupted during different periods of time. This means that the Intertrappean Beds are best understood as a group of different volcanic-associate formations of varying ages.^[10]

Divisions

Kale et al (2020) divided the group into the following provinces:^[10]

• Sahyadri Group or Western Province (age: Late Maastrichtian to Danian, ~67.5 to 62.5 mya)
• Satpura Group or Central Province
• Malwa Group (age: Late Maastrichtian, ~67.7 mya; likely the oldest group)
• Amarkantak Group or Mandla Province (age: early Paleogene, ~64.5 mya - unknown)

Mittal et al (2021) divided the group into the following provinces:^[11]

• Western Ghats-Central Indian Volcanic Province (WVP) (age: Late Maastrichtian to Danian)
• Saurhastra-Kutchh Province (age: ?Maastrichtian^[10] to early Eocene^[12])
• Malwa Plateau Province (age: Late Maastrichtian)
• Mandla Lobe Province (age: early Paleogene)

Formations

Chemostratigraphic definition

Kale et al (2020) divided the group as follows. Subgroups/formations are classified based on oldest to youngest.^[10]

• Wai Subgroup (youngest)
  • Desur Formation
  • Panhala Formation
  • Mahabaleshwar Formation (~63.2 mya)
  • Ambenali Formation
  • Poladpur Formation
• Lonavala Subgroup
  • Bushe Formation
  • Khandala Formation
• Kalsubai Subgroup (oldest, ~67.5 mya)
  • Bhimashankar Formation
  • Thakurwadi Formation
  • Neral Formation
  • Igatpuri Formation
  • Jawhar Formation

Lithostratigraphic definition

Kale et al (2020) divided the group as follows. Subgroups/formations are classified based on oldest to youngest.^[10]

• Sahyadri Group:
  • Bombay Subgroup (~62.5 mya)
    • Borivali Formation
    • Elephanta Formation
  • Khandala Subgroup (~67.5 to 63.2 mya)
    • Mahabaleshwar Formation (~63.2 mya)
    • Purandargarh Formation
    • Diveghat Formation
    • Karla Formation
    • Indrayani Formation
  • Kalsubai Subgroup (oldest: ~67.5 mya)
    • Upper Ratangarh Formation
    • Lower Ratangarh Formation
    • Salher Formation
• Satpura Group:
  • Karanja Formation (youngest)
  • Buldhana Formation
  • Chikli Formation
  • Ajanta Formation
  • Upper Ratangarh Formation
  • Karanja Formation
  • Buldana Formation
  • Chikli Formation (oldest)
• Malwa Group:
  • Singarchori Formation (youngest)
  • Bargonda Formation
  • Indore Formation
  • Kankaria-Pirukheri Formation
  • Kalisindh Formation
  • Mandleshwar Formation
  • Gaganwara Formation (oldest)
• Amarkantak Group:
  • Kuleru Formation (youngest)
  • Khamla/Kampla Formation
  • Amarwara Formation
  • Multai Formation
  • Linga Formation
  • Pipardehi Formation
  • Dhuma Formation
  • Mandla Formation (oldest, ~64.4 mya)

Within the newly defined Saurhastra Group (age: Paleocene to early Eocene), the following divisions were found by Patel & Shah (2023):^[12]

• Ninama Basin:
  • Ninama Limestone (youngest)
  • Sukhbhadar Formation (oldest)
• Chotila Basin:
  • Bamanbor Formation (youngest)
  • Chotila Chert
  • Rangpar Formation (oldest)

Paleobiota

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.

Fish

Genus	Species	Location	Stratigraphic position	Material	Notes	Images
Anthracoperca	A. bhatiai	Naskal, Rangapur		Otolith.	A percoid otolith.
Apateodus	A. striatus	Asifabad[13]			An enchodontoid aulopiform.
Ariidae	incertae sedis	Naskal, Rangapur, Anjar		Otolith.	An ariid catfish otolith.
?Belonostomus	B. indicus	Nagpur[3][14]			An aspidorhynchid.
Coupatezia	C. sp	Asifabad[13]			An eagle ray.
Cyprinidae	incertae sedis	Deothan-Kheri			A cyprinid.
Dapalis	D. erici	Rangapur		Otolith.	A serranid otolith.
"Eotrigonodon"	"E." wardhaensis	Asifabad[13]			Initially described as tetraodontiform, but likely represent grasping teeth of pycnodonts.[15]
Enchodus	E. sp	Asifabad[13]			An enchodontoid aulopiform.
Horaclupea	H. intertrappea	Bamanbor[8]	Early Eocene[12][7]	Complete skeleton.	A clupeid.
Igdabatis	I. indicus	Kisalpuri & Piplanarayanwar[16][17]			An eagle ray.
Indiaichthys	I. bamanborensis	Bamanbor[9]	Early Eocene[12][7]	Multiple complete skeletons.	A possible percoid.[18]
"Indotrigonodon"	"I." ovatus	Asifabad[13]			Initially described as tetraodontiform, but likely represent grasping teeth of pycnodonts.[15]
"Lepidotes"	"L." sp	Asifabad[13]			A lepisosteiform.
Lepisosteus	L. indicus	Kisalpuri & Piplanarayanwar[16][17]			A gar.
Nandidae	incertae sedis	Deothan-Kheri			A nandid.
Osteoglossidae	incertae sedis	Kisalpuri & Piplanarayanwar[16][17]			An osteoglossid of uncertain affinities.
Palaeolabrus	P. dormaalensis	Asifabad[13]			A palaeolabrid.
Palaeopristolepis	P. chiplonkari	Bamanbor[8]	Early Eocene[12][7]	Multiple partial skeletons.	A questionable leaffish.[18]
	P. feddeni
"Perca"	"P." angusta	Bamanbor[8]	Early Eocene[12][7]	Skull.	A possible percoid, classification very doubtful.[18]
Percomorpha	incertae sedis	Bamanbor[9]	Early Eocene[12][7]	Partial skeleton.	A percomorph of uncertain affinities.
Phareodus	P. sp.	Asifabad, Naskal & Marepalli[13]			A bonytongue.
Polycanthidae	incertae sedis	Deothan-Kheri			A polycanthid.
"Pisdurodon"	"P." spatulatus	Asifabad[13]			Initially described as tetraodontiform, but likely represent grasping teeth of pycnodonts.[15]
Pycnodontidae	incertae sedis	Kisalpuri & Piplanarayanwar[16][17]			A pycnodontid of uncertain affinities.
"Pycnodus"	"P." lametae	Asifabad[13]			A pycnodontid.
Raja	R. sudhakari	Asifabad[13]			A skate.
Rhombodus	R. sp.	Asifabad[13]			A stingray.
Serranidae	incertae sedis	Deothan-Kheri			A serranid.
Siluriformes	incertae sedis	Kisalpuri & Piplanarayanwar[16][17]			A catfish of uncertain affinities.
Sphenodus	S. sp.	Asifabad[13]			A shark.
Stephanodus	S. lybicus	Asifabad & Marepalli[13]			A pycnodontid.

Otolith-based taxa

Genus[19]	Species	Location	Stratigraphic position	Material	Notes	Images
"Ambassidarum"	A. cappettai	Nagpur		Otolith	An ambassid otolith.
"Apogonidarum"	A. curvatus	Naskal, Rangapur		Otolith	A cardinalfish otolith.
"Blenniidarum"	B. sp	Rangapur		Otolith	A blenny otolith.
?"Centropomidarum"	C. takliensis	Nagpur		Otolith	A possible snook otolith.
"Clupeidarum"	C. valdiyai	Nagpur, Rangapur		Otolith	A clupeid otolith.
	C. sahnii
"Gonorhynchidarum"	G. rectangulus	Nagpur, Rangapur		Otolith	A gonorynchid otolith.
"Heterotidinarum"	H. heterotoides	Naskal		Otolith	An arapaimine otolith.
"Notopteridarum"	N. nolfi	Naskal, Rangapur, Cheemalagutta		Otolith	A notopterid otolith.
"Osteoglossidarum"	O. deccanensis	Naskal,		Otolith	An osteoglossid otolith.
	O. intertrappus
"Percoideorum"	P. citreum	Naskal, Nagpur, Rangapur		Otolith	Percoid otoliths.
	P. nagpurensis
	P. rangapurensis
?"Pristolepidinarum"	P. jaegeri	Nag		Otolith	A possible pristolepid otolith.
"Serranidarum"	S. sp.	Anjar		Otolith	A serranid otolith.

Amphibians

Genus	Species	Location	Stratigraphic position	Material	Notes	Images
Gobiatidae	incertae sedis	Naskal			A gobiatid frog.[3][20]
"Hemisotidae"/"Leptodactylidae"	incertae sedis	Naskal			A frog of uncertain affinities.[3][20]
Indobatrachus	I. pusillus	Worli Hill	Early Paleocene[10]	Multiple complete skeletons[21]	A frog of uncertain affinities.
Pelobatidae	incertae sedis	Nagpur			A pelobatid frog.[3]
Ranoidea	incertae sedis	Naskal			A ranoid frog.[3][20]
Costata	incertae sedis				A costatan frog[20]
?Caudata	incertae sedis				A possible salamander.[20]

Reptiles

Turtles

Genus	Species	Location	Stratigraphic position	Material	Notes	Images
Carteremys	C. leithii	Worli Hill	Early Paleocene[10]	Carapace, plastron, skull and partial mandible	A turtle of uncertain affinities.
Sankuchemys	S. sethnai	Amboli Quarry[22]		Skull[22]	A bothremydid turtle.

Lepidosaurs

Genus	Species	Location	Stratigraphic position	Material	Notes	Images
Acrosphenodontia	Incertae sedis	Naskal[23]		Dentary with teeth.[23]	An indeterminate rhynchocephalian.
"Agama"	A. sp.	Rangapur			An indeterminate agamid lizard.
Anguidae	Incertae sedis	Naskal			An indeterminate anguid lizard.[20]
?"Contogenys"	?"C." sp.	Nagpur			An indeterminate scincomorph lizard.[20]
Deccansaurus	D. palaeoindicus	Kesavi[24]	Maastrichtian/Early Paleocene	Jaws & several osteoderms.[24]	A scincoid lizard.
?"Exostinus"	"E." estestai	Nagpur			An indeterminate xenosaurid lizard.[20]
"Eumeces"	"E." sp.	Rangapur			An indeterminate scincid lizard.[20]
Indophis	I. sahnii	Naskal[25]		Over 160 vertebrae.[25]	A nigerophiid snake.
"Litakis"	"L." sp.	Nagpur			An indeterminate lizard.
"Pristiguana"	"P." sp.	Nagpur			An indeterminate iguanid lizard.
Serpentes	Incertae sedis	Naskal[25]		A trunk vertebra & left dentary.[25]	A snake.
Serpentes[20]	Incertae sedis				Possibly a primitive form,
Madtsoiidae[20]	Incertae sedis			Three individuals.	Madsoid snakes.
cf. Indophis[20]	cf. I. sahnii				Nigerophiidae snake.
Booidea[20]	Incertae sedis				Possibly a Booid snake.

Crocodyliforms

Genus	Species	Location	Stratigraphic position	Material	Notes	Images
Crocodylidae	incertae sedis	Worli Hill[3][26]		Teeth and dentary.	A crocodylid crocodyliform.
Dyrosauridae	incertae sedis	Kisalpuri[27]		Partial mandible, frontal, and vertebrae	A dyrosaurid crocodyliform.
Crocodyliformes	incertae sedis	Naskal[26]		Teeth.	Shows similarities to Hamadasuchus and perhaps Mahajangasuchus.

Dinosaurs

Genus	Species	Location	Stratigraphic position	Material	Notes	Images
?"Hypselosaurus"	"H." sp	Mohgaon Kalan[3]			A titanosaurian sauropod.
Massospondylus[28]	M. rawesi			Tooth	Previously thought to be Massospondylus now thought to have been an indeterminate Theropod.
Sauropoda	Incertae sedis	Asifabad, Ranipur, Anjar[3]		Bones	Sauropod bones.

Oogenera

Genus	Species	Location	Stratigraphic position	Material	Notes	Images
Megaloolithus	baghensis	Kisalpuri[16]		Eggshell fragments	A Titanosaur egg.
Subtiliolithus	kachhensis	Kisalpuri[16]		Eggshell fragments	A Enantiornithine bird egg.

Pterosaurs

Genus	Species	Location	Stratigraphic position	Material	Notes	Images
Pterosauria	incertae sedis	Sirol-khal locality[5]			An indeterminate dentulous pterosaur. May not be from the Maastrichtian.[29]

Mammals

Genus	Species	Location	Stratigraphic position	Material	Notes	Images
Bharattherium	B. bonapartei	Kisalpuri		A fragmentary cheek-tooth.	A sudamericid mammal.
Deccanolestes	D. hislopi	Naskal microvertebrate site		Molars, calcanea, astralgi, humerus, ulna.	A eutherian mammal.
	D. robustus	Naskal microvertebrate site		"Dental material and an astragalus".	A eutherian mammal.
	D. narmadensis	Kisalpuri		"Isolated rear molar."	A eutherian mammal.
Indoclemensia	I. naskalensis	Naskal microvertebrate site[1]		Right second Molar.	A eutherian mammal.
	I. magnus	Naskal microvertebrate site[1]		Left second Molar.	A eutherian mammal.
Indotriconodon	I. magnus	Kutch[30]		Single lower Molar.	A eutriconodont mammal.
Kharmerungulatum	K. vanvaleni	Kisalpuri[31]		Isolated right lower molar.	A eutherian mammal.
Sahnitherium	S. rangapurensis	Rangapur microvertebrate site[32]		Upper Molar.	A eutherian mammal.

Arthropods

Genus	Species	Material	Location	Time Period	Notes	Images
?Buprestidae	Indeterminate		Maharashtra	Maastrichtian	A Jewel beetle.
Lomatus[33]	L. hislopi		Maharashtra	Maastrichtian	A Jewel beetle.
?Curculionidae	Indeterminate		Maharashtra	Maastrichtian	A Snout beetle.
Meristos	M. hunteri		Maharashtra	Maastrichtian	A Snout beetle.
Ostracoda	Indeterminate		Maharashtra	Maastrichtian	An Ostracod.
Palaeotanymecides	P. hislopi		Maharashtra	Maastrichtian	A Snout beetle.

Mollusca

Genus	Species	Location	Stratigraphic position	Material	Notes	Images
Bamanboria	B. oblongis	Bamanbor	Early Eocene[7]	Shells	A deccanoid freshwater mussel.[7]
Chotilia	C. deccanensis	Bamanbor	Early Eocene[7]	Shells	A deccanoid freshwater mussel.[7]
	C. trappeansis
	C. tuberculata
Deccanoida	D. aleta	Bamanbor	Early Eocene[7]	Shells	A deccanoid freshwater mussel.[7]
	D. congruis
	D. costaria
Limnaea	sp.	Maharashtra	Maastrichtian		A snail.
Valvata	sp.	Maharashtra	Maastrichtian		A snail.
Paludina	sp.	Maharashtra	Maastrichtian		A snail.
Physa	P. prinsepii	Maharashtra	Maastrichtian		A snail.

Flora

Genus	Species	Location	Stratigraphic position	Material	Notes	Images
Connaroxylon	C. dimorphum	Dhagaon, Mandla district[34]		Wood[34]	Affinities with Connaraceae.
Euphorbiotheca	E. deccanensis				Fruit, member of Euphorbiaceae.[35]
Hyphaeneocarpon					Fruit, member of palm tribe Borasseae.[36]
Palmocarpon					Fruit, member of palm tribe Cocoseae.[37]
Palmoxylon	P. dindoriensis				Wood, member of palm subfamily Coryphoideae.[38]
Pantocarpon					Fruit, member of Torricelliaceae.[39]
Phyllanthocarpon	P. singpurensis				Fruit, member of Phyllanthaceae.[40]
Rhizopalamoxylon					Palm rhizome, close affinities to Nypa.[41]
Pediastrum					Algae.[42]
Lecaniella					Algae.[42]
Pierceites	P. deccanensis				A Dinocyst.[42]
Aulacoseira					A Diatom.[42]
Azolla					Member of Salviniaceae.[42]
Crybelosporites					Member of Marsileaceae.[42]
Sparganiaceaepollenites					Pollen grains, Member of [42]Sparganiaceae/Typhaceae.
Marsilea					Member Marsileaceae.[42]
Regnellidium					Member of Marsileaceae.[42]
Nymphaeaceae indet.[42]
Typhaceae indet.[42]
Liliaceae indet.[42]
Acanthaceae indet.[42]
Pontederiaceae indet.[42]
Ovoidites					Member of Zygnemataceae.[42]
Gabonisporis					Pollen grains, member of Marsileaceae.[42]

See also

• Earth sciences portal
• Paleontology portal
• Dinosaurs portal

• Lameta Formation
• List of dinosaur-bearing rock formations
  • List of stratigraphic units with indeterminate dinosaur fossils
• List of pterosaur-bearing stratigraphic units