Rangapur microvertebrate site (Cretaceous of India)

Where: Andhra Pradesh, India (17.2° N, 77.9° E: paleocoordinates 29.3° S, 58.4° E)

• coordinate estimated from map

• small collection-level geographic resolution

When: Maastrichtian (72.1 - 66.0 Ma)

• Upper Cretaceous continental sediments are exposed along the perimeter of the Deccan Traps in peninsular India. The thick sequences stratigraphically below the Deccan basalts and usually deposited on Archaean granite (peninsular gneiss complex) of Gondwana Group are known as Infratrappean (=Lameta Formation) beds. They are generally considered fluvio-lacustrine coastal plain deposits (Mohabey & Udhoji 1993). The thin (1-5 m) sediminstary beds between basal flows are known as Intertrappean (=Takli Formation) beds. These sedimentary beds are generally considered to have formed by the sudden blocking of the drainage system immediately after the eruption of the Deccan volcanic basalt, resulting in the formation of enclosed basins, separated by interfluvial divides (Rana 1990a). Both the Infra- and Intertrappean beds under study are considered Maastrichtian in age on paleontological, geochronological, and paleomagnetic data (see Khajuria et al 1994 for a review).

•The fossiliferous units are situated between salt flows 4 and 5 (sensu Dutt 1975).

Environment/lithology: fluvial-lacustrine; black, brown marl and gray, white marl

• The fossiliferous units are situated between salt flows 4 and 5 (sensu Dutt 1975). The basal unit of this local Intertrappean sequence is a white marl bed (10.5 cm), which is overlain by black chert (10.0 cm) followed by black-brown marl (17.5 cm), black chert (10.0 cm), greenish-pink marl (12.5 cm), grey marl with whitish-grey cherty nodules (52.0 cm), and whitish-grey marl beds (42.5 cm) respectively.

•Fresh water ostracodes, charophytes, and molluscs were recovered from the white marl, black brown marl, and whitish-grey marl beds. Microvertebrates, including mammals, were recovered from the black-brown marl and whitish-grey marl beds (Rana 1988, 1990a,b).

Size classes: macrofossils, mesofossils

Collected by R. S. Rana in 1986, 1995-1998

Collection methods: bulk, sieve,

• ITV/R collection: Intertrappean vertebrates/Rangapur in the Department of Geology, HNB Garhwal University, Srinigar, Uttaranchal, India

Primary reference: R. S. Rana. 1990. Palaeontology and palaeoecology of the Intertrappean (Cretaceous-Tertiary transition) beds of the peninsular India. Journal of the Palaeontological Society of India 35:105-120 [M. Carrano/M. Carrano]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 122240: authorized by Roger Benson, entered by Roger Benson on 19.12.2011, edited by Philip Mannion and Matthew Carrano

Creative Commons license: CC BY (attribution)

Taxonomic list

• Microvertebrate material includes remains from elasmobranchs, bony fish, amphibians, turtles, squamates, crocodiles, and mammals.
 Myliobatiformes - Dasyatidae
Dasyatis sp. Rafinesque 1810 whiptail stingray
 Myliobatiformes - Rhombodontidae
"Rhombodus levis" = Rhombodus laevis
"Rhombodus levis" = Rhombodus laevis Cappetta and Case 1975 stingray
 Myliobatiformes - Myliobatidae
Igdabatis sigmodon Cappetta 1972 eagle ray
 Salmoniformes - Enchodontidae
Enchodus sp. Agassiz 1843
Enchodus ferox Leidy 1855
 Perciformes - Serranidae
Serranidae indet. Swainson 1839 perch-like fish
 Perciformes - Chandidae
Dapalis sp. Gistl 1848 perch-like fish
 Tetraodontiformes - Trigonodontoidae
Stephanodus lybicus Zittel 1888
 Tetraodontiformes - Eotrigonodontidae
Eotrigonodon sp. Jain and Sahni 1983
 Clupeiformes - Clupeoidei
Clupeidae indet. Bleeker 1859 hering
 Osteoglossiformes - Notopteridae
 Pycnodontiformes - Pycnodontidae
Pycnodus lametae Woodward 1908
 Lepisosteiformes - Lepisosteidae
Apateodus sp. Woodward 1901
 Crocodylia - Crocodylidae
"Crocodilus sp." = Crocodylus
"Crocodilus sp." = Crocodylus Laurenti 1768 crocodile
ITV/R/Cr-151 to 200
 Crocodylia -
Asiatosuchus sp.2 Mook 1940 crocodilian
ITV/R/Cr-91, 92
 Crocodylia - Alligatoridae
Alligatorinae indet.1 Cuvier 1807 crocodilian
Allognathosuchus sp.2 Mook 1921 crocodilian
ITV/R/Cr-1 to 90
 Crocodylia -
Thoracosaurus sp.2 Leidy 1852 crocodilian
ITV/R/Cr-93 to 150
 Squamata - Anguidae
Anguidae indet. Gray 1825 lizard
 Squamata -
 Tribosphenida - Adapisoriculidae
? Deccanolestes sp.3 Prasad and Sahni 1988 placental
ITV/R/Mm-9 (left m1 or m2); Mm-8 (right m1 or m2)
Deccanolestes cf. hislopi3 Prasad and Sahni 1988 placental
Deccanolestes cf. robustus3 Prasad et al. 1994 placental
ITV/R/Mm-6 (right m1 or m2)
 Tribosphenida -
Sahnitherium rangapurensis n. gen. n. sp.3 Rana and Wilson 2003 eutherian
ITV/R/Mm-1 (holotype right upper molar M1 or M2)
 Theriiformes -
Theria indet.3 Parker and Haswell 1897 mammal
ITV/R/Mm-5 (right P3); Mm-19 (left p3 or p4); Mm-13 (right p3 or p4); Mm-14 (left p1 or p2); Mm-15 (right p1 or p2); Mm-17 (right p1)