Elasmobranch fauna from the upper most part of the Cretaceous Bagh Group, Narmada valley, India

Abstract

In India, Cretaceous elasmobranchs are known from the uppermost Cretaceous Deccan intertrappean sedimentary sequences of peninsular India and the lower Upper Cretaceous (Cenomanian) Karai Formation of the Cauvery basin, South India. The intertrappean elasmobranchs are represented mainly by rays and skates, whereas the Karai fauna is known by hexanchiform, squaliform, and lamniform sharks. The latter assemblage is dominated by cool temperate water forms in addition to some cosmopolitan forms. Here new shark teeth recovered from the upper part of the marine Cretaceous Bagh Group, in the lower Narmada valley, Western India are described. This is the first detailed description of sharks from the Bagh Group and the first record of sharks from the youngest horizons (Coniacian to Late Maastrichtian) of this marine sedimentary sequence. The fauna, recovered from an oyster shell‐rich green sandstone at the top of the youngest geological unit (the Coralline Limestone) of the Bagh Group, is assigned to Ptychodus sp., Scapanorhynchus sp. aff. S. raphiodon (Agassiz, 1844), Cretodus sp. aff. C. crassidens (Dixon, 1850), Cretalamna sp., Squalicorax sp. aff. S. falcatus Agassiz, 1843, and Elasmobranchii indet. This assemblage, previously widely documented from the Cretaceous deposits of North and South Americas, Europe, North and West Africa, Far East and Near East, demonstrates that there is a clear change in elasmobranch faunal composition of India from cool temperate water forms in the early Late Cretaceous to essentially cosmopolitan forms in the Late Cretaceous.

Vertebrate evolution on the Indian raft - Biogeographic conundrums

“…S. falcatus Agassiz, 1843, and Elasmobranchii indet. (Prasad et al, 2017b). This assemblage, previously widely documented from the Cretaceous deposits of North America, western Europe, North and West Africa, Far East and Near East from the Tethys belt, demonstrates that there was a clear change in elasmobranch faunal composition of India from cool temperate water forms in the early Late Cretaceous to essentially subtropical to tropical forms tracking the changing position of India during its northward drift.…”

Isolated Archosaur teeth from the green sandstone capping the Coralline Limestone (Bagh Group) of the Narmada valley: Evidence for the presence of pre‐Late to Late Maastrichtian abelisaurids in India

“…The archosaur teeth‐bearing level within the green sandstone also yielded a large number of shark teeth representing predominantly the genus Scapanorhynchus Woodward (see Prasad et al . In Press this volume). The specimens described here are deposited in the Dinosaur Fossil National Park, Bagh, Dhar District, Madhya Pradesh , India .…”

Amended lithostratigraphy of the Cretaceous Bagh Group, Western Lower Narmada Valley, India: A comparison with pervasive Tethyan basins

“…Biswas and Deshpande (1983) and more recently, Gangopadhyay and Maiti (2012) divided the Cretaceous sequence into a Nimar Group and upper Bagh Group in ELNV. Racey et al (2016) and Tripathi (2006) proposed a single lithostratigraphy for the whole of the Narmada Basin, while Jaitly and Ajane (2013), Kumar et al (2016), andPrasad et al (2017) proposed a separate lithostratigraphy for the Bagh Group in ELNV (Table 1a-d). Merh (1995) and Tripathi (2006) have acknowledged that the stratigraphy of the Bagh Group in the WLNV (Gujarat) is still controversial with many gaps in it.…”

“…Recently, Ruidas, Paul, and Gangopadhyay (2018) convincingly argued against the separation of the sandstone-dominated unit (Nimar Sandstone) from the rest of the Bagh Group in the ELNV based on marine evidence. Jaitly and Ajane (2013), Kumar et al (2016), andPrasad et al (2017) revised the lithostratigraphy of the ELNV and considered the fluvio-marine sequence as belonging to the Bagh Group, bracketing its age from Cenomanian to Coniacian. Although the rank of the unit was elevated to group in the WLNV, the name 'Bagh' is well-established and is extensively used in the Indian literature; hence, it is retained in the present study.…”

“…Also, the name 'Bagh' (Dangerfield, 1818) for the Cretaceous sedimentary rocks in the LNV is deeply entrenched in the Indian literature for more than two centuries, and it would not be appropriate to replace it. Hence, owing to the invalidity of Poddar's proposed groups, and considering the strong historical background and later usage of the term 'Bagh Group' for the Cretaceous sequence of ELNV (Jaitly & Ajane, 2013;Prasad et al, 2017), the term 'Bagh Group' is formalized for WLNV with variable component formations.…”