Sunil Bajpai is the Chair Professor of Vertebrate Paleontology in the Department of Earth Sciences, Indian Institute of Technology Roorkee.

[2] Sunil Bajpai predominantly works on the Cenozoic vertebrates of India with focus on marine mammals, such as whales and sea cows.

[3][4][5][6] Bajpai and his collaborators fossil discoveries from the Eocene of Kutch (Gujarat) and the Himalayas have helped in understanding how whales have evolved.

[10][11][12] He has also been involved in studies of latest Cretaceous-Paleocene faunas of the Deccan volcanic province of India and their implications in understanding the northward drift of the Indian tectonic plate.

[14] In 2024, he coauthored the descriptions of what may be the largest known madtsoiid snake, Vasuki indicus from Naredi Formation,[15] and the mammal Indotriconodon from the Late Cretaceous Intertrappean Beds.