• Nearly 5.9 million to 9,000 years ago, India was home to the hippopotamus.
  • These entered Eurasia from Africa, then diversified in South Asia before going extinct.
  • Now, studying a small fragmented tooth unearthed in Madhya Pradesh, an international team of researchers has discovered the last known specimen of the Hippo Hexaprotodon species.
  • However, this does not mean that it is the last one to have lived in India.
  • The researchers hypothesise that a “combination of climatic stress and anthropogenic impacts” could have led to their extinction.
  • Dating studies show that this hippo lived during a “particularly dry period in the late Quaternary” period (15,000-16,000 years ago). Severe drought in South Asia and weak Indian monsoons might have led to the extinction.
  • Researchers note that hunting, habitat alteration, ecological human encroachment were the reasons for species extinctions during this period in other parts of the world.
  • While Hexaprotodon and Homo sapiens co-existed for several thousand years, researchers did not find any kill sites, but they note that this reason cannot be ruled out.
  • This is the only directly dated Hexaprotodon from the Indian subcontinent, the report states.
  • A direct date means that the fossil bone of the animal was used to determine the date.
  • Usually, charcoal or shells found alongside the fossil are studied and this known as an indirect or associated date.
  • He explains that carbon isotope analysis showed that the animal had a C4 dominated diet. “It refers to the kinds of plants the animal was eating.
  • The plants leave a specific isotopic signature in the teeth of animals that eat them basically, these hippos were eating grasses, and grasses prefer dry, seasonal climates.
  • The report concludes that ancient DNA could provide insights into the causes of the extinction.
  • DNA does degenerate as soon as the animal dies, but fragments remain, and in some cases, have been isolated from fossils that are a few hundred thousand years old.
  • This Hexaprotodon specimen isn’t very old, so it may be possible to extract DNA fragments