A team of researchers from the University of California (UC), Davis discovered the fossil of a dolphin-like ichthyosaur from China. The fossil is the first of an amphibious ichthyosaur and may help scientists answer evolutionary questions about marine reptiles.
Ichthyosaurs are huge marine reptiles that lived on the planet over 250 million years back. They could grow to about 65 feet in length and, until now, there have been no records or fossils that can explain their evolution from the land to water. The latest fossil discovery is supposed to be the missing link that can unravel many questions about the reptile.
Ryosuke Motani, professor of earth and planetary sciences and leader of the study, explains that ichthyosaur records had an amphibious animal missing and the latest fossil discovery fits perfectly as the missing link.
Motani revealed that the fossil was discovered in the Anhui Province of China and measures about 1.5 feet in length. The fossil record was different from those of other ichthyosaurs, which entirely adapted to marine life. The researchers found that the fossil had unusual flippers that were flexible enough to make the reptile move on land as well. Motani explains that it had flexible wrists that were needed for crawling on land. The fossil had a short nose found in other land reptiles but different from most ichthyosaurs that had long beak-like noses.
The body of the fossil is believed to have thicker bones compared to other ichthyosaurs. Scientists suggest that most of the marine reptiles that evolved from land became heavier so that they could swim in the rough coastal waves.
Motani also suggests that the animal lived around 4 million years following the Earth's most horrible mass extinction about 252 million years back, which wiped out dinosaurs from the planet. Scientists are still trying to understand the time it took for plants and animals to recover after the massive destruction.
"How long did it take before the globe was good enough for predators like this to reappear? In that world, many things became extinct, but it started something new. These reptiles came out during this recovery," says Motani.
The researchers suggest that the latest discovery is important as a missing link in ichthyosaur evolution, but the fossil will also shed light on how animals coped on Earth in response to major climatic changes.
Details of the study are published in the journal Nature.