Researchers have recently discovered a 380 million-year-old heart preserved inside a prehistoric fish. Found in Australia, the fossilized heart is the oldest three-dimensional preserved heart ever found from a vertebrate. The heart found belongs to a fish known as the Gogo, which is extinct. The "jaw-dropping" news was published in the journal Science and is considered one of these scientists' biggest discoveries.
The lead scientist, Prof Kate Trinajstic from Curtin University in Perth, told BBC News that she and her colleagues this was the "biggest discovery of their lives." Trinajstic recalled, "We were crowded around the computer and recognized that we had a heart and pretty much couldn't believe it! It was incredibly exciting." According to the professor, bones are typically turned into fossils, as opposed to soft tissue, but at the Gogo rock formation, the minerals have helped preserve the fish's internal organs, such as the heart. The Gogo fish was the first of a class of prehistoric fish called placoderms. Placoderms were the earth's main life form for around 60 million years and were alive for over 100 million years even before dinosaurs. These fish were the first to have teeth and jaws and could grow up to 29.5 feet, which heavily exceeded the size of fish in the past.
"This is a crucial moment in our own evolution," said Professor Trinajstic. "It shows the body plan that we have evolved very early on, and we see this for the very first time in these fossils." Prof John Long from Flinders University in Adelaide described the find as "a mind-boggling, jaw-dropping discovery." He continues, "We have never known anything about the soft organs of animals this old, until now." The Gogo fish fossil scans showed that the heart was a lot more intricate than the primitive fish, indicating it had two chambers, similar to the human heart.
According to Dr. Martin Brazeu, a placoderm expert at the Imperial College in London, this is a huge step in the evolution of life on Earth and is an "exciting" result. "The fishes that my colleagues and I are studying are part of our evolution. This is part of the evolution of humans and other animals that live on land and the fishes that live in the sea today."