The first ancestor of all four-limbed creatures, including humans, has been identified as a 390 million-year-old fish-like organism with four limbs unearthed in Scotland in the 1890s. This discovery of the ancient creature was in a Caithness prehistoric graveyard.
According to a new study, the organism, known as Palaeospondylus gunni, could likewise be the ‘missing link’ in vertebrate evolution. The researchers discovered a large number of these fish-like creatures at a Neolithic graveyard in Scotland.
Although the discovery occurred over 130 years ago, scientists have struggled to position the Palaeospondylus on the evolutionary tree. It was only about two inches (5 cm) long, making cranial reconstructions problematic.
According to DailyMail.com, experts from Japan’s RIKEN Cluster for Pioneering Research have then discovered evidence indicating the creature had a jaw and four limbs.
As per the research, this creature lies at the bottom of the vertebrate family tree, which includes humans.
The journal Nature published the study. This ancient species had a flat head and an eel-like body. It lived on the bed of a deep freshwater loch, eating on leaves and other organic debris.
Scotland’s landmass was south of the equator during the period, where central Africa is now. According to scientists, it was arid and “semi-hot.”
Palaeospondylus gunni
The first vertebrate to emerge from the water was Palaeopondylus. Its fins eventually developed into limbs, giving rise to mammals, birds, and reptiles.
“Palaeospondylus gunni, from the Middle Devonian period, is one of the most enigmatic fossil vertebrates,” says lead author Professor Tatsuya Hirasawa of Tokyo University in Japan. The Scotsman newspaper quoted the Professor.
“Its phylogenetic position has remained unclear since its discovery in Scotland more than 130 years ago. Whether these features were evolutionarily lost or whether normal development froze halfway in fossils might never be known.”
“Nevertheless, this evolution might have facilitated the development of new features like limbs.”
