A sea monster from the early dinosaur era, astonishingly large, reveals secrets about evolutionary development.
In ancient times, many creatures both on land and underwater evolved to become increasingly larger to avoid becoming “prey,” as well as to survive more effectively with abundant food sources.
Image depicting the ichthyosaur sea monster. (Photo: National Geographic)
Recent research from archaeologists confirms that fish-like marine reptiles developed to gigantic sizes in just 2.5 million years. In comparison, whales took approximately 90% of their 55 million years of existence to achieve the enormous size that ichthyosaurs (a subfamily of marine reptiles) accomplished.
“Ichthyosaurs evolved much faster than whales during a time when the world was recovering from a catastrophic extinction at the end of the Permian period,” said Lars Schmitz, a senior researcher at Scripps Institution of Oceanography.
“This is a beautiful ray of hope and a sign of the resilience of life – if environmental conditions are right, evolution can occur very rapidly and life can recover.”
The researchers first took note of the fossil of an ancient ichthyosaur discovered in 1998, in the Augusta Mountains, northwest Nevada (USA).
However, it wasn’t until 2015, with the help of specialized helicopters, that they were able to excavate the remaining fossil, which included the skull, shoulder, and transport it to the Natural History Museum of Los Angeles, where it was analyzed.
The skull size of the ancient reptile C. youngorum compared to an adult human. (Photo: AP).
According to a study published on December 23 in the journal Science, the team named this new species Cymbospondylus youngorum (C. youngorum).
These reptiles belonged to the large-jawed marine reptile subfamily, living 247 million years ago during the Triassic period, characterized by their elongated bodies and limbs transformed into fins and tails.
Many gigantic creatures lived during the age of dinosaurs, but C. youngorum stands out for several reasons. Notably, they were one of the few large organisms to survive about 5 million years after the mass extinction event 252 million years ago at the end of the Permian period, which killed approximately 90% of species on Earth.
Studies indicate that it took about 9 million years for life on Earth to recover after the aforementioned extinction event. However, somehow, the species C. youngorum survived and thrived remarkably.
C. youngorum survived and thrived remarkably after the extinction.
One hypothesis suggests that there was an explosion of diversification among marine mollusks known as ammonoids within 1 to 3 million years following the mass extinction event.
These species became a food source for C. youngorum, similar to modern whales. However, their evolutionary and developmental paths were different.
“The new fossil shows impressive evolution towards gigantic size in ichthyosaurs. In contrast, whales seem to follow a different path to reach their current size, but not as quickly,” Schmitz assessed.
