The marine environment was home to the world's largest animals. The dolphins and whales (cetaceans) we have today evolved to their humongous size over tens of millions of years owing to enhanced productivity in marine ecosystems. But contrary to what's been believed by many, whales were not the first marine giants to have evolved.
The two-meter skull of a newly found species of giant ichthyosaur, the earliest known, gives new light on the marine reptiles' rapid evolution into Dinosaurian ocean goliaths and helps us better understand modern cetaceans' journey to becoming the largest creatures ever to occupy the Earth.
According to a new study, such ichthyosaurs grew to enormous sizes in under 2.5 million years.
According to the study, whales required roughly 90% of their 55 million-year development to acquire the gigantic sizes that ichthyosaurs developed to in the first 1% of their 150 million-year history.
This Sea Lizard Had a Grand Piano-Size Head and a Big Appetite https://t.co/3Y2IRDpqXw — john slotkin (@john_slotkin) December 26, 2021
The new species appeared in the fossil record only a few million years after the first ichthyosaurs, which were roughly dog-sized. According to a study published in Science, this suggests that these swimmers grew far faster than whales.
Ichthyosaurs originally appeared 249 million years ago, and for the next 150 million years, they hunted the world's oceans before becoming extinct. They had a dolphin-like appearance due to their streamlined bodies, flippers, and huge eyes.
Ichthyosaurs shared several characteristics with cetaceans, such as whales, dolphins, and porpoises. Both groups developed comparable body plans, including powerful tails to push themselves through the water, and grew to vast sizes in some cases.
Scientists studied an ichthyosaur fossil that had a cranium that was more than 6 feet long, as well as pieces of the right arm, spine, and shoulders. They called the new species Cymbospondyus youngorum because it had a long snout with pointed teeth and a thin body.
A well-preserved skull and a portion of the backbone, shoulder, and forefin were excavated from the Augusta Mountains of Nevada's Fossil Hill Member. It dates from the Middle Triassic period (247.2-237 million years ago). It is also the first example of an ichthyosaur reaching colossal dimensions.
Paleontologists have been recovering fossils from the Fossil Hill Member's limestone, shale, and siltstone in various Nevada mountain ranges since 1902, creating a window into the Triassic.
Many species of ammonites, shelled ancestors of modern cephalopods like cuttlefish and octopuses, as well as marine reptiles, have been produced by the mountains, which connect our present to ancient oceans. The Fossil Hill Fauna is a collection of animal specimens that illustrate several of C. youngorum's prey and enemies.
