Marine Reptiles the Size of Whales Once Roamed the Seas

In Earth’s history, there have been iterations of giant species that have come and gone. The ichthyosaurus was a sea-dwelling reptile that achieved giant size. Archeological finds are providing paleontologists with resources to investigate what caused these reptiles to reach such leviathan sizes.

Marine Reptiles the Size of Whales Once Roamed the SeasIchthyosaurus Remains in Different Parts of the World

205 million-year-old partial remains of a whale-sized ichthyosaurus were found in the Swiss Alps, according to what was published this year in the Journal of Vertebrate Paleontology. However, this giant reptile wasn’t alone. Over the past 20 years, fossil sights from England, British Columbia, and Nevada have also unearthed giant ichthyosaurs. As some of the Earth’s first giants, these shark-shaped saurians ruled the seas for a while.

ichthyosaurus depiction
What’s Known of the Giant Reptiles, So Far

Thus far, paleontologists have determined that the earliest ichthyosaurus evolved around 249 million years ago, in the early Triassic Period, at which point they were around six feet long. At this time, the Earth was recovering from a mass extinction event, and new subspecies were forming from the surviving creatures. The ichthyosaurs had land-dwelling ancestors but promptly adapted to life in the water, growing very big very fast. Paleontologists took into account Cymbospondylus Youngorum which was dated back to 244 million years ago and was likely over 50 feet long. This means that the ichthyosaurus took around five million years to become giant sea-dwelling reptiles.


What Caused This Species to Achieve Its Giant Size

The giant ichthyosaurus were apex predator reptiles. With a mouth full of sharp teeth, they were capable of feeding on marine pray of various sizes. University of Manchester paleontologist Dean Lomax speculates that the reason why this species managed to grow so large, in the ocean, is that no other species had done it yet. With 95% of sea-dwelling creatures now extinct, there were endless possibilities for new species to evolve. The greater size and muscle mass meant increased swimming speed, which was a great advantage.