Analysis of a Rare Complete Specimen of Ichthyosaur Reveals a Thick Layer of Blubber Similar to Modern Whales.
Paleontologists from the Natural History Museum in Oslo have recently studied the remains of an ichthyosaur (Ichthyosauria) excavated in the Solnhofen region of southern Germany to understand why its skeleton is so well-preserved, despite dating back to 150 million years ago.
A simulation of an ichthyosaur resembling a dolphin. (Photo: Nobu Tamura)
Ichthyosauria is a group of giant marine reptiles that closely resemble modern dolphins and whales. They could grow up to 16 meters in length and lived in deep waters. The complete fossil discovered in Solnhofen surprised scientists because this area was a relatively shallow lagoon with many islands during the late Jurassic period.
“We do not know why this specimen ended up in the lagoon, but it might be the reason it died,” said Dr. Lene Liebe Delsett from the Natural History Museum, who led the research. “The intact fossil of the creature makes this project unique as it tells a complete story.”
Complete Ichthyosaur fossil in Solnhofen. (Photo: Lene Liebe Delsett)
Researchers believe that the Solnhofen specimen fell to the ocean floor in a belly-up position either during or after death and was quickly covered by a layer of fine sediment.
Delsett and her colleagues sampled the soft tissue still preserved in the fossil, then examined it using scanning electron microscopy and X-ray crystallography, while the bones were scanned with ultraviolet light.
The results showed that phosphates in the ichthyosaur’s tissue may have contributed to the preservation of its skin and connective tissue. However, the main material surrounding and protecting the bones is a thick layer of blubber, similar to that found in modern marine mammals like seals and whales.
“Previous studies had speculated that Ichthyosauria might have a thick layer of blubber, and our new discovery confirms this. Besides body shape, blubber is a strong similarity between ichthyosaurs and whales,” Delsett added.
