Large Ichthyosaur Skull - Temnodontosaurus - 41.3"
This impeccably preserved skull belonged to a prehistoric marine reptile - Temnodontosaurus - a monstrously large Ichthyosaur. It is a spectacular find from the Holzmaden Shale near Stuttgart, Germany, a fossil locale renowned for its incredibly preserved specimens. This ichthyosaur once inhabited warm Jurassic seas that teemed with a variety of ammonites, crinoids (sea lilies) and many fish species.
Temnodontosaurus was among the most massive of the ichthyosaurs, reaching perhaps 12 meters / 39 feet in total length. Furthermore, this genus had absolutely huge eyes (approximately 8 inches in diameter) - likely the largest of any animal to have ever existed!
Considerable time and skill was needed to reveal this specimen from the matrix - meticulous, specialized labour in a state of the art German laboratory. It displays incredible detail and perfect dentition.
- Species: Temnodontosaurus sp.
- Formation: Posidonia Shale
- Location: Holzmaden, Baden-Wuerttemberg, Germany
- Age: Lower Jurassic, approximately 182 million years old
- Specimen measures 41.3" long (105 cm). Matrix measures 55" x 25.6" (140 cm x 65 cm).
Ichthyosaurs made their first appearance on this planet as land dwelling reptiles that braved the oceans before there were dinosaurs. They were the dominant predators of the Mesozoic for 157 million years. Their size range was remarkable: some species were only 70 centimetres long (close to the size of the present day marine iguana from the Galapagos) to giants upwards of 20 meters!
Ichthyosaurs changed dramatically throughout their evolution, starting as elongated lizard-like reptiles that navigated through the warm seas with side to side eel-like movements. Later, they transformed into super fast deep-diving killing machines with a shortened, heavy body, dramatically changed front and hind limbs, and backbone with disc shaped vertebrae. Their eel-like swimming morphed into explosive tuna like rocketing.
Some ichthyosaur species had the largest eyes of any creature on earth - over 26 cm. That surpasses the eyes of the largest mammals, both terrestrial and aquatic – the elephant and great blue whale. Imagine an eye larger than a soccer ball!
Ichthyosaurs were highly adapted to their environment. It is estimated that they could dive to depths of 600 meters (probably in search of their cephalopod dinners) and hold their breath for about 20 minutes.
There are many theories regarding their extinction, which occurred 28 million years before the mass extinction of dinosaurs. New data supports the idea that global warming during the Late Cretaceous changed the marine ecosystems and may have contributed to their demise.
Nature recently published an amazing news feature on ichthyosaurs, rich with the latest information about these amazing animals and wonderful infographics. Read Traci Watson's feature here.
More excellent ichthyosaur information - including their evolution and extinction - can be found in a 2016 article by Valentin Fischer et al. (Nature Communications 7, article number 10825). Read it here.
A comprehensive online resource about Ichthyosaurs, by Ryosuke Motani, can be found here.
Temnodontosaurus burgundiae attack Stenopterygius hauffianus. Lias of Germany
Credit: Dmitry Bogdanov, source Wikipedia.