Giant ichthyosaur with injuries discovered in Northern Bavaria, Germany

The Mistelgau clay pit near Bayreuth, Germany, is known for its well-preserved marine fossils, particularly its abundance of ichthyosaurs. These large marine reptiles resembled modern dolphins in appearance and lived worldwide during the Early Jurassic period, around 180 million years ago. The ichthyosaur from Mistelgau now under investigation belongs to the genus Temnodontosaurus. Several parts of its skeleton have been preserved: fragments of the skull and lower jaw, the shoulder girdle, forefins, the spine, and over 100 teeth. The exceptional three-dimensional preservation allows researchers detailed insights into anatomical structures that have rarely been documented before, such as those in the palate, orbital region, and the fins. Comparisons reveal clear similarities, but also differences to Temnodontosaurus trigonodon—animals of this species are among the largest known ichthyosaurs. Based on its skull length of 1.5 meters, the animal is estimated to have been about 6.6 meters long.

“Our Temnodontosaurus fossil is one of the youngest finds of this ichthyosaur genus to date. Until now, representatives of this genus have mainly been known from older geological layers, such as the Posidonia Shale of Holzmaden. The discovery from Mistelgau now shows that these large marine reptiles survived longer in the Southwest German Basin than previously documented,” says SNSB paleontologist Dr. Ulrike Albert, author of the study. Albert conducts research at the Urwelt-Museum Oberfranken in Bayreuth, one of ten museums belonging to the Bavarian State Collections of Natural History. The team at the Urwelt-Museum Oberfranken has been conducting regular excavations in Mistelgau since 1998. The fossils recovered there are prepared at the Urwelt-Museum and subsequently subjected to scientific analysis.

Particularly striking are several modifications to the skeleton, presumably caused by injuries, including those affecting the reptile’s shoulder and jaw joints. “The injuries likely significantly limited the animal’s ability to catch prey,” explains Stefan Eggmaier, preparator at the Urwelt-Museum and also an author of the study. “The fact that it nevertheless survived is evidenced, among other things, by its heavily worn teeth and gastroliths, which we were able to identify in the abdominal region.” Gastroliths are extremely rare in ichthyosaurs such as Temnodontosaurus. Eggmaier speculates that the animal may have had to change its diet in order to survive its injuries.

The current findings are part of ongoing research into the ecology of the Jurassic Sea in Upper Franconia. Analyses of teeth and bone structures are planned, with the aim of better understanding the ecology of these animals and their habitat.