The world's first complete skeleton of a prehistoric reptile known to science was described in 1819, and at that time it was called a "proteosaurus". But during a German air raid in May 1941, during the Second World War, this fossil was completely destroyed – irretrievably, as was previously thought. However, Dean Lomax from the University of Manchester and Judy Massare from New York State University now describe a sensational find in the journal "Royal Society Open Science": in the archive of the Peabody Museum of Natural History at Yale University, they discovered an imprint of the prehistoric animal, which is now assigned to ichthyosaurs.
Lomax and Massare were researching ichthyosaur fossils at the museum in 2016 when they came across the imprint, which they originally thought was a real fossilized bone skeleton. However, more detailed studies finally revealed that it was actually an impression: it had been painted so well that it made a deceptively real impression. Three years later, Dean finally discovered another copy in the collections of the Museum für Naturkunde in Berlin, whose origin had also not been recognized before – to the surprise of the Berlin curators: "I was really surprised that a cast of this important specimen had been dormant in our collection for more than a century," says Daniela Schwarz, who is responsible for the collection of fossil reptiles at the Museum für Naturkunde.
The cast in Peabody is probably the older of the two and less detailed and more worn out than the Berlin copy. Both deviate somewhat from the original illustration, but the Berlin copy seems to have benefited from more advanced casting technology. As a result, the details of the original were better preserved. And even if they are not quite as important as the original fossils, the copies also have their value. "Disposal is often overlooked in research, but they provide valuable information about the dimensions of fossils," says Lomax. The dimensions of individual bones and skeletons in casts, for example, can be compared to other fossils and can be detailed enough to enable the naming of new genera.
Unfortunately, during the First and Second World Wars, numerous fossils were also lost or destroyed with their museums, for example almost all known Aegyptosaurus fossils as well as the type specimens of well-known dinosaurs such as Spinosaurus aegyptiacus and Carcharodontosaurus. After all, there is a hope that some have been preserved at least as a cast.
