Paleontologists from the Universities of Bonn and Liverpool examined 14 skulls of Plateosaurus trossingensis
“Every person is unique” is a common principle. All people are equal, but of course there are individual differences. This was no different from dinosaurs. A study conducted by researchers at the University of Bonn and the Dinosaur Museum Frick in Switzerland now revealed that he contrasted Plateosaurus trossingensis It was much larger than previously assumed. Paleontologists examined a total of 14 complete skulls of this type, eight of which were described for the first time. The results are now published in the scientific journal.Acta Palaeontologica Polonica“.
Plettosaurus It lived during the late Triassic period, from about 217 to 201 million years ago. “With more than 100 skeletons, some of them perfectly preserved, it is one of the most famous dinosaurs” for several months, says Dr. Jens Lallensack, who has researched dinosaur biology at the University of Bonn and works at Liverpool John Moores University (UK). The herbivores had a small skull, long neck, tail, powerful hind legs and a strong hand. The spectrum is large: the adult specimens ranged from a few meters to ten meters, and weighed between half a ton and four tons.
The first bones Plettosaurus It was found as early as 1834 near Nuremberg, making it the first dinosaur found in Germany, and one of the first dinosaurs ever found. Between 1911 and 1938, excavations uncovered dozens of skeletons from “tombs” of dinosaurs in Halberstadt (Saxony-Anhalt) and Truisingen (Baden-Württemberg). A third tomb was discovered in the 1960s in Frick, Switzerland. “It’s the only one that still has digging work every year,” says Lalinsack. The material from Frick, which was described in detail for the first time, includes eight complete skulls and seven segmented skulls that were excavated by Swiss paleontologist and dinosaur researcher Dr. Ben Babst and his team.
The natural difference between individuals
Dinosaurs were preserved for posterity mainly through bones. Paleontologists rely on anatomical details to distinguish different species. “The enduring difficulty with this is that such anatomical differences can also occur within species, such as natural variation between individuals,” Lalansack reports. Researchers at the University of Bonn and the Dinosaur Museum Frick (Switzerland) are now able to show this Plettosaurus Anatomy was significantly more diverse than previously thought – the viability of some species needs to be re-examined. These results were made possible by analyzing an additional 14 complete and incomplete skulls Plettosaurus. “Such a large number of early dinosaurs is unique,” says paleontologist Prof. Dr. Martin Sander of the University of Bonn.
Can all these fossils from Germany and Switzerland really be assigned to one species? The answer to this question has become more urgent since Martin Sander and Nicole Klein of the University of Bonn published in the journal Science in 2005. Accordingly, Plettosaurus It may have already been warm-blooded like today’s birds, but it was able to adapt its growth to environmental conditions – something that can only be observed today in cold-blooded animals. “This hypothesis is of great importance to our understanding of warm-blooded evolution,” says Lalansack’s report. However, so far individually distinct growth patterns can be alternatively explained by the assumption that not only one species exists, but many species are present. The current study reveals the falsehood of this.
Bone deformities during ossification
Researchers have now carefully documented the differences in skulls of different sizes. A large part of the differences can be attributed to bone deformation during deep subsurface ossification. Individual differences must be distinguished from this: the posterior branch of the zygomatic bone, which is sometimes divided and sometimes not, is what most strikes the researchers. A strongly carved bony bridge over the eye was also present on only some skulls. The relative size of the nostril varies, too.
“It became clear that each skull had a unique blend of features,” Lalensack notes, emphasizing the distinct individual character of these dinosaurs. The unique large number of skulls studied made it possible to show that the differences in characteristics were differences within the species rather than the different types. “Only if the largest number of discoveries possible were excavated and secured,” says Sander, “would we get the bulk of the quantities needed to prove the belonging of the species and answer fundamental questions in biology.”
The study was funded by the German Research Foundation (DFG). The project received financial support for exploration and preparation from the municipality of Frick and Canton Aargau (Swissloss Fund) in Switzerland.
Publication: Lallensack, JN, Teschner, EM, Pabst, B., and Sander, PM: New Skulls of Basal Soropodomorph Plettosaurus trossingensis From Frick, Switzerland: Is there more than one type? Acta Palaeontologica Polonica, DOI: https: /
Prof. Dr. Martin Sander
Institut für Geowissenschaften
Phone + 49- (0) 228-733105
email: [email protected]
Dr. Jens Lalinsack
Liverpool John Moores University
email: [email protected]