Surprising Dinosaur Discovery: Ankylosaur Was Sluggish and Deaf

Struthiosaurus austriacus Dinosaur

Life reconstruction of the dinosaur Struthiosaurus austriacus from the Late Cretaceous of Austria. Credit: © Fabrizio De Rossi

Fossil braincase provides new surprising insights.

German and Austrian scientists took a closer look at the braincase of a dinosaur from Austria. The group examined the fossil with a micro-CT and found surprising new details: it was sluggish and deaf. The respective study was recently published in the scientific journal Scientific Reports.

Ankylosaurs could grow up to eight meters in body length and represent a group of herbivorous dinosaurs, also called ‘living fortresses’: Their body was cluttered with bony plates and spikes. Some of their representatives, the ankylosaurids sometimes possessed a club tail, while nodosaurids had elongated spikes on their necks and shoulders. However, some aspects of their lifestyle are still puzzling.

While many dinosaurs likely lived in groups, at least some ankylosaurs seemed to prefer a lonesome life because of an inferior sense of hearing. That’s what the scientists from the universities of Greifswald and Vienna concluded when they examined the braincase of the Austrian dinosaur with a high-resolution computer tomograph to produce a digital three-dimensional cast.

Fossil braincases, which once housed the brain and other neurosensory tissues, are rare but important for science because these structures can provide insights into the lifestyle of a given animal. For example, the inner ears can hint to auditory capacities and skull orientation.

Struthiosaurus austriacus is a comparably small nodosaurid from the Late Cretaceous (80 Ma) of Austria and comes from a locality near Muthmannsdorf, south of Vienna. The fossil remains of this dinosaur already belonged to the collection of the Institute for Paleontology in Vienna in the 19th century. For their study, Marco Schade (University of Greifswald), Cathrin Pfaff (University of Vienna) and their colleagues examined the tiny (50 mm) braincase to reveal new details of the anatomy and lifestyle of Struthiosaurus austriacus. With these data, it was possible to learn more about its sense of equilibrium and audition.

The results of this study show that Struthiosaurus’ brain was very similar to the brains of its close relatives. For example, the flocculus, an evolutionary old part of the brain, was very small. The flocculus is important for the fixation of the eyes during motions of the head, neck and whole body, which can be very useful if such an animal was trying to target potential competitors or aggressors. “In contrast to its North American relative Euoplocephalus, which had a tail club and a clear flocculus on the brain cast, Struthiosaurus austriacus may rather relied on its body armor for protection,” says Marco Schade. Together with the form of the semicircular canals in the inner ear, this hints towards an exceptionally sluggish lifestyle of this Austrian plant eater. Furthermore, the scientists found the – so far – shortest lagena of a dinosaur. The lagena is the part of the inner ear where audition takes place and its size can help to infer auditory capacities. This study delivers new insights into the evolutionary history of dinosaurs and their world, in which Europe was largely submerged in the ocean.

Reference: “Neuroanatomy of the nodosaurid Struthiosaurus austriacus (Dinosauria: Thyreophora) supports potential ecological differentiations within Ankylosauria” by Marco Schade, Sebastian Stumpf, Jürgen Kriwet, Christoph Kettler and Cathrin Pfaff, 7 January 2022, Scientific Reports.
DOI: 10.1038/s41598-021-03599-9

4 Comments on "Surprising Dinosaur Discovery: Ankylosaur Was Sluggish and Deaf"

  1. Is this a good idea? Basing a claim of a big discovery on a single sample always seems questionable. Might the skull that the “discovery” was based upon not be representative? Base your description of the human species based upon a randomly-chosen example from the Mütter Museum and you will almost never come close to the truth.

  2. Sluggish and deaf? How did it live long enough as a species to actually evolve into that species?

  3. Dinosaur is the most corrupt animal .another scientist cliam found new evidence that was a facts from the past that can not be change.what about sauropod duck bill dinosaur ankyosaur advance stapes not found in predator dinosaur. gator is king of the dinosaur so has superior hearing only dinosaur alive.because has 6 bones fuse to braincase like mammal .dinosaur stapes is like the lizard more advance than the tuatara they have tympanum ear drum .tuatara stapes is simular to primitive bird like velociraptor it is not like dinosaur and lizard.tuatara is the ancestor of lizard and gator .tuatara teeth is like fish they lack gums.gator dinosaur lizard bird mammal are gum animal it’s a advance technology .predator dinosaur can hear but it’s below ankyosaur .bird hearing is better than the gator and gator ancestor the dinosaur .gator has the best hearing in dinosaur.there is different hearing in today dinosaur the modern crocodilian .dwarf caiman has bigger brain than other modern crocodilian because it’s land crocodilian it’s skull is not that flat it’s like dinosaur fossil land mesoeucrocodylia and mammal allso spinosauridae is the same scientific skull name as spinosauridae .dwarf caiman hearing is like land mammal gator is like aquatic mammal both are advance hearing.I just read bird gator have simular hearing bone or something they thought gator hearing was like the early thecodont when they found this clearly gator was a advance dinosaur the same feature found in birds I think the name was duct .early bird the wons who lack flight skull but still can fly or ancestor can fly archaeopteryx velociraptor oviraptor the ducts are different from modern birds and gator.this ankyosaur was not a dig animal and dinosaur is a digetgrade animal like fast mammal they run on there toes. the greatest dinosaur the gator is a very fast animal it has human ankle it’s bipedal like a human .gator vertebrae is like a cat .

  4. Struthiosaurus is a nodosaurid, not an ankylosaurid. Closely related families, but nodosaurs don’t have tail clubs.

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