Aetosaurs are quadrupedal, heavily-armored reptiles in the extinct order Aetosauria. Their name means ‘eagle lizard,’ and comes from the fact that their skulls somewhat resemble that of a bird. These creatures were up to 6 m long and widely distributed geographically during the Late Triassic epoch.
The assemblage of Aetosaurus ferratus skeletons exhibited in the State Natural History Museumin Stuttgart. Image credit: E.M. Teschner.
“Aetosauria is a group of quadrupedal, armored reptiles whose terrestrial ecology is inferred as including both herbivory and omnivory,” said Elzbieta Teschner, a paleontologist at the University of Opole and the University of Bonn, and her colleagues.
“They achieved a nearly global geographic distribution, whereas they are stratigraphically restricted to the Upper Triassic.”
“Most species of aetosaurs reach a total body length between 2 and 6 m. The only exceptions are the relatively small Coahomasuchus from North America (1.5 m total body length) and Aetosaurus ferratus from Germany (between 20 cm and 1.5 m).”
“The latter is best known from an accumulation of 24 individuals (20-82 cm in length) excavated in Kaltental near Stuttgart, but is also reported by specimens from Pfaffenhofen and Eibensbach.”
“Also from the area of Stuttgart, a second, nearly complete specimen of the aetosaur Paratypothorax andressorum is approximately 2 m in length.”
“Dr. Oscar Fraas provided the first description of the skeletons of Aetosaurus ferratus from Kaltental in 1877 and suggested that they had washed up together,” they said.
“Sixteen years ago, Dr. Rainer Schoch of the State Natural History Museum in Stuttgart published a more detailed morphological study. Based on features visible to the naked eye, he determined that they must be juveniles.”
Reconstruction of the Aetosaurus ferratus assemblage in its habitat. Image credit: J. Kowalski / P. Janecki.
In the new study, the authors studied the growth of the humerus bones of the smallest and one of the largest specimens from the Aetosaurus ferratus assemblage from Kaltental.
They found that the specimens are both early juveniles, not older than one year, based on their tissue type and the absence of growth marks and bone resorption.
Moreover, they preserve a tissue resembling hatchling bone.
“This young age can be extrapolated for all members of this assemblage,” Teschner said.
According to the team, the Kaltental assemblage likely contains a group of juveniles of Aetosaurus ferratus that formed biologically, i.e., through gregarious behavior.
“The animals banded together for some reason,” Teschner said.
“Most likely to increase their chances of survival and deter predators.”
Source: sci.news
