 Between 1906 and 1928, Jaekel was a professor at the University of Greifswald, where he founded the German Paleontological Society in 1912.He described a second species of "Plateosaurus" in 1914.During World War I, in which he served as a "Hauptmann" (Captain) in the 210th Prussian Infantry Regiment, he attempted to re-start excavations at the southern Belgian town of Bernissart, where several dozen specimens of the dinosaur "Iguanodon" had been dug up in the 1870s.