As a paleontologist, Jaekel specialized in the study of fossil
vertebrates, particularly fishes and reptiles. However, 27 of his publications were about
echinodermata. In addition, he wrote about politics, law, literature, and art. He was an accomplished painter and used his skills to produce landscape paintings that illustrate the geology of the
Pomeranian coast. Furthermore, his collection of Japanese
Ukiyo-e wood block prints was among the most important in Germany and featured in several exhibitions and catalogs. Apart from his publications, Jaekel's most prominent contribution to vertebrate paleontology lies in the excavations in
Wildungen (1890-1903) and
Halberstadt (1909-1912), both of which he supervised. In Wildungen, various forms of
Devonian fishes were excavated, while Halberstadt yielded a large number (more than thirty) of the
dinosaur Plateosaurus. 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, Jaekel 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. Although he eventually succeeded in persuading the German occupation authorities to support his initiative, the attempt had to be abandoned after the German army withdrew from the area in November 1918, following its surrender. ==Publications==