Karl Gottlieb Grell (28 December 1912, Burg an der Wupper – 4 October 1994) was a German zoologist and protistologist, known for his work on Trichoplax.
[1][2] Karl Grell received his doctorate (Promotion) in 1934 from the University of Bonn, for a dissertation on the digestive tract of the common scorpionfly (Panorpa communis).
[1] After the war he returned to Bonn and started to work on nuclear dimorphism in ciliates.
Back in Germany Professor Grell became a coworker of Max Hartmann at the Max-Planck-Institute for Biology in Tuebingen.
[1]At the University of Tübingen, Grell was a professor of zoology, teaching protozoology and genetics.