He is a vertebrate paleontologist and holds an associate professor position at the Natural History Museum of the University of Oslo.
He is the author of the book Menneskets utvikling ("The Evolution of Man") and the host of the segment Jørns hjørne ("Jørn's Corner") on the popular-science program "Newton" on Norwegian television.
In 2006 his team uncovered an enormous short-necked plesiosaur, the Pliosaurus funkei, possibly the largest carnivore found to date.
In May, 2009, he announced the acquisition and scientific description of a 47-million-year-old, 95% complete skeleton of a primitive primate, Darwinius masillae, that had been in the private collection of an amateur fossil collector for 25 years.
[5] Some experts in the scientific community were critical of the 2009 media campaign Hurum orchestrated to publicize his find Darwinius masillae.