He was a member of the Antarctic Expedition that discovered important sites of fossil fish in Antarctica, including Mount Ritchie, which is named after him.
He not only found a jaw bone, which he extracted with a jackhammer, but a plethora of Devonian fossils of fish that shed new light on continental drift.
[3] Ritchie kept 16 mm film footage of the expedition which lay on a shelf at his home in Canberra for many years, but it was unwatched because he did not have the equipment to view it.
[2] In 1993, Ritchie led an expedition to Canowindra, New South Wales, where roadwork in 1955 had uncovered a large rock slab covered with unusual impressions.
[1][4] During the 1980s, Ritchie clashed with creationist, religious fanatics who believed the world was created in seven days, who wanted to get have their beliefs taught in schools.