Born in Clarinda, Iowa, he grew up in Maryville, Missouri and graduated from Maryville High School. His father was George H. Colbert who was head of the mathematics department at Northwest Missouri State University and had been at the college since its founding in 1906. He received his A.B. from the University of Nebraska, then his Masters and Ph.D. from Columbia University, finishing in 1935. He married Margaret Matthew, daughter of the eminent paleontologist William Diller Matthew, in 1933.^[5] She became a noted artist, illustrator, and sculptor who specialized in visualizing extinct species. The couple had five sons together. The young family moved to Leonia, New Jersey, in 1937 and lived there for decades.His fieldwork in Antarctica in 1969 helped solidify the acceptance of continental drift, by finding a 220-million-year-old fossil of a Lystrosaurus. His popularity and his textbooks on dinosaurs, paleontology, and stratigraphy (with Marshall Kay) introduced a new generation of scientists and amateur enthusiasts to the subject. He was the recipient of numerous prizes and awards commemorating his many achievements in the field of science.