The hoodoos pictured on the stamp are actually near Drumheller, about 200 kilometres from the provincial park. A hoodoo is a fantastic rock pinnacle or column of rock formed by erosion.
"We were just remiss in our research," said Canada Post spokeswoman Anik Losier. "We have a rigorous approval process, and we missed a step, and that's unacceptable. And that's why we are taking full responsibility, and we will find a new image and reissue the series."
The stamp, issued on Friday, was one of five meant to celebrate Canada's UNESCO World Heritage sites.
Losier wouldn't say how many Dinosaur Provincial Park stamps were printed or how many were sold.