Cretaceous angiosperm leaf: Click to enlarge
Cretaceous angiosperm leaf
In October 1995, the Denver Museum of Nature and Science opened Prehistoric Journey, its award-winning exhibition about the history of life on Earth. Not only did the exhibition feature spectacular fossils, it also brought to life ancient landscapes based on Museum field research.

Long before Prehistoric Journey, the Museum had established a reputation for excellent dioramas based on real places. To make dioramas, the DMNS science and exhibits staff members visit the place in question and bring back to the Museum a thorough understanding of what that place is like. In the early planning stages for Prehistoric Journey, paleobotany curator Dr. Kirk Johnson and chief curator Dr. Richard Stucky decided to continue the Museum's tradition.

Prehistoric Journey features seven dioramas or "enviroramas" (displays the visitor walks through). Each one of these is based on an actual fossil locality, and the plants and animals on display are supported by fossil finds shown in nearby evidence cases.

Basing dioramas on specific fossil sites required Richard and Kirk to choose the localities carefully. Most fossil sites preserve plants or animals, but rarely both. Fossil sites that preserve unusually complete fossil records are known as lagerstätten. Of course, finding the lagerstätten is only the first step; to bring these ancient landscapes to life means rigorous research mixed with creativity. While visitors may focus on the animals in Prehistoric Journey, the plant life on display is just as realistic and, because plants are more abundant than animals, very time-consuming to make.

Cretaceous Creekbed envirorama: Click to enlarge
Cretaceous Creekbed envirorama
The Cretaceous Creekbed envirorama resulted from years of research by Kirk, starting with his bachelor's thesis in 1981. He compared fossil finds from North Dakota with a modern broad-leafed forest in Connecticut. In Connecticut, he took square meter samples of leaf litter and compared them to the forest overhead. He showed that you can predict the composition of the forest by looking at its leaf litter. He was so interested in quantifying the forest that he chopped one tree down and counted all of its leaves (the total was 99,284). Using these data, he applied them to fossil finds in the region of Marmarth, North Dakota, to determine the structure of the Cretaceous forest that existed there 66 million years ago.

Boxed leaves: Click to enlarge
Boxed leaves
Before Prehistoric Journey opened, Kirk knew how many leaves should appear in the Cretaceous Creekbed envirorama, but making realistic looking leaves based on fossils was no simple matter. The solution finally emerged when an exhibitor made duplicates of Cretaceous leaves by piecing together veins from modern leaves in the same patterns and shapes. These duplicates became the masters from which thousands of thin plastic leaves were made. Volunteers cut out and painted each leaf by hand. For the Cretaceous Creekbed alone, volunteers handmade more than 25,000 leaves! Just like modern leaves, ancient leaves bore battle scars from pillaging insects, and this damage was replicated too.

Eocene diorama: Click to enlarge
Eocene diorama
Similar attention to detail went into reconstructing plant life in the other dioramas in Prehistoric Journey. For the visitor, the result is an ancient forest that looks like the real thing.

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