1. Dinosaur embryos Jack found the first dinosaur embryos in the world. Some of them are on display in a case between in the Dinosaurs under the Big Sky exhibit in the Hallway of Growth and Behavior.

2. Achelousaurus horneri This fossil is one of two dinosaurs Jack has had named in his honor. The skull of Achelousaurus can be seen in the Hallway of Growth and Behavior in the Dinosaurs under the Big Sky exhibit.

3. Catherine (B-rex) Tyrannosaurus rex (MOR 1125), the skull of Catherine was the first T.rex found that showed that Tyrannosaurus rex replaced its flesh cutting teeth with bone crushing teeth as it matured. This is just some of the evidence suggesting that T.rex was a scavenger. The Catherine skeleton was also the first dinosaur specimen to yield soft tissue, and be shown to have been a pregnant female. Catherine's skull can be seen in the Hall of Horns and Teeth in the Dinosaurs under the Big Sky exhibit.

4. Maiasaura peeblesorum Named by Jack Horner and Bob Makela in 1978, Maiasaura was the first dinosaur found to exhibit parental care. Jack and Bob hypothesized that parent Maiasaura brought food to their nestlings. Specimens of Maiasaura can be seen in the cases in the Hallway of Growth and Behavior in the Dinosaurs under the Big Sky exhibit.