One of the most interesting areas inside Zilker Botanical Garden is the Hartman Prehistoric Garden. The site was established in 1992 following the discovery of dinosaur tracks and the remains of an ancient turtle within the botanical garden. Nearly 100 tracks were discovered and are believed to have been left behind by six or seven prehistoric creatures. The tracks were mapped, cast, and re-buried to protect them from the elements.
Funds were hastily raised and a number of volunteers joined together to develop a two-acre cretaceous habitat around the site. A life-size replica of an Ornithomimus, the species of dinosaur that likely laid the tracks, was situated at the center of the garden. Developers chose over 100 plant species that likely existed when the Ornithomimus roamed the earth. These included: horsetails, cycads, ferns, liverworts, palms, conifers, magnolias, and ginkgos.1