Official U.S. State Dinosaurs

As of 2026, 12 U.S. states have officially designated a state dinosaur: Alabama, Arizona, Arkansas, California, Colorado, Maryland, Missouri, Montana, New Jersey, Oklahoma, Texas, and Utah. That's fewer than a quarter of all states.

The remaining 38 states have not enacted a formal designation, even though many sit on significant fossil-bearing rock formations. Some of those states — like New Mexico, South Dakota, and Connecticut — have designated a dinosaur species as their state fossil, which is a related but separate category. State fossils can be any ancient organism; state dinosaurs are specifically non-avian dinosaurs designated under that title.

Colorado's 1982 designation of Stegosaurus started the practice. Growth has been gradual: a few states added theirs in the late 1980s and 1990s, then the category went quiet for several years. The late 2010s brought the most activity, with Arkansas, California, and Utah all making designations between 2017 and 2018.

A state fossil and a state dinosaur are distinct legal designations, even when both refer to prehistoric animals. A state fossil can be any ancient organism: a trilobite, a mammoth tooth, a shark tooth, a plant impression, or a dinosaur. A state dinosaur is specifically a non-avian dinosaur, designated under that explicit title.

Several states have a dinosaur species as their state fossil but have not designated a separate state dinosaur. New Mexico's state fossil is Coelophysis bauri — a small theropod from the Triassic Period, designated in 1981. South Dakota's state fossil is Triceratops. Connecticut's state fossil is Eubrontes giganteus, a set of large three-toed dinosaur footprints. None of these appear on this page, because they were designated as fossils, not as state dinosaurs.

The distinction matters for building accurate lists — and for why some well-known fossil states like South Dakota (Triceratops) and New Mexico (Coelophysis) don't appear in the table above.

Arkansas designated Arkansaurus fridayi in 2017 — before the animal was formally published in the scientific literature. The peer-reviewed description didn't appear until 2019. It's based on fragmentary foot bones found in 1972 that spent decades in storage before researchers formally described them. No other state has designated an animal that wasn't yet officially named in science at the time.

Texas updated its state dinosaur. The original 1997 designation named Pleurocoelus, a genus applied to Texas material for decades by default. In 2009, after Peter Rose's analysis showed the Texas bones warranted their own name, House Bill 1107 replaced the designation with Paluxysaurus jonesi. Texas is the only state to formally revise an existing state dinosaur designation — and there's a chance it could happen again, if the proposed synonymy with Sauroposeidon is ever settled.

Maryland's Astrodon johnstoni was described in a dental journal. In 1859, Baltimore dentist Christopher Johnston examined unusual teeth from Prince George's County and published his description in the American Journal of Dental Science. That description — in a non-paleontology publication, by a dentist — has stood as the formal scientific record for over 160 years. Maryland designated it as state dinosaur in 1998.