# Dueling Dinosaurs

The Dueling Dinosaurs or Montana Dueling Dinosaurs is a fossil specimen originating from the Hell Creek Formation of Montana. It consists of the fossilized skeletons of a tyrannosaur (generally considered a juvenile Tyrannosaurus rex) and a Triceratops horridus entangled with one another and entombed in sandstone. This is quite similar to the Fighting Dinosaurs, a 74-million-year-old specimen found Mongolia in 1971, in which a Velociraptor and Protoceratops were locked in battle and preserved. The "dueling" inference comes from the numerous injuries sustained by both dinosaurs, including a tooth from the tyrannosaur embedded within the Triceratops, although it is not known whether they were actually buried fighting one another. Despite the scientific importance of the specimen, it remained obscure for decades due to a lengthy legal dispute over property rights to the specimen, which has since been resolved. The fossil is in the possession of and being studied by the North Carolina Museum of Natural Sciences, where it went on display in 2024.

## History

The specimen was originally discovered in 2006 by ranchers Clayton Phipps, Mark Eatman, and Chad O’Connor in Montana. Two different ranching families, the Seversons and the Murrays, owned the land on which the fossils were found. Phipps enlisted the help of CK Preparations, run by Preparer Chris Morrow and Paleoartist Katie Busch, to prepare the specimen.
The Dueling Dinosaurs remained obscure until 2011, when a marketing campaign, including a dedicated website, was launched by the ranchers (with the assistance of commercial paleontologist Pete Larson) to sell them to a prospective buyer. The ranchers unsuccessfully tried to sell the fossil to several museums, including the Smithsonian and the Museum of the Rockies. With no buyers, the fossils were slated to be sold to a private collector instead. In 2013, Larson presented a poster about the tyrannosaur (also referred to as "Bloody Mary", specimen number BHI 6437) at the annual Society of Vertebrate Paleontology meeting, pronouncing it as a potential specimen of the debated tyrannosaur genus "Nanotyrannus". This presentation was met with significant controversy and ethical complaints, due to the opposition surrounding publishing on privately-owned specimens. Shortly afterwards, the specimens went on sale, including auctioning at Bonhams, but no purchase was made.
In 2016, Lindsay Zanno of the North Carolina Museum of Natural Sciences reached out to Phipps, starting negotiations to purchase the fossil, with funds being raised through the private nonprofit Friends of the North Carolina Museum of Natural Sciences. However, legal issues over rightful ownership of the fossils slowed these negotiations: the Seversons had most of the control over mineral rights on Murray land, and whether fossils could be considered minerals (in which case the Seversons would have rights to it) was disputed. Although a previous court had ruled in favor of the Murrays, in November 2018 judges ruled in favor of the Seversons and that fossils could legally be considered minerals in Montana, angering many paleontologists. However, the case was appealed to the Montana Supreme Court in 2020, who ruled that fossils could not be considered minerals, allowing for the Museum of Natural Sciences to acquire the fossils.
The specimens were officially revealed to the public in April 2024, in a ribbon-cutting ceremony led by then-state governor Roy Cooper.

## Significance

The specimen is considered one of the best-preserved and most complete fossils of both species of Triceratops and over 98% completeness of a Tyrannosaurus and contains skin impressions, and potentially internal organs, stomach contents, and proteins.
For a long time, paleontologists, artists, and filmmakers made several depictions of Tyrannosaurus rex pitted against Triceratops. The diet of a T-Rex is indicated by studying bitten bones and coprolites (feces). However, there is no direct evidence T-Rex and Triceratops ever fought. Furthermore, a lot of Triceratops only had traces indicating scavenging. Yet healed injuries on either a T-Rex or Triceratops would be a clear sign of a fight. A juvenile T-Rex has a bite force of 5,641 newtons compared to the 35,000 newtons of a full-grown adult. Paleontologists use this information to confirmed juveniles do not crush bone but that comes with growth and development, advancing their bite power and strengthening their jaws. Therefore, T-Rex bite force rises in strength and power in correspondence to its size and weight with age. The presence of holes on the frill revealed evidence of what could only be done by combat injuries, similar to elk and deer. Chemical analysis indicated the injuries on the bones to be healed. This confirmed Triceratops was capable of battling whether it's two males fighting for dominance or defense against predators.