Dynamoterror

Dynamoterror charges at a nodosaurid covered in algae and turtles. Credit: Brian Engh.

## Statistics

### Diet

Carnivorous

*Dynamoterror* is a genus of tyrannosaurid theropod dinosaur that lived in New Mexico during the Late Cretaceous.

## History

UMNH VP 28348, the holotype, was recovered from the Lower Campanian Allison Member, San Juan Basin, Menefee Formation, northwest New Mexico. They were found in 2012 during an expedition led by Andrew McDonald and Douglas Wolfe, with volunteers Brian Watkins and Eric Gutierrez noticing fragmented bones inside the sandstone. The specimen is now held at the Natural History Museum of Utah collection. *Dynamoterror*, alongside *Lythronax* is one of the oldest Tyrannosaurids.

They named it from the Greek dynamis (δύναμις), "power" and the Latin terror. The epithet derives from δυνάστης, meaning "ruler". In 2020, *Dynamoterror* was considered a nomen dubium because of fragmentary and undiagnostic material, however, new material of Dynamoterror was unveiled in 2019 makes the taxon valid.

## Description

*Dynamoterror* would have been ~9 meters (30 feet) long. The holotype is incomplete skeleton with crania and postcrania, including both frontals, four vertebral centra, partial ribs, a right metacarpal, an ilium and two phalanx bones of the fourth toe on the left foot.

In the September 2019 GSA meeting in Phoenix, Arizona, it was revealed up to 30 more Tyrannosaurid remains were collected. They include fragmented crania, but preparation and study is in very early stages. In August 2021, it was confirmed that not only were these remains of *D. dynaste*s, they were 3D printed and set out for an exhibition. This exhibition, set at the Western Science Center, deals with dinosaur of the Menefee Formation. It includes a *Dynamoterror* bust by Brian Engh, a life-sized *Dynamoterror* skeletal with new material. The new cranial material sustains injury on the maxilla, likely from bite marks.

## Classification

* Dynamoterror skeletal.png**Credit: Clumsystiggy on DeviantArt.**
* Dynamoterror2.pngThe undescribed remains.
**Credit: Clumsystiggy on DeviantArt.**
1/2
McDonald et al. concluded *Dynamoterror* was a Tyrannosaurine, forming a polytomy with other large-bodied Tyrannosaurines. However, this was likely caused by the fragmentary nature of *Dynamoterror*. McDonald et al. (2018) find:

## Paleoecology

Dynamoterror lived in the Lower Campanian Allison Member, Menefee Formation, New Mexico. It lived with *Invictarx, Brachychampsa sealeyi, Deinosuchus, Ornatops* and *Menefeeceratops*. This formation is made of fluvial sandstone, shale and coal, constrained to 84.2-79 million years based on ammonite biostratigraphy. The Cliff House Sandstone overlies and the Point Lookout Sandstone underlies. Indeterminate remains include Ankylosaurs, fish, palms, conifers, laurels, witchhazel and camellia; plants suggest it was moist and subtropical.

## References

1. ↑ 1.0 1.1 1.2 1.3 https://gsa.confex.com/gsa/2019AM/meetingapp.cgi/Paper/335415
2. ↑ https://gsa.confex.com/gsa/2019AM/meetingapp.cgi/Paper/335415
3. ↑ https://twitter.com/alfmuseum/status/1429151365754851330
4. ↑ https://www.instagram.com/p/CSHlTKFlty9/
5. ↑ Museum plaque.
6. ↑ https://doi.org/10.7717%2Fpeerj.11302
7. ↑ https://doi.org/10.7717%2Fpeerj.11084
8. ↑ https://www.nps.gov/chcu/learn/nature/menefee-formation.htm