#enigmacursor

Day 23: Enigmacursor mollyborthwickae

A closer look at yesterdays new dinosaur species, Enigmacursor mollyborthwickae, from the Morrison Formation. It is always a big thrill to be the first to reconstruct a new species.

Day 101 of DDD! The Enigmacursor! A relatively new dinosaur discovery from 2022! So we don't know alot about it so far except that its a neornithischian from Morrison! Its fun to learn more about the little guys when everyone focuses on the massive sauropods in morrison.

Enigmacursor mollyborthwickae is a newly-described species of small neornithischian dinosaur hailing from the Morrison Formation of what is now Colorado, approximately 150 million years ago. It is a 1.5-meter-long North American relative of Yandusaurus from the Asian Shaximiao Formation and joins Nanosaurus and Dryosaurus as one of the few small neornithischians that lived alongside larger, heavier herbivores such as Camarasaurus, Diplodocus and Stegosaurus in the floodplains and around the rivers that made up much of the formation. The genus name, which has the same Greek word for "mystery" as that used for a certain cipher device developed by the Germans from 1918-1945, means "mysterious runner" and refers to the complicated taxonomic history of the Morrison's small ornithischians, and the species name refers to the person who donated the funds for the accquisiton of the type specimen, which was unearthed in 2021-2022 and consists of a well-preserved postcranial skeleton that consists of the forelimbs, shoulders, pelvis, hindlimbs and tail vertebrae and assicated teeth, by London's Natural History Museum in 2024.

Top: Newly-described Monstersaur (the group of lizards that includes the modern Gila Monster) Bolg amondol, whose genus name refers to the Goblin general from J.R.R. Tolkien’s The Hobbit and whose species name is the Sindarin word for “mound-headed” due to the bumpy texture of the animal’s head) crawls into a Utahceratops nest and devours a few eggs just before it is caught unawares…

Here's my skeletal reconstruction of Enigmacursor mollyborthwickae, from the new paper by Maidment and Barrett 2025.

It is always special to be the first to reconstruct a new species!