Newly Discovered Dinosaur Species Enigmacursor Unveiled at NHM

On June 25, 2025, scientists at the Natural History Museum (NHM) in London revealed a significant paleontological discovery: the Enigmacursor mollyborthwickae, a dog-sized dinosaur that lived approximately 150 million years ago. Initially misclassified as a Nanosaurus, this species is poised to enhance understanding of the evolutionary lineage of small dinosaurs that coexisted with larger giants like the Stegosaurus.

The unveiling of Enigmacursor marks the first new dinosaur display at the NHM since 2014. According to Dr. Paul Barrett, a senior paleontologist at the NHM, the discovery is crucial in understanding the evolutionary history of dinosaurs. "The identification of this species is foundational to our work, allowing us to accurately assess the diversity of dinosaurs during the Late Jurassic period," Dr. Barrett stated.

The Enigmacursor, standing at 64 cm tall and measuring 180 cm long, is notably smaller than its contemporaries, which included some of the largest known dinosaurs. Its name, which translates to 'puzzling runner,' reflects its unique characteristics and the confusion surrounding its initial classification. Dr. Susanna Maidment, a paleontologist also at the NHM, emphasized the importance of the dinosaur's leg bones in distinguishing it from related species. "The leg bones are critical; they exhibit features that set Enigmacursor apart from the Nanosaurus," Dr. Maidment noted.

Upon examining the original Nanosaurus specimen in the United States, researchers found that it lacked any definitive bones, leading them to conclude that the NHM's specimen is indeed a distinct species. This finding has led to the formal reclassification and erasure of the Nanosaurus category, with researchers suggesting that other small dinosaur specimens from the same period might also be unique species.

The fossilized remains of Enigmacursor represent one of the most complete skeletons of early small dinosaurs discovered to date, with conservators at the NHM working meticulously to prepare the skeleton for display. Conservator Lu Allington-Jones remarked, "We are excited to present such a rare specimen to the public, as smaller dinosaurs have often been overlooked in favor of their larger counterparts."

Paleontologists believe that studying smaller dinosaurs like Enigmacursor is essential for understanding the evolutionary pressures that eventually led to the development of larger, more bizarre dinosaur species. "These early creatures provide insight into the gradual changes that occurred over time, helping us comprehend the evolutionary trajectory of dinosaurs," Dr. Barrett explained.

The findings regarding Enigmacursor mollyborthwickae have been published in the Royal Society Open Science, contributing valuable data to the ongoing discourse on dinosaur evolution. The NHM aims to encourage further exploration of small dinosaur fossils, which could unveil more insights into the diversity of life during the Jurassic era. With the hope that this discovery will inspire future paleontological endeavors, Dr. Barrett urged researchers to keep an eye out for small fossils, noting, "The small dinosaurs are critical to piecing together the larger puzzle of dinosaur evolution."

As Enigmacursor prepares for its public debut, it stands as a testament to the ongoing quest for knowledge in paleontology, emphasizing the importance of even the smallest discoveries in understanding the vast history of life on Earth.