Pendraig milnerae: New Small-Sized Carnivorous Dinosaur Unearthed in Wales

Friday, October 8, 2021

Life reconstruction of Pendraig milnerae among the fissures of Pant-y-ffynnon and three individuals of the rhynchocephalian lepidosaur Clevosaurus cambrica during the Late Triassic epoch. Image credit: James Robbins.

Paleontologists have described a new genus and species of coelophysoid theropod dinosaur from the Late Triassic deposits of Pant-y-ffynnon in southern Wales.

The new dinosaur species, named Pendraig milnerae, lived during the Late Triassic period, between 200 and 215 million years ago.

Pendraig meaning ‘Chief Dragon’ in Middle Welsh, a reference to the species’ likely position as an apex predator of the area and its discovery in Wales, and milnerae honoring Dr. Angela Milner,” explained Dr. Stephan Spiekman, a paleontologist at the Natural History Museum, London.

“Angela was really important in the Museum for many years, she was not only the premier dinosaur researcher but also in a senior administrative position as Deputy Keeper of Palaeontology when women didn’t generally occupy such roles in the Museum, so for me as a student it was really important,” added Dr. Susannah Maidment, a paleobiologist at the Natural History Museum, London.

“She really inspired me and was incredibly helpful when I joined the Museum. She went out of her way to show me the ropes, and that goes for me and so many others, including three of the authors of this paper.”

Pendraig milnerae is the earliest example of a theropod found in the United Kingdom so far.

It likely had a body size around that of a modern-day chicken and would have been a 1 m long including its tail.

“The area where these specimens were found was most likely an island during the time period in which it lived,” Dr. Spiekman said.

“Species which live on islands often tend to become smaller than those on the mainland in a phenomenon called island dwarfism.”

“Because the fossil reptiles from this area, including Pendraig milnerae, are all quite small-sized, we used statistical analyses to investigate whether Pendraig milnerae might have been an insular dwarf.”

“The results indicate that Pendraig milnerae is indeed small, even for a theropod of that time period, but not uniquely so.”

“Furthermore, based on several characters on the bones, we were able to determine that, although the specimens of Pendraig milnerae were not very young, they were also likely not fully grown. So Pendraig milnerae might have gotten somewhat bigger than the specimens we have so far, which limits our ability to perform reliable body size analyses.”

“With this in mind, we need more evidence from more species to investigate the potential for island dwarfism in this area during that time, but if we could prove it, it would be the earliest known occurrence of this evolutionary phenomenon.”

The fragmentary fossils of Pendraig milnerae. Image credit: Spiekman et al., doi: 10.1098/rsos.210915.

The fragmentary fossils of Pendraig milnerae consist of an articulated pelvic girdle, sacrum and posterior dorsal vertebrae, and an associated left femur, and two referred specimens, comprising an isolated dorsal vertebra and a partial left ischium.

“Dinosaur discoveries are really rare in Wales, and this is only the third dinosaur species known from the country,” said Professor Richard Butler, a paleobiologist at the University of Birmingham.

“It’s very exciting to learn more about the dinosaurs that lived here in the United Kingdom during the Triassic, right at the dawn of dinosaur evolution.”

The team’s paper was published in the journal Royal Society Open Science.


Stephan N.F. Spiekman et al. 2021. Pendraig milnerae, a new small-sized coelophysoid theropod from the Late Triassic of Wales. R. Soc. open sci 8 (10): 210915; doi: 10.1098/rsos.210915