A dinosaur distantly related to Tyrannosaurus rex – but with a body the size of a chicken – that would probably have ruled the roost about 200m years ago has been discovered. The diminutive but fearsome creature, whose fossilised remains were found in a quarry in south Wales, is the oldest theropod – a group that includes T rex and modern birds – found in the UK. It has been named Pendraig milnerae – pendraig meaning “chief dragon” in middle Welsh and milnerae in honour of the late Angela Milner, a stalwart of the Natural History Museum’s dinosaur gallery and a researcher and deputy keeper of palaeontology at the museum for more than 30 years. Fragmentary fossils of Pendraig milnerae were discovered in a quarry in south Wales in the 1950s but in recent years had been stashed away in a drawer with some crocodile samples until they were found by Milner. It is thought the dinosaur lived between 200m and 215m years ago during the Late Triassic period. It probably had a body size similar to that of a modern-day chicken, but with its tail taking it to about a metre-long. Stephan Spiekman, a research fellow at the Natural History Museum, said: “Pendraig milnerae lived near the beginning of the evolution of the meat-eating dinosaurs. It’s clear from the bones we have that it was a meat-eater, but early in the evolution of this group these animals were quite small, in contrast to the very famous meat-eating dinosaurs like T rex which evolved much later.” Spiekman and his colleagues gave it the name dragon chief to honour its probable position as the apex predator. The reference to Milner, who died in August, was apt as she played a vital role in relocating the specimen, as well as contributing significantly to the understanding of theropod dinosaurs. The discovery of this new species could also provide evidence for potential island dwarfism. Spiekman said: “The area where these specimens were found was most likely an island during the time period in which it lived. Species which live on islands often tend to become smaller than those on the mainland in a phenomenon called island dwarfism.” He said that because Pendraig was not fully grown, it was not possible to reach conclusions on this. “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.” Richard Butler, co-author on a paper on the dinosaur and professor of palaeobiology at the University of Birmingham, said: “Dinosaur discoveries are really rare in Wales, and this is only the third dinosaur species known from the country. It’s very exciting to learn more about the dinosaurs that lived here in the UK during the Triassic, right at the dawn of dinosaur evolution.” The remains were found in the 50s by the palaeontologists Pamela Robinson and Kenneth Kermack. They were studied, but the creature was not named. Susannah Maidment, a senior researcher in paleobiology at the Natural History Museum, was trying to track the specimen down and turned to Milner for help. “She went away and about three hours later she had it. She found it in a drawer with crocodile material.”