Pendraig

Chapter • Meet the dinosaur

Overview

Pendraig milnerae was a very small predatory dinosaur, roughly chicken-sized, with an estimated total length of about 75 centimetres to one metre — much of that made up by a long, slender tail. It walked on two lightly built hind legs, held its body horizontally and balanced with the tail carried clear of the ground. The known fossils consist of a pelvis, sacrum, a couple of back vertebrae and a thigh bone, so the skull is unknown. Based on close relatives such as Coelophysis, Pendraig is usually reconstructed with a narrow, elongated head, numerous small serrated teeth and long grasping hands tipped with sharp claws. Whether it bore simple filament-like body covering is unresolved: no skin or filament impressions are known for any coelophysoid. As a small, nimble biped, Pendraig most likely hunted whatever it could overpower — insects and other arthropods, small lizard-like reptiles such as Clevosaurus, early mammal relatives, and perhaps carrion scavenged from larger carcasses. Its build suggests an agile animal moving through low vegetation and among the fissured karst terrain of its island home, though there is no direct evidence of its hunting behaviour such as gut contents, bite marks or trackways. One of the most intriguing questions about Pendraig is whether it was an island dwarf. During the Late Triassic much of what is now southern Britain lay beneath a shallow tropical sea dotted with limestone islands, and animals isolated on islands often evolve smaller body sizes. The team that described Pendraig tested this idea directly, but because bone tissue shows the holotype individual was not yet fully grown, dwarfism could not be confirmed. It may simply have belonged to a naturally small-bodied lineage of early theropods. The fossils were collected back in the 1950s from Pant-y-ffynnon quarry near Bonvilston in the Vale of Glamorgan, South Wales, but sat in the collections of the Natural History Museum in London, partly mixed in with material of the rhynchocephalian Clevosaurus. They were finally recognised as a new genus and species in 2021 by Stephan Spiekman, Susannah Maidment, Martín Ezcurra and colleagues in Royal Society Open Science. The genus name comes from Middle Welsh pen draig, 'chief dragon', while the species name honours the British palaeontologist Angela Milner. Pendraig is regarded as the oldest known theropod dinosaur from the United Kingdom.

Chapter • Where it lived

Habitat

Pendraig lived in the Late Triassic, roughly 214–201 million years ago, in what is now South Wales. At that time the region lay near the equator, and much of southern Britain was covered by a warm, shallow sea studded with islands made of older Carboniferous limestone. The landscape was karstic, riddled with fissures and caves, with dry scrubby vegetation and a strongly seasonal climate. The bones of Pendraig come from fissure fills at Pant-y-ffynnon quarry near Bonvilston in the Vale of Glamorgan — limestone cracks into which sediment and the skeletons of island animals washed down and became cemented. The same deposits preserve the lizard-like Clevosaurus, the slender crocodylomorph Terrestrisuchus and the early sauropodomorph Pantydraco.

Chapter • Wild behavior

Behavior & Ecology

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Chapter • Scientific place

Taxonomy