amino acid – molecular building block of proteins.
bipedal – two-legged, rather than four-legged.
coelurosaurs – a group of theropod dinosaurs related to birds. It includes compsognathids, tyrannosaurs, ornithomimosaurs and maniraptorans.
Cretaceous – the geological period beginning 145 million years ago and ending 66 million years ago.
describe – in the context of discovery of new species the act of ‘describing’ or a ‘description’ means the formal task of naming and defining the characteristics of a novel plant or animal.
dinofuzz – fluffy down-like structures that represented an early stage of feather evolution.
dromaeosaurs – a group of small bird-like theropods (including Velociraptor) that were fast runners, effective predators and perhaps even pack hunters.
enantiornithes – Cretaceous-era offshoots of early birds that still had teeth.
formation – layers of rock laid down, without breaks to divide them, over a relatively short period of geological time.
genome – the entire sum of an organism’s DNA.
Gondwana – southern supercontinent that began to break up into Africa, Australia, South America, India, Madagascar and Antarctica 184 million years ago.
hadrosaurs – the herbivorous duck-billed dinosaurs, a group of ornithischians that included Maiasaura and Parasaurolophus.
integumentary – structures originating from the skin of an organism, such as fluff, scales, fur and feathers.
Jurassic – the geological period beginning 201 million years ago and ending 145 million years ago.
keratin – the protein that makes up nails and claws, reptile scales, mammal fur and bird (and dinosaur) feathers.
maniraptors – theropod dinosaurs most tightly linked to birds. They include dromaeosaurs, oviraptorosaurs and therizinosaurs.
Mesozoic – the geological era comprising the Triassic, Jurassic and Cretaceous periods.
morphology – the form, shape and structure of an organism or physical feature.
ornithischian – one of the two divisions within the dinosaur group; the other is the saurischians. The ornithischian or ‘bird-hipped’ dinosaurs include long-necked sauropods and all the bipedal, predatory theropods.
oviraptorosaurs – a group of parrot-beaked omnivorous theropods with short pygostyle tails that are inferred to have had feather fans attached for display.
paedomorphosis – also known as neoteny, the retention of juvenile traits in an adult animal.
Palaeognathae – (Greek for ‘old jaw’) the most ancient branch of living birds, which includes tinamous and flightless ratites such as the kiwi, rhea, ostrich, cassowary and emu (and also the extinct elephant birds of Madagascar and the moa of New Zealand). All other modern birds fall into the Neognathae group.
pennaceous – (pen-ay-SHUHS) a word used to describe feathers that are the typical modern feather shape, with a central shaft running the length and interlocking barbs running off to either side.
plumulaceous – (ploom-YUH-ley-SHUHS) a word used to describe feathers that have no central vane and are a messy jumble of filaments.
pneumatisation – invasion of air sacs into bird bones creating a lightweight honeycomb structure.
protofeather – simple filament representing one of the earliest stages of feather evolution.
pygostyle – the shortened tail structure of modern birds, to which a fan of feathers attaches.
quill knobs – pits where the ligaments of flight feathers attach to the arm bones of modern birds.
saurischian – one of the two divisions within the dinosaur group; the other is the ornithischians. The saurischian or ‘lizard-hipped’ dinosaurs, include heavy-set and armoured species and herd-living herbivores, such as the hadrosaurs.
soft tissue – any fossilised body part not created by the remains of bones (‘hard tissue’), such as muscles, skin, internal organs, fur and feathers.
sternum – a bone between the ribs that acts like a keel and anchors the breast muscles that power the wings in modern birds.
stratigraphy – the study of the order and relative position of rock layers and how they relate to geological time.
taxonomy – biological discipline concerned with the classification and naming of organisms.
temporal paradox – the confusing problem in unravelling the evolution of flight whereby most of the feathered dinosaurs first discovered had lived significantly later than Archaeopteryx the ‘first bird’, and therefore could not have been ancestral to it.
terrestrial – land-living.
therizinosaurs – (ther-uh-ZIN-oh-SORE) carnivorous theropods whose teeth suggest they had returned to a vegetarian diet. The name means ‘reaping’ or ‘scything’ lizard.
theropods – a large group of bipedal saurischian dinosaurs that included all of the carnivorous species.
Triassic – the geological period beginning 252 million years ago and ending 201 million years ago.
troodontids – a group of small (less than 100-kilogram) theropods related to dromaeosaurs and birds. Examples include Troodon, Anchiornis, Xiaotingia and Mei.
warm-blooded – animals with high metabolic rates that can regulate their internal body temperature to within a narrow range, a process known as thermoregulation.
Pronunciation guide
Chicxulub – (CHIK-shoo-loob) a town on Mexico’s Yucatán Peninsula. Liaoning – (lee-ow-NING) a province in north-eastern China.