PSITTACOSAURUS PARROT LIZARD GENUS EXTINCT CERATOPSIA DINOSAUR THE EARLY CRETACEOUS ASIA EXISTING MILLION YEARS AGO SPECIES UP TO MONGOLIA SIBERIA CHINA THAILAND SPECIES OF PSITTACOSAURUS BIPEDS HIGH SKULL SIMILAR TIANYULONG SCALES THE REST PROBABLY COMPLEX RELATIVE SIZE ACTIVE SHORT PERIODS THE DAY SENSES CERATOPSIANS CLOSER TRICERATOPS YINLONG ONCE PSITTACOSAURIDAE GENERA HONGSHANOSAURUS SENIOR SYNONYM THE BRANCH DERIVED RELATED EXCEPTION AQUILOPS NORTH AMERICA RISE HUNDREDS INDIVIDUALS COLLECTED COMPLETE CLASSES HATCHLING RATES REPRODUCTIVE BIOLOGY ABUNDANCE THE FOSSIL RECORD LABELLING LOWER CRETACEOUS SEDIMENTS EAST ASIA SIZE FEATURES THE SKULL SHARE OVERALL BODY SHAPE THE REACH MAXIMUM ADULT BODY WEIGHT KILOGRAMME SEVERAL SPECIES APPROACH SOMEWHAT SMALLER SINENSIS SMALLER THAN LARGEST NEITHER POSTCRANIAL SKELETONS BIPEDAL ORNITHISCHIAN MANUS THE FIVE ORNITHISCHIANS ORNITHISCHIA DINOSAURS TALL HEIGHT ALMOST ROUND PROFILE FRONT THE ORBIT TOTAL SHORTER JAWS VERTICAL RIDGE DOWN THE CENTRE UPPER SPORT PRONOUNCED ROSTRAL PREDENTARY BONY CORE THE BEAK KERATIN SHARP CUTTING SURFACE CROPPING PLANT MATERIAL GENERIC NAME BEAK MODERN SKULLS ADAPTATIONS UNIQUE ROSTRAL BONE THE TIP FLARED JUGAL NO SIGN NECK FRILL FACIAL HORNS DEVELOP THOUGHT EXAMPLE CONVERGENT EVOLUTION FLAT FOSSA THE OUTSIDE MAXILLA JAW BONE FLANGE PRESENT EDGE DENTARY BONE LOWER JAW MAJOR TYPE SPECIMEN FEMUR DOCUMENTED MEASURING DISTINGUISHED LESS PREMAXILLA CONTACTS FLARE FORMING WIDER EXCEPT ACTUALLY HORN BEHIND THE EYE CONTACT POSTORBITAL BONES FEATURE SEEN MANDIBLE LACKS THE HOLLOW FENESTRA ENTIRE BOWED THE ANIMAL APPEARANCE UNDERBITE REACH IN LONGER NUMBER PROMINENCES POSTORBITAL PALPEBRAL APART THE OTHER COMBINATION PRESENCE VERTEBRAE ON THE FRONT THE TEETH ILIUM BONES BEARS PROCESS ACETABULUM PUBLISHED LENGTH SNOUT NEARLY DEGREE COMPLETE TYPE THE MATERIAL APPEARS FRONTAL BONE ISCHIUM PELVIS FULLY TYPE JUGAL BONES EXHIBIT PRIMITIVE CONSISTENT GREATER GEOLOGICAL STRUCTURALLY PYRAMIDAL DEPRESSION THICKNESS INTEGUMENT BODY CHINESE COMES YIXIAN FORMATION LIAONING PROVINCE PARTICULAR EXPORTED VIOLATION GERMAN MUSEUM AWAITING THE BODY ARRANGED THE SPACES BETWEEN SKIN IMPRESSIONS APPEAR TUBULAR DORSAL CONFIRMED INDEPENDENT SCIENTIST INTEGUMENTARY STRUCTURES THE SKIN ULTRAVIOLET LIGHT GAVE FLUORESCENCE THE POSSIBILITY AUTHORS THE STUDY EVIDENCE SHOWS THEROPOD DINOSAURS FEATHERY INDEED STUDY DERMIS REMAINS NATURAL COMPARE SHOWING DERMAL LAYERS EVOLVED IN PARALLEL COLLAGEN TISSUE VIRTUALLY IDENTICAL VERTEBRATES STRUCTURE FORTY ABDOMEN THE TISSUE MUSCULATURE THE STOMACH INTESTINES PROTECTION THE BRAIN ANATOMY FUNCTIONALITY GENERALLY ENCEPHALISATION QUOTIENT RUSSELL ZHAO BELIEVED SMALL BRAIN RESTRICTIVE BEHAVIOURAL REPERTOIRE MAMMALS BODY SIZE THEORY BE MORE NEGATIVE ALLOMETRY BRAIN SIZE DEVELOPMENT THIS WAS TO BE TRUE SCORE HIGHER RANGE BEHAVIOUR TYRANNOSAURUS WHOSE RANGES BEHAVIOURS PARENTAL CARE THE SENSES INFERRED ENDOCAST OLFACTORY BULBS ACUTE SENSE OF SMELL BULBS PREDATORY THEROPODS PREDATORS SEEK SCLEROTIC RING REPTILES SHOW THE RINGS PROTOCERATOPS EYES CURVATURE SEMICIRCULAR CANALS AGILITY CURVED CANALS MUCH MORE AGILE COMPARISONS BETWEEN SCLERAL RING MODERN BIRDS CATHEMERAL AT NIGHT FORD MARTIN SWIMMING TAIL PADDLING INTERPRETATION SETTING THE POSITION NOSTRILS INTERPRETATIONS OF ARMS LEGS TAILS THE BRISTLES INTERPRETED PROPULSIVE GASTROLITHS TEETH USEFUL SLICING TOUGH SUITABLE GRINDING CHEWING FOOD AS IT THE DIGESTIVE SYSTEM SOMETIMES NUMBERING STONES ABDOMINAL GIZZARD AKINETIC SINGLE UNIT INTERNAL THE ONLY JOINT JAW ITSELF SLIDE FORWARD SHEARING BEAKS BE USED TO CROP RETRACTED INSIDE DIET MATCH PHIL CONDUCTED FORELIMBS TAXA TOO SHORT REACH RANGE OF MOTION PRONATED FORCE LOCOMOTION DIGGING DIG THE GROUND SCRATCHING LIMITED FLEXIBILITY USED TO GRASP CLOSE BELLY FLANK EVEN THOUGH THE HANDS CARRY NESTING MATERIAL DESIRED TAKING LIMB BONES RANGING LESS THAN THE UNIVERSITY OF BRISTOL INFANTS FASTER HIND LIMBS BIRTH THE AGE ARM LEG SWITCH FINDINGS REVEAL THE ANCESTOR QUADRUPEDAL EVENTUALLY ABILITY YOUNG GAIT LEAD HYPOTHESIS FAMILIES PATH POINT JUVENILE THE AMERICAN MUSEUM OF NATURAL AMNH DISCOVERED HISTOLOGICAL DETERMINED GROWTH RATE NINE RAPID MARSUPIAL MODERN BIRD PLACENTAL MAMMALS AN AGE PERFORMED GROWTH RING COUNTS LONGEVITY BASAL CERATOPSIAN WAS TO FIND HERD BURIED VOLCANIC MUDFLOW AGE GROUPS DISTINCT TAKEN GROUP FIDELITY GREGARIOUSNESS BEYOND THE NEST FOR ANY PRECOCIAL AGES FORAGING PARENTAL SPECIMEN CLAIMED ARTICULATED UNDERNEATH ABOVE THE MASS SUGGESTS THE ANIMALS ALIVE MUST COLLAPSE BURROW PAPER BELONG SEDIMENTARY CONNECTION SLAB ONTO ARTIFICIAL ASSOCIATION MOTHER CLAIM BREED REACHED FEMALE OFFSPRING ANALYSIS POSSIBLE COOPERATIVE BREEDING THE HUNDREDS SORT OF PATHOLOGY CONSISTING OF SKELETON BEDS BONE FRACTURE CLEAR SIGNS INFECTION MIDPOINT THE RIGHT FIBULA NECROSIS LACK BLOOD SUPPLY THE PIT MASSIVE AMOUNT SWELLING THE LOWER THIRD THE INJURY INJURY WEIGHT BEARING THE LEG TIBIA ANIMAL ABLE WALK THE SOURCE FOSSIL DIRECT EVIDENCE PREY ANIMAL R