*SPECIAL NOTE* - Ugrunaaluk has now been found to be a synonym to Edmontosaurus. This page remains online for archive purposes.


Name: Ugrunaaluk ‭(‬Ancient grazer‭)‬.
Phonetic: Ug-ru-naa-luk.
Named By: Hirotsugu Mori,‭ ‬Patrick S.‭ ‬Druckenmiller‭ & ‬Gregory M.‭ ‬Erickson‭ ‬-‭ ‬2015.
Classification: Chordata,‭ ‬Reptilia,‭ ‬Dinosauria,‭ ‬Ornithischia,‭ ‬Hadrosauridae,‭ ‬Saurolophinae,‭ ‬Edmontosaurini.
Species: U.‭ ‬kuukpikensis‭ (‬type‭)‬.
Diet: Herbivore.
Size: Roughly about‭ ‬10‭ ‬meters long.
Known locations: USA,‭ ‬Alaska‭ ‬-‭ ‬Prince Creek Formation.
Time period: Early Maastrichtian of the Cretaceous.
Fossil representation: Remains of many individuals.

       Since the closing decades of the twentieth century literally thousands of fossil bones of hadrosaurid dinosaurs have been found in Alaska.‭ ‬Initially considered to be lambeosaurines‭ (‬the type with bony head crests‭)‬,‭ ‬there were later determined to be saurolophines,‭ ‬specifically similar to Edmontosaurus.‭ ‬Most of these remains however have come from juveniles which has made it awkward to identify a specific genus given that juveniles can change form as they grow up.‭ ‬Still,‭ ‬work that began in‭ ‬2014‭ ‬has concluded with‭ ‬the establishment of a new genus for some of these remains in‭ ‬2015,‭ ‬and that genus is Ugrunaaluk.
       Ugrunaaluk was one of the most northern living hadrosaurs that we currently know about,‭ ‬and grew to a fairly large size.‭ ‬This places Ugrunaaluk in good standing to its more immediate relative genera such as Edmontosaurus as well as the particularly large Shantungosaurus from China.‭ ‬As with other hadrosaurs Ugrunaaluk would have been a plant eater and primarily quadrupedal when walking about,‭ ‬though bipedal locomotion and rearing would have still been possible,‭ ‬and perhaps quite common when feeding.‭ ‬Like other saurolophines,‭ ‬Ugrunaaluk had no kind of bony head crest.‭ ‬However,‭ ‬soft tissue preservation and studies in Edmontosaurus have proven that in life Edmontosaurus regalis had a fleshy soft tissue crest-like growth on its head.‭ ‬It is unknown if Ugrunaaluk had a similar display device.
       One thing that stood out about the naming of Ugrunaaluk in‭ ‬2015‭ ‬is the surprise that most people still had at hearing the news that a dinosaur had been discovered in what is now Alaska.‭ ‬For a start it must be remembered that while in the Cretaceous Alaska was cooler that the tropical latitudes,‭ ‬it was still much warmer than it was today.‭ ‬In addition to this,‭ ‬many dinosaurs‭ ‬have‭ ‬been found in Alaska before Ugrunaaluk was.‭ ‬These include ceratopsians such as Pachyrhinosaurus,‭ ‬pachycephalosaurs such as Alaskacephale as well as indeterminate‭ ‬remains of small ornithopods.‭ ‬Predatory dinosaurs such as dromaeosaurs and troodonts such as Dromaeosaurus,‭ ‬Saurornitholestes,‭ ‬and even a variety of Troodon larger than southern relatives are also known.‭ ‬To top all this off there is even a tyrannosaur named Nanuqsaurus known from the same formation as Ugrunaaluk,‭ ‬and this predator may have been a particular danger to Ugrunaaluk.

Further reading
-‭ ‬Dinosaurs on the North Slope,‭ ‬Alaska:‭ ‬High latitude,‭ ‬latest Cretaceous environments.‭ ‬-‭ ‬Science‭ ‬237:‭ ‬1608‭–‬1610.‭ ‬-‭ ‬E.‭ ‬M.‭ ‬Brouwers,‭ ‬W.‭ ‬A.‭ ‬Clemens,‭ ‬R.‭ ‬A.‭ ‬Spicer,‭ ‬T.‭ ‬A.‭ ‬Ager,‭ ‬L.‭ ‬D.‭ ‬Carter‭ & ‬W.‭ ‬V.‭ ‬Sliter‭ ‬-‭ ‬1987.
-‭ ‬Comparative Osteology and Phylogenetic Relationship of Edmontosaurus and Shantungosaurus‭ (‬Dinosauria:‭ ‬Hadrosauridae‭) ‬from the Upper Cretaceous of North America and East Asia.‭ ‬-‭ ‬Acta Geologica Sinica‭ ‬88:‭ ‬1623‭–‬1652.‭ ‬-‭ ‬H.‭ ‬Xing,‭ ‬X.‭ ‬Zhao,‭ ‬K.‭ ‬Wang,‭ ‬D.‭ ‬Li,‭ ‬S.‭ ‬Chen,‭ ‬C.‭ ‬M.‭ ‬Jordan,‭ ‬Y.‭ ‬Zhang‭ & ‬X.‭ ‬Xu‭ ‬-‭ ‬2014.
-‭ ‬Osteology,‭ ‬Relationships And Paleoecology Of a New Arctic Hadrosaurid‭ (‬Dinosauria:‭ ‬Ornithopoda‭) ‬From the Prince Creek Formation Of Northern Alaska.‭ ‬Unpublished Ph.D.‭ ‬thesis‭ ‬-‭ ‬University of Alaska Fairbanks,‭ ‬Fairbanks‭ ‬333‭ ‬pp‭ ‬-‭ ‬Hirotsugu Mori‭ ‬-‭ ‬2014.
-‭ ‬A new Arctic hadrosaurid from the Prince Creek Formation‭ (‬lower Maastrichtian‭) ‬of northern Alaska.‭ ‬-‭ ‬Acta Palaeontologica Polonica.‭ ‬-‭ ‬Hirotsugu Mori,‭ ‬Patrick S.‭ ‬Druckenmiller‭ & ‬Gregory M.‭ ‬Erickson‭ ‬-‭ ‬2015.


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