The First Definite Lambeosaurine Bone From the Liscomb Bonebed of the Upper Cretaceous Prince Creek Formation, Alaska, United States

Ryuji Takasaki,Yoshitsugu Kobayashi,Anthony R Fiorillo,Paul J Mccarthy,Ronald S Tykoski

doi:10.1038/s41598-019-41325-8

Ryuji Takasaki, Yoshitsugu Kobayashi + Show 3 more

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https://doi.org/10.1038/s41598-019-41325-8

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Abstract

The Prince Creek Formation of Alaska, a rock unit that represents lower coastal plain and delta deposits, is one of the most important formations in the world for understanding vertebrate ecology in the Arctic during the Cretaceous. Here we report on an isolated cranial material, supraoccipital, of a lambeosaurine hadrosaurid from the Liscomb Bonebed of the Prince Creek Formation. The lambeosaurine supraoccipital has well-developed squamosal bosses and a short sutural surface with the exoccipital-opisthotic complex, and is similar to lambeosaurine supraoccipitals from the Dinosaur Park Formation in having anteriorly positioned squamosal bosses. Affinities with Canadian lambeosaurines elucidate more extensive faunal exchange between the Arctic and lower paleolatitudes which was previously suggested by the presence of Edmontosaurus, Pachyrhinosaurus, tyrannosaurids, and troodontids in both regions. The presence of one lambeosaurine and nine hadrosaurine supraoccipitals in the Liscomb Bonebed suggests hadrosaurine dominated faunal structure as in the Careless Creek Quarry of the USA that was also deposited under a near-shore environment. It differs from the lambeosaurine dominant structures of localities in Russia and China interpreted as inland environments. This may suggest that lambeosaurines had less preference for near-shore environments than hadrosaurines in both Arctic and lower paleolatitudes.

Highlights

The Liscomb Bonebed is one of the most prolific dinosaur bearing localities within this rock unit
Comparisons based on isolated cranial elements later demonstrated that the Liscomb hadrosaurs showed close similarity to the hadrosaurine Edmontosaurus saskatchewanensis[27], which is considered a junior synonym of Edmontosaurus annectens[28]
While co-occurrences of hadrosaurine and lambeosaurine are widely known in the northern hemisphere (e.g., Careless Creek Quarry[36,37,38] and Jack’s Birthday Site[39] of Montana, United States; Blagoveschensk locality[40,41] and Kundur[42,43] localities of southern Amur region, Russia; and Wulaga locality[44] of northern Heilongjiang Province, China), the Liscomb Bonebed is the first to demonstrate the co-occurrence in the Arctic

Summary

Introduction

The Liscomb Bonebed is one of the most prolific dinosaur bearing localities within this rock unit. It was proposed that the Liscomb hadrosaur bones represent a new distinct hadrosaurine taxon, Ugrunaaluk kuukpikensis[15]. We report the first definitive lambeosaurine hadrosaurid fossil from the Liscomb Bonebed (DMNH 2014–12–266), represented by an isolated cranial material, a supraoccipital. The supraoccipital demonstrates that the Liscomb Bonebed contains both lambeosaurine and hadrosaurine materials. While co-occurrences of hadrosaurine and lambeosaurine are widely known in the northern hemisphere (e.g., Careless Creek Quarry[36,37,38] and Jack’s Birthday Site[39] of Montana, United States; Blagoveschensk locality[40,41] and Kundur[42,43] localities of southern Amur region, Russia; and Wulaga locality[44] of northern Heilongjiang Province, China), the Liscomb Bonebed is the first to demonstrate the co-occurrence in the Arctic. The new discovery offers an important opportunity to infer possible determinant factors of hadrosaurid taxonomic structure in the Arctic, in comparison with lower latitude regions

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