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The oldest occurrence of brachylophosaurin hadrosaurids in Canada
- Source :
- Canadian Journal of Earth Sciences. October, 2021, Vol. 58 Issue 10, p993, 12 p.
- Publication Year :
- 2021
-
Abstract
- Hadrosaurids are a diverse and widely distributed group of ornithischian dinosaurs that are particularly well represented in the upper Campanian Dinosaur Park Formation of the Belly River Group of Alberta. However, the origin of this hadrosaurid diversity in Alberta is poorly understood, as the lower Campanian terrestrial deposits of the underlying Oldman and Foremost formations of the group have produced comparatively few body fossils. Here we provide the first description of a partially articulated hadrosaurid and hadrosaurid material from a bonebed from the Foremost Formation and refer it to the brachylophosaurin Probrachylophosaurus sp. indet. The material represents the oldest occurrence of Brachylophosaurini in Alberta and the oldest known hadrosaurid diagnostic to the genus level from Canada. In Alberta, Hadrosaurinae display a distinct pattern of replacement with the tribes Brachylophosaurini and Kritosaurini being confined to the lower to middle Campanian strata (below the marine Bearpaw Formation) and replaced above the Bearpaw Formation by members of Saurolophini (Prosaurolophus, Saurolophus) and Edmontosaurini (Edmontosaurus), with the latter clade persisting to the end of the Maastrichtian. Although the worldwide stratigraphic distribution of the Hadrosaurinae is complex, this pattern generally holds true for northern Laramidian hadrosaurine tribes, suggesting that their pattern of evolution and replacement may be driven by some common underlying factor such as an environmental response to fluctuations in the margins of the Western Interior Seaway due to sea level change. Key words: Belly River Group, Foremost Formation, Hadrosauridae, Ornithischia, Cretaceous, Probrachylophosaurus. Les hadrosaurides constituent un groupe de dinosaures ornithischiens varie a la vaste repartition, particulierement bien representes dans la Formation de Dinosaur Park du Campanien superieur du Groupe de Belly River de l'Alberta. L'origine de cette diversite des hadrosaurides en Alberta demeure toutefois mal comprise, etant donne le peu de fossiles de corps produits par les depots terrestres campaniens inferieurs des Formations sous-jacentes d'Oldman et de Foremost du groupe. Nous presentons la premiere description d'un hadrosauride partiellement articule et de materiau d'hadrosauride provenant d'un lit a ossements de la Formation de Foremost et le renvoyons au brachylophosaurine Probrachylophosaurus sp. indet. Le materiau represente la presence la plus ancienne de brachylophosaurines en Alberta et le diagnostic d'hadrosauride connu au niveau du genre le plus ancien au Canada. En Alberta, les hadrosaurines presentent un motif distinctif de remplacement, les tribus des brachylophosaurines et des kritosaurines etant confinees aux strates du Campanien inferieur et moyen (sous la Formation marine de Bearpaw) et remplacees au-dessus de la Formation de Bearpaw par des membres des saurolophines (Prosaurolophus, Saurolophus) et des edmontosaurines (Edmontosaurus), ce dernier clade persistant jusqu'a la fin du Maastrichtien. Si la repartition stratigraphique mondiale des hadrosaurines est complexe, ce motif s'avere generalement pour les tribus d'hadrosaurines du nord de la Laramidie, ce qui indiquerait que leur motif d'evolution et de replacement pourrait etre module par un facteur sous-jacent commun tel que la reaction a des fluctuations des conditions ambiantes aux marges de la mer interieure de l'Ouest dues a des variations du niveau de la mer. [Traduit par la Redaction] Mots-cles : Groupe de Belly River, Formation de Foremost, hadrosaurides, ornithischiens, Cretace, Probrachylophosaurus.<br />Introduction Hadrosauroidea was a globally distributed, diverse group of ornithopod dinosaurs that existed during the Late Cretaceous (Horner et al. 2004; Gates and Sampson 2007; Prieto-Marquez 2010b; Godefroit et al. [...]
- Subjects :
- Hadrosaurids -- Natural history
Earth sciences
Subjects
Details
- Language :
- English
- ISSN :
- 00084077
- Volume :
- 58
- Issue :
- 10
- Database :
- Gale General OneFile
- Journal :
- Canadian Journal of Earth Sciences
- Publication Type :
- Academic Journal
- Accession number :
- edsgcl.680920297
- Full Text :
- https://doi.org/10.1139/cjes-2020-0007