Reassessment of a historical collection of sauropod dinosaurs from the northern Morrison Formation of Wyoming, with implications for sauropod biogeography

Title Variants

Alternative: Sauropod dinosaurs from northern Morrison Formation

Related Titles

Series: Bulletin of the American Museum of Natural History, number 437

By

Tschopp, Emanuel , author

Maidment, Susannah C. R., , author
Lamanna, Matthew Carl , author
Norell, Mark A. , author

Type

Book

Material

Published material

Publication info

New York, NY, American Museum of Natural History, [2019]

Notes

"Issued November 4, 2019."

Supplemental data available online in a separate file.

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The Upper Jurassic Morrison Formation of the western United States preserves one of the best-known Mesozoic paleoecosystems worldwide. The formation crops out over an area from New Mexico and Oklahoma to Montana and Utah and encompasses a time span of approximately eight million years. Recent studies indicate a high diversity of gigantic, herbivorous sauropod dinosaurs, but the geographic and temporal distributions of species or even genera of these animals remain poorly understood. In particular, sauropod specimens from northern outcrops of the formation have rarely been studied in detail, and temporal relationships among sites are imprecise. Here, we reassess the taxonomic diversity of the sauropods from a historic Carnegie Museum locality in northern Wyoming. Previous referrals of material to the well-known diplodocid genera Apatosaurus and Diplodocus cannot be confidently confirmed; instead, all these specimens more likely represent elements from the recently recognized Galeamopus. Specimens previously assigned to Camarasaurus and Haplocanthosaurus could not be referred to these genera based on apomorphies, due to a lack of detailed knowledge concerning the genus- and species-level taxonomy of these sauropods. Our findings imply that many referrals of incomplete diplodocid skeletons to Apatosaurus and Diplodocus must be reassessed. These reassessments are particularly important with regard to specimens from northern localities of the Morrison Formation, as it is becoming increasingly evident that diplodocids from this area were distinct from better-known, more southerly taxa. This geographic segregation does not seem to apply to nondiplodocid sauropods; however, these taxa are also in need of systematic revision, which may reveal species-level patterns similar to those observed in Diplodocidae.

Subjects

Carnegie Museum of Natural History , Catalogs , Catalogs and collections , Dinosaurs , Galeamopus , Geographical distribution , Jurassic , Kaycee Region , Morrison Formation , Paleontology , Pennsylvania , Pittsburgh , Reptiles, Fossil , Saurischia , Wyoming

Call Number

QH1 .A4 no.437 2019

Language

English

Identifiers

DOI: https://doi.org/10.1206/0003-0090.437.1.1
OCLC: 1126278486