Any resource stating that Brontosaurus is the same dinosaur as Apatosaurus is outdated. A comprehensive study published in 2015 concluded that Brontosaurus was entirely distinct from its fellow sauropod, Apatosaurus, after observing the anatomies of 81 specimens and comparing 477 traits in their physiology and morphology.  The study explained that Apatosaurus was a bulkier, larger and sturdier dinosaur compared to Brontosaurus. The former’s neck was also much thicker and lower-set.