What is Apatosaurinae?

All taxa more closely related to Apatosaurus than Diplodocus. Apatosaurinae is the robust, power-built branch of Diplodocidae, represented chiefly by Apatosaurus and Brontosaurus from the Late Jurassic Morrison Formation of western North America. Their cervical vertebrae were massively thickened, with enlarged muscle attachment sites that gave the neck a deep, muscular profile distinct from the slender diplodocines. The torso was barrel-chested, supported by stout limb bones—especially the humerus and femur—which reflect a heavier, force-oriented build.

The tail remained long but broadened at the base before tapering into a diplodocid-style distal whip. Skull material shows a low, elongate snout with anteriorly concentrated, peg-like teeth suited for cropping vegetation. The reinforced neck and powerful forequarters indicate animals capable of generating substantial mechanical force, whether bracing against resistant vegetation or engaging in intraspecific shoving or neck-wrestling.

Apatosaurines represent the heavy-duty end of diplodocid evolution: compact, muscular sauropods engineered for strength rather than reach.

Click here to view Dinochecker's A-Z list of apatosaurines. Apatosaurinae is derived from the Greek "apate" (deception/deceptive) and "sauros" (lizard), and the Latin "-inae" (sub family). The name is based on group anchor Apatosaurus—the deceptive lizard, so named by Othniel Charles Marsh because he thought its chevron bones were deceptively similar to those of some sea-dwelling mosasaurs.
Although attributed to Friedrich von Huene in 1927 under the ICZN's principle of coordination (he actually coined the family Apatosauridae, but that includes all subranks as standard), Werner Janensch is often wrongly credited as author of the name, though he was the first to explicitly use it as a subfamily in 1929.