Camarasaurus

Phylogeny: Dinosauria > Saurischia > Sauropodomorpha > Plateosauria > Massopoda > Sauropodiformes > Sauropoda > Gravisauria > Eusauropoda > Neosauropoda > Macronaria > Camarasauridae

Overview: As far as the Late Jurassic is concerned, few geological formations are as famous or as fossil rich as the Morrison Formation, stretching across a large swath, from what is now Montana to as far south as New Mexico. Numerous well known and large sauropod genera have been found in the Morrison, including Diplodocus, Apatosaurus and Brachiosaurus. By far the most common of these sauropods, however, was Camarasaurus. It appears to have been particularly successful in the region, which at that time was a vast, semi-arid and seasonal plain. Camarasaurus is represented by at least three species. The geologically youngest, as well as the largest, was the type species Camarasaurus supremus, which could reach lengths of over twenty meters. Camarasaurus grandis and Camarasaurus lentus were generally smaller, being medium-sized sauropods. Multiple genera of Morrison sauropods would’ve coexisted with each other, so they likely would’ve been adapted for different feeding niches. Aside from sauropods, other notable dinosaurs from the Morrison included Stegosaurus, Camptosaurus, Dryosaurus, Ceratosaurus, Torvosaurus, and Allosaurus.

Camarasaurus possessed a fairly boxy skull, bearing a blunt snout and wide openings. Famously, for a time, the skull of this animal was wrongly associated with Brontosaurus and Apatosaurus. The bite force of Camarasaurus was a bit stronger than that of other sauropods, which paired well with its chisel-like teeth. As with the majority of sauropods, excluding Brachiosaurus and some others, the forelimbs of Camarasaurus were shorter than its hind legs, but due to the profile of its back, it had a somewhat more evenly inclined torso. Camarasaurus and Brachiosaurus were relatively close to one another phylogenetically, belonging to the clade Macronaria, though the latter was a bit more derived. Camarasaurus is the namesake of the family Camarasauridae, though there is controversy over what sauropods actually belonged to it. Lourinhasaurus, from Portugal, was possibly a related to Camarasaurus. The genus Camarasaurus was established in 1877 by the renowned paleontologist Edward D. Cope. Its name, meaning “chambered lizard”, refers to extensive hollow chambers that ran throughout its vertebrae – a common weight reducing adaptation among sauropods.