Camarasaurus, Jurassic Giant

Camarasaurus lentus (Cope, 1889)
Pronounced - Cam- air -ah -sore -us -Lent- us
Means Tough Chambered lizard
Named for the gigantic holes in the side of its dorsal (back) vertebrae
Lived in the Late Jurassic, 155-145 mya


Camarasaurus is the most commonly found sauropod dinosaur of the Morrison Formation.  Sauropods are long-necked, long-tailed, heavy-bodied plant-eaters and were the largest land animals that ever lived.  Camarasaurus supremus was the largest Camarasaurus, coming in at nearly 80’ long and over 50 tons, equalling a herd of elephants in one animal!  The Camarasaurus tooth in this crate belongs to Camarasaurus lentus, the smallest of the Camarasaurus species, and was “only” 50’ long and 25 tons.  

Camarasaurus was named “chambered lizard” because its backbones have huge holes in them.  It was the first dinosaur discovered with such an interesting morphology.  As it turns out these huge chambers are present in nearly all sauropods and were filled with air sacs!  The vertebrae are shaped like an “I-beam”, which happens to be the ideal shape for maximum strength, important for 50,000 lbs animals.  

Camarasaurus likely lived in herds with sauropod tracks suggesting they stayed close to their young like elephants do today.  A baby Camarasaurus would be a fine meal for giant meat-eating dinosaurs such as Torvosaurus, however, even the largest and hungriest predator would think twice before attacking a small Camarasaurus surrounded by 25-ton adults with head-high tails that could shatter ribs and limbs or knock a predator unconscious. 

Camarasaurus relied on size and its powerful tail to keep it safe.  However, should it need to, it had a giant thumb claw, the largest of which approach the size of a dinner plate.  The claw was probably used to rip trees open or dig holes in the ground, but could easily slice a predator in two, especially when powered by a 10’ tall limb weighing over 2,000 lbs by itself!  

Camarasaurus lived amongst other giant sauropods including the longest dinosaur yet known, Supersaurus, as well as the giants Apatosaurus and Brachiosaurus, plus the whip-tailed Diplodocus and its cousins.  Camarasaurus had a shorter neck than the sauropods it co-existed with but its head was held much higher off the ground, likely towering over all but Brachiosaurus, the fabled “arm lizard” that was the tallest dinosaur.  The tall reach and unique tooth shape indicate Camarasaurus ate different plants than its fellow sauropods.  The tooth in the crate is triangular in shape, resembling a thick spoon or round chisel more than a “regular” tooth.  The teeth are substantially thicker and stronger than those of the contemporary diplodocids, only Brachiosaurus had similar teeth (and likely not coincidentally Brachiosaurus had a similarly tall, large skull that was also held high above the ground).  Camarasaurus teeth were replaced roughly every 62 days, allowing it to chew on tough, fibrous plants that other animals didn’t eat.  A recently discovered Camarasaurus skull was so well preserved that it had skin impressions of part of the mouth still present.  This skin impression may represent “lips.”  If so, only the pointy tops of the teeth were exposed to the air, the rest of the teeth were covered in gums.  If so this would change the way most Camarasaurus illustrations show the teeth, which are usually displayed in a fashion that suggests it had a goofy grin.  The illustration below has adopted the “lips” characteristic.

Camarasaurus lived in a dry, desert-like environment with riparian forests and ephemeral streams.  They likely migrated across the present-day western United States as the devastation these super-giant, always-eating animals caused to plant life was incredible.

 

Watch a short video on Camarasaurus here.

Purchase a cast of a Camarasaurus tooth as part of the Ultimate Herbivores crate here.

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