Name Meaning:  Chambered Lizard
stateside Geologic Era:  Late Jurassic
Westfield Location Found:  Wyoming
Vitry-le-François Estimated Range:  Western United States
Size:  Up to 23 meters long
Extinction:  145 million years ago

This chevron is from the tail of a Camarasaurus.  My best guess as to placement would be the more anterior part of the tail (toward the head).  The chevron is incomplete, so I am not 100% certain of my assessment.  The name Camarasaurus comes from the spaces in the vertebrae, which are now known to function as air sacs for the respiratory system.  In addition, they also would have function to lighten the skeleton to some extent.  

JPNHM- 0042

Camarasaurus was probably one of the more common animals in its environment, based on the number of its fossils that have been recovered.  It was average sized for a sauropod, averaging about 60 feet long.  This is larger than many earlier books show it to be.  The reason for this is that the first Camarasaurus remains that were described came from individuals that were not fully grown.  Their relatively small size was taken as the average size for all Camarasaurus individuals.  This mistake has since been corrected, but can still be found in older publications.  Camarasaurus is grouped into the macronarian sauropods.  This group of animals has a shorter, more box-like skull than diplodocid sauropods.  


Camarasaurus had chisel like teeth, which were very well suited to clipping rough vegetation and branches higher in the tree canopy.  This is in contrast to diplodocids, which had peg like teeth.  The two groups of animals lived together in the same regions, but likely fed on completely different material.  The largest predator in the environment was Allosaurus, which would have been unlikely to target a fully grown Camarasaurus.  Allosaurus might be inclined to go after a sick, injured, or old individual, however.  Most of the time, however, a sauropod such as Camarasaurus, with its formidable size, would have been an unappealing prospect for even the bravest predator.  

Cast of pedal ungual

Image Credits:
Full Skeleton:  By Scott Hartman –, CC BY 2.0,

Life Reconstruction:  By Creator:Dmitry Bogdanov –, CC BY 3.0,