Pit Wear in Box 13
The saber-toothed cat femur on the left is currently being excavated in Box 13. The damage to its surface is not from a scavenger but is called "pit wear." The large grooves on the surface of this bone formed when it moved against other bones within the asphalt seep. The cause of the movement is uncertain but could conceivably represent migration of the asphalt within the seep, trampling from other animals that were caught in the seep, or the result of earthquake activity.