a production of Black Hills Institute

  Bone Map & Specimen Notes
 
The Bone Map is an excavation's "key." It tells a visual story of how—and how much of—a fossil was preserved, and how it was deposited (deposition). Once a dinosaur excavation is completed, and the individual bones or blocks are removed, nothing but a map can tie together the bones' relative locations. A bone map can provide tons of information, at a glance.

A Bone List will be built when individual parts and pieces are collected. A number is assigned to packages, bones, or larger blocks—to key them with each other, as well as with their location on the bone map. We will be formulating the bone list once we start collecting and recording pertinent information associated with bones or blocks removed from the site.

The Specimen Notes, below, are compiled observations about empirical data (like bone measurements), deposition and anything else that will help give an overall representation of the specimen for other people to study. It can often be rather dry reading, but often there are clues hidden in information which will form the basis of a theory or two.



  Bone Map & List
On the right is a link to the latest bone list with a skeleton illustration for reference. The initial dig map is about ready and will be added tomorrow.

Scientists use bone maps in the field to:

  • See what bones have been discovered.
  • See how the bones were deposited, in relationship to one another.
  • Get clues to the ancient situation, such as whether the bones washed away from one another in a stream.
  • Make educated guesses about direction of any stream flow.
  • Get clues about where to look for missing bones.

Bone maps are useful in the laboratory, too:

  • Often, big blocks of rock filled with bones are removed at one time, not to be opened until they're in the lab. With a bone map of everything that's accounted for, and how the fossil was positioned, scientists can make guesses as to what might be inside a block.
  • Special lab maps are created with clear plastic, especially when working with big blocks of bones. Think of it this way: in the field, workers remove sediment and matrix from the "top side" of the bones. Then they plaster and remove the blocks. In the lab, the blocks are "flipped" carefully—so as to access the "bottom side" of the bones, the side with no plaster. Being able to "flip" the map makes accurate bone recording much easier!

  Specimen Notes

The bones appear to be gracile (male) morphotype, and of a sub adult.  The femur measures 47” (121 cm), while SUE's, for example, is 54” (138 cm).  The skeleton is lying on its right side, and based on what has been exposed thus far, it appears to be a highly articulated specimen which continues underground in 3 directions.  Preservation appears to be excellent once past the exposed surfaces.  Some concretion is present on the underside of the skeleton, which should not cause significant difficulties.

There appears to have been very little movement of the skeleton prior to preservation.  There are very few scattered bones (a few gastralia).  No evidence of tooth fragments have been found in the exposed area - an indication that the skull with teeth intact, may be protected under the sediments.  The only evidence of a skull thus far, is a probable left surangular, at the end of the exposed skeleton.  Time will tell!

There is an articulated pelvis with attached series of at least 8 caudal vertebrae going underground both ways, an articulated right leg (right foot still buried).  The left foot is partially articulated and present.  The left metacarpal and left scapula have been found.  With the right side down, this is a good indicator that the complete right arm may be present.


  Specimen Notes: Geologic Setting



Copyright © 2004 BHIGR  ~  QuickTime™ is a trademark of Apple Computer, Inc., registered in the U.S. and other countries.