A closer look at a Jurassic dinosaur bone from the Morrison Formation: A dinosaur bone primer
Kurt Lahmers (USA)
A closer look at a dinosaur bone found in the Garden Park area of Cañon City, Colorado (USA) shows some interesting details on the end of the bone. The holes in the dinosaur bone shownin Fig. 1 used to be tube-like structures called Haversian canals. These are branching channels, where the blood vessels and nerve fibres are carried through the bone.
Surrounding these canals are bone tissues called osteons. These are part of the cortical or compact bone, which is the strong part of a bone that holds up the body, while the spongy bone marrow (cancellous bone) produces red blood cells. Therefore, the cortical bone is that part of the outside structure of the bone that surrounds the cancellous spongy bone.
The dinosaur bone inthis study is in siltstone matrix. Siltstone is composed of very fine-grained sandstone that has been deposited as silt. Through heat and pressure, this silt compacted and hardened into siltstone. This material is found depositional areas such as ponds and lakes, where standing or slow moving water permits fine-grained sandstone to fall to the lakebed forming silt. The dinosaur could have died either while in or near abody of water.Silt then covered its bones and the water allowed silica to replace the cells, one-at-a-time, over a huge length of time.
Our large dinosaur bone (Fig. 2) petrified in what became known as the Morrison Formation andquietly waited to be discovered and studied by the Colorado Springs Mineralogical Society(CSMS)‘Pebble Pups and Junior members’, who decided to:
- Investigate some of the structures of a dinosaur bone; and
- Learn how to take pictures of paleontological specimens.
We accomplished this during a 45-minute monthly class.More exciting studies and papers are now planned.
About the author
When Kurt worte this article, he wass a member of the CSMS Junior study group and is a 9th grade student at Doherty High School in Colorado Springs, Colorado.
Further reading
Haversian Canal. Wikipedia. March 2011. 1. USA: Wikipedia Foundation, 2005.