Guest Blogger: Kurt Lahmers

The Garden Park area of Cañon City, Colorado is well-known for the large number of dinosaur skeletons that have been found there since the 1870s.

A closer look at a dinosaur bone found in the Garden Park area shows some interesting details on the end of the bone. The holes in the dinosaur bone shown in figure 1 used to be tube-like structures called Haversian canals. Haversian canals are branching channels where the blood vessels and nerve fibers are carried through the bone.

Figure 1.  As shown in this photo, the Haversian canals have dried out, leaving hollow holes throughout the bone. Photo by K. Lahmers. S.W. Veatch specimen.



Surrounding these canals are bone tissues called osteons. The osteons are part of the cortical bone, or the compact bone.  The cortical bone is the structure of bone that holds up the body, while on the other hand, the spongy bone marrow (cancellous bone) produces red blood cells. The cortical bone is the outside structure of the bone that surrounds the cancellous spongy bone.

Figure 2. This Jurassic dinosaur bone was once a rather large, live, and active dinosaur that was part of a prehistoric ecosystem that included streams and ponds. Photo by K. Lahmers.  S.W. Veatch specimen.

This dinosaur bone that is part of this study is on siltstone. 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 in semi-quiet depositional areas including 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 a body of water. Silt covered the bones and the water allowed silica to replace the cells, one-at-a-time over a millennia.

This large dinosaur bone(fugue 2)—petrified in what became known as the Morrison Formation—quietly waited to be discovered and studied by the Colorado Springs Mineralogical Society(CSMS) Pebble Pups and Junior members. This paper is the result of a CSMS Pebble Pup and Junior member study group to: 1) look some of the structures of a dinosaur bone and, 2) to learn how to take pictures of paleontological specimens. We accomplished our mission in the 45-minute monthly class. More exciting studies and papers are planned.

Bibliography

Unk., . "Bone." Bone. Internet BioEd Project, Unk.. Web. 20 Jul 2011. .

Unk., . "Siltstone." Siltstone. LSF, 18/07/00. Web. 17 Jul 2011. .

Unk., . "Siltstone." Siltstone. B2bchinastone.com, 2008. Web. 21 Jul 2011. .

Unk. "Haversian Canal." Wikipedia. March 2011. 1. USA: Wikipedia Foundation, 2005. Web. .

Author’s biography:  Kurt is a member of the CSMS Junior study group and is a 9^th grade student at Doherty High School in Colorado Springs, Colorado. He is a respected mentor to the younger Pebble Pups.