Sample EC96-001 -- minimal interpretation

NOTE: Some of these images are rather large. Check the sizes before downloading. I could decrease the size, but only at the expense of important details. If you want smaller images anyway, let me know.

Weathered exterior view, reflected light

These images were photographed with a macro lens.

Fig.1 (152Kbytes) Magnification: approximately 5.8x

Fig.2 (25Kbytes) Magnification: approximately 1.2x

Fig.3 (46Kbytes) Magnification: approximately 3x

External view of specimen, with "narrow end" (right -- Fig.1), lateral view (left -- Fig.2), and "wide end" (Fig.3). Note the saw marks on the ends. These were present on the specimen when it was received. The specimen was also already coated with clear laquer, which was partially removed with acetone.

ec96-001 lateral view Fig.4 -- lateral view (39Kbytes) showing outer surface, with specimen flipped over from orientation in Fig.2. Note small black lichens on the surface to the right of centre. Magnification: approximately 1.2x

Polished cross sections, reflected light

To investigate the internal structure of specimen EC96-001, it was cut with a rock saw into three segments, designated EC96-001A, EC96-001B, and EC96-001C. EC96-001A is about 1cm thick, and is from the "narrow end" (left in Fig.2 and 4), EC96-001B is also about 1cm thick, and is the next portion of the specimen, and EC96-001C is the remainder (the "wide end", to the right in Fig.2 and 4), comprising about 3/4 of the original specimen. Each cut surface was polished by hand to show surface features. Because the central core of the specimens was quite fragile, it was partially plucked out during the preparation process. Note that some thickness was permanently lost due to the width of the saw blade and the polishing.

The images were photographed using a reflected light microscope.

EC96-001A -- first segment from "narrow end"

Fig. 5 -- cross section A, same side as "wide end" (296Kbytes), polished surface. Digitally reconstructed from two images. Magnification: approximately 6.5x.

Fig. 6 -- cross section B, same side as "wide end" enlargement of lower left of Fig.5 (160Kbytes). Magnification: approximately 12.8x

Fig. 7 -- cross section B, same side as "wide end" enlargement of upper left of Fig.5 (160Kbytes). Magnification: approximately 20.4x

Fig. 8 -- cross section B, same side as "wide end" enlargement of lower left of Fig.5 (208Kbytes). Same magnification at Fig.7. Magnification: approximately 20.4x

Fig. 9 -- cross section B, same side as "wide end" enlargement of upper right of Fig.5 (224Kbytes). Magnification: approximately 20.1x.

Fig. 10 -- cross section A, same side as "narrow end" (152Kbytes). This is almost the same level as the original "narrow end" of the specimen (i.e. Fig.1), but it has been ground down a few millimetres and polished. Note the original saw marks on the right. White square marks the location of Fig.11. Magnification: approximately 6.6x.

Fig. 11 -- cross section A, same side as "narrow end", enlarged (160Kbytes). Magnification: approximately 29x

Comparison

Comparison of specimen EC96-001 with dinosaur bone microstructure. All illustrations are polished surfaces in reflected light. Each pair of images is at the same magnification.

Fig.12 -- dinosaur bone cross section (left) and EC96-001A (right -- part of Fig.5) (120Kbytes). Same scale. Scale in millimetres in left image. Magnification: approximately 6x.

Fig.13 -- dinosaur bone cross section (left) and EC96-001A (right -- part of Fig.8) (248Kbytes). Same scale. Scale in millimetres. Magnification: approximately 21x.

Back to the evaluation of Carboniferous bone

Andrew MacRae macrae@geo.ucalgary.ca