April 30, 2000 - Pennsylvanian Fossils, Walker Co, AL
University of Alabama
Tuscaloosa, Alabama
The New River Mine is a surface mine which was spotted by Jim Lacefield in early February this year, and shortly thereafter Jim and I scouted the site out. As expected, the site included plant fossils, but one difference compared to other sites that Jim noticed was an abundance of fossils of Artisia, the pith of the gymnospermous tree known as Cordaites. The only other sites where I have seen Artisia fossils are the Kimberly surface mine (see BPS report for May 29, 1999), and another mine near Eldridge that the BPS visited with Wayne Canis's class in March 1998.
Figure 2 View of a rock wall roughly on the east side of the site. |
Bruce
Relihan was the first to find an interesting specimen of Artisia,
shown in the picture here. Artisia is characterized by horizontal
ridges along the pith, which can be found in cast form as well as
impressions, much like a Calamites pith. The specimen Bruce found
appears to be either an impression or a highly flattened cast. The
ridged area is framed by a larger area obviously affected by the plant.
This frame must indicate the true extent of the trunk. | |
Figure
3 Artisia
specimen found by Bruce Relihan. |
Other
types of fossils found were bark impressions of arborescent lycopods. I
show pictures of two different types here. One appears to be of the
type Lepidodendron obovatum, with very large leaf scars. I am not
certain about the type of the other piece shown, other than it is also
likely to be a Lepidodendron. | |
Figure
4 Bark
impression of Lepidodendron obovatum, with large, distinct leaf
scars. |
Figure 5
Bark impression of another likely type of Lepidodendron. |
The
last pieces I illustrate are ones I found in February during my
scouting visit with Jim
Lacefield. One appears to be a mostly unflattened cast of a branch of
Calamites. The piece shows 15 strong, indented nodes, and I must say it
resembles a petrified tootsie roll! I am not sure of the species of
this Calamites, but I did find a type of Calamites at this site that I
was able to identify. I found highly compressed cast pieces of what I
think is Calamites
suckowi, one of the more common species of this genus. | |
Figure 6 Cast fossil of a branch of Calamites, with 15 clear nodes. |
After a couple of hours of searching with limited results, trip attendees decided to return to Union Chapel Mine, about 30 miles east of the New River site. Union Chapel Mine is so rich that it continues to yield good specimens even though many people have visited the site the past 4 months. It is a good site to fall back on when other sites do not live up to expectations. See the reports for January 23, March 19, and May 28, 2000 for information on this mine.