I went back to where I found the first Petalodus tooth, and the first rock I split open held another Pennsylvanian Petalodus tooth. This specimen is longer than the first one. It measures 1.5mm more narrow, however this is due to a chipped left corner.
The limestone is a bit fragile towards the top of the tooth. A preserved horn coral was embedded where the root would normally be. This easily lifted up exposing the dimensions of the tooth embedded in the rock. Due to how fragile the rock is and the cracks on the crown, I have decided against attempting to lift the tooth out.
The specimen displays excellent serrated edges compared to my first Petalodus tooth due. This tooth is different because the edge is completely exposed. The matrix it is attached to is much larger than the first tooth and I am going to attempt to cleave it down to a smaller size.
Photos from the opposite rock
An impression visible on the rock shows the portion of rock that was up against the tooth. While there is not much material on this piece, it does present as the full size of the tooth crown.
Measurements of Petalodus Tooth II
The tooth crown is 9.5mm deep and 21.5mm at its widest point. There is a point missing on the left side, an estimated total tooth width would be around 23-24mm. The right serrated edge is 13mm while the abbreviated left side is 10mm. The crown depth to width ratio is an estimated 23.5:9.5. This makes the second tooth deeper than the first tooth
Further Reading about Pennsylvanian Petalodus Tooth
- Fossils of Parks Township – First Petalodus Tooth
- St. Louis Pennsylvanian Fossils of the Altamont Formation – Petalodus Sp.
- Petalodont Chodrichthyan Teeth from the Pennsylvanian-Permian Horquilla Formation, Big Hatchet Mountains, New Mexico – Fossil Record 3. New Mexico Museum of Natural History and Science, Bulletin 53 – S.G. Lucas, J.A. Spielmann, A.O. Ivanov, L.F. Rinehart, K. Krainer