Fossils – Fact or Myth?

Editor’s note: Reprinted by permission from the Special Friends of the Aurora Fossil Museum newsletter.

by Joyce Drakeford, Friends of the Aurora Fossil Museum

We have all heard things in the fossil world about fossil collecting and wondered if it was true. Well, here are a few top questions I received answered for you!

Is there really such a thing as a honey hole?

MYTH. There are no true places where a limitless amount of fossils will be found every time. In reality when fossil hunting from in situ locations, Dr. Robert Boessenecker notes, that finding a few nice teeth in a location are more about environmental factors such like erosion rate rather than actual fossil abundance. However, some of those factors, particularly in waterways, can cause loose deposits of fossils to erode out of the formation and land in a specific location in higher volumes. Victor Perez adds that consistency of the stratigraphy is also a large factor. Stratigraphy varies everywhere.

Hollow fossilized teeth are teeth that remained when the shark died.

FACT. It is the consensus among experts that the majority of the hollow teeth that are missing roots are those that did not fully develop during the animal’s life. Victor Perez states, “In sharks, teeth are replaced in a conveyor belt fashion, and during the tooth formation the enamel is created before the dentin and root. So when the shark dies, those teeth that haven’t fully formed yet can be preserved leaving behind the enamel.” The enamel is the strongest part of the tooth. So there are a small percentage of teeth that have had the root broken off and the dentin has worn away.

Specimens that have a hazy, foggy, matte or silver sheen have been digested.

MYTH. It is almost impossible to tell if a tooth has been digested or not. It is more likely that a tooth with those characteristics have been subjected to a slew of environmental factors. Two of those are having been reworked and being naturally exposed to acids in the soil.

Lower fossil shark teeth are not found as often because they are swallowed/digested more than upper teeth.

FACT and MYTH. The majority thought this was a good possibility but not necessarily because of digestion. Dr. Ronny Leder feels there is truth in this statement. “It is true that lower teeth break generally more easy because they have to hold the prey whereas that upper jaw teeth saw or cut. From that perspective you should find more lower jaw teeth. But even in our collection at the FLMNH shows the same pattern, nearly half the number of lower jaw teeth.”

If dirt is not collected from the layer it is not called matrix (i.e. Aurora spoil pile).

MYTH. “Matrix is very general term,” advises Victor. The professionals agreed that soil, sediment, dirt and reject (spoil pile) are all interchangeable terms.

Photos taken of fossils where they are found are in situ.

MYTH. In situ refers to the fossil in the formation exactly where it was fossilized. Most shark tooth and other fossils we find on the East Coast have been moved in some way. When you photograph your fossil where you find it, it is referred to as float due to reworking.

Megalodon and pathological teeth are rare.

MYTH. “It is a common misconception that Megalodon teeth are rare when in fact they are relatively common.” says Victor. Pathological teeth are also not rare. A tooth can be pathological due to damage or genetic mutation. Due to the immense number of teeth produced in a shark’s lifetime and continuing to be produced in a deformed manner, this type of tooth can actually be quite common.

I would like to send a HUGE thanks to Victor Perez, Dr. Ronny Leder, Dr. Bruce MacFadden and Dr. Robert Boessenecker for taking time out of their very busy schedules to assist me with this article. If you have any other questions you would like to see answered please send an email to [email protected].

 

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