Traditionally, fossils are a geological record of the remains of once-living organisms that date back over a span of millions of years. However, the definition of fossils today is broader and includes the intact remains of organisms encased like a time capsule in fossilized plant resin rather than in rock. This fossilization phenomenon provides an important picture of what life was like on Earth millions of years ago.
The formation of rock fossils falls under several types: carbonization, petrifaction, replacement, casting and recrystallization. Carbonization is where the oils of organic plants leach out and fossilize into a carbon imprint on rock. Petrifaction is the crystallization of minerals within plant cells. One example is that of petrified wood. Replacement is where sulfide and phosphate minerals replace the soft tissues of an organism that was buried in mud. Casting is a form of replacement where the soft tissues had decayed away leaving behind a shell or exoskeleton that formed an imprint. Recrystallization involves shells made of calcium carbonate that over time recrystallized into the permanent mineral calcite.
Tree Resin Traps
A resin fossil is a mineraloid fossil commonly known as an "amber fossil." Amber is the fossilized opaque, yellowish-brown byproduct of tree resin that has polymerized into a hardened chemical and physical state. While rock-hard to the touch, resin fossils can be dissolved in organic solutions.
Resin in its natural organic state is a viscous and sticky fluid that provides a protective function. Resin is toxic to herbivores and serves as a natural defense during injury and disease. In predominantly tropical and subtropical regions, a broad diversity of insect and fungal species pose a significant threat to many plants. Resin from a damaged branch or trunk heals the wound while simultaneously trapping the invading insect or fungus.
This trapping ability is what led to the classifying of resin fossils as part of the fossil record. Whole, intact insects--and in some cases lizards--from the Early Cretaceous period more than 150 million years ago are found in samples of amber.
The fossilization of amber is primarily a chemical process. Depending on the class of organic compounds within a particular plant's resin, fossilization involves multiple transformations as the organic compounds within resin undergo numerous polymerization and other biochemical reactions. Like fossils in stone, these reactions occur over periods of millions of years. The oldest amber specimens can be dated to the Upper Carboniferous Period more than 320 million years ago.
Significance of Resin Fossils
Resin fossils have provided invaluable data for paleontologists and anthropologists to interpret. Trapped specimens of plants, seeds, pollen and insects have given paleontologists a frozen picture in time of what life was like millions of years ago in specific regions of the world. Resin fossils as precious stones provides historical significance in its use as jewelry found in ancient tombs and along trade routes across Europe ranging from the Bronze and Iron Ages to the relatively more modern Roman and Greek periods.
- "McGraw-Hill Encyclopedia of Science & Technology": AAR-ANO; Amber; 2007
- Fossil Amber: The Perfect Fossil Preservative
- "Sleuthing Fossils: The Art of Investigating Past Life"; Alan Cvancara; 1990
- Photo Credit PhotoObjects.net/PhotoObjects.net/Getty Images Hemera Technologies/Photos.com/Getty Images Hemera Technologies/PhotoObjects.net/Getty Images Photos.com/Photos.com/Getty Images
Definition of Fossil Reconstruction
Fossil reconstruction has been used for decades in the study of archaeology. However, it has become a controversial process. Many fundamentalist Christians...
What Is a Preserved-Remains Fossil and How Are They Formed?
Fossils are the remains of plants or animals from prehistoric times. They are a rarity as most organisms, then and now, are...
How to Polish a Dull Amber Ring
Amber, in technical terms, is a fossilized plant resin that takes millions of years to form. Because of its rarity, coupled with...
How to Replace the Battery In a Fossil Blue Watch
The Fossil Company makes clothing, shoes, jewelry, handbags and watches for men and women that can be purchased at most major department...