The Adventures of Dot and Mae

Since the weather has been nice for the past couple of days, Dot and Mae have been outside exploring. They have made a very exciting discovery! The found a real fossil and they were very excited to show it to you!

Do you know what a fossil is? A fossil is “the remains or evidence of a creature or plant that once lived on Earth.” There are lots of different kinds of fossils.

Type I-the remains of the dead animal or plant or the imprint left from the remains like:

• bones
• teeth
• skin impressions
• hair
• the hardened shell of an ancient invertebrate (an animal without a backbone) like a trilobite or an ammonite, or the
• impression of an animal or plant, even if the actual parts are missing.

Type II- Something that was made by the animal while it was living that has hardened into stone. These are called trace fossils:

 

• footprints
• burrows
• coprolite or animal poop

This is what Dot and Mae found out about fossils by looking them up online:

“Type I fossils can be the actual thing that it once was, like a piece of bone or hair or feather. More often the bone material is replaced by different minerals contained in the liquid of the sediments that buried it. What was once bone is now some sort of crystal.

This process also takes place with shells, exoskeletons and wood. If the spaces in the bone are filled with liquid minerals which later harden it is called permineralization.

Sometimes the organic material is dissolved by the mineral-laden water. The process happens so slowly that each cell is dissolved and replaced by a particular liquid mineral before it hardens. This is called petrification. In petrification, every detail down to the cellular level is duplicated in the minerals.

Type I can also be molds or casts of the original animal or plant part. If the original organism decays, leaving an imprint and an empty space, it is called an exterior mold or simply a mold. If a space in the structure is filled with minerals and then the original animal or plant part dissolves, it is called a cast.”

Dot and Mae think they found fossil that is a Type I fossil. It looks like some imprint of a sea plant or maybe a part of sea creature. They don’t know for sure what it’s a fossil of, but they like to use their imaginations and think about what kind of creature could have lived in this area thousands of years ago. Maybe their house would be under an ocean that was filled with all kinds of strange fish and maybe even mermaids! It could happen!

Wow Dot and Mae feel very scientific now!

Here are some more interesting things they discovered:

How are fossils formed?Freezing (refrigeration)-This is the best means of preservation of ancient materials. It happens only rarely. The animal must be continually frozen from the time of death until discovery. That limits the possibilities to cold hardy animals from the last ice age. There have been remarkable discoveries of mammoth and woolly rhinoceros found in ice from Alaska and Siberia. Specimens with flesh, skin, and hair intact have been found. Some of these finds suggest that they were flash frozen, with food still in the mouth and stomach.

Drying (desiccation)- Mummified bodies of animals including humans have been discovered in arid parts of the world. The soft tissues including skin and organs are preserved for thousands of years if they are completely dried.

How are fossils formed?Asphalt- In what is now downtown Los Angeles lies a 23 acre park called The La Brea Tar Pits, officially Hancock Park. Within the park are over 100 pits filled with sticky asphalt or tar. The tar pits were formed by crude oil seeping through fissures in the earth. The lighter elements of the oil evaporate leaving thick sticky asphalt.

The pits are famous for the number and high quality of Pleistocene fossils that have been pulled from the pits. The fossils date between 10 and 40 thousand years old. Asphalt is an excellent preservative. Bones, teeth, shells, the exoskeletons of insects, and even some plant seeds have been pulled from the pits.

How are fossils formed?Amber- Insects, spiders, and even small lizard have been found, nearly perfectly preserved in amber. Picture this scenario: A fly lands on a tree branch in an area that is now the Baltic sea. While looking for food it steps in sticky sap that the tree has made to protect itself from fungal infection. As the fly struggles to escape it becomes more and more entombed in the sap until it is completely engulfed and suffocates. The tree eventually dies and falls into the swampy water from which it grew. Over the course of millions of years the tree along with countless others becomes a coal deposit and the sap with our fly inside is polymerized and hardened into amber. As more time passes the coal bed is submerged as the sea level rises. Eventually the currents uncover the coal bed, slowly eating into the Surface, little by little. When the erosion reaches the amber it floats to the surface because it is lighter than the salty water. It is then washed ashore where it can be found.

 

How are fossils formed?Carbonization (distillation)- In this process of fossilization plant leaves, and some soft body parts of fish, reptiles, and marine invertebrates decompose leaving behind only the carbon. This carbon creates an impression in the rock outlining the fossil, sometimes with great detail.

How are fossils formed?Permineralization-This is the most common method of fossil preservation. Minerals fill the cellular spaces and crystallize. The shape of the original plant or animal is preserved as rock. Sometimes the original material is dissolved away leaving the form and structure but none of the organic material remains.

Fossils have also been created by peat bogs, paraffin deposits, and volcanic ash.

If you can’t find a fossil where you live, you will still have fun looking at all the cool rocks that you will probably find. Rocks are very interesting too. You can make lots of fun crafts with rocks. You can paint them to look like little animals, or glue them together and make fun creatures. If you wrap them with yarn or wire, you can make jewelry out of them - there are so many good things to do with them! If you find an interesting looking rock maybe you can look up rocks in a book or online and find out what kind of rock it is. If you like to do this, there is a job you could do when you grow up - a person who studies rocks is called a petrographer or maybe you would want to study the earth, those people are called geologists.

Some people just collect rocks for a hobby - that’s what Dot and Mae do - they just like how the rocks look, that’s all. Well, they are off now to look at some more rocks. Maybe this time they will discover dinosaur bones! Fingers crossed!