On this Valentine's Day, we spent one more time reviewing prior material for the math common assessment that will be administered tomorrow and Thursday. I also went over how to make fractions and mixed numbers on the calculator since the second half of the test will be calculator-active.
While students did determine which person's idea they most agreed with, there was still one statement that was the most accurate. Rosa’s response is correct. Over long periods of geologic time, the Earth’s crust goes through several changes. Mountains can exist where oceans once stood. Ancient organisms died and were covered with sediments that, over time, became hardened and formed sedimentary rock. The imprints left behind by the dead organisms remained and are now fossils.
After that, students took notes for the first part of the unit.
Nature – the physical world Model – a limited representation of something that can help us understand its structure or how it works
Imprint - a mark or depression made by pressure. Most imprints are erased by erosion and weathering. Some will become fossils.
Petrified – “turned to stone.” Minerals in water replace the remains, the water evaporates leaving just the minerals
Fossil - preserved parts or traces of animals and plants that lived in the past Fossils are typically preserved when they are buried under many layers of sand and mud. Under great pressure the sand and mud become sedimentary rock. As the organism decays, it is replaced with minerals. Most fossils are found in sedimentary rock.
The oldest fossils are usually found in the lowest layers.
Sometimes the folding of the Earth’s crust can flip layers of rock.
Fossils are evidence of living organisms that once existed on Earth
Fossils can be compared to other known fossils or to living organisms
Fossils share some characteristics based on where, how and from what they formed
Fossil formation is very rare since most dead organisms decay
Today’s live organisms will, under the right conditions, leave fossil evidence
Some organisms that lived long ago are similar to existing organisms, but some are quite different
There are five different types of fossils: petrified, molds and casts, carbon films, trace fossils, and preserved remains
Paleontologists can get a three dimensional cast of an imprint by filling it in with clay and baking it
What don’t fossils tell us? Fossils can’t tell us the exact year the organism died, its colors, behavior, etc.
Extinct - when a plant or animal species has died out and there are no more living members
Amber - a fossil resin formed from hardened tree sap that is yellow, orange, red, or brown. It is the only thing that preserved whole animals.
Paleontologist – a scientist who studies fossils to learn about prehistoric organisms