Backyard Dig By Tara, Anita, Sarah,and Jami

Rock Layers Cenozoic Mesozoic Paleozoic Precambrian

Fossils Trilobites, Paleozoic Shark, Mesozoic Snapping turtle, Cenozoic

Analysis The oldest rock layer is Precambrian, because according to the law of superposition, the oldest rocks are at the bottom, and the Precambrian is at the bottom. The youngest rock layer is the Cenozoic, because according to the law of superposition, the youngest rocks are at the top, and the Cenozoic is at the top. The oldest rock layer is Precambrian, because according to the law of superposition, the oldest rocks are at the bottom, and the Precambrian is at the bottom. The youngest rock layer is the Cenozoic, because according to the law of superposition, the youngest rocks are at the top, and the Cenozoic is at the top.

Analysis No fossils were never alive, because the mold and the cast are not actually alive. They just look like the organism/object that is fossilized into it. There are two parts of a fossil. One part is the cast and the other is the mold. The cast part is the part that looks like the organism/object. The mold part is the part that looks like the imprint. No fossils were never alive, because the mold and the cast are not actually alive. They just look like the organism/object that is fossilized into it. There are two parts of a fossil. One part is the cast and the other is the mold. The cast part is the part that looks like the organism/object. The mold part is the part that looks like the imprint.

Analysis We know that our backyard was probably really old because we found fossils and rocks from the Precambrian era, Paleozoic era, Mesozoic era, and the Cenozoic era.