Fossil Record Research You will choose a vertebrate animal from an aquatic ecosystem and a vertebrate organism from a terrestrial ecosystem. You will research the fossil record of each. You will analyze the fossil evidence and determine past organisms they are related to, how the fossil of the modern organism is similar to the past organisms, and how the organisms have changed over time. You should also look for relationships between the terrestrial and aquatic organisms. Questions to guide your research: ●What is the habitat for your organism like?
●What role does your organism play in the ecosystem?
● Is there evidence of relationships between aquatic organisms and terrestrial organisms?
● Does the fossil record show a possible relationship between aquatic organisms and terrestrial organisms?
● How did the organisms change over time?
Final product: You will construct an explanation about how your aquatic organism compares to the terrestrial organism. You need to also refer to possible connections in the fossil records of aquatic vertebrates and terrestrial vertebrates. Write in complete sentences.

Preservation of remains in amber or other substances is the rarest from of fossilization; this mechanism allows scientists to study the skin, hair, and organs of ancient creatures.

Permineralization, where minerals like silica fill the empty spaces of shells, is the most common form of fossilization.

Molds form when shells or bones dissolve, leaving behind an empty depression; a cast is then formed when the depression is filled by sediment.

Replacement occurs when the original shell or bone dissolves away and is replaced by a different mineral; when this occurs with permineralization, it is called petrification.

In compression, the most common form of fossilization of leaves and ferns, a dark imprint of the fossil remains.

Decay, chemical weathering, erosion, and predators are factors that deter fossilization.

Fossilization of soft body parts is rare, and hard parts are better preserved when buried.

Key Terms

amber: a hard, generally yellow to brown translucent fossil resin

permineralization: form of fossilization in which minerals are deposited in the pores of bone and similar hard animal parts

petrification: process by which organic material is converted into stone through the replacement of the original material and the filling of the original pore spaces with minerals

Explanation: