October 02, 2013
Book, p. 44: Do 1-­‐2g. Answer the following:
1. De:ine paleontologist. A scientist who studies fossils and the history of life on earth, in fossils :inds clues to biological change over time
2a. What is stratigraphy? Study of strata What are strata? sediment or rock layers
#2b Which layer of materials is the oldest? Deepest
#2b What inferences might you make about the relationship between the depth of the layer and the age?
The deeper the layer, the older it is.
#2c Which colored marker would be oldest? _____________________
#2f Which fossil is oldest? _______ Which is youngest? _______________
#2g Compare the 3 fossils. October 02, 2013
10. Read p. 102-­‐105 and answer the following:
a. What are the steps in the formation of a fossil?
I. layers of mud or silt cover dead organism quickly to protect it from scavengers and from decomposition
II. minerals in water replace minerals in organism’s tissues, molecule by molecule (any remnant of organism's tissue is completely encased in minerals so it is preserved)
what type of rocks are fossils found? Sedimentary
c. What 3 parts of organisms can be fossilized? I. Hard parts – shells, bones
II. Soft parts (such as frozen or in sap)
III. Imprints of soft tissues (skin, hair, feathers)
d. Which is most likely and why? Shells and bones – more likely to stay intact in process in “a” above
e. What can fossils tell us about climate and land conditions? Type of organism found can tell what climate and land condition must have been present when that organism was alive – for instance, aquatic fossils indicate there was water; tropical plant fossils indicate warm and wet climate
f. De:ine extinction. Complete disappearance of species, dying out
October 02, 2013
g. The age of a fossil can be calculated indirectly from the __age of the ______surrounding rock layer in which it is found_. Why is this called a relative method? It lets scientists determine age only in relation to another fossil or rock; for instance, fossil A found in a layer below fossil B must be older than fossil B; or fossil A found just above rock layer B must be younger than rock layer B
h. Scientists infer that any fossil that they :ind in a __particular rock layer___ is older than ____any fossils found above that layer and younger than fossils found below that layer____________.