Download Historical Geology 1. Describe three advantages that animals might

Historical Geology
Learning Objectives and Study Questions for Chapter 13
1. Describe three advantages that animals might gain by developing mineralized hard parts.
2. Describe what a geologist mapping Paleozoic limestones might look for to distinguish a reef
formed during Cambrian time from one formed later during Middle or Late Paleozoic time.
3. Explain why, despite being found at only a single locality, the Burgess Shale fauna is
considered crucial to our understanding of marine life during Middle Cambrian time.
4. Outline the fossil and physical observations that support the interpretation that the mass
extinction that ended the Ordovician Period was caused by an episode of global cooling and
glaciation.
5. Apply the concept of isostasy to explain why the rise of the Taconic Highlands along the
southern margin of Laurentia led to the burial of shallow marine platform limestones by
deep marine clays and sands (turbidity current deposits).
1. The widespread development of calcified hard parts in early Cambrian time appears to have
been for _____.
A. predation
B. defense
C. speed
D. respiration
E. fun
2. The Burgess Shale fauna of Middle Cambrian age is especially important because it
preserves _____.
A. a diverse assemblage of trilobites
B. an ancient deep-water community
C. large Anomalocarid predators
D. the earliest reef-builders
E. soft-bodied animals
3. The preferential extinction of tropical species at the end of the Ordovician was likely the
result of _____.
A. an asteroid impact
B. ocean anoxia
C. glaciation in Gondwanaland
D. massive wildfires
E. early Paleozoic boredom
4. During the Cambrian and Ordovician, Laurentia lay _____.
A. near the south pole
B. near the north pole
C. in the northern mid-latitudes
D. in the southern mid-latitudes
E. astride the equator
5. The Taconic orogeny of Ordovician time records a collision of a/an _____ along the eastern
margin of Laurentia.
A. continent
B. supercontinent
C. offshore island chain
D. asteroid
E. runaway train
6. Animals preserved in the Burgess Shale were swept into a deep, anoxic basin by _____.
A. wave action
B. turbidity currents
C. thermohaline circulation
D. aggressive predators
E. political unrest