Exam 21: Paleozoic Life History

All except which of the following are important fossils groups from Silurian and Ordovician age rocks?

What was the evolutionary advantage of having a mineralized skeleton?

Therapsids developed mammal-like features including hairy skins.

Chordates are animals that have,during at least part of their life cycles,a dorsal hollow nerve chord,a(n)____________________ and ____________________.

What is the significance of the different types of cell cleavage between echinoderms and chordates versus other invertebrates? What other evidence is there for this idea?

Fusilinids,greatly diversified in the Pennsylvanian and Permian,are one of the most useful guide fossils for those periods.

What hypotheses have been put forward to explain the rise of so many different types of organisms at the time of the Cambrian explosion?

Organisms that live on the seafloor are called ____________________; those that move are ____________________,and those that remain stationary are ____________________.

The evolution of jaws played an important role in the evolution of fish because it allowed them to do what?

____________________ in jawless fish eventually developed into jaws.

The first evidence of shelled organisms is in the early Cambrian in the Ediacaran fauna.

The amalgamation of Pangaea may have played an important role in the Permian extinction because the shallow marine environment was greatly reduced.

Benthic plants are called __________ and benthic animals are called __________.

What is the age of the Burgess Shale? What is its significance,and why did this unique preservation occur?

Which of the following is not one of the basic feeding groups?

The Precambrian-Cambrian boundary represents the first appearance of ____.

The most critical barriers for animals in making the transition from sea to land were the development of ways to deal with what?

There is no evidence in the geologic record that multi-celled organisms of any kind existed prior to the Cambrian.

What was the distribution of trilobites in time and space during the Paleozoic? What niches did trilobites fill? Most were bottom dwellers,crawling around on the seafloor eating detritus.