Describe and discuss the marine communities of the Ordovician, Silurian, and Devonian. How
do they compare with present-day marine communities? What will be an ideal response?
The Middle Ordovician was noted for a major marine transgression causing wide-spread epeiric
seas over much of the North American craton. This shallow marine environment was home to a
variety of brachiopods, bryozoans, and corals. Acritarchs also were abundant. A major mass
extinction occurred at the end of the Ordovician and was followed by a rediversification of
marine organisms. Eurypterids and ammonoids made up a large part of the populations during
these periods. Another mass extinction occurred at the end of the Devonian.
You might also like to view...
Which organisms burrow into the deep-ocean muds in a process called bioturbation?
A. clams B. sea urchins C. starfish D. sea cucumbers E. sponges
Of the following, ________ requires the least land to produce 1 kg of protein
A) milk B) beef C) pork D) chicken E) eggs
Which columns o the periodic table is commonly called the halogens?
A) 1A B) 4A C) 7A D) 8A
Organic matter accumulated from grassland vegetation has played a major role in creating the fertile soils of the central U.S
True False Indicate whether the statement is true or false