The Devonian Marine Habitat
Devonian Period Invertebrates
The Devonian Period existed during one of Earth's greenhouse stages. During greenhouse times there is little fresh water frozen in polar ice caps, making average sea level higher in contrast to cooler periods. So much water was in the Devonian Period oceans, in fact, that much of the land in North America and elsewhere was covered by shallow inland seas. These waters were warm and expansive and were host to a number of familiar and foreign marine ecosystems.
Devonian Period continental margins were characterized by extensive reef ecosystems. Reefs are buildups constructed by photozoans in clear, shallow marine waters. Modern reefs are built almost exclusively in tropical settings between approximately 30°N latitude and 30°S latitude with a band of suppressed reef abundance at, and directly adjacent to, the equator. Devonian reefs were both similar and different from those of today. They were constructed in much the same manor as modern reefs such as the famous Great Barrier Reef of Australia. They were not; however, made up of the familiar corals we see today. Instead, Devonian Period reefs were dominated by a group of calcareous sponges known as stromatoporoids. Stromatoporoids filled the same ecological niche as the stony corals of today, and thus, played the same role in reef construction.