The Ordovician fossil record contains a diversity of marine
invertebrates, including graptolites, trilobites, brachiopods, and
conodonts (early vertebrates). A typical marine community consisted of
these animals, plus red and green algae, early fish, cephalopods,
corals, crinoids, and gastropods. A drop in sea level may have
contributed to the mass extinctions that characterized the end of the
Ordovician, in which perhaps 60% of all marine invertebrate genera went
extinct.
During the Ordovician Period in New Jersey, shallow seas gave way to deeper oceanic conditions. The shallow water limestone's and their reef-building organisms were replaced by dark colored shale's and mud stones and organisms typical of a deep-water environment. This change between environments is evident in the Valley and Ridge Province of northwestern New Jersey.
During the Ordovician Period in New Jersey, shallow seas gave way to deeper oceanic conditions. The shallow water limestone's and their reef-building organisms were replaced by dark colored shale's and mud stones and organisms typical of a deep-water environment. This change between environments is evident in the Valley and Ridge Province of northwestern New Jersey.