Devonian

Approximately 66 million years ago, the first, and most recent extinction event of ‘the Big Five’ took place- the Cretaceous-Paleogene (K-Pg) Extinction, also known as the Cretaceous-Tertiary (K-T) Extinction. While this event is known primarily for its involvement in the extinction of dinosaurs, it also had quite the effect on a large majority of other plant and animal species, to the point where no tetrapod (four-legged vertebrae) weighing above 25 kilograms survived. The original trigger is

resource regions, which extend from Maine to Alabama, and as far as the eastern part of Nebraska. Much of the soils found near me are left behind the glaciers that carved out the Great Lakes. 3. Bedrock North Ridgeville is associated with the Devonian time period as it is in the northeastern part of Ohio, and has deposits of shale,

The Cambrian period kicked off the Paleozoic era, from there came the Ordovician, Silurian, Devonian, Carboniferous periods. The Paleozoic era ended with the Permian period. Throughout each period came many new and different crustaceans. One, in particular, were trilobites. Trilobites are extinct but are closely related to horseshoe crabs, who are

Paleozoic Era The Houston Museum of Natural Science features Trilobites from the Middle Devonian, which were found in Silica Shale in Lucas County of Ohio. This particular genus of trilobites, “Eldredgeops milleri,” have large eyes containing a separately set lenses without a common cornea. Its thorax has 11 segments. Trilobites are some of the earliest known arthropods. Since these particular trilobites had good vision, I imagine that they were one of the few genus of trilobites that were either

of mostly shallow oceans covering the continents. Skeletons grew in life forms and new life forms exploded across the shallow seas. Shortly after this time, the Earth underwent its first mass extinction. The extinction led into the Silurian and Devonian periods where life moved onto land. Plants began to grow and new fishes began to

modified swim bladder, which in most fish is used for buoyancy in swimming, but in the lungfish also absorbs oxygen and removes wastes. Dipnoi is an interesting group of fishes showing affinities with teleosts and amphibians.They evolved during middle Devonian and flourished in Permian and Triassic periods. The earliest known fossil lung fish is Dipterus

Insert Name: Instructor’s Name: Course: Date: 08/July/2010 Sharks have been in existence for more than 300 million years. Their evolution occurred over 150 million years earlier than that of the dinosaurs. Most of the existing fossil data of early sharks was collected from fossilized teeth together with several skin impressions. primitive sharks (Cladodonts) , had teeth which were double-pointed, up to 2metres in length, ate fish as well as crustaceans, and existed approximately

1) Ostracoderm. What are their characteristics? Did they all look the same? Do they possess the chordate characteristics? Vertebrate characteristics? Ostracoderm was regarded as the primitive and oldest chordates according to (Gregory 1995).They possessed small fins i.e. medial fins but they lacked lateral fins. Their mouths were always open. Their body size is small with non beyond 15 cm long. They move food with help of ciliated motion and their muscular gill pouch assist them in creating suction

Precambrian Time 4.6 bil.-544 mil. The earth is a Molten Lava World. The earth was formed by countless collisions of meteors/molten rock which made it a world of fire and molten rock. Temp. exceeded 8,000 degrees F radioactivity prevented the molten world from cooling quickly Scientists used radioactive dating to date the Earth.The earth is a Waterworld. Meteors with 5% water help cover the Earth with water, but it was mainly because volcanoes gave of huge amounts of carbon dioxide which formed

the waters column. The pace of advancement found in the Cambrian times of the explosion is not paralleled amongst the marine creatures: it changed all metazoan clades where Cambrian fossils were found. Later radiations, the fish in the Silurian and Devonian era, included less taxa, for the most part with basically the same body plans. Despite