Igneous Intrusions. Igneous intrusions form when magma cools and solidifies before it reaches the surface. Three common types of intrusion are sills, dykes, and batholiths (see image below). form when magma intrudes between the rock layers, forming a horizontal or gently-dipping sheet of igneous rock.The Whin Sill (top left image) in N. England provided a defensive cliff-line on which the Romans built Hadrianâs Wall.form as magma pushes up towards the surface through cracks in the rock.orm when magma intrudes between the rock layers, forming a horizontal or gently-dipping sheet of igneous rock. The Whin Sill (top left image) in N. England provided a defensive cliff-line on which the Romans built Hadrianâs Wall. form as magma pushes up towards the surface through cracks in the rock.
The scientific name for the phylum of cartilaginous fishes is Chondricthyes. More specifically, sharks are categorized under subclass Elasmobranchii which is then divided into â¦ the subdivisions Selachii (sharks) and Batoidea (skates and rays).
When you have finished this page, take the Echinoderm Quiz: Starfish belong to a group or phylum of animals called echinoderms. This means spiny skinned in Greek. Echinoderms live in salt water only. They sgenerally have five arms and dwell at the bottom of oceans' levels.There are around 6000 species of echinoderms. Echinoderm has a mouth and stomach area. Some have a mouth on the bottom and an anus on the top.Starfish can actually turn their stomachs outside of their body and insert it into its prey's such as a clam. Echinoderms have a relatively big gut area.