rangeomorphs造句

• It is the type genus of the rangeomorphs.
• The rangeomorphs lived from 560 to 575 million years ago, in a geologic period known as the Ediacaran.
• Rangeomorphs are a key part of the Ediacaran biota which survived about 30 million years, until the base of the Cambrian.
• Rangeomorphs consist of branching " frond " elements, each a few centimetres long, each of which is itself composed of many smaller branching tubes held up by a semi-rigid organic skeleton.
• Known as rangeomorphs, they were a worldwide clan that lived and evolved nearly 600 million years ago, thrived briefly, and then faded to extinction long before a time-- millions of years later-- when animal forms in all their variety exploded into existence and began the long eons of evolution.