Cambrian

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What happened in the Cambrian Period?

By |2018-04-21T11:56:36+00:00June 23rd, 2017|Geology|

Mossy rocks At the beginning of the Cambrian Period, about 542 million years ago, there were sea creatures like hydras, jellyfish, sponges and seaweed living in the oceans, but only one-celled algae on land yet. Small arthropods like beetles were beginning to appear, and by 540 million years ago the first land plants [...]

What is moss? Plant Biology and Evolution

By |2017-05-29T22:55:45+00:00May 29th, 2017|Biology|

A moss-covered rock During the Cambrian period, about 540 million years ago, some early plants evolved from earlier algae that could live on land, outside of the water. These plants were like modern moss. All of the animals were still living in the water, so on land there was only moss and mushrooms. [...]

Evolution of bones – Skeletons and Biology

By |2017-05-28T00:44:16+00:00May 28th, 2017|Biology|

A fish skeleton One-celled animals don't have any support system that holds them in a certain shape. Plants do have a support system, but it's the cellulose in the cell wall of each cell, rather than bones. Early multi-celled animals like jellyfish and sponges and worms also didn't have skeletons, but beginning with [...]

What are segmented worms? Annelids, evolution, and biology

By |2018-04-13T14:37:43+00:00May 27th, 2017|Biology|

An annelid, or segmented worm Roundworms probably evolved into segmented worms, or annelids, about 545 million years ago. The earliest annelids all lived in the ocean, as most kinds of annelid still do today. Some annelids live inside of sponges. Their long bodies were shaped like a hollow tube, with a long tunnel running [...]

What are mollusks? What’s a cephalopod? Biology and Evolution

By |2018-04-16T08:32:28+00:00May 26th, 2017|Biology|

Evolution of mollusks: Slugs are a kind of mollusk. When did the first mollusks appear? Mollusks are animals like mussels, clams, snails and slugs. Their name means "soft", because mollusks don't have any skeletons. The first mollusks probably evolved from early segmented worms around 500 million years ago.  That was in the Cambrian period. At [...]

What does a stomach do? – Digestion and Evolution

By |2017-05-26T19:21:38+00:00May 26th, 2017|Biology|

Fish Stomach The first multi-cellular animals like hydras had no stomachs, or you could say they were all stomach, because they were shaped like a bag. Roundworms, a little later, were shaped like a tube, and the cells along that tube made mucus to protect the tube from the bacteria that digested food [...]

History of Fish – Biology

By |2018-04-09T23:39:25+00:00May 26th, 2017|Biology|

History of fish: it looks like a severed tentacle but it's a lamprey. About 510 million years ago, in the Cambrian period, some of the worms on Earth evolved into the earliest fish. Fish were different from worms because they had spinal cords, nerves running all along their backs that carried messages to [...]