The Cambrian explosion of animal life

Question 1

The origin of metazoans (multicellular animals) & characteristics

Answer 1

Metazoans share characteristics
-Multicellular body formed from different kinds of cells
-The ability to manufacture collagen
-A reproductive cycle with gametes produced by meiosis
-A nervous system composed of neurons

The fossil record suggests that the first metazoans appeared in the late Precambrian, around 600 MA

Question 2

The Ediacara fauna

Answer 2

The Ediacara fauna refers to a group of extinct, soft-bodied organisms that lived during the Ediacaran Period, which lasted from about 635 to 541 million years ago.

They represent some of the earliest evidence of complex, multicellular life on Earth.

The Ediacara fauna includes a wide variety of organisms, some of which resemble modern-day animals, such as jellyfish and worms

Feed by photosynthesis, through the body wall, chemosymbiosis

Diploblastic

Question 3

Phosphatized embryos

Answer 3

3D organisms preserved perfectly in phosphate rich environments

Soft tissues of the embryo are replaced with phosphate minerals

Question 4

Small shelly fossils (SSFs)

Answer 4

Disarticulated elements of skeletal covering

Either extinct phylum (mollusca) or annelid form