Lecture 5 - Biomineralization

Fossil record is made up of primarily…

mineralized skeletons

• having a mineralized skeleton greatly improves organism’s chances of being preserved in fossil record

Why do organisms make skeletons?

What are organisms made of?

organic and inorganic materials

Collagen (protein)

most common structural fiber in animals

• bone, skin, cartilage

• high tensile strength, little elasticity

Keratin (protein)

tough, sulfur-rich

• claws, nails, hair, horn, skin, feathers

Silk

produced y modified salivary glands

• spider webs

Cellulose (organic polysaccharide)

most abundant organic polymer

• structural material in plants

• high tensile strength

Chitin (organic polysaccharide)

second most common structural fiber in animals

• nitrogen-rich

Biologically-controlled process

• organic-matrix mediated

• template of organic components is formed

• genetically controlled

• common in animals

Biologically-induced process

• organisms alter their chemical microenvironment

• not under strict genetic control

• common in green algae

Mineral

natural inorganic solid that occurs in crystalline state

Phosphate minerals

Carbonate minerals

Silica minerals

Iron oxide minerals