Exam 2 Dino class

Element

A basic substance that cannot be broken down into simpler substances by chemical means. Examples include oxygen, silicon, and iron.

Mineral

A naturally occurring, inorganic solid with a specific chemical composition and a crystalline structure. are made of one or more elements. Examples include quartz, feldspar, and calcite.

Rock

A solid, naturally occurring combination of one or more minerals or mineraloids. can be classified into three types: igneous, sedimentary, and metamorphic. Examples include granite, limestone, and basalt.

Most common elements in the earths surface

• Crust: Oxygen (O), Silicon (Si), Aluminum (Al), Iron (Fe), Calcium (Ca), Sodium (Na), Potassium (K), Magnesium (Mg).

• Entire Earth: Iron (Fe), Oxygen (O), Silicon (Si), Magnesium (Mg), Nickel (Ni), Sulfur (S).

Five defining properties of minerals

1. Naturally occurring

2. Inorganic

3. Solid

4. Definite chemical composition

5. Ordered atomic structure (crystalline structure)

Volcanic Igneous Rocks

Formed from lava that cools and solidifies quickly on the Earth’s surface. Examples include basalt and rhyolite.

Plutonic

• Formed from magma that cools and solidifies slowly beneath the Earth’s surface. Examples include granite and diorite.

Mafic Magma

Rich in magnesium and iron, low in silica. It tends to form dark-colored rocks like basalt.

Felsic Magma

Rich in silica, aluminum, potassium, and sodium, low in iron and magnesium. It tends to form light-colored rocks like granite.

Formulation of Basalt

Formed from mafic magma that cools quickly at the Earth's surface (volcanic).

Formulation of Granite

Formed from felsic magma that cools slowly beneath the Earth’s surface (plutonic). The slower cooling allows larger crystals to form.

Types of Sedimentary Rocks

• Clastic: Formed from fragments of other rocks. Example: sandstone.

• Biochemical: Formed from the remains of organisms. Example: limestone.

• Organic: Formed from the accumulation of plant material or other organic matter. Example: coal.

• Chemical: Formed by the evaporation of water, leaving behind minerals. Example: rock salt.

How Transportation Affects Clastic Sediment

• Size: Longer transportation distances lead to smaller sediments due to wear and tear.

• Shape: Longer transportation causes more rounding of particles.

• Sorting: Longer transport leads to better sorting, where similar-sized particles are grouped together.

Conditions for Metamorphism

High temperature and pressure, typically deep beneath the Earth's surface. This causes changes in mineral composition and structure without the rock melting.

The Rock Cycle

• Igneous rocks form from cooling magma or lava.

• Sedimentary rocks form from the erosion and deposition of pre-existing rocks.

• Metamorphic rocks form from the alteration of other rocks due to high temperature and pressure.

Terrestrial Depositional Enviroments

Rivers, lakes, deserts, and swamps.

Sedimentary Characteristics in Terrestrial Environments

• Rivers: Coarse-grained sediments like sand and gravel.

• Lakes: Fine-grained sediments like mud and clay.

• Deserts: Well-sorted, fine-grained sand.

• Swamps: Organic-rich sediments, such as peat.

Fossil Definition

A fossil is the preserved remains, impression, or traces of a once-living organism.

Two types of Broad Fossils

Body and Trace Fossils

Body Fossils

Direct evidence of life; remains that were once part of the organisms biology

bone,skin, teeth, mummified dinosaurs, claw sheaths, feathers

Trace fossils

indirect evidence of past life (left behind from the organism but not from their body)

trackways, poop, burrows, borings, gastroliths

Two types of Taphonomy

Biostratinomy and Diagenisis

Biostratinomy

Processes that occur between death and burial, such as decay and scavenging.

Diagenisis

Processes that occur after burial, such as compaction and mineralization.

Biostratinomic Processes After Dinosaur Death:

• Scavenging, decay, transportation, and burial can affect how a dinosaur fossil is preserved.

Biostratinomic Processes and Fossilization:

Decay and scavenging can destroy soft tissues, while burial and mineralization preserve hard tissues like bones.

Diagenetic Factors and Dinosaur Preservation:

Heat, pressure, and chemical conditions can alter or preserve fossils. For example, the presence of minerals can cause bones to become petrified.

Saurichia

• Lizard-hipped" dinosaurs, including theropods and sauropodomorphs.

Ornithiscia

Bird-hipped" dinosaurs, herbivours, and Retroverted pubis

• Predentary (before teeth) bone 

• Rostral (front) end of premacilla, toothless

• Teeth in maxillia & dentary (uppper and lower jaw) ridged with denticulate margians

• Jaw joint set below the level of the maxillary tooth row

• No gastralia

• Ossified tendons on sacral (hip) & caudal vertebrae

Saurichia

"Lizard-hipped" dinosaurs, including theropods and sauropodomorphs.

Explain the Baron et al. phylogenetic hypothesis for Dinosauria (Saurischia and
Ornithoscelida).

• Saurischia: Theropods (T. rex) + Sauropodomorphs (Brachiosaurus)

• Ornithischia: Triceratops, Stegosaurus, etc.

Baron et al.'s Revision:

• Ornithoscelida (new clade): Theropods + Ornithischians (suggesting a closer relationship)

• Saurischia (redefined): Sauropodomorphs + Herrerasaurids

Key Implications:

• Closer link between theropods (birds) and ornithischians.

• Early dinosaurs may have been omnivorous.

• Challenges traditional dinosaur classification.

Thyreophorans

These were plant-eating dinosaurs with body armor like plates or spikes. Two main groups:

1. Stegosaurs – Had large plates or spikes on their backs and tails. Walked on four legs with small heads.

   • Example: Stegosaurus

2. Ankylosaurs – Had heavy armor covering their bodies and often a clubbed tail for defense.

   • Example: Ankylosaurus