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Questions and Answers

What is the primary basis for the numerical (or absolute) time scale?

Fossil correlation

Radiometric dating (correct)

Geographical distribution

Stratigraphic columns

Which rock type is most accurately dated through numerical time scales?

Igneous rocks (correct)

Sedimentary rocks

Organic materials

Metamorphic rocks

Why can't carbon 14 dating be used for dating dinosaur remains?

Carbon 14 is only effective for rocks

The half-life of carbon 14 is too short for dinosaur bones (correct)

Dinosaur bones are too fragile for dating

Dinosaurs were not around when carbon 14 was formed

Which group of reptiles is characterized by having two openings behind the eye?

Diapsids Signup and view all the answers

What does the temporal fenestrae in dinosaurs primarily accommodate?

Jaw muscle attachment Signup and view all the answers

What distinguishes the ankle structures of crocodilians from those of avemetatarsalians?

Hinge below the ankle Signup and view all the answers

Which of the following is the closest relative to dinosaurs?

Silesaurs Signup and view all the answers

Which characteristic is considered a diagnostic feature of the clade Dinosauria?

Specific bone structures Signup and view all the answers

What is a key characteristic of thecodonts?

Their teeth are embedded in sockets. Signup and view all the answers

Which skull type is characteristic of synapsids?

Synapsid Signup and view all the answers

Why are replicas of bones created?

To protect the original bones for future research. Signup and view all the answers

What is the primary reason paleontologists do not collect every dinosaur they find?

The dinosaur may already be well-studied or common. Signup and view all the answers

What is involved in the process of curation?

Conservation and documentation for future research. Signup and view all the answers

Why is it important for paleontologists to map bone locations in excavations?

To create a precise record of features and artifacts. Signup and view all the answers

What factors influence where paleontologists search for dinosaur bones?

Specific environments and mesozoic rock types. Signup and view all the answers

How do amateur fossil hunters contribute to paleontological research?

They provide access to fossil discoveries and local knowledge. Signup and view all the answers

What is microevolution primarily concerned with?

The evolution of populations leading to new species Signup and view all the answers

Which of the following is a strength of the dinosaur fossil record?

It offers solid evidence of past life forms Signup and view all the answers

What does sexual dimorphism refer to?

The systematic difference in form between different sexes in the same species Signup and view all the answers

Which of the following describes a monophyletic group?

A natural grouping that includes all of its descendants Signup and view all the answers

In a cladogram, what represents a clade?

A grouping that includes a common ancestor and all its descendants Signup and view all the answers

What characterizes a polyphyletic group?

Includes unrelated organisms without a common ancestor Signup and view all the answers

Which term describes the traits that differentiate organisms on a specific branch of a cladogram?

Apomorphies Signup and view all the answers

What defines an amniote within cladistics?

The most recent common ancestor of reptiles and mammals, along with all of its descendants Signup and view all the answers

What is the official stance of the LDS Church on evolution?

The Church has no official stance. Signup and view all the answers

What is the LDS Church's general attitude towards science?

The Church leaders have historically had a positive attitude towards science. Signup and view all the answers

What differentiates doctrines from dogmas in the LDS Church?

Dogma is what is considered true by the Church, while doctrine is subject to change. Signup and view all the answers

How do most religions perceive materialism?

As anti-God. Signup and view all the answers

What is a scientific theory defined as?

The most reliable model of how nature works. Signup and view all the answers

Who stated that most religions limit the scope of their God?

Carl Sagan Signup and view all the answers

What is the correct hierarchy of scientific terms from law to facts?

Law, Hypothesis, Theory, Facts Signup and view all the answers

Which of the following describes a dinosaur?

A clade that contains Triceratops, birds, and their most immediate common ancestor. Signup and view all the answers

Which of the following characteristics is associated with dinosaurs?

Teeth in sockets Signup and view all the answers

What distinguishes the ankle structures of Crocodilia from those of Avemetatarsalia?

Crocodilia has a crurotarsal ankle Signup and view all the answers

Why do cladists prefer the term 'Archosauria' when discussing dinosaurs?

Archosauria is monophyletic Signup and view all the answers

Which clade of dinosaurs has the pubis and ischium in the same direction?

Ornithischia Signup and view all the answers

What was the status of dinosaurs during the Late Triassic compared to other vertebrates?

Dinosaurs were rare compared to other tetrapods Signup and view all the answers

What defines the muscle attachment on the humerus in dinosaurs?

It is attached on an elongate crest Signup and view all the answers

Which of the following clades of non-dinosaurian vertebrates originated in the Late Triassic?

Pterosaurs and mammals Signup and view all the answers

What feature is NOT a characteristic of Archosaurs?

Three-chambered heart Signup and view all the answers

Study Notes

Microevolution and Macroevolution

Microevolution: evolution within a population leading to new species.
Macroevolution: evolution above the species level, involving significant adaptations.

Dinosaur Fossil Record

Strengths: Provides evidence of past life forms.
Weaknesses: Incompleteness and subjective interpretation.

Species and Genus Recognition

Genus is capitalized and italicized, comes first.
Species is lowercase and italicized, comes second.

Challenges in Species and Genus Determination

Individual variation can create confusion.
Sexual dimorphism (differences between sexes) can pose challenges.
Crushing and distortion of bones can obscure features.
Incompleteness of specimens can hinder analysis.

Cladogram Basics

Clade: A group containing a shared ancestor and its descendants.
Sister taxa: Two clades sharing a recent common ancestor.
Outgroups: Closely related species outside the studied clade.
Apomorphies: Traits unique to a clade (evolutionary novelties).
Stems: Collection of extinct species within a clade.
Branches: New traits distinguishing organisms in a branch.

Types of Groups

Monophyletic: Includes all descendants of a common ancestor (natural group).
Paraphyletic: Excludes some descendants, leading to an incomplete group.
Polyphyletic: Combines unrelated organisms, forming an artificial group.

Cladistic Definition of Amniotes

Amniotes: Group encompassing reptiles and mammals, including their shared ancestor and all descendants.

Mesozoic Era

Divided into the late Triassic, Jurassic, and Cretaceous periods.
Spanned roughly 225-230 million years ago.

Numerical Time Scale

Based on radiometric dating using half-lives.
Directly applicable to organic materials and certain rocks.
Igneous rocks provide the most accurate dating results.

Carbon 14 Dating

Produced by cosmic rays hitting the earth.
Used for dating materials up to around 50,000 years old.
Not applicable to dinosaurs due to their age.

Dating Fossils

Igneous rocks, especially mineral crystals, provide absolute ages.
Fossils themselves cannot be dated using radiometric methods.
Dinosaur bones and sedimentary rocks containing fossils are not suitable for absolute dating.

Anapsids, Diapsids, Synapsids, and Euryapsids

Anapsid: No openings behind the eye (primitive).
Diapsid: Two openings behind the eye (dinosaurs).
Synapsid: One upper opening behind the eye (mammals).
Euryapsid: One lower opening behind the eye (marine reptiles).
Dinosaurs possess the diapsid skull type.

Temporal Fenestrae

Openings in the skull behind the eye in diapsids.
Functioned as attachment points for jaw muscles.

Diapsid Groups

Lepidosaurs: Include lizards and snakes.
Archosauria: Includes dinosaurs, crocodiles, and pterosaurs.

Archosauria

Clade nested within Diapsida, including Dinosauria.
Key characteristic: Hinge ankle structure.
Crocodilians have a hinge between the ankle.
Avemetatarsalians have a hinge below the ankle.

Silesaurs

Closest relatives to dinosaurs, sharing a common ancestor.

Diagnostic Characteristics of Dinosauria

Thecodonts (teeth in sockets).
Two fenestrae (antorbital, mandibular).
Muscle attached to the humerus on an elongate crest.
Hinge below the ankle bone.
Upright posture.
Hip socket is a hole.

Dinosaur Definition

Clade encompassing Triceratops, birds, and their common ancestor.

Dinosaur Posture

Fast running.
Energy efficient.
Hunting efficient.
Feeding efficient.

Upright Posture

Shared with mammals, but evolved independently.

Unidirectional Lung

Present in diapsids, including dinosaurs.
Air enters and exits without backtracking, enhancing efficiency.

Archosauria vs. Reptiles and Thecodonts

Archosauria is a monophyletic group.
Reptiles and thecodonts are not precise phylogenetic groups.

Archosaur Characteristics

Diapsids.
Fenestrae on the lower jaw and in front of the eyes.
Serrated teeth.
Unidirectional lungs.

Archosaur Clades

Crocodilia: Possess a crurotarsal ankle.
Avemetatarsalia: Possess an advanced mesotarsal ankle.

Dinosaur Clades

Saurischia: Pubis and ischium in perpendicular directions.
Ornithischia: Pubis and ischium in the same direction.

Saurischian and Ornithischian Differences

Ornithischians have a predentary bone on the jaw and ossified tendons in the tail.
Saurischians have air-filled bones like birds.

Dinosaur Origins

When: Late Triassic.
Where: Every continent.
From what: Dinosauromorphs.

Dinosaur Abundance in the Late Triassic

Dinosaurs were relatively rare compared to other tetrapods.

Late Triassic Fauna

Dicynodonts: Cow-sized herbivores.
Aetosaurs: Armored reptiles.
Phytosaurs: Similar to crocodilians.

Other Late Triassic Clades

Pterosaurs, mammals, plesiosaurs, crocodiles, and turtles originated in the late Triassic.

Science and Scientism

Science: Method of acquiring knowledge.
Scientism: Belief that science alone can provide all truth.

LDS Church and Evolution

No official stance on evolution.

Man and God in LDS Theology

Man is the literal offspring of God.

LDS Church’s Attitude Towards Science

Generally positive.

Evolution and LDS Believers

Some oppose evolution and the idea of an ancient Earth.
Others believe that evolution may be God's method of creating diversity.

Materialism and Religion

Most religions view materialism as anti-God.
The LDS Church can be considered materialistic due to its emphasis on tithing.

Carl Sagan on Religion

Advocated for a religion with a vast God, creator of countless worlds.

Church Terms: Dogma, Doctrine, and Policy

Dogma: Unchanging truths defined by the Church.
Doctrine: Teachings of the gospel, also unchanging.
Policy: Church practices that can be modified.

Scientific Theory vs. Lay-Person's Concept

Scientific: Most reliable model of how nature works.
Lay-person: Wild guess.

Law, Hypothesis, Theory, and Facts

Law: Explains how something happens.
Hypothesis: Testable explanation.
Theory: Most reliable explanation.
Facts: Proven to be true.

Museum of Paleontology

Dinosaur definition: Clade encompassing Triceratops, birds, and their common ancestor.
Diagnostic characters: Posture, skeletal traits (thecodonts, fenestrae, muscle attachments, ankle structure, upright posture, hip socket).

Human and Mammal-like Reptile Skull Type

Synapsids.

Curation

Conserving information for future generations.
Creation of casts and replicas for research and sharing.

Collecting Dinosaur Bones

Probing for size: Determining the bone's dimensions.
Channeling around: Digging a trench around the bone to isolate it.
Binding with consolidant: Stabilizing fragile bones with a protective layer.
Protective paper layer: Covering the bone with paper for further protection.
Plaster and burlap field jacket: Encasing the bone for safe transport.

Fossil Hunting Locations

Dinosaurs lived on all continents, but fossils are found in specific environments and Mesozoic rocks.

Reasons for Not Collecting All Dinosaurs

Common or well-studied species.
Poorly preserved or difficult to collect specimens.
Lack of relevance to ongoing research.

Importance of Amateurs and Rockhounds

Access to discoveries.
Specialized knowledge of fossil-rich areas.

Mapping Bone Locations

Creating a precise map of the excavation site to record artifact locations.

Replication of Dinosaur Bones

Replicas for exhibits and study, capturing anatomical detail.

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