Biological Classification and Paleontology Concepts

Binomial nomenclature

Formal way scientists name organisms.

Structure of Binomial nomenclature

Genus species.

Genus

Closely related organisms can share the same genus name (Ex: last name).

Species

Specific individual type within genus.

Example of Homo Sapiens

Homo is the genus name shared with extinct relatives Homo neanderthalensis; Sapiens is the species name of modern humans.

Clade

Group of organisms that share a common ancestor and ALL its descendants - no one left out.

Family tree

Can be broken down into subclades; members in each subclade are more closely related to each other.

Synapomorphies

Defined by shared derived traits that help define a group.

Example of Clade

Dinosauria; birds and dinosaurs are an example of a clade because birds evolved from certain dinosaurs.

Dinosaur / Dinosauria Synapomorphy

Clade for dinosaurs and relatives.

synamorphy

Shared derived trait

Examples include number of holes behind the eye socket (2 holes for Dinosauria vs 1 for mammals) and an open hip socket.

Empirical

Things that can be recognized by the senses (sight, touch, etc); science: facts are about observations in the empirical world like raw data, measurements, etc.

Hypothesis

A proposed explanation for a set of observations of the natural world; 'educated guesses'.

Example of Hypothesis

If plants get more sunlight, then they will grow faster.

Theory

An explanation about some part of the natural world that's been repeatedly tested and confirmed.

Example of Theory

The Theory of Evolution explains how species change over time through natural selection — backed by fossils, genetics, anatomy, etc.

Law

A generalization about some aspect of the natural world that appears to be true in all cases; descriptive account of how nature will behave in a specific situation.

Morphology

The form and structure of an organism.

Normative

Value judgments, opinions, or standards about how things ought to be; it's about right/wrong, good/bad, better/worse — not just facts.

Example of Normative Statement

We should reduce carbon emissions to fight climate change.

Example of Descriptive Statement

Carbon dioxide levels have increased 50% since 1850.

Body fossil

Preserved remains of a prehistoric organism, organism needs to be buried under sediment to become fossil.

Bone beds

Sites where hundreds or thousands of fossils are preserved.

Fossil

Any preserved remains of ancient life (ex: bone, shell, footprint, leaf, etc).

Lagerstätte

Fossil deposit with exceptional preservation.

Minerals

Solids with well defined chemical composition and crystal structure.

Molecular fossil

Molecules that can be preserved and extracted from fossils; ancient DNA, DNA proteins, lipids.

Peer review

A process used by scientific journals where multiple scientists (anonymously) argue for the publication or rejection of an article.

Corroboration

When multiple studies and techniques support the same hypothesis; important in theory building.

Scientific Journal

Specialized publication for evaluating and sharing specific scientific research between scientists.

Trace fossil (ichnofossil)

Remains of organism but not organism itself. Ex: fossil poop, bite marks, foot prints.

Erosion

Weathering of rock by wind and water.

Igneous rocks

Formed through cooling and solidification of magma and lava.

Mesozoic

Era where dinosaurs lived.

Metamorphic rocks

Formed by transformation of other rocks through extensive heat and pressure.

Paleontology

Branch of science that deals with discovery, collection, and preservation of fossils.

Sedimentary rocks

Formed by accumulation and cementation of sediment at Earth's surface.

Sedimentation

The laying down of dirt and mud, eventually turning into layers of rocks.

Stratigraphy

Science and mapping the order of rocks.

Biostratigraphy

Dating rocks based on the fossils.

Geochronology

Provides absolute dates for strata.

Geology

Scientific study of the physical earth, its composition and processes that change it over time.

Index fossil

Fossils from the organism that had a broad distribution but were short lived.

Lithostratigraphy

Dating rocks based on their order and mineral composition.

Law of lateral continuity

Layers of rock are continuous until they encounter other bodies that block their deposition.

Law of superposition

In undeformed stratigraphic sequences, the oldest strata lie at the bottom while youngest at top (deeper you go, farther back in time).

Law of cross cutting relationships

When one rock is intruded by another, that rock must be older than the intrusion.

Acetabulum

A hole in the pelvis allows the femur to lock in place and gave dinosaurs upright stance like birds and mammals.

Anterior

Front of body (face).

Distal

Farther away from point where limb attaches to body (ex: your fingers are distal compared to your shoulder).

Dorsal

Back side of the body (ex: your back).

Fenestra

Holes (opening in bone); lots of them in dinosaur's skulls to make them lighter and stronger.

Kinetic skull (cranial Kinesis)

Significant movement of skull bones relative to each other.

Law of natural selection

Shows how populations become better adapted to environment by preserving favorable traits.

Posterior

Behind, back.

Proximal

Near the body, close to.

Theory of common descent

All living things are connected through series of common ancestors.

Ventral

Onto or relating to the belly.

Cladistics

Formalized process of determining evolutionary relationships (phylogeny).

Cladogram

Evolutionary tree made from cladistic phylogenies.

Comparative anatomy

Study of similarities and differences between species.

Evolutionary tree / phylogeny

A representation of the evolutionary relationships among species.

Monophyletic clade

Group made up of common ancestor and all its descendants.

Paraphyletic clade

Group made up of common ancestor and some, but not all its descendants; useful for constraining ancestral condition.

Taxa

Any unit in biological classification of life: can be populations, species, or larger clades (plural: taxon).

Evaporite

Sedimentary rock formed from deposit of precipitated material; caused by evaporation of salt water.

Latorite / Kaolinite

Sedimentary rock formed when extreme weathering of parent rock.

Paleobiogeography

Distribution of fossils over space.

Paleoclimatology

Reconstruction of climate through deep geologic time.

Plate tectonics theory

Provides framework for understanding geological features.

Tillite

Sedimentary rock containing unsorted and unstratified rock material.