Final Flashcards
Carl Linnaeus
Swedish naturalist
Founding father of modern taxonomy
Taxonomy
The science of naming and organizing organisms into related groups
Binomial Name
Two-part name consisting of a genus name and a specific epithet
Genus Name
Taxonomic rank above species
First part of a species binomial name
Specific Epithet
Second part of a species binomial name
Rule of Priority
Once a species has officially been given a binomial name it cannot be changed
Peer-Reviewed
Scientific publication that is not published until it has been reviewed by other scientists to verify that the contents are legitimate and scientifically reasonable
Holotype
A physical example of a new species
Does not need to be a complete specimen but must show the unique characteristics that make it a new species
Interspecific Variation
Individuals that differ in morphology because they belong to a different species
Intraspecific Variation
Individuals that belong to the same species but that have different morphologies
Sexual Dimorphism
A form of intraspecific variation
Differences in morphology between the males and females of a species
Also known as sexual variation
Ontogenetic Variation
A form of intraspecific variation
The variation you can see between young individuals and old individuals of the same species
Individual Variation
A form of intraspecific variation
The normal variation that exists among individuals of a given species
Taphonomic Variation
Variation that is caused by taphonomic processes like plastic deformation
Biological Species Concept
Defines a species as a group of organisms that can successfully interbreed
Cannot be applied to asexual organisms or extinct organisms
Population
Any grouping of organisms that live in the same geographic area and interbreed
Morphological Species Concept
Defines a species as a group of organisms that share a certain degree of physical similarity
Lumpers
Paleontologists who require more differences before they consider two species to be distinct
Splitters
Paleontologists who require fewer differences before they consider two species to be distinct
Charles Darwin
British naturalist
Proposed the theory of evolution
Heritable
A trait that is part of an organism’s genetic code and has a chance to be passed on to the organism’s offspring
Variation
Required for selection to occur on any given trait
Advantage
Variation that increases the number of reproductive opportunities an organism has
Also known as differential success
Competition
Permits only some organisms to successfully reproduce before they die
Natural Selection
The competitive selective process by which detrimental traits are discarded and advantageous traits are retained
Shared Common Ancestors
Provide a framework that modern taxonomy uses to categorize organisms
Character
Any heritable trait that can be described and labeled
Shared Derived Character
A character that is present in two or more groups and their common ancestor but not more distantly related groups
Also known as a synapomorphy
Convergent Evolution
The evolution of similar traits in two different lineages as a result of similar environments or modes of life
Parsimony
The idea that all other things being equal, the simplest answer is usually the right one
Also known as Occam’s razor
Phylogenetic Trees
Diagrams that show the evolutionary relationships between large numbers of species
Node
The point at which two lineages shared a common ancestor
Branch
Shows how the descendants of a common ancestor continued to diverge from each other
Clade
A group of species that share a common node
Thomas Henry Huxley
The first scientist to recognize that birds evolved from dinosaurs
Archaeopteryx
A transitional fossil that bridged the gap between dinosaurs and birds
Sinosauropteryx
The first non-avian dinosaur to be discovered with feathers (used for insulation not flight)
Yutyrannus
Large tyrannosauroid that had feathers
Principle of Superposition
The tendency for rock layers to be chronologically stacked
Allows a stratigrapher to infer the relative age of rock layers but not the absolute age
Stratigraphy
The science of using the arrangement and composition of rock layers to interpret geological history
Formation
A large uninterrupted sequence of rock that is made of multiple layers that all share similar properties and that all formed under similar conditions
Radiometric Dating
A technique used to determine the absolute age of a rock (does not work on sedimentary rocks)
Isotope
A variant of a chemical element that has an unusual number of neutrons
The Geologic Time Scale
A standardized series of chronological divisions that parses the Earth’s history into discrete named units
The Hadean Eon
4.6 to 4 billion years ago
Formation of the Earth and the moon
The Archean Eon
4 to 2.5 billion years ago
Formation of oldest known fossils (single cells organisms)
Oxygenation of the Earth’ atmosphere
The Proterozoic Eon
2.5 billion to 541 million years ago
First multicellular organisms
Poorly represented in the fossil record
The Phanerozoic Eon
541 to 0 million years ago
Diversification of animals
The Paleozoic Era
541 to 252 million years ago
The Cambrian Period
541 to 485 million years ago
The Cambrian Explosion
Dramatic diversification of aquatic animal life that took place during the Cambrian period
The Ordovician Period
485 to 443 million years ago
Fish became the dominant aquatic animals
The Silurian Period
443 to 419 million years ago
Evolution of predatory fish and terrestrial plants
The Devonian Period
419 to 359 million years ago
First forests, huge jawed fish and first tetrapods
The Carboniferous Period
359 to 299 million years ago
First amniotes evolved
The Permian Period
299 to 252 million years ago
Formation of Pangaea
Evolution of reptiles into the anapsids, diapsids and synapsids
Pangaea
Supercontinent formed during the Permian period
The Mesozoic Era
252 to 66 million years ago
Also known as the Age of Dinosaurs
The Cenozoic Era
66 to 0 million years ago
Also known as the Age of Mammals
The Paleogene Period
66 to 23 million years ago
Diversification of mammals and birds
The Neogene Period
23 to 2.6 million years ago
First hominids evolved
The Quaternary Period
2.6 to 0 million years ago
Several large glaciation events
Evolution of modern humans
The Triassic Period
252 to 201 million years ago
Evolution of mammals, dinosaurs and pterosaurs
Ichthyosaurs
“Fish lizard”
Group of reptiles that adopted an aquatic lifestyle during the Triassic period
Plesiosaurs
Group of reptiles that adopted an aquatic lifestyle during the late Triassic period
Pterosaurs
Close relatives of dinosaurs
The first vertebrates to fly
Rhamphorhynchoids
Early pterosaurs
The Jurassic Period
201 to 145 million years ago
Diversification of sauropods, ornithopods, stegosaurs, pterodactyloids and birds
Pterodactyloids
Pterosaurs of the Jurassic period
Shorter tails, different wrist bones and large head crests
The Early Cretaceous Period
146 to 100 million years ago
Evolution of flowering plants, theropods and iguanodonts
Mososaurs
Group of reptiles that adopted an aquatic lifestyle during the early Cretaceous period
The Late Cretaceous Period
100 to 65 million years ago
The apex of non-avian dinosaur diversity
Ended with the Cretaceous extinction
Alfred Wegener
German researcher
Suggested that continents had once been together and had drifted apart
Crust
Outermost layer of the earth consisting of continents and ocean basins
Mantle
Layer below the crust with a solid upper portion and a flowing lower portion
Lithosphere
The crust and the upper mantle
Composed of many discrete plates that fit together
Asthenosphere
The lower, viscous portion of the mantle
Core
Divided into an inner core and an outer core
Composed primarily of nickel and iron
Outer Core
Molten liquid
Inner Core
Solid ball
Plates
Pieces of the lithosphere affected convection currents in the asthenosphere
Plate Tectonics
The movement of the lithosphere
Provides an explanation for continental drift
Panthalassa
Single-super ocean that surrounded Pangea
Diplodocids
Jurassic long-necks with short front legs and nipping teeth
Macronarians
Jurassic sauropods with more robust bodies and longer front legs
Ecological Niche
An animals way of life
Niche Partitioning
Similar animals avoid competition by specializing in specific niches
Thyreophorans
Jurassic herbivores with body armour
Allosauroids
Late Jurassic predator with longer legs and stiffer vertebrae
Coelurosaurs
Jurassic theropods with a long series of sacral vertebrae, narrow hands, and lightweight tails
Laurasia
Composed of North America, Europe and Asia
Gondwana
Composed of India, South America, Antarctica, Africa and Australia
Titanosaurs
Macronarian sauropods found in Cretaceous Gondwana
Most robust sauropods with broad hips and armour/spikes
Carcharodontosaurs
Allosaurid theropods of Cretaceous Gondwana
Big heads and long jaws
Abelisaurs
Carnivorous theropods of Cretaceous Gondwana
Short muzzles, short teeth and small arms
Ankylosaurids
Ankylosaurs backward pointing horns and tail clubs
Herbivores in Cretaceous Laurasia
Nodosaurids
Ankylosaurs with smaller skulls and no tail clubs
Herbivores of Cretaceous Laurasia
Lambeosaurines
Hadrosaurs with large hollow bony crests that were used to amplify their calls
Herbivores of Cretaceous Laurasia
Hadrosaurines
Hadrosaurs without hollow bony crests (some had different crests thought)
Herbivores of Cretaceous Laurasia
Also known as saurolophines
Marginocephalians
“Fringe heads”
Includes pachycephalosaurs and ceratopsians
Herbivores of Cretaceous Laurasia
Ornithomimids
Coelurosaurs with long clawed forelimbs and a large tail
Maniraptorans
Coelurosaurs that evolved a highly specialized wrist bone (semilunate carpal) that allowed the hand to be folded backwards at a sharp angle
Includes the oviraptorosaurs, therizinosaurs, dromeosaurs and birds
Semilunate carpal
Crescent-shaped bones that allowed the hand to be folded backwards at a sharp angle
Oviraptorosaurs
Maniraptorans with large beaks and feathers
Therizinosaurs
Maniraptorans with large claws and small herbivorous teeth
Faunal Interchange
When plate tectonics bring continents back together leading to the dispersal of animals from one region into another
Anapsids
Amniotes that completely lack fenestrae
Synapsids
Amniotes with one fenestra on each lateral side of their skull
Dimetrodon
Synapsid with a sail that lived during the Permian period
Diapsids
Amniotes with one set of fenestrae on the lateral sides of their skulls and one set of fenestrae on the top surfaces of their skulls
Lepidosauromorphs
Diapsids with no additional fenestrae
Archosauromorphs
Diapsids with two additional sets of fenestrae
Antorbital Fenestra
Fenestra in front of each orbit
Mandibular Fenestra
Fenestra on the rear of the lower jaw
Avemetatarsalians
Archosauromorphs with hinge-like ankles that are more suited to an upright stance
Gorgonopsids
Large, sabre-toothed synapsids of the late Permian period
Dicynodonts
Large herbivorous synapsids that dominated in the late Permian period
Cynodonts
Synapsids that would evolve into mammals
Pseudosuchians
Crocodile-line archosauromorphs that dominated in the Triassic period
Extinct
Species whose members have all died off
Extant
Species that are still present today
Iridium
An element that is rare on earth but is a common component of meteorites
Tektites
Tiny pieces of rock that have been melted and then cooled
Shocked Quartz
A form of the mineral quartz with a unique internal structure that can only be created by exposure to a powerful shockwave
Cenotes
Limestone sinkholes arranged in a crescent shape around the Chicxulub crater
