PALEO 200 final

Carl Linnaeus

18th century Swedish naturalist who created binomial nomenclature

• the founding father of modern taxonomy

taxonomy

the science of naming and organizing organisms into related groups

binomial name

the two part scientific name of a species; composed of a genus name and a species epithet; written in italicsspe

genus name

the first half of a binomial name - e.g. Tyranosuarus from tyrannosaurus rex

specific epithet

the second half of a binomial name e.g. rex, from Tyrannosaurus rex

rule of priority

taxonomic law stating once a species has officially been given a binomial name, the cannot be changed

peer-reviewed

the process by which a scientific publication gets reviewed by other scientists to verify that the contents of the publication are legitimate and scientifically reasonable

interspecific variation

when individuals differ in morphology because they belong to different species

intraspecific variation

when individuals differ in morphology, but belong to the same species

sexual dimorphism

differences between males and females of a given species, beyond genitalia

ontogenetic variation

changes that you can see between young individuals and old individuals of the same species

individual variation

normal differences that exists among individuals of a given species. e.g. hair or eye colour

taphonomic variation

when geological processes like plastic deformation change the shape of a bone, resulting in apparent anatomical differences

biological species concept

definition of a species as a group of organisms that can successfully interbreed

population

any grouping of organisms that live in the same geographic area and interbreed

morphological species concept

definition of species as a group of organisms that share a certain degree of physical similarity

lumpers

palaeontologists who require more differences before they consider two species to be distinct

splitters

palaeontologists who require fewer differences before they consider two species to be distinct

Charles Darwin

british naturalist who first conceived the theory of evolution

adaptation

an evolved trait that serves a specific function

heritable trait

a characteristic that is part of an organism’s genetic code and has a chance to be copied to the organism’s offspring

evolution

theory that states that differential success of certain variations of a heritable trait, because of competition for limited resources, leads to the change over time of that trait in a population

natural selection

the competitive selective process by which detrimental traits are competitively discarded and advantageous traits are retained

Dinosauria

a group formed by ornithischians, saurischians, their most recent common ancestor and all of its descendants

Ornithschia

a group formed by all hadrosaurs, ceratopsians, ankylosaurs, and stegosaurs, their most recent common ancestor and all of its descendants

Saurischia

a group formed by the theropods, sauropods and prosauropods, their most recent common ancestor and all of its descendants

character

any heritable trait that can be described and labelled

synapomorphy/shared derived character

a character that is present in two or more groups and their common ancestor, but is not present in any more distantly related groups

convergent evolution

the independent evolution of similar structures in two different lineages, usually due to both lineages facing similar ecological or environmental pressures

principle of superposition

chronological organization of rock layers; the oldest rocks are at the bottom, and the layers become increasingly younger towards the top

stratigraphy

the science of using the arrangement and composition of rock layers to interpret geological history

a formation

a large, uninterrupted sequence of rock that is made of multiple layer that all share similar properties, and that all formed under similar conditions

radiometric dating

the use of isotopic ratios to calculate age of a rock

radioactive isotopes

variations of an element that differ in the number of neutron; has a specific half-life or rate of decay

the geologic time scale

a standardized series of chronological divisions that parses the Earth’s history into discrete named units

stratigraphic column

geologic diagram that illustrates a sequence of rock layers, with the oldest at the bottom and the youngest at the top; often illustrates the thicknesses of each layer

the Cambrian Explosion

dramatic diversification of aquatic animal life that occurred approximately 541 million years ago

trilobites

extinct group of marine arthropods; first evolved during the Cambrian and died out at the End-Permian Mass Extinction

Pterosaurs

group of flying archosaurs closely related to dinosaurs; lived during the Late Triassic to the Cretaceous; the first group of vertebrates to evolve flight

examples: Quetzalcoatlus, Rhamphorhynchus

Plesiosaurs

a group of diapsids specifically adapted to a marine life; lived during the Early Jurassic to Late Cretaceous

examples: Dolichorhynchops, Elasmosaurus, Kronosaurus

Pikaia

though to be one of the oldest known animals with a notochord; lived during the Cambrian

Permo-Triassic Mass Extinction

the single largest mass extinction event in Earth history; occurred 252 million years ago and wiped out an estimated 96% of all marine life and 70% of all terrestrial life

Pangaea

supercontinent, comprised of all the Earth’s major landmasses, that formed around 300 million years ago and began breaking up around 200 million years ago

Mosasaurs

a group of extinct lepidosaurs, related to modern snakes and monitor lizards, that were highly adapted to a marine life; evolved in the Late Cretaceous

ammonite

a kind of extinct marine cephalopod with a spiral shell; thrived from the Devonian through the Cretaceous but died out during the End-Cretaceous Extinction

The Burgess Shale

fossil rich deposit in British Columbia, Canada; famous for its exceptional preservation of 505 million years old marine organisms

isotope ratio

the ratio of a naturally occurring radioactive isotope and its decay products

ichthyosaurs

a group of marine reptiles that first evolved in the Triassic and went extinct towards the end of Cretaceous. they look similar to dolphins, due to convergent evolution of body types. name literally means: “fish lizard”, even though they aren’t fish or lizards

Rhamphorhynchoids

early group of flying reptiles, which were common in the Late Triassic and throughout the Jurassic. typically had long tails compared to later flying reptiles

Pterodactyloids

flying reptiles that differed to early relatives in morphology of their tails, which were short, and the carpels in their wrists, which were elongated and made a greater contribution to the length of the wing. often had large head crests

the crust

the outermost layer of the earth consisting of the continents and ocean basins. between 5 and 25 kilometres deep

Alfred Wegner

founder of the theory of plate tectonics

Mantle

highly viscous layer of the Earth; layer between the crust and the outer core; roughly 2900km thick

Lithosphere

ridged outermost layer of the Earth; composed of the crust and the upper portion of the mantle

Asthenosphere

the viscous layer of the upper mantle below the lithosphere; between roughly 80 and 200 km below the Earth’s surface

inner core

the innermost layer of the Earth; a solid mass composed of iron and nickel

outer core

layer of the Earth composed of molten iron and nickel; roughly 2270 km thick

plates

pieces of the lithosphere affected by convection currents

Panthalassa

the giant ocean that surrounded pangaea

plate tectonics

the movement of the lithosphere that provides the explanation for the drifting continents that Alfred Wegner theorized

Diplodocids

a group of sauropod dinosaurs with long necks and long “whip like” tails; lived during the Middle to Late Jurassic

examples: Apatosaurus, Diplodocus, Supersaurus

Macronarians

group of Jurassic sauropods with robust bodies, front legs not noticeably shorter than their back legs, and that lack whip-tails.

e.g. Brachiosaurus and Giraffatitan

Thyreophorans

group of ornithischians with body armour. includes stegosaurs

niche partitioning

when similar animals avoid direct competition for food resources, by exploiting different ecological niches

e.g. predation vs scavenging

ecological niche

an animal’s role in the ecosystem; how it survives in that ecosystem

allosauroids

large predators that originated in the Jurassic, with vertebrae that interlock more rigidly, so their spines were held stiffer. their legs are proportionately longer, suggesting that they were faster than either megalosaurids or ceratosaurids

e.g. allosaurus

coelurosaurs

group of theropods that originated in the Jurassic, characterized by a long series of sacral vertebrae, narrow hands, and tails with back halves that are skinny, stiff, and lightweight. the group from which birds arise

Laurasia

northern of the two supercontinents that were formed as Pangaea split in the Early Jurassic; comprised Asia, Europe, and North America

Gondwana

Southern of the two supercontinents that were formed as Pangaea split in the Early Jurassic; comprised Australia, Antarctica, Africa, South America, Madagascar and India

Titanosaurs

group of advanced sauropod dinosaurs; lived during the Late Jurassic to Late Cretaceous; globally distributed but most abundant in Gondwana

examples: Argentinosaurus, Saltosaurus, Alamosaurus

Carcharodontosaurids

a group of theropod dinosaurs with teeth that somewhat resemble those of modern sharks; lived during the Late Jurassic to Late Cretaceous

examples: Giganotosaurus, Carcharodontosaurus, Concavenator

Abelisaurids

a group of ceratosaurid theropods that thrived throughout Gondwana during the Middle Jurassic to Late Cretaceous; characterized by short forelimbs, small teeth, and ornamented skulls

examples: Carnotauris, Majungasaurus, and Rugops

ankylosaurs

heavily-armoured quadrupedal ornithischian dinosaurs

examples: Ankylosaurs, Edmontonia, Polacanthus

Nodosaurids

the second major group of ankylosaurs. they lacked tail clubs, but some have offensive weapons at the other end, in the form of large osteoderm spikes that project outwards from their shoulders

e.g. Borealopelta

ankylosaurids

the first major group of ankylosaurs. the ankylosaurs with the famous tail clubs; also typically have large backwards-pointing horns at the rear of their skulls and a short rounded snout at the front

Lambeosaurines

advanced group of hadrosaurs with a big crest on their heads. inside this crest is a complex and hollow nasal passageway.

e.g. Parasaurolophus

Hadrosaurines

advanced group of hadrosaurs that lacked complex sound amplifying crests. some still did have small bony, or soft tissue crests

e.g. Edmontosaurus

Marginocephalians

diverse group of Laurasian dinosaurs that includes the ceratopsians and pachycephalosaurs. the name literally means “fringe heads” and refers to an overhanging lip of bone at the back margin of the skull

Ornithomimids

group of coelurosaurs that evolved a body plan similar to that of a modern ostrich or emu, but with long clawed forelimbs and large tail

maniraptorans

group of coelurosaurs that developed a highly specialized wrist bone called a semilunate carpal

includes birds, dromaeosaurs and oviraptorosaurs

Dromaeosaurs

group of maniraptorian theropods with a large, sickle-shaped claw on each foot

e.g. deinonychus

oviraptorosaurs

group of maniraptoran theropods that adapted to a mostly vegetarian life and lost their teeth in favour of large beaks. many had cranial crests and fans of feathers on the ends of their tails

Therizinosaurs

bizarre group of maniraptoran theropods, with large hand claws, small skulls on the end of long necks and hind feet with four forward pointing toes. they also have backwards pubis and jaws with small herbiverous teeth in the back and a beak in the front

faunal interchange

when animals from one region can move into another, leading to similar species in both regions

e.g. Mongolians and W. Canadian dinosaurs

anapsids

a group of amniotes that have no skull fenestrae; turtles are a modern example; note: the validity of this clade is contested among palaeontologists

synapsids

a group of amniotes with only one pair of fenestrae; includes mammals and their extinct close relatives

Dimetrodon

famous, sail-backed synapsid that lived during the Permian period. often mistakenly identified as a dinosaur

diapsids

a group of amniotes with two pairs of skull fenestrae: the supratemporal and laterotemporal fenestrae. includes crocodiles, lizards, snakes, tuataras, dinosaurs, birds, and many extinct groups

lepidosauromorphs

group of non-archosaur diapsids that includes lizards, snakes, tuatara, and many extinct groups

archosauromorphs

a group of diapsids that includes archosaurs and many more primative groups; first evolved during the late Permian

Archosaurs

a group of advanced archosauromorphs diapsids includes crocodiles, dinosaurs, birds, and many extinct groups; characterized by mandibular and antorbital fenestrae

antorbital fenestrae

opening in the skull in front of the orbits; characteristic of archosuars

mandibular fenestra

opening in the lower jaws of archosaurs

avemetatarsalians

special group of archosaurs characterized by ankles that flex like a hinge. includes dinosaurs, pterosaurs and some of their close relatives

pseudosuchians

group of archosaurs that includes modern crocodilians and all archosaurs more closely related to crocodilians than to birds; “crocodile-line” archosaurs. have a peg and socket ankle joint.

gorgonopsids

group of carnivorous synapsids characterized by sets of elongated fangs; lived from the Middle to Late Permian

dicynodonts

a group of herbiverous synapsids with characteristic tusks and beaks; first evolved in permian and thrived during the Triassic

cynodonts

a group of synapsids that led to modern day mammals; first evolved in the Late Permian

what is the length of an eon

length of one billion years, (1,000,000,000 years)

what is the length of an era

several hundred million years, (14 in total)