swedish naturalist Carl Linnaeus in 18th century
the science of naming and organzing organisms into related groups
Genus (generic, capaitlaized); specific epiphet (not capaitlized)
- full binomial name is italicized
-can be only given to one species
can be used for various different organisms disregardin gtheir differences
similar organisms can share the same genus name but differetn epithets
once a species has a binomial name it cannot be changed until it is concluded the species isnt new
biologist must publish a despction of the species that makes it unique, in a peer reviewed scientific publication and designate a holotype speciemen
physical example of the new species (doesn't have to be complete, rarley are) kept in a reasearch institiution so it can be studied and compared
ex. UALVP 48778 (hesperonychus elizabethae;small dino) only had a partial pelvis but was classfied a dromaesourid theropod
- interspecific variation
-intraspecific variation
differ in morphology becasue they belong to different species
same species but differences because of sexual dimorphism, ontogenic variation (old and young), individual variation, taphnomic varian (plastic deformation changing the shame of bone; geological difference)
no
msot common concept of what a species is, defines them as a group of organisms that can succesfully interbreed
- can't apply to those who reproduce asexually and doesnt work for extinct animals
any grouping of organisms that live in the same geogrpahic area and interbreed ( 1 or more pops can make a species)
what paleontologists use, groups organisms that share a certain degree of physical simialrty, if these simialrites align with what is expected based on modern species that succesfully interbreed
paleotologists who require more differences to classify two species distinct
paleontologists who require less differences to classify two species distinct
determined a new species bc of its unique features on pelvis that hadn't been seen on other dromaeosauird theropods. Sexual dimporisim was hard to find but there was no indications of it, or ontogentic change, or taphonomic deformation.
discover a complete skeleton
as a group of organisms that can interbreed
Tyrannosaurus
a species may be made up of more than one population
the science of naming and categorizing organisms
british naturalist charles darwin
how species came into existence, how they adapted to their environments and why specific groups have specific traits
- stated all life on earth is related and share a common origin
- heritable
-variation
-provides an advantage
- competition for resources
trait is part of organisms genetic code and can or will be copied to offspring
yes through random genetic mutation
if varaition is present in a trait in a population then selection can occur on that trait
- effect are indirect, imporves or hinders and organisms ability to survive which affects how many reproductive oppportunities it has
a varaition of the trait must provide an adavantge or differential success over othe variations for evolution to happen
natural enviroment onnly having limited resources, causes competion which on lets some organisms reproduce sucesfuuly, traits need to be selected out for evolution to happen
differential successes of certain variation of a heritable trait, because of competition of limited resources leads to change over time of that trait in pop (evolution)
one benefitical trait becomes widespread, others join and become the norm, when these traits become widespread the new traits are so different from their ancestors constitiuting a new species
no, new species cna just branch of ancestors if only a single pop of the ancestor species was exposed to new environmental conditons
no, while new traits may be introduced by random mutation, how these traits are passed on is not random its based on how it improves reproductive success of the organism
- most random muations diminsh success
the competitive selective process by which detrimental traits are competitvely discarded and advantageous traits are retained
on their most recent shared common ancestors
ex. hadrosaurs, ceratopsians, ankylosaurs and stegosaurs share a MCRA than they do w sauropods, prosauropods and theropods so they are grouped and ornithisican.
ex. ornitschians and saurischians sharing a MRCA (amniote tratrapod) than with other amniotes so they are dinosauria
any heritable trait that can be described and labeled
a character that is present in 2 or more groups AND their common ancestor but not in any distantly related groups
ex. predentary (lower jaw that makes beak) passed on to all ornithischians
evolution of similar traits in 2 different lineages
ex. sail evolving in dinosauria with spinosaurus (saurischian) and ouranosaurs (ornithischian)
when two linages must adapt to similar environments and modes of life
ex. wings in bats, birds, pterosaurs
ex. jaws in spinosaurus, piscivorous animals, crocs
all other things being equal, the simplest answer is usually the right one
- use a computer program, analyzes a list of compiled characters (character matrix), computer applies parsimony to arrange organisms in a sequence of realtionships that require the fewest instances of convergent evolution
two branches that diverge and show the point at which two linages shared a common ancestor, the pattern of branches and nodes after node show how the descendant continued to diverge from the common ancestor.
group of species that share a common node. They can be small or large ( no limit). Must include the ancestor and all the descendants.
kingdom, phylum, class, order, family, genus, and species. Worked well before but with more solidified ideas of natural selection and evolution doesn’t work as well
evolutionary connection between 2 major groups of orhanisms by showing traits that are charactesrtic of one group and the other group
colleauge of darwins, first scientist to recognize birds evovled from dinos cited new species of archaeopteryx (missing link between the 2 groups)
found in fossil kae deposits, had long wing feathers and tail feather like a bird, teeth , clawed fingers and long tail vertebrae like a dino
sino: another bird dino fossil evidence, first no avian (non bird) dino to be found with feathers, simple strcutre compared to modern birds and used for insulation not flight
Yuty: large dino with feathers
only clade of dinosauria alive because they evolved from theropod dinos, line between the 2 is blurry
refer to a crown group of birds liking living birds and extinct taxa
flying dinos, which includes extinct species that look similar to modern birds
archaeopteryx and all its descendants, featehred dinos, flying dinos, crown dinos
issue is that new info shows the archapeopteryx is more closley related to the dromaeosaurid theropods than to modern birds
issue is that lots of dinos are now being found w feathers, so even a tyrannosaur could be called a bird
issue is that its diffcult to know which dinos could fly vs glide
issue is that it doesnt recognize many feathered and flying dinos that are more closely realted to modern birds than to archaopteryx as birds this defintion is majorily favoured by palaeontoligsts.
parsimony
a toothless beak
any derived character that is present in 2 or more species and their common ancestor
the similarties in the wings of bats, bird, and pterosaurs
the point at which species shared a common ancestor
for rocks layer to be chrologically stacked (oldest at bottom youngest at top)
- there are exceptions, igneous rocks from volcanoes can cut through layers of rocks and moutain building events may titly, fold and veen flip rock layers
the science of using the arrangment and composition of rck layers to interpret gelogical history
large uninterrupted sequence of rock made of multiple layers that all share similar properties formed under similar conditions
-when rocks change formation it means a large scale change in the environment happened
it gives info on the relative age of rock layers (how olde one is ompared to the other), but cant determine absolute age
used for aging rocks in absolute terms, rocks are composed of elements, composed of atoms, composed of electrons, protons and neutrons and some are isotopes
variant of a chemical element that has an unusal number of neutrons, some are unstable and go through radioatic decay (when energy is released and a new atom/atoms with a different particple compositon is made), these atoms are called decay products
when energy is released and a new atom/atoms with a different particple compositon is made
no, but but finding when a large collection of isotopes decay will radioactivey decay is at a mathematically predictable rate
- as a rock ages the istopes decay and the isotope:decay ratio decreases, using the spec you can measure the isotope ratio and this ratio shows when this rock was formed
sedimentary rocks cannot because they are never really new but igenous rocks can because they are formed anew
since fossil are usally found in sedimentary rocks these 2 techniques can be used
-if fossils are found in between to igneous rocks, than dating the igrnous rock above and below the sedimentary layer will show the age range of the fossil
volcanic ash bc it forms the moment of eruption
Hadean (4.6-4 BYA), archean (4-2.5 BYA), Proterozoic (2.5 B- 541 MYA), Phanerozoic (541 M-today)
HAPP
hadean archean protezoric (precambrian- most of earths history)
with stratigraphy and radiometric dating
standardized series of chronlogical divisions that parses the Earths history into discrete named units
Eons, then eras, periods, epochs
- 4.6 to 4 BYA
- named for hades, rest of uni was already 9 BY old
- surface of earth was molten and volcanic activity was widespread
- 4.5 BYA earth collided with a small planetoid the debris that was held in the orbit made the moon
- near the end the earth cooled, oceans covered most of the surface, earliest true life possibly formed, oldest rocks on earth are 4.4 BYO but moon rocks are older
-4-2.5 BYA
- where the oldest fossils of simple single celled organisms are from
-cyanobacteria formed later, they were photysnethic and produced large amount of O2 which concentrated in the erath atmosphere
- some cyanobacteria made stromatolites, some of the best records of early life
look like lumpy stones but in the layers of the sticky films that trapped sediment that cyanobacteria secreted
- 2.5 B to 541 MYA
* 1.7 BYA first multicelluar organisms evolved, they had no bone or hard parts so fossil record i spoor
* 630-542 is known as the ediacaran period when the larger forms of life with harded parts evolved (animal life)
- 541 MYA to today
- subdivided into 3 eras which are subdivided into 12 periods
- rapid evolution of animal life into diverse forms (incl dinos)
paleozoic (541 to 252 MYA), mesozoic (252 to 66MYA) , cenozoic (66 MYA to 0)
PMC
- The cambrian period (541 to 485 MYA)
- The ordovician period (485 to 443 MYA)
- The silurian period (443 to 419 MYA)
- The devonian period (410- 359 MYA)
- the carboniferous period (359- 299 MYA)
-The permian period (299-252 MYA)
cam-o-s-d-c-p
- The triassic period (252-201 MYA)
- the jurassic period (201 to 145 MYA0
- cretaceous peirod ( early 146-100 and late 100 to 65 Mya)
- the paleogene period (66-23 MYA)
- The neogene period (23-2.6 MYA)
- the quaternany period (2.6 to now)
- 541 to 252 MYA
- animal life was restricted to primitive invertbrates in the ocean but near the end there were great forests with reptiles, amphibians and insects
- 541 to 485 MYA (paleo)
- dramatic diversification of aquatic animal life (cambrian explosion)
- sponges, molluscs, worms, other arthopods (trilobites) evolved
- closley early relative of vertebrates (pikaia) didnt hav evertebrates
-invertebrate ANOMALOCARIS top predator on the ocean
-485 to 443 (paleo)
- global sea levels were high, ocean life continued to diversify, fish increasingly becoming dominatn large aquatic animals
- 443 to 419 (paleo)
- fish had not evovled jaws till this point allowed them to evovle into large predatory fish
- primitive plant life flourished on land
ex. osteostracans group of early jawless vertebrates
410 to 359 MYA (paleo)
- firsts forests appeared on land
-huge jawed fish (dukleosteus) and first true sharks
-lobe finned fishapods (tiktaalik) came on land and gave rise to tetrapods
359.-299 MYA ( paleo)
- amphibians were widespead in swamps
- reptiles (first amniotes) evovled
- where modern coal came from (rotting plants of swamps)
- split into 2 first half (missipian 359-318) and (pennsylvanian (318-299)
299-252 (paleo)
- panagea was created
-reptiles evovled into anapsids, diapsids, and synapsids
-terrestrial rocks that formed represent desert environments
-single greatest mass extinction at the end (most notable losses being the trilobites)
252 to 66 Mya (2nd era of phane)
- age of dinos
-dinos became dominant form of large land animal life
- many marine reptiles (ichthyosaurs, plesiosaurs, mosasurs)
-first true turtles, crocs, lizards, snakes, mammals, birds
-flowering plants at end
66 MYA to now (3rd era of phane)
- age of the mammals
- mammals had been around since triassic but after dinos died (not birds) they got to evovle into larger form and fill new ecological rules
-grasses became abudant
66 to 23 MYA (ceno)
- global temps cooled
- mammals diversified into primates, bats, whales
-birds diversified
23 to 2.6 MYA (ceno)
- global temps still cooling
- first hominids evolved in Africa
2.6 MYA to now (ceno)
- earth experienced several large glacaition event (ice age)
- modern humans evolved and spread
135 MYA
- there is less time seprating first humans and dinos then there is between first dinos and last dinos
- not all clades of dinos were present through the entire mesozoic
252- 201 MYA (meso)
- first 10 MY life recovered from permian mass extinction
-first mammals and dinos, anf first pterosaurs (first flying vertebrates) evolved during later portion
-pangaea began to break apart
- most dinos look similar to eachother in this period
- Ornithischians (pisanosaurus), theropods (eoraptors and herrerasaurus), and sauropodomorphs (panphagia) were all mostly small and bipedal began to evolve
-Prosauropods like platesauras were some of the first large herbivorous Dino’s.
- ichtyosaurs (fish-lizard but isnt either of those), fish like body and lifestyle, land reptiles as ancestors, successs found by returning to water
-paddle like front and hind limbs, finned tail, shark like dorsal fin, long snouts, conical teeth (ate fish), no gills so hap to come up to breathe
- plesiosaurs later evolved too
- later in the triassic
- broad paddle shaped limns, realtivley short tails, some had short necks and huge jaws some had long serpent necks w small head
- close realtive of dinos that branched of reptiles same time as dinos did in the triassic
- first flying vertebrates
- diff from birds and bats bc they had membranous wings supported by a single extremely elongated finger
- rhamporhynchoids (early pterosaurs) common in the late triassic and jurassic
201 to 145 MYA (meso)
- dinos diversified, peak sauropod diversity (dominant land herbivores)
- small/med ornithopods were common
- non coelurosaurian theropods (allosaurus) dominant land carnivores
the jurassic
- first ankylosaurs, ornithopod and ceratopsians but not abudant or diverse
-first birds (archapoteryx)
- the morrison formation of west USA
- solnhofen limestone of Germany
rhamphorhynchoid pterosaurs
- although they differed from them because they had short tails, carpel wrists which made their wings longer, large head crests (display), some were robin size some had 10 m wingspans (largest animals to every fly)
( 146-100 MYA) meso
- dinos still diverisifying
- first flowering plants
- New theropods, spinosaurids and carcharodontosauridae evolve, coelurosaurian theropods become more diverse and iguanodon become larger and more abundant.
- yixian formation of china
-the wealden supergroup of england
- the cedar mountain formation of utah
mosaurusas
- realtives of the monitor lizards/snakes
- had tail fins, paddle limbs, elongated, ate small/med fish some were massive (large jaws, 18 m long)
-big ones did deep sea big game hunting ad ate large fish/marine reptiles
100-65 MYA (meso)
- apex of non avain dino diversity (most famous dinos evovled)
- coelurosaurian theropods are abundant and diverse in the northern hemisphere ( tyrannosaurs, ornithomimids, therizinosaurs, oviraptorosaurs, dromaeosaurids, troodontids and other interesting clades)
-ended with the meteor collison that killed all non avian dinos
- tail clubbed and clubless nodosaurids
-Ceratopsians and hadrosaurs are the dominant large herbivores in the north
-only a single lineage of sauropods remain (titanosaurid sauropods) dominant herbivores of the south
- only known from the late cretaceous
volcanic ash layers
mesozoic
4.6 BYA
the moon formed
around same time as dinos were evolving
remnants of giant submerged land bridges
alfred wegener
the crust and mantle
australia and africa
widespread jungles
lepidosauromorphs
1
permian
pseudosuchians
quadrupedal stance
trilobites
small body size
rocks formed by the volcanic activity in the deccan traps
huge firestorms
piecing together dino DNA from insects preserved in amber
species that are still present today
- number of extant is a fraction of species that are now extant
species whose members have all died off
The end ordovician
The late devonian
The end permian
The end triassic
The end cretaceous
-palaeozoic era
- marine organisms
- palaeozoic
- marine organisms (invertebrates)
- but also some vertebrate clades
- palaeozoic
- marine invertebrates, insects, synapsids, anapsids
-mesozoic
- most lineages of pseudochina archosaurs, many synapsids, marine organisms
-cenozoic
- marine invertebrates, marine reptiles, pterosaurs, dinosaurs, types of Cretaceous birds, large marine diapsids; mosasurs & plesiosaurs, various corals, plankton and amniotes, insects and some land plants
Mammals, turtles , crocodiles, amphibians and fish all made it through
- in general large animals and photosynethic organisms were most likely to die off
- semi aquatic small animals had best chance of survival (champsosaurs croc like aquatic diapsids)
- thylacine (tasmanian wolf)
-carolina parakeet
- passenger pigeion in 1914 (billions of them in prevois decades)
- caused by habitat loss/ intense hunting
- many biologists argue that the earth is in the middle of sixth mass extinction, brought about by sudden global climatic change and large scale ecosystem destruction and degradation caused by human activities
thing layer of gray layer that began to be found all over the world, close inspection revealed it had iridium, tekities and shocked quartz
rare element on earth but common in meteorites
tiny pieces of rock melted and cooled
form of mineral quartz wiht unique internal structure only created by powerful shock wave (nuclear exploision/meteroite impact)
would require a shower of large meteroites or for a tremnoudly large meteroite impact
no crater was found for many years but then geologists near chicxulub in mexicos yucatan peninsula saw them
arranged in a crescent shape for many miles at each end it was thought that it terminated at an edge of the peninsula
no, the cenotes were caused by a displaced portion of limestone layer than had been pushed upwards, the structure did not actually end at the peninsula but it continued along the ocean floor and was a huge continuous ring over 180 km in diameter.
66 million years old, a crater from the end of creatceous the meterotie must have been 10 km in diamter (larger than mount everest)
- small mammals eating all dino eggs
- ice age
-methane gas from digestive systems causing climate change
-super nova or viral outbreak
- volcanic outgassing of CO2
- meteorite strike
wrong cause mammals and Dino’s were successfully coexisting for 160 mil years
misinfromation, the ice age did not immediatly follow after the creatceous period ( 1 mil after), althought temps did drop
cant be tested with fossil evidence and the exticntion killed more than just dinos
could be probable, there is high volcanic activty in the deccan traps of india during this time that would have killed many organims
meteriote struck
- impact caused tsunamis
- great cloud of super heated rock and dust in atmosphere, -debris falling on earth
-wildfires start, global temp inc (cooked large animals), small animals could hide intially,debris sayed for moths or years, -residual haze reduced sunlight (no photosynthesis for almsot a decade), food chain affected,
- small animals with low metabloism
- supported by geological evidence/ fossil records
ex. champsosaurus, crocodillians, turtles, birds too
dna is delicate substance that degrades over time, cant find a complete dino strand persevred for 66+ mil years
- cloning is diffcult process, no clones survive for more than few minutes
althought soft tissues and protein can survive a long time, this material is not enough
Proposal of hatching a bird with advanced dna sequences turned off and its ancient ancestral sequences turned back on, it would develop long bonds tail, teeth, clawed fingers could possibly be a way to resurrect dinosaurs but performing genetic manipulation like this is past our understanding and technology
do not house sensory organs, provide and opea are for large muscles
number and arrangment of fenstrae help classify amniotes into major lineages
amniotes that lack fenstrae are called anapsids (turtles)
- realtivley rare, more common in earlier history
- an NO (no fenestrae)
amniotes with 1 fenestare on each lateral side of their skull
- all mammals and some close reptile ancestors like sail backed dimetrodon
amniotes with 1 set on the lateral sides of their skulls and 1 set on top
is more closely related to humans than dinosaurs, it lived during the Permian period so millions of years older than dinosaurs
diapsids with no additonal fenstrae
- lizards, snakes, tutatars
Lepi (lizards)
diapsids with an additional fenstra in front of each orbit ( antorbital fenestrae) and on the rear of the lower jaw (mandibular fenestra)
- crocodillians, birds, dinos, pterosaurs
- name applied to evoluntionary lineage even if features are lost
anti orbital fenestra
mandibular fenstra
-lepidosauromorphs
-archosaurmorphs
pseudochina
avemetatarsalia
- hinge like ankles, stiffer ankles, better wieght support for running and upright (non sprawling ) limbs
- dinos, pterosaurs, birds, other close realtives
- peg socket ankles that rotate around during locomotion
-crocodiles, their ancestors
no they are groupe as a single clade outside
the synaspids, they dominated ecological roles of mega herbivores/ carnviors across pangea
- dimetrodon thrived for millions of years
- eventually became more mammal like
- large saber toothed synasipds called goronopsids were top preators and tusked dicynodonts were top herbivores
cynodonts, would go onto evolve into true mammals and the early forms looked like short legged dogs
252 mYA, percentage of species that went extinct varies
- 70% land vertebrates and 90-95% marine species, synapsids cut down in their evolutionary prime
- cause is uncertain
huge lava deposits that formed at this time, eruoptions that formed these eruptions goin gon for 200 k year, released large quantintes of volcanic gasses
volcanic gasses frome eruptions of siberian traps into the atmosphere increasing global temp
might have caused methan hydrates (frozen chimals) deep in the ocean to melt, causing more global warming and then more melting
- by end permian global temp may have 6 degree inc.
possible but no crater has been found, single greatest extinction event ever
- synapsids who survive rebounded and resumed their top roles
- ex. cynodonts and dicynodonts
- first true mammals appear but diapsids (archosaurs) were diversifying and growing
- large archosaurs were more abudant and large synapsids dec.
pseuduschian later evovled into crocodillains
- includes huge and slender snouted phytosaurs (semi aqautic predators), heavy armoured herivorus aetosaurs, rauisuchids, and prestosuchians ( land predators with upright limb posture)
- propsaurid sail back that show convergent evolution of dimetrodon
-250 mya, footprints of small an bipedal animals that lacked specialtization of true dinos (hip socket with a hole)
- some were quaderupedal (silesaurids)
- 228 MYA in argentina
- eoraptor, eodromaeus, herrersaurus, panphagia examples of early carnivore saurischian dinosaurs
- pisanosaurus early herbivorus ornitshcian dinos
carnivroes were, although early carnivorous dino were small (under a meter) but the herrersaurus was tiger size compared to toher archosaurs (large dinos rare)
wolf sizes triassic theropod found in new mexico, common predator of this time and place
- end triassic dinos began gaining ground
evovled late triassic, hugely succesful
- plateosaurus best known, weighed more than 3 tons record breaking, largest herbivores of the time
- slow but steady at the misfortune of others 9end of permian extinction)
- chance and oppurtunity, they got lucky and some aspect of their biology made them better able to survive and the end triassic pseudochians which left ecological roles vacant
- got to diversify from pangea and hen pangea broke apart they go to evovle with geogrpahic isolation
- jurrasic age of dinos truly began
diversifed and becaem very common coexited alongside more primitve dinosaurmophs, many speudochina evovled dino body plans
- unkown cause, hit many archosaur groups hard, no evidence dinos outcompeted them bc they were also very adapted to the triassic enviornemnt but still they were less lucky in surving the end triassic
in 1912 he niticed the eastern coastline of sotuh americ aand western coastiline of africa looked connectable and acnient animals were found in both sotuh americ and africa even though they would be unable to swm across the atlanic, suggested pangea
he could not offer a mechanism for how land masses as big and "immbolie" could move
no, it involes a crust, then mantle which is composed of the lithosphere and asthensophere, and below the matnle is the core which has an outer and inner part
Cum mommy lick and cum
outer most layer consits of conitnetns and ocean basisn, thickness is 5-25 km, realtively thin
has an upper lithosphere and ilower asthensophere
- 2500km deep
uppermost part of the mantle, solid, composed of discrete pieces. plates that fit together and are rigid
lower portion of mantle below the lith
- visocus solid not a liquid from intense heat and pressure (like play doh and plasticine),slowly flowing, deromed under the even weight of the lith,
below the mantle
-primarily made of iron and nicel
- has an outer and inner
molten liquid
solid ball, temp of 5700 c (same as surface of sun)
caused by extreme heat of of core in the visoucs part of the asthen, the lower portion of asthen slowly heat, expand, rise upwards and then cool and sink
current pull along the plates of the lith causign them to slowly move, th cool crust is more solid and dense than the layers beneath, causing the plates to slowly sink and melt into lower layers.
as one edge sink a small gap is made along the opposite edge, molten rock can escape through this gap, this rock cools, solid is and puts it own mass to the edge. This cycle continues, moving the lith.
- movemental of lith
- disocver of mid ocean ridges revealed plate edges where new crust was being formed & Crustal rocks on either side of the ridges have been slowly drifting apart
detect ongoing continetn movement adn record their speed, sometimes they collide, boundaary where they collide can have lots of pressure often sites of pressure realese (volcanoes, earthquakes, or slolwy can build mountain ranges)
end of permian and start of triassic
pathalassa
Jurrasic morrison formation of Usa has similar counterparts in tendaguru formation of Tanzania and lourinha formation of portugal
late into the triassic
- when panega was connected in early jurrasic sauropods surpassed prosauropods in both abudance and body size
thriving jurassic long neck, front legs much shorter than hind, unusal faces, elongated skulls (like horse or deer), simple peg like teeth at the fron not the sides (nipping teeth-> for leaves)
around the same time as diplodocoids, sauropods, no whip tails, robut bodies, front and hind legs almsot equal
- some like brachiosaurus and giraffiatin had much longer front lengs
- filled ecological niche of high browsers
a way of an animals life, how it makes it living and what it does to survive
since there were so many sauropods at this time it might seem like there was a lot of competeiton but there was not
ex. macroanian camarasaurus and diplodocus found together in many fossil quarries
camara: short snouth, teeth line the entire jaw not limited to front and not simple pegs but broad and robust (spoon shape), less picky, can munch harder stuff and eat diploids leftovers
Diplodocus: selective snipper mouth, could reach higher and eat the more delectable jurrasic foliage
avodid direct comp; ecoligical phenomenon
ornithshcians, with body armor
- most famous: stegosaurus which were widespread in jurassic, grazed and browsed in shadows of sauropods
small ornithscians, had longs legs, fast (jurrasic gazelle)
- later ones had greater size (captosaurus; early iguanodont)
giant megalosaurus and ceratosaurids
the allosaurids: differ from other big predators, bc their vertbrate interlock more rigifly so they had stiffer spines, proprotionally longer legs, faster tahn the big carnivores before them
the allosauroid; allosaurus
chicken sized carnivorous theropod from the jurrasic like the allosaur it had a rigid spine and long legs
- belong to the theropod group; coelurosaur
had a long series of sacral vertebrae, narrow hands, tails with skinny ends, stiff and light weight
- in the creatceous would evolve to the top of the food chain
coelurosaurs
- Laurasia and Gondwana
northern of two, north america now
- europe + asia (no india)
southern of the two, now south america
- africa, australia, antarctica, madagascar and india
they split into small continent but did not assume their modern postion till long after dinos extinction , population drifted apart when continets did some going extinct or diverisfying in respective continets.
creatceous
iguanodonitnas, ankylosaurs, branchiosaurus sauropods
spinsaurus and carcharodontosaurus
coelurosauring theropods were the most common and certaopsians first evolved there
in the late creatceous but antarcica and australia remained connected till the end of the creataceous
sauropod dinos, however they were not the same that populated during the jurrasic
diplodocids and specifcally brachiosaurid macronaraians
titanosaurs; most robust of sauropods, broad chest, wide hips, spaced apart hind libs (stable base), many osetoderms, som w spinky armor, ranged in size estimated to be the same size as aregentinosaurus (100 ton sauropod; largest creature to walk to earth)
specialized giant slayers, named after teeth shape (resemebled the great white shark carcharodon)
- type of allosaurid, descendant of big theropods, rose to promience in the late jurassic, igger head w longer jaw than other allosaurids
- grew alongside the titanosaurus, the largest was the suth american giantsarus (13m outsized t rex)
big carnviore of the late creatceous of south america
- famous horned species (carnotaurus) last survivor of certaosaurid lineage, grew 8m in length, limited to godwana but thrived there
- adaptions due to niche paritioning: short muzzles, tiny teeth, short sturdy arm, small claws, ate small titanosaurs/less scary herbivores
hadrosaurs and nakylosaurs
-some were found in the late cretaceous sugesting a land bridge between north and south america
- titanosaurs
- what is now asian, tiatnosaurs were present but rare compents of the ecosystem
- only a handful of them in north america
under abudance of sauropods in the north meaning the northern herbivore niche were filled by other plant eater
stegosaurus didnt but ankylosaurus did
-ankylosaurids
-nodosaurids
famous ones with tail clubs, large backward pointing horns at read of their skulls, short rounded snout
didnt have tail clubs but some had offensive weaponds ath other end (large osteoderms pikes) that project outwards over their should, dint hvae big skull horns, narrow and elongated snouts
iguandont orithinopods
in laurasia hadrosaurs evolved and flourished
hadrosaurs
- among advancing hadrosaus, big crests on their head (kind of muscial instrument), crest had a complex and hollow nasal passageway, air through this passge amplified the dinos calls. crest came in different shapes and sizes
didnt have ampligying crests but some did have crests (saurolophus; prominent solid bony crest)
hadrosaurin with a big fleshy crest like a rooster comb, reveleased some hadrosaurines had cresst even though their skulls provided no proof of them
ran close to hadrosaurs in laurasia for diversity and success , the name means fringe heads reffering to the overhanging lip of bone at the back margin of the skull
pachycephalosaur and ceratopsians
first ceratopsians way different that later and famous ones (triceratops)
- primitve ceratopsians like psittacosaurus are small, bipedal, large beaks, small jugular cheek horns, well known in asia but larger ones (triceratops) were exclusive to north america
coelurosaurs which became the msot diverse theropod group and gave ride to the tyrannosaurs
tyrannosaurs, achieved success by extreme adaptions of what the allosaurids took
- evovled with even longer lefs, stiffer vertebral columns, massice skulls, tremendous jaw muscles
dilong and guanlong, eotyrannus
- had normal head and body proptions similar to coelurosaurs but kept growing in absolute size and reduced weight through small arms and hands finally evolvinf into the last and largest form Tyrannosaurus rex
a coelurosaurs sam body plan as ostrich/emu but long clawed forelimbs and large tail
wrist bone evolved by a group of coelurosaurs, cresent shaped bone allowed backward folding of hand at a sharp angle
-possessed my maniraptorans
birds are part of this group, its what allow them to delicatley fold their wings when not flying
maniraptorans, close relatives of birds
- oviraptorosaurs are a group of theropods that ate mostly vegetarian, lost teeth in favour of large beaks, many had cranial crests and fans of feathers on tail ends
strangest laurasain coelurosaurs, first fossil was a huge 60 cm claw (mistaken for turtle claw), more fossil were found making it a clear dino but not which type of dino
- small skulls on long necks, hid feet with 4 backward poiting toes, thought to be prosauropods
- backward directed pubis and jaws with small herbivorous teeth in the back and beak in the front so classified them as ornithschians
- now classified as maniraptorans theropods (close realtive of oviraptorosaurs)
plate tectonic brought some seperate continetn back together, dinos can. migrate creating similar species
north america and asia could have been connected via alaska at this time
tyrannosaurs, dromaesaurs, therizinosaurs, ornithomimids and oviraptorosaurs
hadrosaurs, certopsians, ankylosaurs and pachycephalosaurs
- high volcanic activity-> co2 (green house gas that hold salr heat)
- concentration of earth land in supercontients affected circualtion of air and water through polar regions, ocean current distrbute heat, gulf steams flow from mexico gulf to west europe, gulf water is warm and heat is carrried to north
the gulf stream
- why maretime provinces of canda are frigid place in winter while italy and spain rarely see snow
a strong cold ocean crest encircle it
-70 mya when antartica was attached to australia the current went up and around australia as the current moved through the more equatorial area it got warmer and carried heat down to antartica
no poalr icecaps or glaciers during mesozoic
- antartica and australia located with antartic cricle and part of north america abve artict further north than it is now
discovery of lush plant fossils
along trans artic mountaitn
- cyrolophosaurus and prosauropod glacialisaurus
in polar forests
-leaellynasuara, small ornithopod
hadrosaur edmontosaurus, tyrannosaurus albertosaurus, and ceratopsian pachyrhinosaurus
- although climate was wamrer and suppurtoed lush polar forests
-cons: reduced sunlight or total darkness, reduction of photosynethsis
- debate if polar dinos overwintered at the poles of migrated to lower latitudes during these periods (south for north america . north for antartica/australia )
-water held in polar ice caps and glaciers today were liquid then
- avg global ocean temp was higher, causing thermal expansion so worlds oceans swelled and rose
- they were 250 m higher than today, flooding of regions across earth, exposed land was limited what split areas into isoalted islands now
interior North America was covered by a Massive inland sea (the western interior seaway) spread from the arctic ocean to the Gulf of Mexico.
Larmidida in the west where most Dino species are known and Appalachia in the east.
allowed for mesozoic fossils to be found in alberta and through the american midwest because they were underwater
marine sediments in southern alberta, produced the remaines of marine reptiles like mosasurs, plesiosaurs and invertebrates like ammonites