exam 4 !

The Jurassic Period

200-146 mya: first birds evolved from small feathered theropods, marine ammonites, and more! Many reptile orders, Nevadan oregony, Morrison Formation.

Which era includes the Jurassic Period?

The Mesozoic Era.

What is the nickname for the Jurassic Period?

The Age of the Dinosaurs.

What was the Triassic-Jurassic Extinction event also known as?

The CAMP (Central Atlantic Magmatic Province) extinction event.

How did the Triassic-Jurassic extinction lead to the rise of dinosaurs?

Caused other archosaurs to vacate terrestrial ecological niches

What is a 'disaster taxon'?

A species that benefits from an extinction event by filling vacant ecological niches.

What is the literal etymological meaning of the word 'dinosaur'?

Terrible lizard.

Are dinosaurs biologically classified as lizards?

nah bruh they evolved from a branch of archosaurs (diapsid reptiles).

What evidence suggests that dinosaurs were warm-blooded?

Growth rates and the discovery of fossils in arctic regions.

key distinguishing feature of dinosaur skeletal stance compared to other reptiles?

Their hind limbs are positioned directly beneath the body, rather than having a sprawling leg posture.

What anatomical feature is commonly found on the feet of many dinosaurs?

Three-toed feet.

How long did dinosaurs dominate the Earth in total?

Approximately 165 million years.

How does the dinosaur pelvis differ from that of other reptiles?

Dinosaurs have a hole in the center of the pelvis (the acetabulum)

the Triassic Period?

251 to 200 mya: Pangea extends almost from pole to pole/ begins to break up. Andest Rocky mt oregony. Relativley high temps, dry climates (deserts, sandstones)

What was the primary continental configuration during the Triassic?

Pangaea

Mezozoic Era

251-66 mya: “age of dinosaurs” —appeared mid-triassic (230mya): beginning of long-term subduction + mountain building in the west.

What occurred in the western US during the Late Permian to Triassic?

The 2nd rocky mt orogeny (Sonoma)

What were the dominant types of vegetation in the Triassic?

Conifers, ginkgos, and cycads

What is a 'disaster taxon'?

A species that survives a mass extinction and subsequently thrives

characteristics of Cynodonts?

Specialized teeth, three ear bones, egg-laying, and potentially fur

Which group of reptiles became the dominant land vertebrates during the Triassic?

Archosaur reptiles

therapsids cynodonts

mammal like features increase during the mid triassic era: teeth, 3 ear bones, laid eggs

what are Archosaur reptiles

diapsid reptiles that emerged in the Early Triassic +++ dinosaurs, pterosaurs, crocodiles, and birds, all descended from a common ancestor.

Diapsid reptiles

not mammal like synopsids @modern snakes, lizards, tuataras, crocodiles, and birds, as well as extinct groups like dinosaurs and pterosaurs.@@@

What is a prosauropod? @

An ancestor of sauropods, typically characterized by 4 legs and long necks

what does CAMP stand for in the context of the End Triassic extinction?

Central Atlantic Magmatic Province

geological process caused the breakup of Pangaea in the Late Triassic?

Rifting (crustal extension)

What environmental factors caused by CAMP volcanism led to the End Triassic extinction?

Climate change and ocean acidification

What is an ecological niche?

The set of environmental conditions in which a species lives

what acts as a pathway for magma during crustal extension?

Normal faults

what does normal faults allow at the top of the crust

extension of rifts and fed volcanoes around the surface

What is a feeder dike ?

vertical intrusion in igneous rock that acts as a volcanic plumbing conduit, transporting magma from a deeper chamber to the surface, where it erupts to form lava flows

what is a sill?

horizontally intrusion between older layers of sedimentary rock, beds of volcanic lava, or along foliation planes in metamorphic rock.

When did true mammals first evolve?

Mid-Triassic

what are the two reptile orders

Saurischia and Ornithischia

what is Saurischia

meat eaters including Therapods and plant eaters including saurapods

what is Ornithischia

diverse groups of herbivorous dinosaurs known for their distinctive "bird-hipped" pelvic structure, and being duck-billed.

what is a ornithopod?

ornithischians: well-developed forelimbs, could walk on all fours including hardrosours@ (duck-billed dinos)

Ceratopsians

ornithischians: herbivores, beecked dinos with parrot-like beaks, cranial frills, and facial horns, thriving in the Late Cretaceous

Pachycephalosaurs

Ornithischians: late creatceous period, bipedal herbivores, thick skulls with done heads.

Ankylosaurs

Ornithichians: Herbivores with backward-pointing pubis, thick armor, and some with spikes

Stegosaurs

Ornithichians: Herbivores: Jurassic + early Cretaceous period, many plates and spines along the back and tail@

what was the 3rd rockies oregony in the jurassic period

the nevadon: subduction of Pacific Ocean crust. Multiple volcanic arc terranes created which lead to huge magma bodies.

what happened to Sauropods in the jurassic@

reached their peak in size and diversity. Largest land animals in Earth's history roaming the landscape

feathers

Fuzz, bristles and complex plumage on >24 dinosaur genera

the cretaceous period

145-66mya: Dinosaurs at their most diverse and abundant, Pangaea finishes in breakup, Sevier and Laramide orogenies, the Zuni transgression

what was the last Rocky mt oregonies in the Cretaceous period ?

Sevier and Laramide

Sevier Oregony

thrust faulting (shallow/flatter faults) + thin-skinned tectonics only in upper sedimentary phanerozoic layers

Laramide oregony

createous: reverse faults (deeper/steeper angles) + thick-skinned tectonics in ancient Archean basement

what are the importance of mines in the mountains

major locations of copper gold and other economically important ore minerals

importance of orogenies and mines

causes migration of hydrothermal (hot water) fluid that carry dissolved minerals and concentrate them.

what happened between orogenies and ore minerals

they heat the crust and produce magma and cause hot water to circulate the crust and dissolve elements. Elements get concentrated in the hot water, then get deposited as ore minerals

Angiosperms

first flowering plants in the Cetaceous period

What are Cretaceous Interior Seaways

Zuni Transgression: shallow epicontinental seas that split North America—- leading to modern day continents!

What caused the end of the Mesisoic Era

66mya: the cretaceous-paleogene extinction

One of the pieces of evidence for the Mesozoic end with the founding of this ore within clay layers (typically found low in Earth’s core, surrounded by iron, as well as concentrated in meteorites)

Iridium

One of the pieces of evidence for the Mesozoic end involving minerals in a clay layer found near an impact crater/nuclear explosion layers due to extremely hot pressures

Shocked Quartz

One of the pieces of evidence for the Mesozoic end involving drops of glass beads and such on Earths rocks melted during impact, thrown in the atmosphere + rain back down

Spherals and Tecktites

One of the pieces of evidence for the mesozoic end involving debris deposits from huge waves

Tsunami deposits

One of the pieces of evidence for the Mesozoic end involving mexico formation in weakened limestone overlaying a crater

Cenotes (sinkholes)

One of the pieces of evidence for the mesozoic end involving the discovery of half of a crater being on land, other half under the gulf of Mexico by an oil company

Chicxulub crater

the last extinction of the mesiosoic era

Many mammals (93%) fish birds lizards insects plants sharks plankton when extinct. Not just dinos, but 75% of ALL species on Earth vanished.

The Cenozoic Era

66 mya-recent: 1.4% of Earths History, period including epoch timeline mostly because of new diversifications. Climate generally decreasing temps + ice accumulation at poles

MEM for Cenozoic Era!

Pancakes (paleocene) Not ( neogene) Quaker oats (quaternary)

Paleocene

66-23mya: Laramide Orogeny ends,himalayan mt oregony begins, crust extends in Basins (range continues today!), climate is warm, sea levels fall, early lizards, snakes, and the largest predators. Rodents still abundant mammal groups but then… mammal radiation + first primates! Rodents are still an abundant mammal group, but then… mammal radiation + first primates!

What are the (surviving) major kinds of mammals?

Monotremes, Marsupials, Placentals

Monotremes

Egg-laying, milk producing (platypus, echidna)

Marsupials

Milk-producing, give birth+ live young at an early state of development, nurture in puchs (opsum, Kangaroos)

Placentals

Milk-producing, give birth to more advanced young (horses, mice, humans) Placenta feeds offspring during preg—90% of mammals

where are the first whales?

paleogene

rise of mammals when?

triassic period

Mammals have what?

Mammary glands (milk for young), hair, 3 middle ear bones, a single-bone lower jaw, and a region of a complex brain called the neocortex

Vestigial feature

usually small and subdued. (evidence for a 4-legged land ancestor + lost original function thru evolution)

primates

paleogene: opposite thumbs, fingernails, hand-like feet, forward looking eyes

horse evolution in mid-paleogene

Dog sized, had toes, woodlands of the norther hemp, low crowned teeth no ridges

Neogene

23-2.6 mya: Major geo processes in the Western U.S continuously happening today! Sea level falls, decreasing temps, drying climate, many forests change to grasslands, earliest hominins (primate human ancestor)

The connection between horse evolution in North America and climate change?

rise of on open grasslands==grew in size w/ longer legs for running. Molars became high-crowned with complex ridges, shifting from browsing to grazing diets. Toes reduced from 4 to 3 and eventually to a single hoof, with vestigial toes remaining today.

What body features of early primates suggest they were tree-dwellers?

Fingers, which indicate adaptation to the 'fine branch niche.'

Which part of the human body has the most problems?

The lower back.

What are the three major parts of the brain found in nearly every vertebrate?

Forebrain, midbrain, and hindbrain.

What evolutionary changes occurred in horses over time?

Larger, longer legs, and molars evolved from browsers to grazers.

What did Darwin conclude about fossils?

life has changed and species go extinct over time.

What is overproduction in the context of Darwin's theory?

More offspring are born than the environment can support, leading to competition.

What is natural selection?

The process by which the environment selects individuals best adapted to survive and reproduce.

What role do mutations play in evolution?

Create new variations in species, which can lead to evolution.

What is artificial selection?

Humans breed animals and plants to enhance specific traits.

Who co-discovered the mechanism of natural selection?

Charles Darwin and Alfred Wallace.

What is the importance of genetic variation in a species?

leads to survival inequalities among individuals.

What did Darwin not know about genetics?

did not understand the role and inheritance in evolution.

What is a germline mutation?

change in a body's reproductive cell (sperm or egg) that becomes incorporated into the DNA of every cell in the body of the offspring

What did Darwin mean by 'variety happens'?

diversity among individuals in a species, which can aid survival.

How do species adapt to changing environments?

Through natural selection, where the best-adapted individuals survive and reproduce.

What is the role of paleontology in understanding evolution?

provides fossil evidence that supports the theory of evolution.

What did Alfred Wallace contribute to the theory of evolution?

independently developed the concept of natural selection alongside Darwin.

How does natural selection explain the evolution of new species?

environments change, species must adapt and evolve into new forms.