1 Tem 2022 ... “Dinosaurs were there during the Triassic under the radar all the time ... periods/Mesozoic era/Triassic period; /Physical sciences/Earth ...Triassic Period, in geologic time, the first period of the Mesozoic Era. It began 252 million years ago, at the close of the Permian Period, and ended 201 million years ago, when it was succeeded by the …Jul 28, 2022 · The Mesozoic era began roughly around the time of the end-Permian extinction, which wiped out 96 percent of marine life and 70 percent of all terrestrial species on the planet. Life slowly ... In the older literature, the term Phanerozoic is generally used as a label for the time period of interest to paleontologists. The term seems to be falling into disuse in more modern literature with greater emphasis being placed on the eon's three basic divisions, the Paleozoic era, the Mesozoic era, and the Cenozoic era.The Triassic period was the first period of the Mesozoic era and occurred between 251.9 million and 201.3 million years ago. It followed the great mass extinction at the end of the Permian period and was a time when life outside of the oceans began to diversify.Mesozoic Era. The Permian mass extinction paved the way for another burst of new life at the start of the Mesozoic Era. This era is known as the “age of dinosaurs.” It is divided into three periods. Triassic Period. During the Triassic Period, the first dinosaurs evolved from reptile ancestors.The idea that women should not exercise during period times is a myth, as this is when the benefits of exercise are greatest. According to a gynaecologist Try our Symptom Checker Got any other symptoms? Try our Symptom Checker Got any other...Dinosaur communities were separated by both time and geography. The 'Age of Dinosaurs' (the Mesozoic Era) included three consecutive geologic time periods (the Triassic, Jurassic, and Cretaceous Periods). Different dinosaur species lived during each of these three periods. The Mesozoic Era was a time of great change. The ancestors of major plant and animal groups that exist today first appeared during the Mesozoic, and the generally warm and habitable environment of the era supported great diversity of life-forms. However, the era is best known as the time of the dinosaurs. The Mesozoic Era began 252 million ...How long did Mesozoic era last? Following the Paleozoic, the Mesozoic extended roughly 186 million years, from 251.902 to 66 million years ago when the Cenozoic Era began. This time frame is separated into three geologic periods. From oldest to youngest: Triassic (251.902 to 201.3 million years ago)geologic time - chronology of Earth™s formation, changes, development, and existence Pangaea - a supercontinent in existence during the Mesozoic and Paleozoic Eras that contained all seven continents present on Earth™s surface today in a single land mass Period - division of geologic time smaller than an era, based on rock layers and the ...Examples of Mesozoic Era animals include dinosaurs, pterosaurs, ammonites, sharks, plesiosaurs, ichthyosaurs, mosasaurs, pseudosuchians, insects, and early mammals. Although dinosaurs were the dominant land animals of the Mesozoic Era, many other important animal groups evolved and thrived during this time. On this page is a list of Mesozoic ...Figure 29.4 C. 1: Quadruped dinosaurs: Edmontonia, an example of an extinct quadruped reptile, was an armored dinosaur that lived in the late Cretaceous period, 145.5 to 65.6 million years ago. Dinosaurs dominated the Mesozoic Era, which was known as the “Age of Reptiles.”. The dominance of dinosaurs lasted until the end of the Cretaceous ...The Mesozoic Era lasted about 180 million years, from about 245 million years ago to about 65 million years ago. The Mesozoic is divided into just three time periods: the Triassic, …The Cretaceous is defined as the period between 145.5 and 65.5 million years ago,* the last period of the Mesozoic Era, following the Jurassic and ending with the extinction of the dinosaurs (except birds). By the beginning of the Cretaceous, the supercontinent Pangea was already rifting apart, and by the mid-Cretaceous, it had split into ... Jun 23, 2021 · Examples of Mesozoic Era animals include dinosaurs, pterosaurs, ammonites, sharks, plesiosaurs, ichthyosaurs, mosasaurs, pseudosuchians, insects, and early mammals. Although dinosaurs were the dominant land animals of the Mesozoic Era, many other important animal groups evolved and thrived during this time. On this page is a list of Mesozoic ... Test your knowledge of the fluffy, winged dinos of the bygone Mesozoic era, from little Microraptor to the enormous Yutyrannus with this quiz. Advertisement Advertisement Advertisement Advertisement Advertisement Advertisement Advertisement...Examples of Mesozoic Era animals include dinosaurs, pterosaurs, ammonites, sharks, plesiosaurs, ichthyosaurs, mosasaurs, pseudosuchians, insects, and early mammals. Although dinosaurs were the dominant land animals of the Mesozoic Era, many other important animal groups evolved and thrived during this time. On this page is a list of Mesozoic ...The Triassic ( / traɪˈæsɪk / try-ASS-ik; sometimes symbolized 🝈) [8] is a geologic period and system which spans 50.5 million years from the end of the Permian Period 251.902 million years ago ( Mya ), to the beginning of the Jurassic Period 201.4 Mya. [9] The Triassic is the first and shortest period of the Mesozoic Era. Triassic Period (240 to 208 million years ago) At the beginning of the Mesozoic Era, the “supercontinent” began to break up. Deserts covered part of the interior, but shallow seas re-invaded the lowlands. Reptiles evolved rapidly, and two important new groups appeared. Therapsids (mammal-like reptiles) gave rise to true mammals by the end ... Dinosaurs. The prehistoric reptiles known as dinosaurs arose during the Middle to Late Triassic Period of the Mesozoic Era, some 230 million years ago. They were members of a subclass of reptiles ...The Triassic period was the first period of the Mesozoic era and occurred between 251.9 million and 201.3 million years ago. It followed the great mass extinction at the end of the Permian period and was a time when life outside of the oceans began to diversify.Triassic Period, in geologic time, the first period of the Mesozoic Era. It began 252 million years ago, at the close of the Permian Period, and ended 201 million years ago, when it was succeeded by the Jurassic Period. The Triassic Period marked the beginning of major changes that were to take place throughout the Mesozoic Era, particularly in ...The Mesozoic Era (252 to 66 million years ago) The Mesozoic Era had a lot of “firsts”. For example, it had the first birds, first mammals, first dinosaurs, and first …The Mesozoic Era began 252.2 million years ago, following the conclusion of the Paleozoic Era, and ended 66 million years ago, at the dawn of the Cenozoic Era. Dinosaurs lived during the Mesozoic Era (252 to 66 million years ago), often called the “Age of Dinosaurs.”. The Mesozoic Era is divided into three time periods, the Triassic, Jurassic, and Cretaceous. The Utah Geological Survey recognizes the presence of over 27 sequential, non-overlapping dinosaur faunas spanning 165 million years from ... The Mesozoic era was a time of geological and biological transformation. During this time period, the continents began to evolve into their current configurations. An infinite number of geological periods are known by two names: the Precambrian and the Phanerozoic.Oct 18, 2023 · Cretaceous Period, in geologic time, the last of the three periods of the Mesozoic Era. The Cretaceous began 145.0 million years ago and ended 66 million years ago; it followed the Jurassic Period and was succeeded by the Paleogene Period (the first of the two periods into which the Tertiary Period was divided). Dinosaurs lived during the Mesozoic Era (252 to 66 million years ago), often called the “Age of Dinosaurs.”. The Mesozoic Era is divided into three time periods, the Triassic, Jurassic, and Cretaceous. The Utah Geological Survey recognizes the presence of over 27 sequential, non-overlapping dinosaur faunas spanning 165 million years from ...Study the diagram of the geologic time scale. A time scale measured in Millions of years ago or M Y A. Cenozoic Era includes Quaternary Period, 0 to 1.6 M Y A, and Tertiary Period, 1.6 to 66.4 M Y A. Mesozoic Era includes Cretaceous Period, 66.4 to 144 M Y A, Jurassic Period, 144 to 208 M Y A, Triassic Period, 208 to 245 M Y A. Paleozoic Era includes Permian Period, 245 to 286 M Y A ...The Mesozoic Era began approximately 252 million years ago at the close of the Paleozoic Era and ended 66 million years ago at the dawn of the Cenozoic Era. The Mesozoic is best known as the time of the …Series: Geologic Time Periods in the Mesozoic Era. The Mesozoic Era (251.9 to 66 million years ago) was the "Age of Reptiles." During the Mesozoic, Pangaea began separating into the modern continents, and the modern Rocky Mountains rose. Dinosaurs, crocodiles, and pterosaurs ruled the land and air. As climate changed and rapid plate tectonics ...Triassic Period, Interval of geologic time, c. 252.2–201.3 million years ago, that marks the beginning of the Mesozoic Era. Many new vertebrates emerged during the Triassic, heralding the major changes that were to occur in both terrestrial and marine life forms during the Mesozoic Era. The seas became inhabited by large marine reptiles.The Mesozoic Era was a time of great change. The ancestors of major plant and animal groups that exist today first appeared during the Mesozoic, and the generally warm and habitable environment of the era supported great diversity of life-forms. However, the era is best known as the time of the dinosaurs. The Mesozoic Era began 252 million ...The Triassic period, which opens the Mesozoic era, follows a near-complete extinction of life. Recovery from the brink is predictably slow. While mountain ...An era of geologic time from the beginning of the Tertiary period to the present. Its name is from Greek and means "new life." Quaternary. (1.8 million years ago - Present) The second period of the Cenozoic era. It contains two epochs: the Pleistocene and the Holocene.Cretaceous last of the dinosaur Periods (145–66 mln years ago) Of the three dinosaur periods of the Mesozoic, the Cretaceous was undoubtedly the golden age of evolution. It was a time of massive reorganization or “upgrading” of ecosystems, both on land and marine realms. Photo Credit: Wikimedia Commons.The Mesozoic begins where the upheavals of the Permian Extinctions end. A mass extinction at the end of the Permian Period had eliminated most of the species of ...Non-bird dinosaurs lived between about 245 and 66 million years ago, in a time known as the Mesozoic Era. This was many millions of years before the first modern humans , Homo sapiens, appeared. Scientists divide the Mesozoic Era into three periods: the Triassic, Jurassic and Cretaceous. During this era, the land gradually split from one huge ... Here we meet the Mesozoic Era’s three defining time periods. This video runs through 186 million years in 10 minutes to show how reptiles emerged to become some of the largest animals to fly, stomp or swim across our planet. This prehistoric epic takes place in one single era: the Mesozoic.After the Mesozoic, the Cenozoic or the "Age of Mammals" began. Forty percent of the known dinosaurs date from the last 15 million years of the Cretaceous period. The earliest period of the Mesozoic Era was the Triassic period (248 - 208 million years ago), in which the first small dinosaurs and mammals developed.Jan 3, 2022 · The final period of the Mesozoic era, the Cretaceous period, which happened about 145 to 65 million years ago, saw the largest and the most diverse range of dinosaurs. Some of the most heaviest and brutal dinosaurs, like the Tyrannosaurus rex, lived in the Cretaceous period. The end of the Mesozoic era was marked by the mass extinction, wiping ... The Cretaceous is defined as the period between 145.5 and 65.5 million years ago,* the last period of the Mesozoic Era, following the Jurassic and ending with the extinction of the dinosaurs (except birds). By the beginning of the Cretaceous, the supercontinent Pangea was already rifting apart, and by the mid-Cretaceous, it had split into ... The Mesozoic Era began 252.2 million years ago, following the conclusion of the Paleozoic Era, and ended 66 million years ago, at the dawn of the Cenozoic Era.The Mesozoic Era is a geological time period that lasted from approximately 252 to 66 million years ago. ... periods: the Triassic, Jurassic, and Cretaceous ...The Mesozoic Era began approximately 252 million years ago at the close of the Paleozoic Era and ended 66 million years ago at the dawn of the Cenozoic Era. The Mesozoic is best known as the time of the …The Triassic period is the first stage of the Mesozoic era. Triassic Lasted for thirty-five million years. After the catastrophe that occurred at the end of the ...Figure 27.4.1 27.4. 1: (a) Earth’s history is divided into eons, eras, and periods. Note that the Ediacaran period starts in the Proterozoic eon and ends in the Cambrian period of the Phanerozoic eon. (b) Stages on the geological time scale are represented as a spiral. (credit: modification of work by USGS)Examples of Mesozoic Era animals include dinosaurs, pterosaurs, ammonites, sharks, plesiosaurs, ichthyosaurs, mosasaurs, pseudosuchians, insects, and early mammals. Although dinosaurs were the dominant land animals of the Mesozoic Era, many other important animal groups evolved and thrived during this time. On this page is …Geologic Time Scale Ma = mega-annum (million years). Most ages are rounded to the nearest Ma. Common map age symbols shown in (). ... Mesozoic Cenozoic Eon Era Period Epoch 4540 4000 2500 1600 541 485 444 419 359 323 299 252 201 145 66 56 34 23 2.58 Ma Mesoproterozoic (Y) Archean (W) Hadean Triassic (T ) Pennsylvanian (P) Cambrian (C)The Mesozoic Era was a time of great change. The ancestors of major plant and animal groups that exist today first appeared during the Mesozoic, and the generally warm and habitable environment of the era supported great diversity of life-forms. However, the era is best known as the time of the dinosaurs. The Mesozoic Era began 252 million ...The Mesozoic Era [3] is the second-to-last era of Earth's geological history, lasting from about 252 to 66 million years ago, comprising the Triassic, Jurassic and Cretaceous Periods. The Mesozoic Era began 252.2 million years ago, following the conclusion of the Paleozoic Era, and ended 66 million years ago, at the dawn of the Cenozoic Era.The Mesozoic Era began approximately 252 million years ago at the close of the Paleozoic Era and ended 66 million years ago at the dawn of the Cenozoic Era. The Mesozoic is best known as the time of the dinosaurs. Dinosaurs first appeared early in the Mesozoic and came to dominate life on Earth throughout the rest of the era. The Mesozoic is ... The Mesozoic Era lasted about 180 million years, from about 245 million years ago to about 65 million years ago. The Mesozoic is divided into just three time periods: the Triassic, the Jurassic, and the Cretaceous. Since lots of things were going on in each time period, we can only summarize the events. You can learn more by going to your ... Delivery time is estimated using our proprietary method which is based on the buyer's proximity to the item location, the shipping service selected, the seller's shipping history, and other factors. ... (we're talking Mesozoic Era) is new again in Robert Sabuda and Matthew Reinhart's knockout new pop-up book ENCYCLOPEDIA PREHISTORICA: …. The Mesozoic era spans from about 252 million years ago to 66 million years ago. It is also called the age of reptiles or the age of dinosaurs. In the Mesozoic era, the animals that existed ranged ...Reptile - Evolution, Paleontology, Adaptation: The first land vertebrates, the Tetrapoda, appeared near the middle of the Devonian Period. The earliest known reptiles, Hylonomus and Paleothyris, date from the Late Carboniferous. The Mesozoic Era is known as the “Age of Reptiles.” Today's reptiles represent only a fraction of the reptile groups and species that have lived.The Mesozoic (from the Greek prefix meso meaning “between” and zoon, animal or "living being") era is an interval of about 186 million years defined on the geologic timescale as spanning roughly from 251 to 65 million years ago (mya), and as being the second of three eras of the Phanerozoic eon. The Mesozoic era lies between the earlier ...Dec 14, 2021 · The Mesozoic era spans from about 252 million years ago to 66 million years ago. It is also called the age of reptiles or the age of dinosaurs. In the Mesozoic era, the animals that existed ranged ... The Mesozoic Era is divided into three time periods: the Triassic (251-199.6 million years ago), the Jurassic (199.6-145.5 million years ago), and the Cretaceous (145.5-65.5 million years ago).*The Mesozoic era spans from about 252 million years ago to 66 million years ago. It is also called the age of reptiles or the age of dinosaurs. In the Mesozoic era, the animals that existed ranged ...CO 2 concentrations have been high during periods of particularly warm climate (such as during most of the Mesozoic era and the Eocene epoch) and low during times of cold climate, including the major epochs with periodic glaciations (namely, the Permo-carboniferous and late Cenozoic glaciations), as illustrated in Figure 5.11 and Figure 14.1 in ...The Mesozoic Era is literally the era of “middle life.”. It is also known as the age of dinosaurs. It lasted from 245 to 65 million years ago and is divided into the three periods described in Figure below. The Mesozoic began with the supercontinent Pangaea. Then, during the era, Pangaea broke up and the continents drifted apart.Only Daqing was in the Cretaceous Period and the Mesozoic Period. No other strata were involved. ... After a period of time, its performance will decline and fall off, and individual wires will be broken, because after the battery is made, it is welded one by one and collected. ... We have entered such a high speed era, the era of terabits ...Principal Asset Management's chief global strategist sees this decade as vastly different from the previous - but there's still upside for investors. Jump to With the Fed committed to tighter monetary policy following a decade of near-zero ...The Mesozoic and Cenozoic eras make up the youngest half of the Phanerozoic. The Triassic Period, the youngest period of the Mesozoic Era, was the time in which ...The Mesozoic (from the Greek prefix meso meaning “between” and zoon, animal or "living being") era is an interval of about 186 million years defined on the geologic timescale as spanning roughly from 251 to 65 million years ago (mya), and as being the second of three eras of the Phanerozoic eon. The Mesozoic era lies between the earlier ...The final period of the Mesozoic era, the Cretaceous period, which happened about 145 to 65 million years ago, saw the largest and the most diverse range of dinosaurs. Some of the most heaviest and brutal dinosaurs, like the Tyrannosaurus rex, lived in the Cretaceous period. The end of the Mesozoic era was marked by the mass extinction, wiping ...9 Haz 2020 ... The Cretaceous period:This is the final period of the Mesozoic era occupies a period of 79 million years. ... The Cretaceous period is a time when ...The period, which spans from about 252 million years ago to about 66 million years ago, was also known as the age of reptiles or the age of dinosaurs. Life Through Time: Mesozoic era Boundaries English geologist John Phillips, the first person to create the global geologic timescale, first coined the term Mesozoic in the 1800s.16 Mesozoic Era Facts for Kids. The Mesozoic Era is a geological time period that lasted around 186 million years. The Mesozoic Era is also called the Age of Reptiles and the Age of Conifers. The Mesozoic Era is the geological time period when dinosaurs dominated the planet. The Mesozoic Era starts with the evolution of dinosaurs and ultimately ...In fact, the first mammals evolved from a population of vertebrates called therapsids (mammal-like reptiles) at the end of the Triassic period and coexisted with dinosaurs throughout the Mesozoic Era. But part of this folktale has a grain of truth. It was only after the dinosaurs went kaput that mammals were able to evolve beyond their tiny ...The Mesozoic Era is literally the era of “middle life.”. It is also known as the age of dinosaurs. It lasted from 245 to 65 million years ago and is divided into the three periods described in Figure below. The Mesozoic began with the supercontinent Pangaea. Then, during the era, Pangaea broke up and the continents drifted apart.Jun 23, 2021 · Examples of Mesozoic Era animals include dinosaurs, pterosaurs, ammonites, sharks, plesiosaurs, ichthyosaurs, mosasaurs, pseudosuchians, insects, and early mammals. Although dinosaurs were the dominant land animals of the Mesozoic Era, many other important animal groups evolved and thrived during this time. On this page is a list of Mesozoic ... Mesozoic Era (248 to 65 mya) Cretaceous (144 to 65 mya) ... Precambrian Time (4,500 to 543 mya) Proterozoic Era (2500 to 543 mya)Pangea, supercontinent that incorporated almost all of Earth’s landmasses in early geologic time. Fully assembled by the Early Permian Epoch (some 299 million to about 273 million years ago), it began to break apart about 200 million years ago, eventually forming the modern continents and the Atlantic and Indian oceans.Sep 25, 2023 · Phanerozoic Eon, the span of geologic time extending about 541 million years from the end of the Proterozoic Eon (which began about 2.5 billion years ago) to the present. The Phanerozoic, the eon of visible life, is divided into three major spans of time largely on the basis of characteristic. In a relatively short period of time, ... one of the most distinguished characteristics of the ammonites lies among those that lived at the end of the Mesozoic Era during the Cretaceous Period (145The Cretaceous is defined as the period between 145.5 and 65.5 million years ago,* the last period of the Mesozoic Era, following the Jurassic and ending with the extinction of the dinosaurs (except birds). By the beginning of the Cretaceous, the supercontinent Pangea was already rifting apart, and by the mid-Cretaceous, it had split into ...geologic time - chronology of Earth™s formation, changes, development, and existence Pangaea - a supercontinent in existence during the Mesozoic and Paleozoic Eras that contained all seven continents present on Earth™s surface today in a single land mass Period - division of geologic time smaller than an era, based on rock layers and the ...Mesozoic The middle of three eras that constitute the Phanerozoic period of time. The Mesozoic (literally ‘middle life’) was preceded by the Palaeozoic Era and followed by the Cenozoic Era. It began with the Triassic approximately 245 Ma ago and ended around 65 Ma at the start of the Tertiary.Orden Cronologico de PVZ 2Mesozoic Era 251 to 65.5 million years ago. This is the era of the dinosaur. The Mesozoic is broken up into three periods. The Triassic, the Jurassic, and the Cretaceous Period. Triassic period. In the Triassic period, there were many primitive dinosaurs forming as well as many species of marine reptiles.The Cenozoic ( / ˌsiːnəˈzoʊ.ɪk, ˌsɛn -/ SEE-nə-ZOH-ik, SEN-ə-; [1] [2] lit. 'new life') is Earth's current geological era, representing the last 66 million years of Earth's history. It is characterised by the dominance of mammals, birds and flowering plants. It is the latest of three geological eras, preceded by the Mesozoic and Paleozoic.Delivery time is estimated using our proprietary method which is based on the buyer's proximity to the item location, the shipping service selected, the seller's shipping history, and other factors. ... (we're talking Mesozoic Era) is new again in Robert Sabuda and Matthew Reinhart's knockout new pop-up book ENCYCLOPEDIA PREHISTORICA: …Off and on throughout the Cretaceous (the last period of the Mesozoic era, during which dinosaurs flourished), large shallow seas covered extensive areas of the continents. Data from diverse sources, including geochemical evidence preserved in seafloor sediments, indicate that the Late Cretaceous climate was milder than today's.The period, which spans from about 252 million years ago to about 66 million years ago, was also known as the age of reptiles or the age of dinosaurs. Life Through Time: Mesozoic era Boundaries English geologist John Phillips, the first person to create the global geologic timescale, first coined the term Mesozoic in the 1800s.The final time period on the Geologic Time Scale is the Cenozoic Period. With large dinosaurs now extinct, smaller mammals that had survived were able to grow and become dominant. The climate changed drastically over a relatively short period of time, becoming much cooler and drier than during the Mesozoic Era.Jun 23, 2021 · Examples of Mesozoic Era animals include dinosaurs, pterosaurs, ammonites, sharks, plesiosaurs, ichthyosaurs, mosasaurs, pseudosuchians, insects, and early mammals. Although dinosaurs were the dominant land animals of the Mesozoic Era, many other important animal groups evolved and thrived during this time. On this page is a list of Mesozoic ... The idea that women should not exercise during period times is a myth, as this is when the benefits of exercise are greatest. According to a gynaecologist Try our Symptom Checker Got any other symptoms? Try our Symptom Checker Got any other...The Mesozoic era spans from about 252 million years ago to 66 million years ago. It is also called the age of reptiles or the age of dinosaurs. In the Mesozoic era, the animals that existed ranged ...Mesozoic Era (248 to 65 mya) Cretaceous (144 to 65 mya) ... Precambrian Time (4,500 to 543 mya) Proterozoic Era (2500 to 543 mya)Triassic period: 248 to 213 million years ago. Jurassic period: 213 to 144 million years ago. Cretaceous period: 144 to 65 million years ago. Dinosaurs and other archosaurs (which means "ruling reptiles"), including crocodiles, Champsosaurs and Pterosaurs, first evolved in the Triassic period . These animals remained the dominant land-creatures ...May 29, 2018 · Allosaurus, Jurassic Central period of the Mesozoic era, lasting from 213 to 144 million years ago. In this period there were saurischian and ornithischian dinos… Paleozoic Era, In geologic time , the Paleozoic Era, the first era in the Phanerozoic Eon , covers the time between roughly 544 million years ago (mya) and until 24… May 29, 2018 · Allosaurus, Jurassic Central period of the Mesozoic era, lasting from 213 to 144 million years ago. In this period there were saurischian and ornithischian dinos… Paleozoic Era, In geologic time , the Paleozoic Era, the first era in the Phanerozoic Eon , covers the time between roughly 544 million years ago (mya) and until 24… The supercontinent Pangaea in the early Mesozoic (at 200 Ma). Pangaea or Pangea (/ p æ n ˈ dʒ iː. ə /) was a supercontinent that existed during the late Paleozoic and early Mesozoic eras. It assembled from the earlier continental units of Gondwana, Euramerica and Siberia during the Carboniferous approximately 335 million years ago, and began to break apart …Cretaceous Period, in geologic time, the last of the three periods of the Mesozoic Era. The Cretaceous began 145.0 million years ago and ended 66 million years ago; it followed the Jurassic Period and was succeeded by the Paleogene Period (the first of the two periods into which the Tertiary Period was divided).