Mesozoic era

Lepidoptera is the second largest insect group and includes nearly 150,000 described species, which have evolved over 100 million years since the Mesozoic era. For the birth of a new species, it must be isolated from other species by some factor to prevent inter-species crossing. The sex pheromone, which is secreted by the adult (usually by a female moth and sometimes by a male moth or butterfly) for the benefit of a specific partner, plays an important role in reproductive isolation. Therefore, it is no wonder that the chemical structures of the species-specific pheromones exhibit considerable differences. 

Section 8.6.2, the Permian period ended with the largest mass extinction event that has yet occurred on planet Earth. As the ocean began a sustained recovery at the beginning of the Mesozoic era, opportunities likely abounded for the survivors to take over empty ecological niches through evolutionary adaptation. Prior to the advent of planktonic... 

Cretaceous The last period of the Mesozoic era, therefore just following the Jurassic and just preceding the Tertiary. 

Amber can be found in rocks dating back to the Mesozoic era, about 80 million years ago. There undoubtedly were deposits of plant resin before that time, but they have failed to survive to this day. This may be due to the gradual breakdown of the hydrocarbons that constitute most amber, as well as its dehydration after burial. 

Cenozoic Era The period of geologic time beginning after the end of the Mesozoic Era 65 million years ago and encompassing the present. Commonly referred to as the age of mammals. 

Jurassic Period Middle period of the Mesozoic Era, between 185-135 million years ago. Characterized by the (possible) origin of angiosperms and the continued split of the worldwide supercontinent of Pangaea. 

Mesozoic Era The period of geologic time beginning 245 million years ago and ending 65 million years ago the age of the dinosaurs and cycads, the Mesozoic falls between the Paleozoic and Cenozoic Eras and includes the Triassic, Jurassic, and Cretaceous Periods. 

Paleozoic Era The period of time beginning 570 million years ago ending 245 million years ago falls between the Proterozoic and Mesozoic Eras and is divided into the Cambrian, Ordovician, Silurian, Devonian, Carboniferous, and Permian Periods. 

Triassic Period The first period of the Mesozoic Era between 225 and 185 million years ago. Pangaea began to breakup during this time. The ancestors of dinosaurs were present, as were early mammals and mammal-like reptiles. 

Mass extinctions have been recognized in the fossil record since the middle of the nineteenth century. Levels of mass extinction of species were selected as marker levels in the stratigraphic record because the death of index-fossil species provided a convenient marker to subdivide and correlate strata. The mass-extinction level called the Permian-Triassic boundary is so profound in terms of faunal and floral change that it was early on noted and chosen to represent the transition from Paleozoic to Mesozoic era. The mass-extinction level called the Cretaceous-Tertiary boundary is also quite distinctive in terms of faunal and floral change, and it too was noted early on and chosen to represent the transition from Mesozoic to Cenozoic era. Other less profound, but nevertheless distinctive levels of mass extinction of fossils have been selected to represent marker points in the stratigraphic record at which geological periods, epochs, ages, and other intervals of lesser temporal value are defined. 

Cretaceous-Tertiary boundary—In the geological column of sediments, the transition from sediments of the Cenozoic era to those of the Mesozoic era. A thin layer of iridium-rich material at this boundary was probably laid down by the asteroid that created the Chixulub crater in Mexico. 

North America, and its volcanos have been erupting frequently from the dawn of the age of dinosaurs (the Mesozoic era) until today. 

In fact, evidence exists that since the Paleozoic and through the Mesozoic era, taxonomic groups have moved in and out of vent ecosystems through time no single taxon has been able to escape evolutionary pressures. Some independent support for deep-water extinction has also been presented (Jacobs and Lindberg, 1998). These findings mle out the possibility that deep-sea environments are refuges... 

Being bracken a relic of the Mesozoic era when it evolved amidst ancient forest in which insect pressure conceivably may have been considerable, the production of ecdysteroids in today s ferns may be a vanishing vestige of a relatively ineffective line of chemical defense for herbivory pressures found in present-day ecosystems. a-Ecdysone, on the other hand, has been deemed responsible for the induction of neoplasms in toads [204] which, in spite of not being natural enemies of ferns, may function as physiological models for other real-world plant predators. 

Most of us are familiar with the geologic column from high school textbooks. In short, the geologic column divides the supposed history of Earth into five eras, each of which has its appointed age. (The Cenozoic Era runs from 25 thousand to 70 million years ago, the Mesozoic Era from 70 million to 200 miUion years ago, the Fhleozoic Era from 200 to 600 rruUion years ago, the Proterozoic Era from 600 million to 1 biUion years ago, and the Archeozoic Era from 1 biUion to 1.8 biUion years ago.)... 

Jurassic The second geological period of the Mesozoic era It followed the Ttiassic, which ended about 200 miUion years ago, and extended untU the beginning of the Cre-... 

Mesozoic The geolojpcal era that extended from the end of the Palaeozoic era, about 251 million years ago, to the beginning of the Cenozoic era, about 65 million years ago. it comprises the Triassic, lurassic, and Cretaceous periods. The Mesozoic era is often known as the Age of Reptiles as these animals, which included the dinosaurs, pterosaurs, and ichthyosaurs, became the dominant lifeform most became extinct before the end of the era. 

Palaeozoic The first era of Phanerozoic time. It follows the Precambrian and is subdivided into the Lower Palaeozoic, comprising the Cambrian, Ordovician, and Silurian periods, and the Upper Palaeozoic, comprising the Devonian, Carboniferous, and Permian periods. It extended from about 542 million years ago to about 251 million years ago, when it was succeeded by the Mesozoic era. 

The Beacon rocks in the Transantarctic Mountains attract attention because they are the products of geological processes that occurred in Gondwana during the late Paleozoic and early Mesozoic eras. In addition, they contain fossilized remains of plants and animals that inhabited the landscape at this time in history of the Earth. The Beacon rocks also contain coal... 

Fig. 13.39 The magmatic activity that was initiated by the rifting of Gondwana during the Mesozoic Era occurred in a belt that now extends across four continents of the southern hemisphere. The chemical and isotopic compositions of the resulting continental flood basalts and intrusives depend on the make-up of the...

During the early part of the Mesozoic Era a subduction zone in Fig. 15.3 stretched from the west coast of South America to the paleo-Pacific coast of East Antarctica. This subduction zone dipped under the Antarctic Peninsula, Thurston Island, Marie Byrd Land, Southern New Zealand, and Tasmania all of which were later moved into the positions they occupy at the present time (Elliot 1991). The subduction of oceanic crust caused the eruption of large amounts of... 

Fig. 15.6 The subduction of a lithospheric plate during the Mesozoic Era caused the eruption of felsic and mafic lavas in the Antarctic Peninsula and in Marie Byrd Land. The crust of Gondwana in the back-arc basin was stretched which caused block-faulting and subsidence of the Byrd Subglacial Basin. Crustal extension of the back-arc basin may also have caused rifts to form in the Ross orogen and in the overlying rocks of...

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