Age of the Dinosaurs
.docx
School
Lafayette High School, Lafayette**We aren't endorsed by this school
Course
SCI 23
Subject
Biology
Date
Dec 16, 2024
Pages
2
Uploaded by GrandEaglePerson1252
Age of the DinosaursWhen did Reptiles Develop?While amphibians were dominant across Earth for a while, during the Carboniferous period land _______________ began to diverge from amphibians in terms of how they reproduced: amphibians returned to water in order to lay eggs and their larval young to develop while these new organisms laid eggs on _______________ that allowed the young to hatch as smaller versions of the adult instead of needing to metamorphose. This was the beginning of the clade of _______________, or organisms that develop from eggs laid either internally or externally. Amniotes spread to areas far from bodies of water, and as a result _______________ themselves to the point that the reptiles that we see today first appeared, and eventually pushed amphibians from the position of dominant land vertebrates during the _______________ period.What is a Dinosaur?It is a common misconception that reptiles are direct _______________ of dinosaurs. Through the study of fossils that dinosaurs are different from modern reptiles and their ancestors in that their ________ bones are structured differently than other reptiles, allowing them to stand upright like birds and mammals. Another major difference from reptiles theorized by scientists is that dinosaurs were _______________ like birds and mammals instead of being cold-blooded. In addition, a dinosaur has a specific physiological description, which means that several groups of reptiles commonly considered to be dinosaurs are not actually dinosaurs, such as marine reptiles and _______________. The three groups of organisms who make up the clade of dinosaurs are as follows:Sauropods, such as _______________ or Diplodocus.Ornithischians, such as Stegosaurusor _______________.Theropods, such as _______________ or Tyrannosaurus Rex.How did Dinosaurs Become Dominant Land Animals?During the early Triassic period, dinosaurs were one of several types of land vertebrates competing for resources, including traditional reptile clades (crocodiles and lizards), as well as _______________, or the direct ancestors of mammals that had established themselves after the Permian-Triassic extinction event. Dinosaurs like Eoraptorwere small opportunistic omnivores that initially had a small niche, but by the end of the Triassic period, the dinosaurs became the _______________ land animals due to a mass extinction that devastated their competitors. Why the dinosaurs were less affected by this event than their competitors is not easily explained through the fossil record.How did Dinosaurs Fill Ecological Niches?During the Jurassic (251-201 mya) and Cretaceous (201-66 mya) periods, dinosaurs (and dinosaur-like reptiles) filled virtually all ecological _______________ because there was almost no competition for resources. Traditional reptiles had already established themselves, and the cynodonts’ were reduced to rat-sized _______________ animals. Due to the continents moving away from Pangea, changes in habitat required more _______________ adaptations. These adaptations are seen in the herbivorous Sauropods and Ornithischians, as well as the wide variety of Therapods who preyed on them. Relatives of dinosaurs like _______________ and ichthyosaurs filled the niches of modern marine mammals, and pterosaurs were the first vertebrates to fly.What Happened to the Dinosaurs?The end of the Cretaceous period occurred when there was a massive _______________ event on the Yucatan Peninsulathat created a total collapse of both marine and land ecosystems. The huge dinosaurs that occupied almost all niches were killed off almost immediately in a geologic sense, save a small group of _______________ from the clade that includes velociraptors. These dinosaurs apparently were small, ground-dwelling, and had some ability to fly, giving them a critical a_______________ to survive. Throughout the Cenozoic Era the descendants of these evolved into the modern _______________ that we see today.
True or False: Amniotes have an evolutionary advantage over amphibians in that their need for water is less than for amphibians.Which of the following is not a dinosaur?PterodactylTriceratopsIguanodonVelociraptorTrue or False: The first dinosaur was a sauropod.How were ichthyosaurs similar to modern marine mammals? (Hope you watched the video!)They had live young.Their tailfins were horizontal.They had jaws and teeth similar to baleen whales.Their skeletons were made of cartilageWhy were theropods the only dinosaur family to survive the end of the Cretaceous period?They were best-adapted to survive out of all dinosaur families.Velociraptors were the most intelligent of all dinosaur species.Theropods were herbivores and could eat the small amount of vegetation left.They were eventually able to evolve into mammals.