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Mollusks, Arthropods, and Echinoderms
Mollusks, Arthropods, and Echinoderms

... Characteristics of Echinoderms • Echinoderms, such as this sea star, have a water vascular system that helps them move and catch food. ...
ExamView - SOL Review Life at the Systems and
ExamView - SOL Review Life at the Systems and

... Cricket ...
Chapter 11 - BELIfeScience7
Chapter 11 - BELIfeScience7

... Have 2 pairs of legs for each segment of their body Herbivores Roll up in ball when in danger Live under logs and rocks ...
INVERTEBRATES
INVERTEBRATES

... Cnidarians digest food externally, like fungi Cnidarian body types come in two forms: Polyp (Ex. hydra) Medusa (Ex. jellyfish) ...
Palaeos Invertebrates: Cnidaria
Palaeos Invertebrates: Cnidaria

... Evolutionary History Despite this primitive grade of organization they are no more ancient than any other group of animal. The Edicarian biota, supposed jellyfish and soft coral (sea pen) fossils from the latest Proterozoic (Ediacaran) era have turned out to belong to a totally different type of org ...
Origin
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... cord. It is a flexible structure that forms the main support of the body in the lowest Chordates, such as the Lancelet, a primitive backbone. From a similar structure in embryos of higher Vertebrates, the vertebral column is developed.A semiflexible rod is running along the length of the animal. Cho ...
Phylum of Arthropoda
Phylum of Arthropoda

... Phylum of Chordate Second : Chordata possess backbone  This group is called vertebrates as the embryonic notochord is normally replaced during development by a backbone.  Vertebrates are divided into : 1 - Class cartilaginous fishes e.g. sharks and rays 2 - Class bony fishes salmon and tilapia 3 ...
The Evolutionary Emergence of Vertebrates From Among Their
The Evolutionary Emergence of Vertebrates From Among Their

... evidence to support evolutionary trees has been derived from analysis of skeletal, muscular, and nervous systems, development and embryology, and cell characteristics. Invariably, these different aspects of organismal biology were studied in isolation and resulted in conflicting ideas of animal rela ...
AP Biology Survey of the Kingdoms CHAPTER 27 – Bacteria and
AP Biology Survey of the Kingdoms CHAPTER 27 – Bacteria and

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Trilobites - Geology Rocks
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Multicellular Organisms
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Phylum Lab - National Aquarium
Phylum Lab - National Aquarium

... ago. Of the eight major phyla, two were known from fossils of this time -Porifera and Cnidaria. Shortly thereafter, a profuse radiation of fossils representing the other animal body plans occurred over a relatively brief span of about 10 million years (by some estimates, 530 million years ago.) The ...
4 Chapter
4 Chapter

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What is an animal? Part 2
What is an animal? Part 2

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Invertebrates - Cloudfront.net
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... • More recently, paleontologists have identified beautifully preserved, microscopic fossils, between 610 and 570 million years old, that seem to be the developing embryos of early multicellular animals • From the same time period, they also identified what are called trace fossils – Trace fossils ar ...
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AP Biology
AP Biology

... Fossils are usually formed when an organism is covered by sediments that then harden into sandstone, slate, mudstone or flint. Most of the time, organisms die in locations that are not conducive to fossilization. Most organisms do not fossilize and those that do are usually destroyed by geological ...
ScienceWorld 7
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404 Error - Page Not Found| University of Houston
404 Error - Page Not Found| University of Houston

... without salinity (as opposed to salt water) Gill – In water-dwelling creatures, a breathing organ that extracts oxygen. Invertebrate – Animals without backbones. Examples include insects, worms, spiders, crayfish and sowbugs. Larva – Immature form of an animal that is physically very different from ...
1 Evolution of Animal Diversity
1 Evolution of Animal Diversity

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Biology 212: February 7, 2003
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... 5. From the monophyletic perspective, from what type of organism is Kingdom Animalia supposed to have evolved? Name its Kingdom (pre-Animalia) as well as the more specific name of the organism, and briefly describe it. 6. What single feature separates members of Phylum Porifera from their protistan ...
IN-DEPTH FILM GUIDE
IN-DEPTH FILM GUIDE

... them have found fossils. Ask those students who found fossils if their fossil finds were lucky or a product of deliberate searching. Explain that paleontologists do not accidentally stumble upon the fossils they discover, but that paleontology is a process of hypothesis testing. Through careful pl ...
Creature Features - Dauphin Island Sea Lab
Creature Features - Dauphin Island Sea Lab

... together just by saying they don’t have one thing is misleading, because Invertebrates are so amazingly different from one another. This group accounts for 97% of all animal species. They range from the super simple sea sponges to the complex camouflaging octopus. Animals are classified into taxonom ...
An Overview of Animal Diversity
An Overview of Animal Diversity

... control of gastrulation has remained unchanged for more than 500 million years (Figure 32.6). This early evolutionary innovation was of fundamental importance: Gastrulation helps to explain why most animals are not a hollow ball of cells. As we’ll discuss, however, other aspects of animal body plans ...
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Cambrian explosion



The Cambrian explosion, or less commonly Cambrian radiation, was the relatively short evolutionary event, beginning around 542 million years ago in the Cambrian Period, during which most major animal phyla appeared, as indicated by the fossil record. Lasting for about the next 20–25 million years, it resulted in the divergence of most modern metazoan phyla. Additionally, the event was accompanied by major diversification of other organisms. Prior to the Cambrian explosion, most organisms were simple, composed of individual cells occasionally organized into colonies. Over the following 70 to 80 million years, the rate of diversification accelerated by an order of magnitude and the diversity of life began to resemble that of today. Many of the present phyla appeared during this period, with the exception of Bryozoa, which made its earliest known appearance in the Lower Ordovician.The Cambrian explosion has generated extensive scientific debate. The seemingly rapid appearance of fossils in the “Primordial Strata” was noted as early as the 1840s, and in 1859 Charles Darwin discussed it as one of the main objections that could be made against the theory of evolution by natural selection. The long-running puzzlement about the appearance of the Cambrian fauna, seemingly abruptly and from nowhere, centers on three key points: whether there really was a mass diversification of complex organisms over a relatively short period of time during the early Cambrian; what might have caused such rapid change; and what it would imply about the origin of animal life. Interpretation is difficult due to a limited supply of evidence, based mainly on an incomplete fossil record and chemical signatures remaining in Cambrian rocks.Phylogenetic analysis has been used to support the view that during the Cambrian radiation, metazoa evolved monophyletically from a single common ancestor: flagellated colonial protists similar to modern choanoflagellates.
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