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6 Magical Mystery Tour: The Biological Psychedelia of the Burgess Shale

John Foster Indiana University Press ePub

6.1. Members and relationships of the Burgess Shale Formation, Cathedral Formation, and Stephen Formation. Glossopleura Zone range for Burgess Shale Formation shown on left; same range for Cathedral Formation on right.

OUR NEXT DESTINATION NEEDS LITTLE INTRODUCTION. QUITE THE opposite of the desert localities of the Great Basin, the localities we must visit next are mostly high on mountainsides. The mountains and glaciers of Banff, Jasper, and Yoho National Parks in Alberta and British Columbia, Canada, are some of the most beautiful on the continent, and their fossil treasures are as impressive and important. In 1885 the Canadian Pacific Railway (CPR) completed a line across the Rockies, a route that ran over a mountain pass from Lake Louise and off to the west into British Columbia. Along this route, just on the downhill side west of the pass along the Kicking Horse River, was a small encampment of rail workers that developed into the small town of Field, British Columbia. Named in honor of one Cyrus Field, an investor who – despite his namesake town – never did invest in the CPR project, the town of Field has remained small and incredibly scenic. In September 1886, soon after the railway was completed, a Geological Survey of Canada geologist named Richard McConnell climbed to the slopes of Mount Stephen above town and collected fossils from what would eventually become known as the Burgess Shale. These fossils proved to be particularly important because they were the first to be found in what has turned out to be one of the most important Cambrian formations in the world; McConnell’s finds set off a series of small events that led to one of the most important discoveries in the history of paleontology, and within little more than a century whole books (and not a small number of them) have been dedicated just to this one formation’s fossil record.1

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6 A Numerical Scale for Quantifying the Quality of Preservation of Vertebrate Tracks

Daniel Ma Edited by Peter L Falkingham Indiana University Press ePub

6.1. Photos of the emu tracks used to define Farlow’s (unpubl.) preservation scale. (A) Grade 1; (B) grade 2; (C) grade 3; (D) grade 4.

A Numerical Scale for Quantifying the Quality of Preservation of Vertebrate Tracks

6

Matteo Belvedere and James O. Farlow

FROM ITS BEGINNING, VERTEBRATE ICHNOLOGY HAS described fossilized footprints in a qualitative, descriptive way. At the same time, considerable effort has gone into illustrating footprint morphology. In recent years, new technologies (e.g., laser-scanning and close-range photogrammetry) and methods (e.g., geometric morphometrics) have allowed more objective, quantitative approaches to vertebrate ichnology. However, quantitative shape analyses need to be based on data of high quality, and comparisons are best made between tracks comparable in quality of preservation. Thus, determining which footprints constitute the most reliable sample for quantitative analyses is fundamental for the progress of ichnology.

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11 Arthropods: Trilobites and Other Legged Creatures

Richard Arnold Davis Indiana University Press ePub

Figure 11.1. The Ordovician trilobite Triarthrus. Left, dorsal view, right, ventral view. Drawings by Kevina Vulinec.

 

In terms of sheer abundance, species diversity, and exploitation of habitats, arthropods rank as the most successful of all living animals. More than 750,000 species (mostly insects) inhabit a vast range of environments on land, in the sea, and in fresh water. Living arthropods include the insects, crustaceans, horseshoe crabs, arachnids, centipedes, and millipedes. During the Ordovician, arthropods had not yet invaded the land, but trilobites were abundant and diverse in the sea, along with the eurypterids, ostracodes, and a few other minor groups.

Despite their bewildering variety of form, all arthropods share certain basic features. Like their close relatives, the annelid worms, arthropods have a segmented body. Unlike the annelids, the body and its appendages are encased in an exoskeleton composed of the protein chitin. The exoskeleton is much like a suit of armor in having rigid components articulated by flexible joints. (The name arthropod means “jointed legs.”) Not only does the exoskeleton shield the internal organs from predation and some environmental hazards, but it also provides rigid points for muscle attachment. Consequently, arthropods are capable of rapid locomotion by walking, swimming, or flying. The nature of the exoskeleton has two important implications for the fossilization potential of arthropods. First, because the chitinous exoskeleton decomposes after death, many arthropods are poor candidates for fossil preservation. However, arthropods that have thicker exoskeletons or incorporation of calcium carbonate into their skeletons (such as some crustaceans and trilobites) will have enhanced potential for preservation. Second, all arthropods grow by periodically shedding the exoskeleton and forming a new skin that accommodates growth. Each individual arthropod can contribute numerous shed exoskeletons (molts) as potential fossils during its lifetime. Molting may thus explain in part the abundance of some arthropod fossils.

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5. Grasslands

Jr John O Whitaker Indiana University Press ePub

This chapter includes all grasslands, including the original tall grass prairie, which comprised more than 2 million acres, mostly in the northern half of Indiana; pasture; haylands; strip-mined land in southwestern Indiana; vegetated dunes; savanna; and agricultural land put into the various reserve programs. “Grassland” often includes more or less forbs or other nongrassy herbaceous plants.

Original Prairie

An understanding of Indiana’s native grassland community, the tall grass prairie, is essential to appreciating the changes to this habitat category in the past 200 years. The French word prairie means “meadow.” But the “Indiana prairie” encountered by early European settlers was unlike any meadows they had ever experienced in the forested regions of Europe. Indiana’s prairie was dominated by grass species, especially big bluestem (Figure 5.1), switchgrass, Indian grass, and in wetter sites slough grass, which all can grow to 10 ft tall or more. A human on horseback could be swallowed up in the vast sea of tall grass. Scattered among the grasses were perennial wildflowers and legumes, collectively called “forbs,” such as blazing star, partridge pea, black-eyed Susan, and various sunflowers (Figure 5.2). Small trees and shrubs, such as hazelnut, occurred at grassland edges, especially along drainages.

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2. Use of Models in Ecosystem-Based Management of the Southern Everglades and Florida Bay, Florida

John W Day Texas A&M University Press ePub

Christopher J. Madden

The trend toward comprehensive ecosystem management of coastal ecosystems throughout the United States is accelerating. In June 2003, the Pew Oceans Commission released the report America’s Living Oceans: Charting a Course for Sea Change, which asserted that on a national scale, comprehensive ecosystem-based management (EBM) strategies must be implemented for management and stewardship of our coastal marine ecosystems: “Ecosystem-based management entails developing a new perspective that acknowledges and understands that there are limits to our knowledge; marine ecosystems are inherently unpredictable; ecosystems have functional, historical, and evolutionary limits that constrain human exploitation. . . . Flexible, adaptive management that incorporates new knowledge and provides some level of insurance for unpredictable and uncontrollable events embodies ecosystem-based management.” (Pew Oceans Commission 2003).

The US Commission on Ocean Policy (2004) stated that an EBM perspective is necessary “to address the pervasive scientific uncertainty inherent in natural systems and the failures of single species management approaches to adequately address that uncertainty. . . . US ocean and coastal resources should be managed to reflect the relationships among all ecosystem components, including human and nonhuman species and the environments in which they live. Applying this principle will require defining relevant geographic management areas based on ecosystem, rather than political, boundaries.” (US Commission on Ocean Policy 2004).

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