Turtles of Mexico

Turtles of Mexico: Land and Freshwater Forms

JOHN M. LEGLER
RICHARD C. VOGT
Copyright Date: 2013
Edition: 1
Pages: 416
https://www.jstor.org/stable/10.1525/j.ctt3fh33w
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  • Book Info
    Turtles of Mexico
    Book Description:

    The Turtles of Mexico is the first comprehensive guide to the biology, ecology, evolution, and distribution of more than fifty freshwater and terrestrial turtle taxa found in Mexico. Legler and Vogt draw on more than fifty years of fieldwork to elucidate the natural history of these species. The volume includes an extensive introduction to turtle anatomy, taxonomy, phylogeny, biogeography, and physiology. A key to the turtles of Mexico is included along with individual species accounts featuring geographic distribution maps and detailed color illustrations. Specific topics discussed for each species include habitat, diet, feeding behavior, reproduction, predators, parasites, growth and ontogeny, sexual dimorphism, growth rings, economic use, conservation, legal protection, and taxonomic studies. This book is a complete reference for scientists, conservationists, and professional and amateur enthusiasts who wish to study Mexican turtles.

    eISBN: 978-0-520-95689-6
    Subjects: Biological Sciences

Table of Contents

  1. Front Matter
    (pp. i-vi)
  2. Table of Contents
    (pp. vii-viii)
  3. ACKNOWLEDGMENTS
    (pp. ix-xii)
  4. TURTLES:: A PARADIGM OF VARIABILITY, VENERABILITY, AND VULNERABILITY

    • Introduction
      (pp. 3-13)

      This book concerns the diverse chelonian fauna of Mexico: 15 families, 14 genera, 38 species, and 66 terminal taxa of freshwater and terrestrial chelonians occurring within the political boundaries of Mexico (Los Estados Unidos de Mexico). These represent all of the families of nonmarine cryptodires that occur in the Western Hemisphere.

      The authors of this book (hereinafter JML and RCV) have a cumulative experience of nearly a century with chelonian studies in general and with Mexican turtles in particular.

      Smith and Smith (1979) gave complete and accurate synonymies for all Mexican testudinates and we make no attempt to do so....

    • Materials and Methods Used for This Book
      (pp. 15-18)

      This book is intended for use as a reference source. It is not a field guide. Few people will read it from cover to cover.

      The first part of the book presents general information on turtles: origins, structure, function, natural history, techniques for study, and conservation measures. Much of this information is general, some of it is philosophical, and much of it is applicable to all chelonians.

      The rest of the book contains accounts of taxonomic groups that we hope include all or most of existing knowledge about these taxa from the level of order to terminal taxon.

      The taxonomic...

    • Structure and Function
      (pp. 19-34)

      The chelonian shell (see Figure 2.3) consists of a dorsal carapace and a ventral plastron joined on each side by a bridge (to which both contribute). The limb girdles lie inside the shell and are surrounded by the axial skeleton—a bauplan that is unique among vertebrates (Figure 2.2).

      The shell is a combination of discrete bony elements and epidermal elements (Figure 2.2). From outside to inside, it consists of three layers: skin, in the form of large keratinized scutes; a layer of usually planar dermal bones which articulate inter se; and the endochondral bones of the axial skeleton—vertebrae...

    • Natural History
      (pp. 35-46)

      Knowledge of Mexican turtles was chiefly at an alpha taxonomic level at mid-twentieth century. As collections were enlarged and field observations were recorded and analyzed, it became possible to form autecological profiles of many species. This phase is still ongoing and should ultimately lead to the same quality and magnitude of synecological studies that have produced massive bases of knowledge for species such as Chrysemys picta and Chelydra serpentina. If we do not understand the elements of an animal’s life history—how it conducts its life from day to day, from season to season, and from natality to death (with...

    • Turtles, Humans, and Research
      (pp. 47-52)

      Turtles have lived in balance among their natural predators for more than 200 million years, and it may be assumed that they will continue to do so. Their human predators tend not to live in balance with anything. Turtles are now most at risk when subject to anthropogenic habitat degradation (e.g., draining of wetlands—see account of Terrapene coahuila) and to commercial collecting for food and the pet trade.

      Human primates have fancied turtles and their eggs as food, ornaments, and pets since the dawn of intelligence. The hunter-gatherer way of life probably had minimal impact on turtle populations (but...

    • Field and Laboratory Techniques
      (pp. 53-58)

      Much of the information presented in this book is based on large collections of turtles. Some of these (e.g., U.S. National Museum, American Museum of Natural History, Museum of Comparative Zoology, Harvard) were built up over time as parts of general herpetological collections. The largest collections of turtles (e.g., University of Utah, University of Florida, Tulane University, and Carnegie Museum of Natural History) were made chiefly in the second half of the 20th century, a time when turtles from anywhere in Mexico were a desideratum. The following treatment of collecting and preservation techniques is based on these specialized collections and...

    • Modern Taxonomic Studies and Techniques
      (pp. 59-60)

      Early alpha taxonomic descriptions of turtles, although often diagnostic, were brief and seldom very informative. Size was quantified subjectively (ʺmoderateʺ) or with a single measurement (assumed to be carapace length). Our own scientific careers span the time of purely morphological analysis (e.g., Legler, 1959) to the advent of molecular and morphological analysis combined (e.g., Vogt and McCoy,1980).

      At mid 20th century some cheloniologists used a suite of measurements (e.g., length, width, and height of carapace) to quantify shape. The use of ʺratiosʺ (Milstead, 1969)—the expression of one dimension as a percentage of another—was popular. Klauber (1941) introduced descriptive...

  5. ACCOUNTS OF TAXONOMIC GROUPS

    • A Key to the Families and Genera of Mexican Chelonians (Excluding the Sea Turtles)
      (pp. 62-64)
    • Superfamily Trionychoidea

      • Family Dermatemydidae
        (pp. 67-76)

        ʺTortuga Blancaʺ is the most common name in Mexico and alludes to the pale plastron; Central American River Turtle (Iverson, 1992a); Giant River Turtle (Iverson and Mittermeier, 1980); Hachac (Mayan; pers. comm. Niko Chin).

        Gr., derma, skin; dermatinos, leathery; Gr., emys, freshwater turtle. Probably alluding to the leathery appearance of the thin epidermal covering of the carapace, on which the scutes may be poorly defined in large adults; mawi is a patronym honoring the donor, a British naval officer named Solomon Maw (see the following).

        Two live specimens, presumably from a port on the Gulf Coast of Mexico, were brought...

      • Family Kinosternidae
        (pp. 77-182)

        The Family Kinosternidae (Gray) 1968 comprise a unique and varied family of trionychoids with an extensive distribution in the Western Hemisphere. They range from the northeastern United States and southeastern Canada (45°N) through the eastern and southeastern United States, and through Mesoamerica to Bolivia and northern Argentina (27°S). There are 31 named taxa within the family representing 22 full species and 4 genera; 24 of these occur in Mexico, and 17 are endemic to Mexico and adjacent Mesoamerican countries. Three extant genera occur in Mexico: Kinosternon, Staurotypus, and Claudius. Sternotherus probably occurred in northern Mexico at one time but is...

      • Family Trionychidae Softshell Turtles
        (pp. 183-200)

        L. tres, G. treis, three; G. onyx, -ychos, fingernail, talon, claw; alluding to the three claws on each manus and pes.

        The Family Trionychidae Fitzinger, 1826 are here regarded as the most morphologically specialized of nonmarine turtles. They have achieved these specializations without altering the basic chelonian Bauplan.

        The term ʺsoftshell turtleʺ is at once descriptive but misleading. Only the periphery of the shell (lacking peripheral bones) is ʺsoftʺ and flexible. The rest of the carapace, which is underlain by dermal bone, is as stout and almost as protective as that of typical chelonians.

        The work of Meylan (1987) is...

    • Superfamily Testudinoidea

      • Family Testudinidae
        (pp. 203-230)

        Family Testudinidae Batsch, 1788—The testudinids are the ʺtortoisesʺ in the strict sense of that vernacular term—chiefly medium to large, predominantly herbivorous, completely terrestrial chelonians. Most tortoises are the quintessence of slow, deliberate movement. They are docile and innocuous and are usually depicted as happy creatures in childrenʹs books. ʺThe Tortoiseʺ is a principal character in an Aesop fable (sixth century BC) and the international symbol for ʺslowʺ on lawn mowers.

        The family is considered a natural group with 19 genera, 54 species, and 85 terminal taxa (Bickham et al., 2007). They share characters with geoemydids and emydids but...

      • Family Emydidae Pond Turtles
        (pp. 231-336)

        There is no satisfactory vernacular name that applies accurately to all members of the Family Emydidae Rafinesque, 1815. Emydids are a natural group but are far more diverse than the testudinids. Diet ranges over the entire scale of omnivory, and habits range from completely terrestrial to completely aquatic.

        As treated here with full family status, the emydids are a chiefly western hemisphere group, ranging from Canada (ca. 52°N) to temperate South America (ca. 36°S; Legler, 1990). The single exception is the genus Emys (northern Africa and Eurasia). The family is comprised of 12 genera, 39 species, and a total of...

      • Family Geoemydidae
        (pp. 337-352)

        Family Geoemydidae Theobald 1868—The familial name ʺGeoemydidaeʺ has been in proper but unpopular use since about 1994 (David, 1994; Spinks, Shaffer, Iverson, and McCord, 2004). Membership of the family is equivalent to the formerly used ʺBataguridaeʺ (Gaffney and Meylan, 1988) or ʺBatgurinaeʺ (McDowell, 1964). The geoemydids are the chiefly Asiatic representatives of the once broadly inclusive Family Emydidae. Bour and Dubois (1986) showed that the name, Geoemydidae, has priority over Bataguridae or Batagurinae.

        Geoemydids share many characters with the familiy Emydidae (see account of Emydidae), most of which distinguish the two families from the Testudinidae. Bickham et al. (2007)...

    • Superfamily Chelydroidea

      • Family Chelydridae
        (pp. 355-364)

        Family Chelydridae Gray, 1831—The relationship of American snapping turtles (chelydrids) to Asiatic big-headed turtles (Platysternon megacephalum) has been debated for more than a century. Most recent taxonomic works place the genera Chelydra and Macrochelys in the family Chelydridae and Platysternon in the Family Platisternidae (see Smith and Smith, 1979, p. 341, for discussion of family name authorship).

        Agassiz (1857) placed Chelydra, MacrochelysGypochelysʺ), and Platysternon in the same family on the basis of sheer external morphological similarity. This premise has been fortified in bits and pieces since that time. The only major exception (based on actual, erudite study) was...

  6. LITERATURE CITED
    (pp. 365-392)
  7. INDEX
    (pp. 393-402)