This lifeform is found in the SW USA (Texas, New Mexico, and Arizona). This lifeform is found in Mexico.

Desert Tortoise (Gopherus agassizii) is found from Nevada south to Arizona and southwest California into Baja California and Sonora. This tortoise can become quite large as specimens up to fifteen inches long are known. The under-shell is not hinged. The elephant-like feet help identify this species.

North American Tortoises are limited to three different species as follows (an * indicates pictured and discussed):

     SCIENTIFIC NAME          GENERAL NAME  
       (Common Name)

     Gopherus agassizii*      Southwest United States
       (Desert Tortoises)
     Gopherus berlandieri     Big Bend Texas and Mexico
       (Texas Tortoises)
     Gopherus polyphemus*     Southeast United States
       (Gopher Tortoise)

Tortoises (Family Testudinidae) are characterized by their club  shaped feet. Although primarily found in the Old World, several  species are found in the western and southern United States and a few are found in South America. Some giants inhabit the Galapagos Islands. Tortoises are not adept swimmers, and are essentially land animals and vegetarians.  There are about 40 species in this family. (David Alderton in his excelllent 1993 book lists 38 full species plus various subspecies in the appendix, but mentions 41 known species earlier in the text. This book also has a check list of known turtle species.)

Turtle and Tortoise group (Order Chelonia) are among the most  primitive reptiles. They are egg-laying creatures characterized  by having four legs, a tail, and two shells each made up of many scales that are joined together. There are about two hundred and fifty species of turtles in the world. Carl  Ernst and Roger Barbour published a book entitled "Turtles of the World" by the Smithsonian Press in l989. This work covers all of the known species. The authors note that there are two hundred and fifty-seven species of living turtles. Many of these species are pictured and discussed here.

The following overview of the various families included in the Turtle Order is based on the aforementioned publication:

       SCIENTIFIC NAME     COMMON NAME         NUMBER OF SPECIES
       Pelomedusidae       Side Necked        23  species
       Chelidae            Side Necked        36  species
       Kinosternidae       Mud and Musk       22  species
       Dermatemydidae      River Turtle        1  species
       Carettochelyidae    Pig Nose            1  species
       Trionychidae        Soft Shelled       22  species
       Dermochelyidae      Leatherback         1  species
       Cheloniidae         Sea Turtles         6  species
       Chelydridae         Snapping turtles    2  species
       Platysternidae      Big Headed          1
       Emydidae            Pond and Box       91  species
       Testudinidae        Tortoises          50  species
                                       256 total species

While the above counts are currently reliable, they will be impacted by findings as research continues. For example, the exact count of the species of tortoises in the Galapagos and placement of the Florida Snapping Turtle might change these counts.

Reptiles (Class Reptilia) are an ancient group of scaled  chordates. These scales may be permanently joined, as in the  turtles, or flexible, as in the snakes. Reptiles are land-based. Their eggs are laid on land and the young are air breathing.

Backboned Animals (Phylum Chordata) are the most advanced group of animals on earth. These animals are characterized by having a spinal cord or backbone. Most members have a clearly defined brain that controls the organism through a spinal cord. Fish, amphibians, reptiles, birds, and mammals are in this phylum.

Currently, some taxonomists believe that the fish should be divided into two groups (sharks and regular fishes) and that there are some other primitive groups in the phylum such as hagfish or lampreys.

Animal Kingdom contains numerous organisms that feed on other animals or plants. Included in the animal kingdom are the lower marine invertebrates such as sponges and corals, the jointed legged animals such as insects and spiders, and the backboned animals such as fish, amphibians, reptiles, birds, and mammals.