Taxonomy and Species List

Taxonomy is the science of grouping naming things in a logical way.  A taxa is the name of a classification group. We generally use the Linnaean system, developed by Carl Linnaeus who, in 1735, developed a bi-nomial system for naming animals. The first of the names refers to the Genus of the animal, and the second represents the species. They are Latin words, or words from other languages written using Latin conventions.

Originally, living things were grouped by shared characteristics, such as shells for the chelonians, or types of hooves for horses, cows, etc. This evolved into grouping things based on how closely related they are, either by evolution and development, or by ability to successfully interbreed.

As we learn more, these relationships and names change, so any of this can be obsolete at any time!

Here is the classification tree for Tortoises:

Kingdom: Animal (Animalia)  The other kingdoms include plants, fungi, and assorted micro-organisms.

Phylum: Spinal chords (Chordata)

Sub-phylum: Spines (Vertebrata)  Humans and tortoises share the above categories, since we are both animals with spinal chords and a protective backbone. After this, we are in different groupings.

Class: Reptiles (Reptilia) Described by Josephus Nicolaus Laurenti in 1768.
The other classes include mammals, birds, fish, etc.

Order: Chelonians (Testudines) Described by August Batsch in 1788.
Chelonians (kell-OWE-knee-anz, a generic word for all turtles and tortoises) are usually considered an “order”.  Currently, Chelonians are one of 3  orders in the Reptilia class, the others being snakes/ lizards and Crocodilians. Some research suggests that Chelonians and Crocodilians may not be “reptiles” for several reasons, mostly due to the evolution of the skull openings. If they are their own class, it would be called Chelonians, and would be considered as described by Joseph Collins and Taggert in 2002. In this case, the sub-order Crytodira (described below) becomes a full order under the
class of Chelonians.

Chelonian ancestors split off from the “tree of life” during the Carboniferous Period about 260 million years ago. Their ancestors, called the Anapsids, have skulls that only have one opening for all facial nerves to go through. The Anapsids developed into several groups but only the Chelonians are still around. Later, in the Permian Period, another branch, the Diapsids, developed 2 skull openings and split off to become many other classes, including the reptiles, birds, and dinosaurs. We will only consider the Chelonians. The class is pretty easy to identify — just look for a shell!
The first true turtle, Proganochelys, seems to have appeared in the Triassic Period, about 213 million years ago.

(There is also good evidence that the Chelonians WERE diapsids at one point, and the other skull openings closed up.)

Turtles originally protected their heads by wrapping them sideways under the overhang of their shells. These turtles were called the Side-necks (order Pleuroira) and are still found today in tropical and semi-tropical fresh water habitats similar to their prehistoric homes.

Sub-order: Hidden-neck turtles (Cryptodira) Described by Edward Cope in 1871.
During the Jurassic Period, some 144 million years ago, turtles learned how to pull the head totally inside the shell in a vertical “S” curve, “hiding” the neck totally, hence the name. With their increased protection, they were able to colonize more habitats from temperate to tropical, salt water to desert. All tortoises are Cryptodira.

Family: The true tortoises (Testudinidae) Described by August Batsch in 1788
The phrase “the true tortoises” is used to differentiate the tortoises from other land turtles, especially in those places where species like North American Box Turtles are called “tortoises”. Around about the Eocene Period 38 million years ago, the first Chelonians that live totally on land, Hadrianus, appeared. Prehistoric tortoises ranged much farther than tortoises do today. Nebraska, for example, had tortoises back when it also had rhinos. Today, there are about 80 recognized species and sub-species, but as mentioned earlier, this is changing as we speak. Key characteristics of tortoises include:

– A lack of inframarginal scutes (scutes between the carapace and plastron)
– Deeply concave palate (high roof of the mouth, possibly for room for bulkier foods)
– The shape and muscle attachment of the ilium (the broad bones of the pelvis)
– The shape of the eighth cervical vertebra (biconvex)
– Heavy, high-domed shells in most species
– Heavy scales on the forelimbs
– Elephant-like legs without defined or movable toes (unlike other land turtles with more “turtle-like” feet)
– No scent glands or cloacal bursae (sacks on either side of the inside of the cloaca)
– Terrestrial habits: hunting, feeding, mating, nesting, and brumating on land. In fact, most tortoises will sink in water and avoid open water in the wild.

Dr. Peter Pritchard divides the tortoises into eleven functional groups (in which there is some overlap):

1. Generic tropical or near-tropical/arid-to-humid climate species with large, high domed shells, like the Red-footed Tortoise. 
2. General temperate/arid climate species. Usually smaller with less-domed shells, they are also designed to hibernate. Most Mediterranean Tortoises and Testudo species go here.
3. Dwarf sub-tropical/arid climate species, like the Padloppers, whose small size allows them to take advantage of all possible shelters and microclimates.
4. Species with moving shells, like the Hingebacks.
5. Specialized rock dwellers- the African Pancake Tortoise.
6. Burrowing species, like the Gopher Tortoises.
7. Highly armored species- now extinct.
8. Thick-shelled giant tortoises- now extinct.
9. Thin-shelled giant tortoises, such as the Galapagos Tortoises.
10. Super-giant mainland tortoises, such as the extinct Atlas Tortoise from India.
11. Humid forest species adapted to damp conditions, like the Manuoria species and Yellow-foot Tortoise which nest above the ground to avoid ground water in the nest.

Genus and species: This is a list of the currently recognized tortoise genera, species, and subspecies. Sizes listed are typical.

I.   Genus: Agrionemys (or Testudo) – Central Asian Tortoises (Khozatsky & Mlynarski, 1966) (Note: This is now considered to be Testudo since they freely interbreed with other members of Testudo.) Range: Southwestern Europe and Southeastern Asia in steppe habitats.

   A. horsfieldii, Horsfield’s Tortoise (Gray, 1844), 9in/22cm
      a.  A. h. horsfieldii, Russian, Steppe, or Horsfield’s tortoise (Khozatsky & Mlynarski,
          1966)
      b. A. h. bogdanovi, Fergina Valley Steppe Tortoise (Chkhikvadze, Brishko, Kubykin,
          2008)
       c. A. h. kazachstandica, Kazakhstan Steppe Tortoise (Chkhikvadze, 1988)
       d. A. h. kuznetzovi, Turkmenistan Steppe Tortoise (Chkikvadze, Ataev, Shammakov,
         and Satoka, 2009)
       e. A. h. rustamovi, Kopet-Dag Steppe Tortoise (Chkikvadze, Amiranashvili, and
         Ataev, 1990)
       f. A. h. terbishi, Mongolian Steppe Tortoise (Chkikvadze, 2009)

II. Genus: Aldabrachelys – Seychelles Giant Tortoises (Loveridge and Williams, 1957) (Note: The last three species listed here are probably extinct, but unusual specimens of Aldabran Tortoises have been found in zoos, private collections, and at a few very remote sites. They are believed to be examples of the last three species, but there is a lot of debate about this.) Range: Seychelle Island group off eastern Africa.

   A. gigantea, Aldabra Giant Tortoise (Schweigger, 1812), 47in/120cm
       a. A. g. gigantea, Aldabara Giant Tortoise (Schwigger, 1812)
       b. A. g. arnoldi, Arnold’s Giant Tortoise (Bour, 1982) possibly extinct
       c. A. g. daudinii, Daudin’s Giant Tortoise (Dumeril and Bibron, 1835) possibly extinct
       d. A. g. hololissa, Seychelle Giant Tortoise (Gunther, 1877) possibly extinct

III. Genus: Astrochelys – Radiated Tortoises (Gray, 1873) (Note: ALL tortoises from Madagascar are critically endangered due to habitat destruction and over-collection.) Range: Madagascar, off southeastern Africa.

  A.  A. radiata, Radiated Tortoise (Shaw, 1802), 16in/40cm, endangered

   B. A. yniphora, Angulated or Plowshare Tortoise (Valliant, 1885), 17in/43cm, critically
    endangered, less than 200 in the wild

IV. Genus: Chelonoidis (or Geochelone) – South American Tortoises (Fitzinger, 1835) Range: Southern part of Central America to South America, and assorted islands.

  A.  C. carbonaria, Red-footed Tortoise (Spix, 1824), 14in/36cm   
      May have up to 5 sub-species or species- such as Northern, Northeastern,
      Northwestern, Southern and Eastern
   B. C. chilensis, Pampas or Chilean Tortoise (Gray, 1870) S. America, 10in/26cm
   C. C. denticulata, Yellow-footed Tortoise (Linnaeus, 1766) S. America, 16in/40cm
   D. C. nigra, Galápagos Giant Tortoise Complex (Quoy & Gaimard, 1824) S. America,
     48in/122cm, endangered unless otherwise noted. Exact division of species and sub-
     species is debatable.
       a. C. n. nigra, Charles Island Giant Tortoise, possibly extinct
   E. C. abingdonii. Abingdon Island Giant Tortoise (Gunther, 1877) considered extinct as
     of 6-24-2012. R.I.P “Lonesome George”.
   F. C. becki, Vulcan Wolf Giant Tortoise (Rothschild 1901)
   G. C. chathamensis, Chatham Island Giant Tortoise (Van Denburgh, 1907)
   H. C. darwini, James Island Giant Tortoise (Van Denburgh, 1907)
   I. C. duncanensis, Duncan Island Giant Tortoise (Garman in Pritchard, 1996), critically
     endangered
   J. C. hoodensis, Hood Island Giant Tortoise (Van Denburgh, 1907) critically
     endangered
   K. C. phantastica, Narborough Island Giant Tortoise (Van Denborough, 1907), probably
     extinct
   L. C. porter, Indefatigable Island Giant Tortoise (Rothschild, 1903)
   M. C. vincina, Isabela Island Giant Tortoise (Gunther, 1875)
   N. C. petersi, Peter’s Tortoise (Freiberg, 1973), S. America, 10in/36cm. Considered a
     type or subspecies of the Chaco Tortoise by many sources.

V. Genus: Centrochelys (or Geochelone) – African Tortoise (Gray, 1872) Range: Southern edge of the Sahara in northern Africa.

   G. sulcata, African Spurred or “Sulcata” Tortoise (Miller, 1779), 30in/76cm

VI. Genus: Chersina – Bowsprit Tortoise (Gray, 1831) Range: South Africa.

   C. angulata, Bowsprit Tortoise (Schweigger, 1812), 8in/20cm, threatened

VII. Genus: Chersine (or Testudo) – Hermann’s Tortoise (Merrem, 1820) Range: Southern Europe.

   C. hermanni, Hermann’s Tortoise (Gmelin, 1789), 8in/20cm   
       a. C. h. hermanii, Western Hermann’s Tortoise (Gmelin, 1789)
       b. C. h. boettgeri, Eastern Hermann’s Tortoise (Mojsisovics, 1889)

VIII. Genus: Geochelone – “Typical” Tortoises (Fitzinger, 1835) Range: South-central Asia- India and Myanmar.

   A. G. elegans, Indian Star Tortoise (Schoepff, 1795), 10in/26cm  
   B. G. platynota, Burmese Star Tortoise (Blyth, 1863), 10in/26cm, critically endangered,
      nearly extinct in the wild

IX. Genus: Gopherus – Gopher Tortoises (Rafinesque, 1832) Range: Southern United States and northern Mexico.

A. G. agassizii, Desert Tortoise (Cooper, 1863), 15in/38cm, critically endangered
B. G. berlandieri, Texas Tortoise (Agassiz, 1857), 8in/20cm, threatened
C. G. flavomarginatus, Bolson or Mexican Giant Tortoise (Legler, 1959), 18in/46cm,
     endangered 
D. G. polyphemus, Gopher Tortoise (Daudin, 1801), 12in/30cm, endangered

X. Genus: Homopus – “Padlopers” or Cape Tortoises (Dumeril & Bibron, 1835) Range: Southern Africa.

   A. H. aerolatus, Parrot-beaked Cape Tortoise (Thunberb, 1787), 12in/30cm, threatened
   B. H. boulengeri, Boulenger’s Cape Tortoise (Duerdin, 1906), 4in/12cm, threatened
   C. H. femoralis, Karroo Cape Tortoise (Boulinger, 1888), 10in/15cm, threatened
   D. H. signatus, Speckled Cape Padloper (Gmelin, 1789), 4in/10cm, critically
      endangered
   E. H. solux, Nama Padloper (Branch, 2007), ??, endangered

XI. Genus: Indotestudo – Asian Tortoises (Lindholm, 1929) Range: Southern Asia and related islands. 

   A. I. elongata, Elongated Tortoise (Blyth, 1853), 12in/30cm
   B. I. forstenii, Forsten’s Tortoise (Schlegel & Muller, 1845), 12in/30cm, endangered
   C. I. travancorica, Travancore Tortoise (Boulenger, 1907), 12in/30cm, endangered

XII. Genus: Kinixys – Hingeback Tortoises (Bell, 1827) Range: Southern Africa.

   A. K. belliana, Bell’s Hingeback Tortoise (Bell, 1831), 8in/20cm, threatened
       a. K. b. belliana, Bell’s Hingeback Tortoise (Bell, 1831)
       b. K. b. domerguei, Madagascan Hingeback Tortoise (Vuillemin, 1972)
       c. K. b. nogueyi, Western Hingeback Tortoise (Lataste, 1886)
       d. K. b. zombensis, Southeastern Hingeback Tortoise (Hewitt, 1931)
   B. K. erosa, Serrated Hingeback Tortoise (Schweigger, 1812), 12in/30cm, threatened 
   C. K. homeana, Home’s Hingeback Tortoise (Bell, 1827), 8in/20cm, threatened
   D. K. lobatsiana, Lobatse Hingeback Tortoise (Power, 1927), 6in/15cm, threatened
   E. K. natalensis, Natal Hingeback Tortoise (Hewitt, 1935), 6in/15cm, threatened
   F. K. spekii, Speke’s Hingeback Tortoise, 8in/20cm, Grey, 1863, threatened

XIII. Genus: Malacochersus – Pancake Tortoise (Lindholm, 1929) Range: Tanzania and Kenya in Africa.

   M. tornieri, Pancake Tortoise (Siebenrock, 1903), 7in/18cm, threatened

XIV. Genus: Manouria – Indochinese Tortoises (Gray, 1854) Range: South-central Asia.

   A. M. emys, Asian Giant Tortoise (Schlegel & Miller, 1840) Asia, 24in/60cm, critically
    endangered
       a. M. e. emys, Asian Brown Giant Tortoise (Schlegel & Miller, 1840)
       b. M. e. phayrei, Burmese Black Giant Tortoise (Blyth, 1853)
    B. M. impressa, Impressed Tortoise (Gunther, 1882) Asia, 12in/30cm, threatened

XV. Genus: Psammobates – South African Star Tortoises (Fitzinger, 1835) Range: Southern Africa.

   A. P. geometricus, Geometric Tortoise (Linnaeus, 1758) Africa, 6in/15cm, critically
     endangered
   B. P. oculifer, Serrated Star Tortoise (Kuhl, 1820) Africa, 6in/15cm, endangered
   C. P. tentorius, African Tent Tortoise (Bell, 1828) Africa, 6in/15cm, endangered
       a. P. t. tentorius, Southern or Common Tent Tortoise (Bell, 1828)
       b. P. t. trimeni, Western Tent Tortoise (Boulenger, 1828)
       c. P. t. verroxii. Northern Tent Tortoise (Smith, 1839)

XVI. Genus: Pyxis – Spider Tortoises (Bell, 1827) (Note: ALL tortoises from Madagascar are critically endangered due to habitat destruction and over-collection.) Range: Madagascar.

   A. P. arachnoides, Spider Tortoise (Bell, 1827) Africa, 6in/15cm, critically endangered
       a. P. a. aracnoides, Common Spider Tortoise (Bell, 1827)
       b. P. a. brygooi, Northern Spider Tortoise (Vuillemin and Domergue, 1972)
       c. P. a. oblonga, Southern Spider Tortoise (Gray, 1869)
   B. P. planicauda, Madagascan Flat-tailed Tortoise (Grandidier, 1867) Africa, 5in/13cm,
     critically endangered

XVII. Genus: Stigmochelys (or Geochelone) – Leopard Tortoises (Gray, 1873) Range: Savannahs of eastern and southern Africa. 

   S. pardalis, Leopard Tortoise (Bell, 1828) Africa, 18in/46cm
       a. S. p. pardalis, Common or Northern Leopard Tortoise (Bell, 1828)
       b. S. p. babcocki, Southern Leopard Tortoise

XVIII. Genus: Testudo – Mediterranean or Paleartic Tortoises (Linnaeus, 1758) (Note: This species is undergoing revision and re-evaluation.) Range: Mediterranean Ocean region.

   A. T. graeca, Greek or Spur-thighed Tortoise complex (Linnaeus, 1758) Europe,
     8in/20cm
       a. T. g. graeca, Mediterranean Spur-thighed Tortoise (Linnaeus, 1758)
       b. T. g. armeniaca, Araxes Tortoise (Chkhikvadze and Bakradze, 1991)
       c. T. g. buxtoni, Buxton’s Tortoise (Boulenger, 1921)
       d. T. g. cyrenaica, Cyrenanican Spur-thighed Tortoise (Pieh and Perala, 2002)
       e. T. g. iberia, Asia Minor Tortoise (Pallas, 1814)
       f. T. g. marrokensis, Morocco Tortoise (Pieh and Perala, 2004)
       g. T. g. nabeulensis, Nabeul Tortoise (Highfield, 1990)
       h. T. g. soussensis, Souss Valley Tortoise (Pieh, 2001)
       i. T. g. terrestris, Mesopotamian Tortoise (Forskall, 1775)
       j. T. g. zarudny, Iranian Tortoise (Nikolsky, 1896)
   B. T. kleinmanni, Egyptian or Negev Tortoise (Lortet, 1883) Africa, 6in/15cm, critically 
     endangered
   C. T. marginata, Marginated Tortoise (Schoepff, 1793) Africa, 15in/38cm

Terrestrial or semi-terrestrial turtles

Family: Emydinae – The Pond Turtles (Rafinesque, 1815)

I. Genus: Glyptemys – American Bog Turtles (Agassiz, 1857) Range: Eastern United States.

   A. G. insculpta, Wood Turtle (LeConte, 1830) N. America, 5in/13cm, threatened
   B. G. muhlenbergi, Muhlenberg or Bog Turtle (Schoeph, 1801), 4n/11cm, endangered

II. Genus: Terrapene – American Box Turtles (Merrem, 1820) Range: United States and Mexico.

   A. T. carolina, Common Box Turtle (Linnaeus, 1758), 6in/15cm
       a. T. c. carolina, Eastern Box Turtle (Linnaeus, 1758)
       b. T. c. bauri, Florida Box Turtle (Taylor, 1895)
       c. T. c. major, Gulf Coast Box Turtle (Agassiz, 1857)
       d. T. c. mexicana, Mexican Box Turtle (Gray, 1849)
       e. T. c. triungus, Three-toed Box Turtle (Agassiz, 1857)
       f. T. c. yucatana, Yucatan Box Turtle (Boulinger, 1895)
   B. T. coahuila, Coahuila Box Turtle (Schmidt and Owens, 1944), 6in/15cm, critically
      endangered
   C. T. nelson, Spotted Box Turtle (Stejneger, 1925), 5in/14cm
       a. T. n. nelson, Northern Spotted Box Turtle (Stejneger, 1925)
       b. T. n. klauberi, Southern Spotted Box Turtle (Bogert, 1942)
   D. T. ornata, Ornate or Western Box Turtle (Agassiz, 1857), 5in/14cm
       a. T. o. ornata, Ornate or Western Box Turtle (Agassiz, 1857)
       b. T. o. luteola, Desert Box Turtle (Smith and Ramsey, 1952)

Family: Geoemydinae – Semi-terrestrial Turtles (Theobald, 1868)

I. Genus: Cistoclemmys (or Cuora) – Asian Box Turtles (Gray, 1856) Range: Southeastern Asia.

   A. C. bourreti, Bourret’s Box Turtle (Obst and Reinmann, 1994), 7.5in/19cm, critically
     endangered
   B. C. flavomarginata, Yellow-margined Box Turtle (Gray, 1863), 7in/17cm, endangered
   C. C. galbinifrons, Indochinese or Flower-back Box Turtle (Bourret, 1939), 7.5in/19cm,  
     endangered
       a. C. g. galibinifrons, Flower-back Box Turtle (Bourret, 1939)
       b. C. g. bourreti, Bourret’s Box Turtle (Obst and Reimann, 1994)
       c. C. g. hainanensis, Hainan Island Box Turtle (Li, 1958)
   D. C. picturata, Southern Vietnam Box Turtle (Lehr, Fritz, and Obst, 1998), 7in/18cm,
     critically endangered

II. Genus: Cyclemys – Asian Leaf Turtles (Bell, 1834) Range: Southeastern Asia.

   A. C. dentata, Asian Leaf Turtle (Gray, 1831), 9in/23cm, endangered
   B. C. oldhami, Southeast Asian Leaf Turtle (Gray, 1863), 8in/20cm, endangered

III. Genus: Geoemyda – Black-breasted Leaf Turtles (Gray, 1834) Range: Okinawa and Indochina.

   A. G. japonica, Ryuku Black-breasted Leaf Turtle (Fan, 1931), 6in/15cm, endangered
   B. G. spengleri, Vietnamese or Black-breasted Wood Turtle (Gmelin, 1789),
       4.5in/11cm, endangered

IV. Genus: Heosemys – Indochinese Pond Turtles (Stejneger, 1902) Range: Indochina.

   A. H. depressa, Arakan Forest Turtle (Anderson, 1875), 11in/29cm, critically
     endangered
   B. H. spinosa, Spiny Turtle (Gray, 1830) Indochina, 9in/23cm, endangered

V. Genus: Luecocephalon – Sulwanese Forest Turtles (McCord, Iverson, Spinks and Shaffer, 2000) Range: Indonesia.

   A. L. yuwonoi, Sulawesi Forest Turtle (McCord, Iverson, and Boeadi, 1995), 11in/28cm,
     critically endangered

VI. Genus: Melanochelys – Indo-asian Black Turtles (Gray, 1869) Range: India.

   A. M. tricarinata, Tricarinate Hill or Three-keeled Land Turtle (Blyth, 1856), 6in/16cm,
     endangered 
   B. M. trijuga, Indian Black Turtle (Schweigger, 1812) India, 15in/38cm, endangered

VII. Genus: Pangshura – Roofed Turtles (Gray, 1856) Range: India.

   P. sylhetensis, Assam Roofed Turtle (Jerdon, 1870), 9in/24cm, endangered

VIII. Genus: Pyxidea (or Cuora) – Keeled Box Turtles (Gray, 1826?) Range: Indochina.

   P. mouhotii, Keeled Box Turtle (Gray, 1826) Indochina, 7in/18cm, endangered

IX. Genus: Rhinoclemmys – Central and South American Wood Turtles (Fitzinger, 1835) Range: Central and South America.

   A. R. annulata, Tropical Wood Turtle (Gray, 1860) Central and South America,
     9in/23cm
   B. R. areolata, Furrowed Wood Turtle (Dumeril and Bibron, 1851) Central America,
     9.5in/24cm
   C. R. pulcherrima, Painted Wood Turtle (Gray, 1855) Central America, 8.5in/22cm,
     threatened
       a. R. p. pulcherrima, Guerrero Wood Turtle (Gray, 1856)
       b. R. p. incisa, Incised Wood Turtle (Bocourt, 1868)
       c. R. p. manni, Central American Wood Turtle (Dunn, 1930)
       d. R. p. rogerbarbouri, Western Mexico Wood Turtle (Ernst, 1978)
   D. R. rubida, Oxaca Wood Turtle (Cope, 1870) Mexico, 9in/23cm, forest

X. Genus: Vijaychelys – Cane Forest Turtles (Prashag, Schmidt, Fritzsch, Muller, Gemel and Fritz, 2006) Range: India.

 V. silvatica, Cochin Cane Forest Turtle (Henderson, 1912) India, 5in/13cm, critically
     endangered.

Resources

• Bonin, Devaux and Dupre “Turtles of the World” (1996)
• Fritz and Ernst’s “Turtles of the World Database” (2002)
• Pritchard, Peter C. H. and Pedro Trebbau. Turtles of Venezuela (Contributions to Herpetology). SSAR, 1984. ISBN 0916984117.
• World Conservation Union’s (IUCN) Tortoise and Freshwater Turtles Specialist Group “Turtles of the World 2010 Checklist”