Reptile Phylogeny
The reptile family tree below includes only living reptiles.  The phylogeny of the reptiles is in a state of considerable flux, and some of the relationships indicated below may be regarded as controversial. The traditional taxonomy, with its neat division into turtles, crocodiles, snakes and lizards, has become inadequate to capture the complexities of this fascinating group of animals.  Because the reptiles are a group of such great interest,I have attempted to make a simplified representation of relationships thought to exist among the various reptilian taxa.  This has been a daunting task for somebody practicing herpetology without a license.  The tree you see below has been redrawn from cladograms and other information from several sources; the phylogeny of the squamates has recently been updated from molecular data (Vidal and Hedges, 2005). However, the fault for any errors or misinterpretations in the tree rests with me, not with the original source.  I have omitted some branches in the interest of simplification; I hope your personal favorite is not among them.  Corrections of errors, gross omissions or misinterpretations will gratefully be received.  With the exception of the Tuataras, examples of all of the reptilian taxa below can be seen at the Fort Worth Zoo's outstanding Herpetarium. 
Herp Phylogeny Link to Bird Phylogeny Page Link to Picture of Alligator Lizard Link to Picture of Caiman Lizard Link to Mexican Tiger Rat Snake Picture Link to Snake Necked Turtle Picture Link to Aldabra Tortoise Page Link to Gharial Page Link to Rhino Viper Page Link to Green Mamba Page Link to Green Tree Python Page Link to Beaded Lizard Page Link to Water Monitor Page Link to Solomon Island Skink Page Link to Giant Madagascar Day Gecko Page Link to Parson's Chameleon Page Link to Frilled Lizard Page Link to Green Iguana
Invertebrate
Tree
Fish
Tree
Tetrapod
Tree
Reptile
Tree
Bird
Tree
Mammal
Tree
Rhinoceros Iguana Frilled Lizard Chameleon Day Gecko  
Iguanid
Rhinoceros Iguana
Agamid
Frilled Lizard
Chameleon
Parson's Chameleon
Gecko
Giant Madagascar Day Gecko
*Amphisbaenid
(No picture)
Blue tongued skink Caiman Lizard Alligator Lizard Chinese Croc Lizard Green Tree Monitor
Skink
Blue-tongued Skink
Teid
Caiman Lizard
Anguid
Atitlan Alligator Lizard
Xenosaurid
(Oaxacan Rock Lizard)
Monitor
Green Tree Monitor
Mexican Beaded Lizard Annulated Boa NW Neotropical Rattler Honduran Milk Snake Tentacled Snake
Beaded Lizard
Mexican Beaded Lizard
Boid
Annulated Boa
Viper
Northwestern Neotropical Rattlesnake
Colubrid
Honduran Milk Snake
Elapid
Tentacled Snake
To the Amphibians
Dwarf Cayman Snake-necked turtle Star Tortoise
To the Birds
Crocodilian
Dwarf Caiman
Side-necked Turtle
Australian Snake-necked Turtle
Hidden-necked Turtle
Indian Star Tortoise
*Examples of snakes and lizards not pictured here can be seen at this page from the University of Aberdeen Zoology Museum.






Sources of information:


WhoZoo Home
Reptile and Amphibian Index
AnimalIndex