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Integrated Taxonomic Information System (ITIS)

squamates

    Kingdom: Animalia
    Division: Chordata
    Subdivision: Vertebrata
    Class: Reptilia
    Order: Squamata

Gecko Field Guide

Peninsular Leaf-toed Gecko (Phyllodactylus nocticolus) - feet ventral view
Peninsular Leaf-toed Gecko (Phyllodactylus nocticolus) - feet ventral view [Photo: Yuri Huta, Copyright: Finding Species]

Visit GeckoWeb for an online field guide to geckos of the United States.

Lizards

Western fence lizard (Seloporus occidentalis) Five-lined skink (Eumeces fasciatus) Black spiny-tailed iguana (Ctenosaura similis) White-spotted wall gecko (Tarentola annularis)
Western fence lizard (Sceloporus occidentalis) [Photo: John J. Mosesso: NBII Digital Image Library] Five-linked skink (Eumeces fasciatus) [Photo: John J. Mosesso: NBII Digital Image Library] Black spiny-tailed iguana (Ctenosaura similis) [Photo: John J. Mosesso: NBII Digital Image Library] White-spotted wall gecko (Tarentola annularis) [Photo: Yuri Huta, Copyright: Finding Species]

What are Lizards?

Lizards are members of the taxon Squamata. Like other squamates (i.e., amphisbaenians and snakes) lizards have elongated bodies, skin that sheds in large fragments, a pair of hemipenes (male copulatory organs), and other typical squamate features.

Lizards are the largest and most diverse group of reptiles. The diversity of the group is apparent from its variety of reproductive strategies, including egg-laying (oviparity), live birth (viviparity), and sex determined by genes or temperature. In terms of basic morphology, most lizards have claws and four limbs, and many are able to shed their tails (caudal autotomy) to evade a predator. The New World (North, Central, and South America) is home to some unique lizard groups including all teiids (whiptails, etc.), all helodermatids (i.e. the gila monster and beaded lizard), and most of the world's iguanids (iguanas, horned lizards, chuckwallas, etc.).

References for Lizards

Lizard Identification and Distribution
Showing 10 of 81 ( Show All )
CollapseAmphibians and Reptiles of North America
Description: Listing of amphibians and reptiles of North America.
Resource Type: Checklists and Identification Guides
Resource Format: URL
Publisher: University of Puget Sound
CollapseAnguidae (Anguidae) Potential Distribution Map Services
Description: These map services represent GAP potential species distributions developed from habitat affinity models by the GAP Analysis Program, a dataset used in determining the conservation status of common species within a given state. The select species included in this map are defined as belonging in the order of Lizards and snakes (Squamata) and family of Anguidae (Anguidae). These map services are available through OGC WMS 1.1.1 enabled for public access.
Resource Type: Internet Map Services
Resource Format: Interactive Mapping
Publisher: National Biological Information Infrastructure ( NBII )
CollapseAnimal Diversity Web
Description: Animal Diversity Web (ADW) is an online database of animal natural history, distribution, classification, and conservation biology at the University of Michigan.
Resource Type: Databases and Information Systems, Digital Photographs, Issue Overviews, K-12 Curriculum and Lesson Plans, Life Histories and Species Profiles, Museum Collections
Resource Format: URL
Publisher: The Regents of the University of Michigan and its licensors
CollapseAnoles (Polychrotidae) Potential Distribution Map Services
Description: These map services represent GAP potential species distributions developed from habitat affinity models by the GAP Analysis Program, a dataset used in determining the conservation status of common species within a given state. The select species included in this map are defined as belonging in the order of Lizards and snakes (Squamata) and family of Anoles (Polychrotidae). These map services are available through OGC WMS 1.1.1 enabled for public access.
Resource Type: Internet Map Services
Resource Format: Interactive Mapping
Publisher: National Biological Information Infrastructure ( NBII )
CollapseArizona Herpetological Association
Description: The AHA offers the public a reptile removal service. Several members volunteer to remove unwanted reptiles from homes and offices. This site provides identification guides for snakes and lizards found in Arizona.
Resource Type: Checklists and Identification Guides
Resource Format: URL
Publisher: Arizona Herpetological Association
CollapseBaja California Collared Lizard
Description: Profile of the Baja California Collared Lizard. Information about nomenclature, morphology, home range, habitats, life history and conservation status are included.
Resource Type: Life Histories and Species Profiles
Resource Format: URL
Publisher: San Diego Natural History Museum
CollapseBeaded lizards (Helodermatidae) Potential Distribution Map Services
Description: These map services represent GAP potential species distributions developed from habitat affinity models by the GAP Analysis Program, a dataset used in determining the conservation status of common species within a given state. The select species included in this map are defined as belonging in the order of Lizards and snakes (Squamata) and family of Beaded lizards (Helodermatidae). These map services are available through OGC WMS 1.1.1 enabled for public access.
Resource Type: Internet Map Services
Resource Format: Interactive Mapping
Publisher: National Biological Information Infrastructure ( NBII )
CollapseBiologyBase: Reptiles
Description: This site provides the user with access to the BiologyBase checklist of reptiles of Eastern North America.
Resource Type: Checklists and Identification Guides, Databases and Information Systems, Taxonomies
Resource Format: URL
Publisher: Robert B. Hole, Jr.
CollapseBlue-Tailed Day Gecko: Phelsuma cepediana
Description: This site provides information on the blue-tailed day gecko (Phelsuma cepediana) and includes taxonomy, description, and status.
Resource Type: Life Histories and Species Profiles
Resource Format: URL
Publisher: Encyclopedia Mauritiana
CollapseBoa snakes and pythons (Boidae) Potential Distribution Map Services
Description: These map services represent GAP potential species distributions developed from habitat affinity models by the GAP Analysis Program, a dataset used in determining the conservation status of common species within a given state. The select species included in this map are defined as belonging in the order of Lizards and snakes (Squamata) and family of Boa snakes and pythons (Boidae). These map services are available through OGC WMS 1.1.1 enabled for public access.
Resource Type: Internet Map Services
Resource Format: Interactive Mapping
Publisher: National Biological Information Infrastructure ( NBII )

Reptiles as Pollinators

Blue-tailed day gecko on flower
A male blue-tailed day gecko (Phelsuma cepediana) feeding on a Trochetia blackbumiana flower [Photo: Courtesy Dennis Hansen]

Did you know that reptiles pollinate plants? In fact, there are at least 37 known occurrences of different lizard species visiting flowers and/or providing pollination services.

Learn more about reptiles as pollinators.

Invasive Lizards

Brown anole (Norops sagrei)
Brown anole (Norops sagrei) [Copyright: Tanya Dewey, courtesy Animal Diversity Web]

Numerous species of lizards have been introduced into the United States - most of them in Florida. These animals come in as hitch hikers on cargo and imported plants. Others are released pets that manage to thrive.

Learn more about invasive lizards.

Species Spotlight

Texas horned lizard (Phrynosoma cornutum)
Texas horned lizard (Phrynosoma cornutum) [Photo: National Park Service]

Texas horned lizard
Phrynosoma cornutum

Description: A flattened, wide-bodied lizard. The skin is mostly brown, yellowish, tan, reddish, or grey, with dark lines radiating from each eye, and dark, brown splotches on its neck, back, and tail.

Habitat: Desert, grassland/herbaceous, shrubland/chaparral. The lizards occur in dry, open habitats with sparse vegetation.

Distribution: South-central United States and northern Mexico.

Status: Widespread and common in some areas, but faces some threats such as fire ants, insecticides, loss of habitat, and overcollecting.

Resources:

NatureServe Explorer: An Online Encyclopedia of Life

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