Herpetology Reptiles - Squamata & Serpentes

Glass Lizard

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Spiny Lizard

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Gila Monster

A heavy, typically slow-moving lizard, up to 60 cm (2.0 ft) long, the Gila monster is the only venomous lizard native to the United States and one of only two known species of venomous lizards in North America, the other being its close relative, the Mexican beaded lizard (H. horridum). Though the Gila monster is venomous, its sluggish nature means it represents little threat to humans. However, it has earned a fearsome reputation and is sometimes killed despite being protected by state law in Arizona. The tail is about 20% of the body size and the largest specimens may reach 51 to 56 cm (20 to 22 in) in total length. Body mass is typically in the range of 350 to 700 g (0.77 to 1.54 lb), with 11 males having been found to average 468 g (1.032 lb). They are preyed upon by coyotes and raptors.

Pit Vipers

All viperids have a pair of relatively long solenoglyphous (hollow) fangs that are used to inject venom from glands located towards the rear of the upper jaws, just behind the eyes. Each of the two fangs is at the front of the mouth on a short maxillary bone that can rotate back and forth. When not in use, the fangs fold back against the roof of the mouth and are enclosed in a membranous sheath. The left and right fangs can be rotated together or independently. During a strike, the mouth can open nearly 180° and the maxilla rotates forward, erecting the fangs as late as possible so that the fangs do not become damaged, as they are brittle. The jaws close upon impact and the muscular sheaths encapsulating the venom glands contract, injecting the venom as the fangs penetrate the target. This action is very fast; in defensive strikes, it will be more a stab than a bite. Viperids use this mechanism primarily for immobilization and digestion of prey.

Pigmy Rattlesnakes

Although bites from Sistrurus species are regarded as less dangerous to humans than those from Crotalus rattlesnakes, primarily due to their lower venom yield, every venomous snake bite should be considered serious and prompt medical treatment should always be sought. They are smaller in size, but also their scalation is different

Earless Lizard

Earless lizards have a peculiar defense mechanism which is coupled to their cold-blooded lifestyle. They have a small opening on the top of their head called a 'blood sinus' which helps the lizard to gain heat quickly during the daytime. However, the blood can also be channelized to the eyes of the lizard when a predator looms close by, efficiently spitting the blood onto the predator giving it enough time to escape.

Iguanids

Iguanas can range from 1.5 to 1.8 meters (5 to 6 ft) in length, including their tail. The two species of lizard within the genus Iguana possess a dewlap, a row of spines running down their backs to their tails, and a tiny "third eye" on their heads. This light-sensing organ is known as the parietal eye, visible as a pale scale on the top of the head, and cannot make out details, just brightness. Behind their necks are small scales which resemble spokes, known as tuberculate scales. These scales may be a variety of colors and are not always visible from close distances. They have a large round scale on their cheeks known as a subtympanic shield. Iguanas have developed a herbivorous lifestyle, foraging exclusively on vegetation and foliage. In order to acquire, process, and digest plant matter, herbivorous lizards must have a higher bite force relative to their size in comparison to carnivorous or omnivorous reptiles.

Green Iguana

It grows to 1.5 meters (4.9 ft) in length from head to tail, although a few specimens have grown more than 2 meters (6.6 ft) with body weights upward of 20 pounds (9.1 kg). Agile climbers, Iguana iguana can fall up to 50 feet (15 m) and land unhurt (iguanas use their hind leg claws to clasp leaves and branches to break a fall). During cold, wet weather, green iguanas prefer to stay on the ground for greater warmth. Green Iguanas are primarily herbivores, with captives feeding on leaves such as turnip greens, mustard greens, dandelion greens, flowers, fruit, and growing shoots of upwards of 100 different species of plant. Green iguanas will thrive only in temperatures of 79 °F (26 °C) to 95 °F (35 °C)

Rattlesnakes

Rattlesnakes are heavily preyed upon as neonates, while they are still weak and immature. Large numbers of rattlesnakes are killed by humans. Rattlesnakes are found in almost every type of habitat capable of supporting terrestrial ectothermic vertebrates, but individual species can have extremely specific habitat requirements, only able to live within certain plant associations in a narrow range of altitudes. Most species live near open, rocky areas. Rocks offer them cover from predators, plentiful prey (e.g. rodents, lizards, insects, etc. that live amidst the rocks), and open basking areas. However, rattlesnakes can also be found in a wide variety of other habitats including prairies, marshes, deserts, and forests.

Skinks (Lizards)

Skinks look like true lizards, but most species have no pronounced neck, and their legs are relatively small; several genera (e.g., Typhlosaurus) have no limbs at all. Skinks are generally carnivorous and in particular insectivorous. Typical prey includes flies, crickets, grasshoppers, beetles, and caterpillars. Various species also eat earthworms, millipedes, snails, slugs, isopods, moths, other lizards, and small rodents. A trait apparent in nearly all species of skink is a love of digging and burrowing. Most spend their time underground where they are mostly safe from predators, sometimes even digging out tunnels for easy navigation. They also use their tongues to sniff the air and track their prey. When they encounter their prey, they chase it down until they corner it or manage to land a bite and then swallow it whole. As a family, skinks are cosmopolitan; species occur in a variety of habitats worldwide, apart from boreal and polar regions. Various species occur in ecosystems ranging from deserts and mountains to grasslands.

Coral Snakes

Some species, like Micrurus surinamensis are almost entirely aquatic and spend most of their lives in slow-moving bodies of water that have dense vegetation. Coral snakes feed mostly on smaller snakes, lizards, frogs, nestling birds, small rodents, etc. Like all elapid snakes, coral snakes possess a pair of small hollow fangs to deliver their venom. The fangs are positioned at the front of the mouth. The fangs are fixed in position rather than retractable, and rather than being directly connected to the venom duct, they have a small groove through which the venom enters the base of the fangs.

Copperhead

The body is relatively stout and the head is broad and distinct from the neck. Because, the snout slopes down and back, it appears less blunt than that of the cottonmouth, A. piscivorus. Consequently, the top of the head extends further forward than the mouth. The color pattern consists of a pale tan to pinkish tan ground color that becomes darker towards the fore line, overlaid with a series of 10-18 (13.4) crossbands. These crossbands are light tan to pinkish tan to pale brown in the center, but darker towards the edges. They are about 2 scales wide or less at the midline of the back but expand to a width of 6-10 scales on the sides of the body.

Wall Lizards

The common wall lizard is a small, thin lizard whose small scales are highly variable in color and pattern. Its coloration is generally brownish or greyish, and may occasionally be tinged with green. This lizard has six distinct morphological forms which are identified by the coloration of its throat and underbelly. Three of these are pure morphs consisting only of solid colors on their scales: white, red (orange) or yellow, and three other morphs are distinguished by a combination of colors: white-yellow, white-red and yellow-red.

Blind Snakes

The cranium and upper jaws are immobile and no teeth are in the upper jaw. The lower jaw consists of a much elongated quadrate bone, a tiny compound bone, and a relatively larger dentary bone. These relatively small snakes rarely exceed 30 cm in length

Desert Iguana

The desert iguana is a blunt, medium-sized lizard which grows to 61 cm (24 in) including the tail. The tail is usually around 1½ times longer than the body from snout to vent. Mating takes place in the early spring. It is believed that only one clutch of eggs is laid each year, with each clutch having 3-8 eggs. Desert iguanas are primarily herbivorous, eating buds, fruits, and leaves of many annual and perennial plants. Predators of these iguanas and their eggs are birds of prey, foxes, rats, long-tailed weasels, some snakes, and humans. These lizards can withstand high temperatures and are out and about after other lizards have retreated into their burrows. They burrow extensively and if threatened will scamper into a shrub and go quickly down a burrow. Their burrows are usually dug in the sand under bushes like the creosote. They also often use burrows of kit foxes and desert tortoises.

Alligator Lizard

The southern alligator lizard measures from 3 to 7 inches (7.3 - 17.8 cm) in snout-to-vent length (SVL). Including tail, it can reach a foot in length (30 cm). It has a round thick body with small legs and a long somewhat prehensile tail that can be twice as long as the lizard's body. Like many lizards, this species can drop its tail if attacked, possibly giving it a chance to flee. It lives on average 10 to 15 years, but probably shorter in captivity.The southern alligator lizard is native to the Pacific coast of North America, ranging from the state of Washington to Baja California. These lizards can be found in many diverse habitats, including grassland, open forest, chaparral, suburban and urban areas, and even into the desert along the Mojave River.

Horned Lizards

Their coloration generally serves as camouflage. When threatened, their first defense is to remain still to avoid detection. If approached too closely, they generally run in short bursts and stop abruptly to confuse the predator's visual acuity. If this fails, they puff up their bodies to cause them to appear more horned and larger, so that they are more difficult to swallow. Population declines are attributed to the loss of habitat, human eradication of the ant populations upon which the lizard's prey, displacement of native ant populations by invading fire ants (aided by synergistic effects of native ant eradication), and predation by domestic dogs and cats.

Fringe-toed lizards

These lizards have a brown and tan coloration that helps them to blend in with the sand. The dorsal surface has a velvety texture with intricate markings. In addition, they also have prominent elongated scales which form a fringe on the sides of their hind toes. These fringes aid with traction and speed and help the lizard avoid sinking into loose, sandy dunes. They are found in low desert areas having fine, loose sand. They primarily eat insects, including ants, beetles, grasshoppers, and caterpillars. Flower buds, stems, leaves and seeds of plants are also eaten These lizards range throughout southeast California and southwest Arizona, and extend into northwest Sonora and northeast Baja California.

Brahminy Blind Snakes

They are completely fossorial (i.e., burrowing) animals, with habits and appearance similar to earthworms, for which they are often mistaken, although close examination reveals tiny scales rather than the annular segments characteristic of true earthworms. As adults, they measure 2.5-6.5 inches (6.4-16.5 cm) long. These snakes live underground in ant and termite nests. They are also found under logs, moist leaves, and humus in wet forest, dry jungle, and even city gardens.

Chuckwalla

They are sexually dimorphic, with males having reddish-pink to orange, yellow, or light gray bodies and blackheads, shoulders, and limbs; females and juveniles have bodies with scattered spots or contrasting bands of light and dark in shades of gray or yellow. Males are generally larger than females and possess well-developed femoral pores located on the inner sides of their thighs; these pores produce secretions believed to play a role in marking territory. Chuckwallas prefer lava flows and rocky areas typically vegetated by creosote bush and other such drought-tolerant scrub. The lizards may be found at elevations up to 4,500 ft (1,370 m). Primarily herbivorous, chuckwallas feed on leaves, fruit, and flowers of annuals and perennial plants; insects represent a supplementary prey. Harmless to humans, these lizards are known to run from potential threats. When disturbed, a chuckwalla wedges itself into a tight rock crevice and inflates its lungs to entrench itself.

Gecko Lizards

They range from 1.6 to 60 cm (0.64 to 24 inches). Most geckos cannot blink, but they often lick their eyes to keep them clean and moist. They have a fixed lens within each iris that enlarges in darkness to let in more light. Many species are well known for their specialized toe pads that enable them to climb smooth and vertical surfaces, and even cross indoor ceilings with ease. Geckos occur in various patterns and colors and are among the most colorful lizards in the world. Some species can change color and may be lighter in color at night. Some species are parthenogenetic, which means the female is capable of reproducing without copulating with a male. Like other reptiles, geckos are ectothermic, producing very little metabolic heat. in order to accomplish their main functions such as locomotion, feeding, reproduction, etc. geckos must have a relatively elevated temperature

Rubber Boa

adults can be anywhere from 38 to 84 cm (1.25 to 2.76 ft) long; newborns are typically 19 to 23 cm (7.5 to 9.1 in) long. Colors are typically tan to dark brown with a lighter ventral surface but sometimes olive-green, yellow, or orange. Newborns often appear pink and slightly transparent but darken with age. Rubber boas have small eyes with vertically elliptical pupils and short blunt heads that are no wider than the body. One of the most identifiable characteristics of rubber boas is their short blunt tails that closely resemble the shape of their head.

Collared Lizards

collared lizard is a North American lizard that can reach 8-15 in (20-38 cm) in length (including the tail), with a large head and powerful jaws. They are well known for the ability to run on their hind legs, looking like small versions of the popular images of theropod dinosaurs. Like many other lizards, including the frilled lizard and basilisk, collared lizards can run on their hind legs, and are relatively fast sprinters. Record speeds have been around 16 miles per hour (26 km/h). The name "collared lizard" comes from the lizard's distinct coloration, which includes bands of black around the neck and shoulders that look like a collar. It is a member of the collared lizard family

Sea Snake

grow to between 120 and 150 cm (3.9 and 4.9 ft) in length with the largest, Hydrophis spiralis, reaching a maximum of 3 m (9.8 ft). Their eyes are relatively small with a round pupil and most have nostrils located dorsally. The skulls do not differ significantly from those of terrestrial elapids, although the dentition is relatively primitive with short fangs and (with the exception of Emydocephalus) as many as 18 smaller teeth behind them on the maxilla. Most Hydrophiinae are completely aquatic and have adapted to their environments in many ways, the most characteristic of which is a paddle-like tail that has improved their swimming ability.

Whip tails (Lizards)

they have large rectangular scales that form distinct transverse rows ventrally and generally small granular scales dorsally, they have head scales that are separate from the skull bones, and the teiid teeth are solid at the base and "glued" to the jaw bones. Additionally, all teiids have a forked, snake-like tongue. They all possess well-developed limbs.