Lizard as pet
Any of the more than 5,500 species of reptiles that are members of the order Squamata (which also contains snakes, suborder Serpentes) that are classified as lizards (suborder Sauria). Reptiles with scaly skin, such as lizards, can be identified from snakes by having legs, eyelids that can move, and external ear holes. Some conventional lizards, or non-snake species, do not have any of these characteristics. For instance, glass lizards (Ophisaurus) and other lizard species have been known to have limb degeneration and loss. Some skinks, night lizards, and geckos have lost their ability to move their eyelids. There are species in the genera Cophosaurus and Holbrookia that no longer have external ear holes.
Most lizard species still exist and live in warm climates, while some can be found in Eurasia close to the Arctic Circle and others as far south as South America.
Since snakes are descended from lizards, they are considered a very specific kind of limbless lizard. Snakes are frequently distinguished from other lizards in popular literature in addition to the characteristics they have in common with lizards that are not snakes.
Common features
Lizards are the most varied group of contemporary reptiles in size and shape. The length of their noses to vents in geckos (family Gekkonidae) ranges from 2 cm (0.8 inches), while the overall length of monitor lizards (family Varanidae) reaches 3 meters (10 feet). Adult lizards can weigh anything from less than 0.5 grams (0.02 ounces) to over 150 kg (330 pounds). There are only a few species to whom the common misconception that lizards are sprinting reptiles measuring around 30 cm (12 inches) in length overall and with thin tails may truly be applied. Some members of certain families are limbless and have a snake-like appearance, while others have extended legs that allow them to walk on two feet.
Lizards live in various environments, from the surface and tall vegetation to underground tunnels and warrens. While some can travel quickly across desert sands, others move more slowly and rely on their cryptic coloring for safety. The Mosasauridae family of extinct lizards was exclusively marine. There were enormous mosasaurs that reached lengths of 10 meters (33 ft). The Galapagos Islands’ marine iguana (Amblyrhynchus cristatus) is the only extant reptile that consumes marine algae. On the islands, though, it spends most of its time tanning on lava rocks. There are now numerous species of lizards that are somewhat aquatic and feed on freshwater creatures, but none of them are marine.
Reproduction cycle
For reproduction, most lizards deposit eggs. Certain tiny species lay roughly the same eggs in each clutch or laying. For instance, not all skinks have clutches of two eggs; many geckos lay one or two eggs at a time (depending on the species), and all anoles (Anolis) only lay one egg at a time. Clutch size depends on the mother’s size, age, and health. Large lizards, like iguanas, can lay up to 50 eggs simultaneously, although a clutch of four to eight eggs is considered normal. Typically, lizard eggs have porous, leathery shells that allow them to swell as the embryos develop through moisture absorption. Most egg-laying geckos are an exception, with their eggs having shells that solidify quickly after they are deposited and do not vary in size or shape in any way.
Care from parents
After they deposit their eggs, lizards often don’t give much thought to their offspring. However, there are a few notable exceptions. Many species bury their eggs in leaf litter or the cracks and crevices of trees or caves, while others dig holes to lay their eggs. On the other hand, during the incubation period, which lasts approximately six weeks, the females of certain species, such as the five-lined skink (Eumeces fasciatus) found in the United States and its cousins, stay with their eggs; they only occasionally leave the clutch to feed. Regularly rotating their eggs, these skinks will bring them back to the nest cavity if they are accidentally spread. Family ties are broken as soon as the youth leave. The behavior of glass lizards, or Ophisaurus, belongs to the Anguidae family. Furthermore, several viviparous lizards remove and consume their young’s placental membranes just after birth.
Evolution
Squamates are one of two orders that comprise the clade of reptiles known as Lepidosauria, along with the Rhynchocephalia (a group of which the tuatara [Sphenodon] is the only extant representative). The last common ancestor of the orders Squamata and Rhynchocephalia, as well as all of their progeny, is found in Lepidosauria. The tuatara is lizardlike in its overall appearance. It does, however, differ significantly from squamates. Tuatara males lack paired copulatory organs, although they have sac-like structures that are probably the ancestors of squamate-paired hemipenes.
Furthermore, as with all squamates, the tuatara lacks a moveable quadrate bone in its jaw. The major groupings of squamates’ relationships are still evolving. According to one theory, a significant split that took place early in the lizard’s evolutionary history affected not only how taxonomic units were arranged but also had a domino impact on the lizard ecosystem and resulted in the diversity of snakes. This initial break resulted in two sizable groups within the order Squamata that were essentially distinct: the scleroglossans (infraorder Scleroglossa) and the iguanians (infraorder Iguania). All lizards descended from ancestors who could control and catch prey with the mouth (lingual prehension).
Iguania kept the capacity, but this probably prevented the tongue from evolving into an organ that allowed this group’s primitive vomeronasal system to receive chemical signals (see Jacobson’s organ). Another theory, primarily based on ambiguous gene sequence data, holds that the iguanians are deeply nested within the stock of surviving lizards (that is, the autarchoglossans) and that the group containing geckos (and maybe the dibamids) diverged from all other squamates. Numerous ecological, physical, and behavioural features seen in iguanians imply that they evolved separately within a group of squamates that had already diverged significantly from their squamate progenitors if more data confirm this theory. Herpetologists currently work under the presumption that the first hypothesis has more substantial evidence.
