unknown-endangered: What is a snake?
Snakes are reptiles of the order Squamata. They are all carnivorous and kill their prey by either envenomation or constriction, although most are non-venomous and harmless to humans. They occur on nearly every continent apart from Antarctica, but are notably absent from Ireland, Iceland, and New Zealand. Snakes are believed to have descended from lizards during the Cretaceous, a theory supported by the boas and pythons, which have vestigial hind limbs, called spurs.
The anatomy of snakes is adapted to life in trees and underground. Climbing trees and burrowing is actually easier for snakes when not impeded by limbs. They have multiple ways of moving in different situations, such as sidewinding seen in snakes living on the unstable sand dunes of deserts. The internal organs are also modified, usually elongated and paired organs are placed one in front of the other instead of side by side. In many snakes, one lung is reduced, and in some species, one lung is lost entirely.
Contrary to popular belief, a snake’s jaws don’t dislocate when feeding, but instead are simply highly mobile. The lower jaw is separated into two halves, which can move independently of each other. This allows them to move in a “walking” motion when feeding on a large prey item, as they lack any other way of manipulating food.
All snakes reproduce using internal fertilisation, with the male inserting one of two hemipenes into the cloaca of the female. Most are oviparous, and lay eggs, with some species providing parental care until they hatch. The boas, however, are ovoviviparous and produce eggs that develop inside the female until hatching, who then gives birth to live young.
Photo: My bb Scarlett the common boa (Boa constrictor imperator).
![biomedicalephemera:
Zonurus giganteus - [now Smaug giganteus] - The Sungazer or Giant Girdled Lizard
Yes, the Sungazer’s current scientific name (Smaug giganteus) is named after the antagonistic dragon in J.R.R. Tolkein’s The Hobbit. The current sources don’t indicate the exact reason for the renaming of the genus, but as many genuses are being renamed during the gradual transition to phylogenetic cladistics, I am not surprised this fairly unique lizard was put in a new group. J.R.R. Tolkein grew up in the area of South Africa where the majority of its range lies.
Given its common name for its tendency to appear to stare at the sun while gathering warmth for the day, the Sungazer lizard is also fairly unique in its choice of home, as the vast majority of members of its family do not dig their own burrow-holes. These holes are where the lizard spends the vast majority of their day, eating passing insects, and never venturing far once established.
As over 40% of the habitat for these lizards is active agricultural land, their population has been steadily declining for many years. The fearsome-looking spines that keep them safe from almost all native predators can’t do much against a combine thresher, or poacher for the pet or “natural medicine” trade.
Proceedings of the Scientific Meetings of the Zoological Society of London. 1913.](http://25.media.tumblr.com/tumblr_lzogpkWx0x1qk931ho1_500.jpg)
