In a modern world, an animal is just an animal to most of us. Though research says that snakes have their set of legs before, say around 100 million years ago.
According to Wiki, by definition, SNAKES are elongated, LEGLESS, carnivorous reptiles of the suborder Serpentes that can be distinguished from legless lizards by their lack of eyelids and external ears. Snakes are ectothermic, like all squamates, amniote vertebrates covered in overlapping scales. Many species of snakes have skulls with several more joints than their lizard ancestors, enabling them to swallow prey much larger than their heads with their highly mobile jaws. To accommodate their narrow bodies, snakes' paired organs (such as kidneys) appear one in front of the other instead of side by side, and most have only one functional lung. Some species retain a pelvic girdle with a pair of vestigial claws on either side of the cloaca.
Except Antarctica, living snakes are found on every continent, and on most smaller land masses — exceptions include some large islands, such as Ireland and New Zealand, and many small islands of the Atlantic and central Pacific. Additionally, sea snakes are widespread throughout the Indian and Pacific Oceans. More than 20 families are currently recognized, comprising about 500 genera and about 3,400 species. They range in size from the tiny, 10 cm-long thread snake to the reticulated python of up to 6.95 meters (22.8 ft) in length. The fossil species Titanoboa cerrejonensis was 13 meters (43 ft) long. Snakes are thought to have evolved from either burrowing or aquatic lizards, perhaps during the Jurassic period, with the earliest known fossils dating to between 143 and 167 Ma ago. The diversity of modern snakes appeared during the Paleocene period (c 66 to 56 Ma ago). The oldest preserved descriptions of snakes can be found in the Brooklyn Papyrus.
Most species are nonvenomous and those that have venom use it primarily to kill and subdue prey rather than for self-defense. Some possess venom potent enough to cause painful injury or death to humans. Nonvenomous snakes either swallow prey alive or kill by constriction.
"How snakes lost their legs has long been a mystery to scientists," Dr. Hongyu Yi says in a press release from the University of Edinburgh. But that mystery may have finally been solved thanks to a 90 million-year-old skull and advanced CT scan technology.
It's been long theorized that the ancestors of modern snakes lost their limbs when they evolved to live in the sea. Well, that's not quite right when researchers at the University of Edinburgh used a CT scan to create a detailed 3D model of the skull of a Dinilysia patagonica—a close relative of modern snakes—and compared it to those of modern reptiles.
They have discovered that a unique structure in the inner ear that controls balance and hearing and is shared only by burrowing animals. Modern snakes that live in water don't have it.
Researchers have determined, using that information that the ancestors of modern snakes actually lost their limbs in order to hunt and live in burrows, per the press release.
"The inner ears of fossils can reveal a remarkable amount of information, and are very useful when the exterior of fossils are too damaged or fragile to examine," Yi says.
Dinilysia patagonica as the largest burrowing snake ever, this was confirmed by the said study as it is 6.5-foot-long. The results were published Friday in Science Advances. The study confirms a Yale study from earlier this year that found snakes evolved on land and not in water, UPI reports.
To determine the ancestors of modern snakes lost their front legs approximately 128 million years ago, that study used genomes, fossils, and more; though they still had tiny hind legs.
I’m trying to imagine how those snakes looks like with legs, and how fast they go compared today, hmmmmnnn, scary!