But scientists say a handful of surviving snake species were able to thrive in a post-apocalyptic world by hiding underground and going long periods without food. The resilient reptiles then spread out across the globe, evolving into the 3,000 or more species known today.
A new study suggests that all living snakes evolved from a handful of species that survived the giant asteroid impact that wiped out the dinosaurs and most other living things at the end of the Cretaceous.
Researchers have unearthed the fossil remains of four snakes that are 70 million years older than the oldest snake previously discovered. The finds rewrite what scientists know about the creatures, showing that they were slithering alongside pterodactyls and other dinosaurs as early as 167 million years ago.
Before the K-T extinction event, snakes tended to have a diet of insects. However, the two researchers found that after the event, snake diets expanded to include birds and mammals. This may be because these animals became more abundant after the disappearance of non-bird dinosaurs, some of which ate birds and mammals.
"So the hypothesis that came out of this was the animals that survived the extinction preferentially survived because they were able to dig to get underground, survive that immediate impact period and the fires, the nuclear winter, and just hunker down for a bit."
There are two main reasons. First, crocodiles can live for a very long time without food. Second, they lived in places that were the least affected when the asteroid hit Earth.
Tardigrades have been around a long time.
Fossils date their existence on Earth to more than 500 million years ago. This means tardigrades have survived the planet's last five mass extinction events.
Comparisons between CT scans of the fossil and modern reptiles suggest that snakes lost their legs when their ancestors evolved to live and hunt in burrows, habitats in which many snakes still live today. The findings disprove previous theories that snakes lost their legs in order to live in water.
Dominating this era was Titanoboa, the undisputed largest snake in the history of the world. Most of the fossil record of ancient snakes is comprised of vertebrae like the one that launched the Titanoboa investigation.
About 150 million years ago, snakes roamed about on well-developed legs. Now researchers say a trio of mutations in a genetic switch are why those legs eventually disappeared. Taken together, the mutations in the enhancer of a gene known as “Sonic hedgehog” disrupt a genetic circuit that drives limb growth in snakes.
In fact, birds are commonly thought to be the only animals around today that are direct descendants of dinosaurs. So next time you visit a farm, take a moment to think about it. All those squawking chickens are actually the closest living relatives of the most incredible predator the world has ever known!
Crocodiles relatives are believed to have existed either before dinosaurs or right when dinosaurs first appeared! Crocodile ancestors date back 240 million years to the Triassic period, that's the same era that dinosaurs first began to flourish.
Crocodiles
Well, crocodiles share a heritage with dinosaurs as part of a group known as archosaurs (“ruling reptiles”), who date back to the Early Triassic period (250 million years ago). The earliest crocodilian, meanwhile, evolved around 95 million years ago, in the Late Cretaceous period.
They live near the water
However, for some reason, freshwater rivers and lakes were less impacted by the meteor. This helped the Crocodiles survive, as their amphibious lifestyle let them roam the rivers to escape the land and sea disasters.
There are two main reasons crocodiles survived the asteroid that killed the dinosaurs. First, crocodiles can live for a very long time without food. Second, they lived in places that were the least affected when the asteroid hit Earth.
They could grow up to 12.8 m (42 ft), perhaps even 14.3 m (47 ft) long and reach a body mass of 730–1,135 kg (1,610–2,500 lb). This snake lived during the Middle to Late Paleocene epoch, around 60 to 58 million years ago, following the extinction of all non-avian dinosaurs.
Titanoboa, (Titanoboa cerrejonensis), extinct snake that lived during the Paleocene Epoch (66 million to 56 million years ago), considered to be the largest known member of the suborder Serpentes.
As the Earth's temperatures rise, there's a possibility the Titanoboa - or something like it - could make a comeback. But scientist Dr Carlos Jaramillo points out that it wouldn't happen quickly: "It takes geological time to develop a new species. It could take a million years - but perhaps they will!"
The super snake's kryptonite was natural climate change. In this case, it was probably shifting tectonics that disrupted ocean currents and lowered temperatures. Warm-blooded animals that could handle the cooler, drier conditions were now kings and queens of the jungle.
Snakes used to have legs. Now they have evolved, but the gene to grow limbs still exists.
Burmese python and the DNA sequence responsible for limb loss. Snakes used to wander the Earth on legs about 150 million years ago, before they shifted from strut to slither.
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.
Extinct Species: Pyrenean Ibex
The Pyrenean ibex is possibly the only extinct animal that has successfully been brought back to life — though it only lasted for a few minutes.
How did sharks survive five mass extinction events? There is no single reason sharks survived all five major extinction events - all had different causes and different groups of sharks pulled through each one. One general theme, however, seems to be the survival of deep-water species and the dietary generalist.