Snakes: Amazing Animals From Prehistoric Times

Ever since humanity was fabled to have resided in a garden perfect beyond belief snakes have been given a bad reputation that has followed them through the millennia. Turns out the human race is pretty good at holding a grudge when an entire family of the animal kingdom is blamed for the fabled damnation of one fairly young species, and consequently snakes are more often than not cast in the role of the nightmarish fiend. Beginning with the words on this page and the video to accompany them, I have set off on my proverbial war against the negativity that is thrown towards serpents and I cannot rest until their public image has improved.

Welcome to the first “Serpent Sunday.”

The journey to repair a tarnished reputation must begin at the beginning, and in this particular case, we must travel way back in time somewhere between 174.1 and 163.5 million years ago to the Middle Jurassic Epoch. It is during this time dominated by massive conifer forests and sauropods of legend that a group of reptiles set off down an evolutionary path that resulted in the limbless creatures we now know as snakes. It may be impossible to know the exact moment that the ancestors of modern-day snakes began to populate the prehistoric forests, but the oldest known snake fossil found in Southern England has been determined to be 167 million years old, suggesting that they had to have been around for a while at that point in history.

Snakes managed to outlive the dinosaurs by staying fairly small, that is until their gargantuan counterparts met their fiery end and snakes entered the race for global domination. It was during this period deep within the swamps of what is not northern Colombia the infamous 40 foot Titanoboa evolved alongside other massive reptiles ultimately doomed for extinction as the climate cooled and made way for mammalian domination. While some modern-day snakes have regained some of their ancestor’s size (namely reticulated pythons, and anacondas), most species today range between very small to six feet in length and anywhere from a few ounces to a hundred pounds.

No matter how one looks at it, snakes have come a long way from their humble prehistoric beginnings. During the millennia since they have slithered onto the planet, snakes have managed to evolve into more than 3,000 species with a phylogenetic tree that tends to raise more questions than answers as researchers attempt to put together the genetic puzzle that is the history of all things snake. These many species that are all at least distantly related have managed to conquer almost every part of the planet from the treetops to the seas (all without excess limbs), stopped only by the extreme cold of the polar regions and the barrier to dispersal that fledgling islands pose for any organism.

This diversity has translated into a multitude of survival strategies that differ just enough among species to allow for the specialization required to conquer the kaleidoscope of habitats that paint the globe. Snakes (and other reptiles) have had to improve upon the amphibian reproduction strategy of laying eggs that depend upon the water for survival, in order to do this, a watertight shell was developed that allowed for expansion beyond prehistoric marshes, but some species have cast off even the conventional egg and instead give live birth. Of course, this live birth strategy is not the same as mammalian live birth as there is no placenta, reptilian live birth is more like the mother acting as an incubator until the young are ready to take on the world.

In order to be ready to take on the world, it has been essential for snakes to evolve modes of locomotion and ways to catch prey that do not require limbs. Now locomotion comes in a handful of methods, some of which are shared with other limbless species, and utilizes specialized scales and modified muscles. Luckily for them, limbless bodies have evolved many times in the animal kingdom, so this challenge seems to not have been a massive hurdle to overcome, but prey capture is where snakes seem to have hit a fork in the evolutionary road. Some species (like pythons and boas) have developed strong muscles to subdue their prey with constriction, these constrictors range from very small (anthill python) to massive (anaconda) and specialize in eating a wide array of prey animals. The other method snakes use to score a meal involves a fast bite that injects deadly venom through hollow fangs. Even the venom utilized by snakes varies from species to species with a range of chemical makeups that is just as diverse as the entirety of the serpent family.

The diversity in the serpent family, however, does not need to be reduced of the chemical makeup of venom to be observed, one only needs to look at the skin. The scales on snakes range from muted browns to bright reds and occur in a wide array of patterns that all serve their own unique purposes. The more muted browns and green tones are usually for camouflage that hides them from both prey and potential predators, sometimes in plain sight, while the bright patterns advertise their toxicity (or supposed toxicity in the case of mimics like king snakes). All of these patterns can be observed with the naked eye either on the animal itself, or the remnants of an old skin that a snake has shed and left behind as it grows.

As a snake grows and continues on with their life, they play important roles in the ecosystem and ultimately help keep their communities healthy. The main diet of most snake species is heavily comprised of rodents that feed heavily upon seeds and may ultimately inhibit the dispersal and survival of some plants. By feeding on the rodents snakes are controlling some of the pressures put on the plants and protecting the ecosystem from the ground up, but that is not their only role in the food web. Since they are not apex predators, snakes are an important food source for medium predators like birds of prey and foxes, and without them, there are multiple holes left in the food web. Besides acting as both predator and prey, new research from Cornell University has been published that suggests snakes also play a role in seed dispersal because while they do not eat seeds by choice, some are accidentally ingested when stored in the cheek pouches of the rodents that they do consume. Since snakes do not possess the ability to digest plant matter, the seeds harmlessly pass through their digestive tract (sometimes begging to germinate in the process) and are able to take root once they are passed.

Coral snake. Credit: Ashley Wahlberg via flickr

While they are important in the environment, that is not where the value of snakes comes to an end, they also play multiple roles in the lives of humans. The most obvious role snakes play is one of free pest control for the agriculture industry because they do prey upon rodents that have a taste for grains and other products grown in the field, but they are not limited to this narrow role. Venom has been utilized in medicine dating as far back as the ancient Greeks and is now important in the world of cancer research and the production of medicines that save lives. If this isn’t enough, snakes are a popular attraction in educational facilities and mandy species are fairly easy to breed in captivity for the purpose of education and the pet trade.

The pet trade can be a controversial topic, but there is an entire community (that I am a part of) of enthusiasts that spans the globe promoting proper snake education and husbandry. Many snake species popular in the pet trade are low maintenance pets that may be more feasible for someone to properly take care of than a cat or a dog if they do not have copious amounts of time every day to spend with their pet. Since the low maintenance option to enter the world of snake ownership is available, more people every day can pop into the local reptile shop and pick out their new animal companion. This helps stimulate the economy as animals and supplies are bought and sold and promotes creativity as people set up detailed enclosures and produce custom decorations to display their new scaley friend.

Now we are reaching the end of our first journey into the wonderful world of serpents and the first step in the plan to mend the image of these misunderstood creatures. I am excited about what the future will bring to this series, and I hope that you come along for the ride and perhaps learn something on the way. Until next time, this has been “Serpent Sunday.”

Accompanying Video:

https://www.youtube.com/watch?v=2jZU1AnUrVI

References: