Newly discovered snake species provides insight into reptile social behaviour and development | Folio
The discovery of the new snake species has yielded insights into the evolution of modern snakes like the Amazon tree boa (left) and scrub python (right).
Photos: Michael Lee, Flinders University/South Australian Museum.
Red-sided garter snakes hibernate together in a hibernaculum.
Photo: Greg Schechter via Wikimedia Commons, CC BY 2.0
The evidence the new paper reveals is that of a collection of fossilised snakes found in Oligocene rocks in western Wyoming are those of a new species from 38 million years before creationists believe the Universe was created out of nothing by magic, when snakes had legs and could talk, and didn't have to eat nothing but dust [sic].
Give me a brief evolutionary history of snakes, please. The evolutionary history of snakes is a fascinating journey that spans millions of years, highlighting their adaptation and diversification. Here’s a brief overview:The discovery by an international team of palaeontologists led by Professor Michael W Caldwell of the Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada, is explained in a University of Alberta press release:
Origins
- Early Ancestors: Snakes evolved from lizards. The oldest known snake fossils date back to the Late Cretaceous period, about 100 million years ago.
- Transitional Forms: Some early snake ancestors, such as Tetrapodophis, had vestigial limbs, indicating a gradual transition from lizards to limbless reptiles.
Major Evolutionary Milestones
- Loss of Limbs: Over time, snakes gradually lost their limbs, which is believed to have aided their burrowing lifestyle. Fossil evidence shows a reduction in limb size until they completely disappeared.
- Elongation and Specialization: Snakes evolved elongated bodies and specialized their vertebrae to enhance flexibility, aiding in their unique mode of locomotion.
- Development of Jaws and Skulls: Snakes developed highly mobile jaws and skulls, allowing them to consume prey much larger than their head. This adaptation includes the evolution of a quadrate bone, enabling their jaws to open widely.
Diversification
- Ecological Niches: Snakes adapted to a variety of ecological niches, from burrowing underground to climbing trees and swimming in aquatic environments.
- Venom Evolution: The evolution of venom in some snake lineages provided a significant advantage for capturing prey and self-defense. This trait likely evolved independently multiple times within different groups of snakes.
Major Groups of Snakes
- Scolecophidia (Blind Snakes): One of the earliest and most primitive groups, adapted to a burrowing lifestyle.
- Alethinophidia: This diverse group includes most modern snakes. It further splits into various families such as:
- Boidae (Boas): Non-venomous constrictors.
- Pythonidae (Pythons): Similar to boas, with some of the largest snake species.
- Colubridae: The largest snake family, encompassing a wide range of species, both venomous and non-venomous.
- Elapidae: Includes highly venomous snakes like cobras, kraits, and mambas.
- Viperidae: Known for their long, hinged fangs, includes vipers and pit vipers.
Recent Evolution
Overall, snakes' evolutionary journey is marked by significant anatomical and physiological changes, allowing them to become one of the most successful groups of reptiles on Earth.
- Adaptations: Modern snakes continue to evolve, adapting to new environments and challenges. Genetic studies have provided deeper insights into their evolutionary history, revealing complex patterns of diversification and adaptation.
How does the discovery in western Wyoming, USA, of fossils of four boidae probably hibernating together from 38 million years ago fit with this evolutionary history?
The discovery of boid fossils in western Wyoming, USA, dating back 38 million years ago, provides significant insights into the evolutionary history and behavior of ancient snakes, specifically within the Boidae family. Here's how this fits into the broader evolutionary narrative:
Evolutionary Significance
Broader Evolutionary Context
- Ancient Lineage Confirmation:
- The presence of Boidae fossils from 38 million years ago confirms that this family, which includes modern boas and pythons, was already well-established by the Eocene epoch. This aligns with molecular and morphological evidence suggesting that boids are an ancient lineage of snakes.
- Behavioral Insights:
- The discovery of four boids potentially hibernating together is one of the earliest pieces of evidence of communal behavior in snakes. This indicates that some behavioral traits observed in modern snakes, such as communal hibernation, have deep evolutionary roots. Communal hibernation is known in several modern snake species as a strategy to conserve heat and survive in colder climates, suggesting that such behaviors were already present in ancient boids.
- Climate and Environmental Adaptations:
- During the Eocene, the Earth's climate was warmer, but there were still seasonal variations. The fact that these snakes might have been hibernating suggests they were adapted to survive cooler periods, indicating an ability to thrive in diverse environmental conditions. This adaptability could have been a significant factor in their evolutionary success and widespread distribution.
- Geographical Distribution:
- The discovery in Wyoming provides evidence of the geographical range of boids during the Eocene. It shows that these snakes were present in North America, contributing to our understanding of their historical biogeography. This complements findings from other regions, showing that boids had a wide distribution even in ancient times.
- Transition and Diversification:
- The Eocene epoch was a period of significant diversification for snakes. The existence of these boid fossils during this time frame fits into the broader pattern of snake evolution, where different families were branching out and occupying various ecological niches.
- Adaptation Mechanisms:
- The evidence of hibernation hints at early behavioral adaptations that may have contributed to the survival and evolution of snakes. Behavioral flexibility, such as the ability to hibernate communally, would have provided a survival advantage during periods of climatic stress, potentially influencing evolutionary pathways.
- Comparative Anatomy and Physiology:
- Studying these fossils can provide comparative data on the anatomy and physiology of ancient snakes. This can help scientists understand the evolutionary changes that have occurred over millions of years, particularly in relation to other boids and modern snake families.
In summary, the discovery of the boid fossils in Wyoming from 38 million years ago enriches our understanding of snake evolution by providing evidence of early communal behavior, geographical distribution, and environmental adaptations. This fits well with the broader evolutionary history of snakes, highlighting the ancient and adaptable nature of the Boidae family.
Newly discovered snake species provides insight into reptile social behaviour and development
Four unusually well-preserved snake specimens deepen our understanding of an entire category of snakes and the way they behave.
A newly discovered snake species, Hibernophis breithaupti, provides rare insight into the social behaviour of snakes and fills some gaps in our knowledge of the evolution of boas, or boidae. The quartet of fossilized snakes discovered in western Wyoming dates back 38 million years.
The snake specimens were preserved in a cluster within a hibernaculum, a space where animals shelter together during colder months. The position in which the specimens were found “represents social behaviour in snakes, which is something that we don’t often see,” Michael Caldwell explains. According to Caldwell, a professor in the Faculty of Science, this is the first clear evidence of reptilian social behaviour in the fossil record.
This behaviour also sets this new species apart from other reptiles. Though many mammals hibernate during the winter, only one species of snake is known to follow suit: the garter snake.
This is really unusual for reptiles. Of the almost 15,000 different kinds of reptile species alive today, none of them hibernate in the way that garter snakes do.
Professor Michael W. Caldwell, lead author
Department of Biological Sciences
University of Alberta, Edmonton, AB, Canada.
In addition to being an indication of snakes’ social behaviour, the practice of gathering in a hibernaculum is an adaptation that allows garter snakes to survive in colder climates.
They can’t regulate their body temperature so they need to find a way to conserve as much heat as they can through the winter and they do this by forming these big masses.
Professor Michael W. Caldwell.
While this particular hibernaculum featured just four fossilized snakes, modern garter snakes gather in the hundreds or even thousands. Their adaptation is so well known, Caldwell explains, that sometimes clever solo snakes from other species, such as rattlesnakes, will hide amongst the garter snakes, benefiting from the group’s protection.
The ancient snake specimens were also articulated, meaning they were found in one piece with the bones still in the proper order, which is extremely uncommon.
There are probably, in the world’s museum collections, nearly a million disarticulated snake vertebrae. They are easy to find. But finding the whole snake? That’s rare.
Professor Michael W. Caldwell.
The articulated specimens give us a better understanding of the evolution of boidae, a family of snakes with more than 50 species, including burrowing boas like Hibernophis breithaupti. One of the snakes within the quartet is approximately twice the size of the others, allowing the researchers to see the same species of snake at different stages of development.
We learn quite a bit more about boidae evolution in the broad sense. It seems that they probably started out as relatively small-bodied snakes, which is interesting.
Professor Michael W. Caldwell.
The skulls are a key area to gauge growth and development. Just as the proportions of head to body change dramatically in humans from infancy to adulthood, a snake’s skull and head-to-body proportions change over its lifespan. Since snake skulls are very thin and delicate, though, they’re typically not preserved well enough to track that progression.
These new specimens also indicate how a snake’s vertebrae differ in shape and size based on where on the body they are located. Even a small snake has anywhere from 200 to 400 vertebrae, which commonly get separated and scattered in different areas before fossilization occurs. The ability to see the entire spine is a valuable reference point. Caldwell says it raises the question of whether bones previously ascribed to new species were indeed new. Perhaps particular vertebrae clusters just gave that impression, but actually came from different parts of the fossilized spines of the same species.
These rare articulated snake specimens have remained so remarkably well preserved for tens of millions of years because of their location. As Caldwell explains, 38 million years ago, when these particular Hibernophis breithaupti snakes were alive, the Southern Basin and Range Volcanic System was incredibly active and emitting huge quantities of volcanic ash. The ash settled and helped preserve the bodies of the creatures, which were found in a matrix of “fine, sandy mudstone” typical of the White River Formation, according to the paper the researchers published about the fossil find. The researchers speculate that the animals fell victim to a “small flood episode.”
They were preserved in a very unusual circumstance, geologically speaking. Fossilization is a rough process. You need exactly the right conditions to preserve something.
Professor Michael W. Caldwell.
The study was published in the Zoological Journal of the Linnean Society.
AbstractOf special concern for creationists is the fact that these fossils were formed during a period of high volcanic activity in the area, so the matrix in which they are embedded can be dated with extreme accuracy by a Uranium/lead analysis of zircons formed during the volcanic eruptions.
Extinct snake taxa are recognized primarily from isolated vertebrae. A new specimen from the early Oligocene of Wyoming provides a rare opportunity to examine four nearly complete and articulated fossil snakes. Informally assigned previously to the ‘erycine’ vertebral form taxa Ogmophis and Calamagras, a detailed comparison reveals that this fossil snake exhibits vertebral differences from both taxa and is, furthermore, a new taxon, Hibernophis breithaupti gen. et sp. nov., based on a combination of apomorphies such as absence of basal tubera, low subrectangular prootic, low parasphenoid wings obscuring the anterior opening of the Vidian canal, and foramen for the mandibular branch of the trigeminal nerve posteriorly displaced inside the adductor fossa of the compound. Parsimony and Bayesian phylogenetic analysis of combined morphological and molecular data from a broad selection of snakes places Hibernophis breithaupti as sister taxon to all other booids, distant from both Old and New World ‘erycines’. However, an alternative position close to New World ‘erycines’ and ungaliophiines cannot be rejected.
Jasmine A Croghan, Alessandro Palci, Silvio Onary, Michael S Y Lee, Michael W Caldwell
Morphology and systematics of a new fossil snake from the early Rupelian (Oligocene) White River Formation, Wyoming Zoological Journal of the Linnean Society, 2024;, zlae073, https://doi.org/10.1093/zoolinnean/zlae073
© The Author(s) 2024. Published by Oxford University Press on behalf of The Linnean Society of London.
Reprinted under the terms of s60 of the Copyright, Designs and Patents Act 1988.
The traditional parrot squawk of creationists when radiometric dating is mentioned is to assert that radioactive decay rates have changed over time. I am still waiting for a creationist to find the courage and intellectual integrity to tackle the problem that this causes them, in that for decay rates to have been very much higher 10,000 years ago, to make 38 million years look like 10,000 years, the weak and strong nuclear forces would have been so much weaker that atoms would not have been able to form, making a planet with life on it impossible when creationists believe it was created.
With such radically different fundamental forces, the Universe as we know it with atoms, stars and galaxies would have been impossible and the universe would not have been 'fine-tuned for life', as creationists claim. But then creationism wouldn't exist if creationists weren't so ignorant of science that they are able to hold two or more mutually exclusive views simultaneously, and often with equal conviction, without realising it.
"There's no use in trying", said Alice: "One can't believe impossible things."
"I daresay you haven’t had much practice,” said the queen. “When I was your age, I always did it for half-an-hour a day. Why, sometimes I’ve believed as many as six impossible things before breakfast.”
"I daresay you haven’t had much practice,” said the queen. “When I was your age, I always did it for half-an-hour a day. Why, sometimes I’ve believed as many as six impossible things before breakfast.”
Lewis Carroll, Through a Looking Glass
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