A snake fossil discovery in Wyoming has given palaeontologists an unusually close look at the lives of these ancient reptiles.
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discovery → give → reptiles
Four complete skeletons belonging to a newly recognised species, have helped researchers understand an early member of the ‘boa family’ and the history of small, burrowing snakes in North America.
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researchers → belong → America
Three of the snakes were preserved together in a burrow-like cast, while a fourth specimen from the same formation provided additional evidence for identifying the species.
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specimen → preserve → species
The fossils date to the early Oligocene, more than 30 million years ago, and were found in the White River Formation.
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fossils → date → Formation
Their preservation is especially important because ancient snakes are usually known from scattered vertebrae rather than complete skeletons.
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snakes → know → skeletons
The findings, published in the '
Zoological Journal of the Linnean Society,' offer a rare glimpse into snake evolution and possibly ancient communal sheltering behaviour.
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findings → publish → evolution
What makes these 38-million-year-old snake fossils unique
Fossil snakes are often frustratingly incomplete.
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snakes → make → ?
Their slender skeletons can break apart and become scattered before fossilisation, leaving researchers with isolated vertebrae rather than a complete animal that can be studied from head to tail.
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that → break → tail
The discovery described is therefore particularly valuable.
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discovery → describe → ?
Researchers examined four fossil snakes belonging to the newly established species ‘Hibernophis Breithaupti.
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Researchers → examine → species
Three are part of specimen UW-11120, preserved together in two matching blocks of rock.
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Three → preserve → rock
Two can be seen on the surface, while CT scanning revealed a third snake hidden inside the rock.
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scanning → see → rock
A fourth specimen, UW-11990, came from a different locality in the same formation.
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specimen → come → formation
The arrangement of the first three fossils had already attracted attention decades ago.
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arrangement → attract → attention
According to the research paper, scientists Brent H. Breithaupt and David Duvall first described them in 1986 and suggested that they could represent a fossil snake hibernaculum, essentially a place where snakes sheltered together.
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snakes → accord → hibernaculum
The new study has now provided the detailed anatomical work needed to identify what these animals actually were
Overview of UW-11990, the referred specimen of Hibernophis breithaupti.
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animals → provide → breithaupti
Image Credit: Zoological Journal of the Linnean Society
How did these ancient snakes become preserved together
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snakes → preserve → Society
The fossils were found in Wyoming's White River Formation, in rocks dating to the early Oligocene.
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fossils → find → Oligocene
The study explains that surrounding material is a fine, sandy mudstone and that the sediments were probably deposited during a small flood.
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sediments → explain → flood
The volcanic connection comes from the geology of the wider formation.
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connection → come → formation
The study notes that volcanic ash layers elsewhere in the White River Formation have been used to establish a minimum age of about 32 million years for these rocks.
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layers → note → rocks
The Daily Galaxy describes the preservation as the result of volcanic ash, mud and floodwater working together to bury and protect the snakes.
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ash → describe → snakes
That combination created an unusual fossil record.
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combination → create → record
Instead of being scattered by the environment, the snakes remained sufficiently intact for researchers to study their bones.
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researchers → scatter → bones
The researchers determined that the fossils represented a previously unknown snake and named it Hibernophis Breithaupti.
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fossils → determine → it
The genus name combines the Latin ‘hibernare,’ meaning to pass the winter, with the Greek word ‘ophis,’ meaning snake.
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name → combine → snake
The name reflects the unusual preservation of the four individuals and the earlier suggestion that they may have occupied a shared winter shelter.
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they → reflect → shelter
The study found that Hibernophis could not simply be placed among previously recognised fossil snakes such as Ogmophis and Calamagras.
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Hibernophis → find → Ogmophis
Detailed examination showed differences in the vertebrae and skull, allowing the researchers to establish it as a distinct species.
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researchers → show → species
The researchers' evolutionary analysis places HibernophisBreithaupti as the sister group to all other booids.
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analysis → place → booids
But another possible position close to some New World 'erycines' and ungaliophiines could not be completely ruled out.
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position → rule → erycines
Did the snakes really hibernate together
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snakes → hibernate → ?
This is perhaps the most intriguing question raised by the fossils, but it requires some caution.
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it → raise → caution
The three snakes preserved together were found in an arrangement that resembles a shared shelter or hibernation site.
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that → preserve → shelter
The study records that their unusual preservation had previously been interpreted as a possible fossil hibernaculum.
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preservation → record → hibernaculum
The Daily Galaxy also highlights the comparison with modern garter snakes, which can gather in large numbers inside dens and burrows during cold periods.
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which → highlight → periods
However, the fossil evidence cannot prove exactly why the snakes were together.
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snakes → prove → ?
The researchers can identify their position and anatomy, but behaviour is much harder to establish millions of years later.
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behaviour → identify → position
The arrangement is therefore best treated as possible evidence of communal sheltering rather than definite proof that the snakes were hibernating.
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snakes → treat → sheltering
Analysing snake evolution through these complete fossils
The discovery matters beyond the unusual sight of several snakes preserved together.
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discovery → analyse → snakes
…and 7 more, not listed.
The Aporia
