Those enthusiastic scientists and educationalists at Wollaton Hall (Nottingham), are hosting an exclusive “Prehistoric Secret Science Show” on Tuesday 24th May, 2022 (4.30pm to 8.45pm). It will feature a veritable cornucopia of talks, presentations and workshops plus the chance to meet professionals engaged in current scientific research on Tyrannosaurus rex!
Led by the Nottingham City Museum’s Learning and Education team, the evening event (Prehistoric Secret Science Show), will showcase a range of speakers from the University of Nottingham, the University of Birmingham, Rutland Water Nature Reserve, as well as Nottingham City Museum’s Curator of Natural Sciences, Dr Adam Smith.
An Exclusive Event
Organised by those dedicated and talented members of Nottingham City Museum’s Learning and Education team, this evening event “Prehistoric Secret Science Show”, will showcase a range of speakers from the University of Birmingham, Rutland Water Nature Reserve and the University of Nottingham. Palaeontologist Dr Adam Smith (Nottingham Museum’s Curator of Natural Sciences), a world authority on Mesozoic marine reptiles will also be presenting.
Those enthusiastic scientists at Wollaton Hall (Nottingham) are hosting an exclusive “Prehistoric Secret Science Show” which will feature a tour of the “Titus” T. rex is King exhibition as well as chance to meet some of the scientists currently studying this iconic dinosaur.
Natural Science and Dinosaurs
This exclusive event is ideal for anyone interested in prehistoric life, palaeontology, Natural Science and dinosaurs, it has been especially designed for children at upper primary or secondary school, college, university and adults. It looks set to be an interesting evening that covers a wide range of topics, plus gives everyone the opportunity to meet “Titus” the Tyrannosaurus rex exhibit too!
Schools and other large groups have one free adult per ten children with additional adults at the usual £15. Contact the event organisers for more information.
Event is open to all ages, including children at secondary school, college, university and adults. It is aimed especially for children over ten years old, although anyone with a keen interest in dinosaurs would be welcome.
Free entry for carers when accompanying a paid ticket. Please note car parking charges apply.
It can be difficult to visualise the immensely long geological time scale and to demonstrate what lifeforms developed along the way, so, why not knit one and use prehistoric animal models to illustrate key moments in the history of life on Earth.
That’s exactly what Sue Mallender, Learning Programmes Science Officer, (Nottingham City Museums) and the Learning and Engagement team did – creating a colourful and striking depiction of the evolution of life on Earth.
The coloured bands represent geological periods and epochs. Picture credit: Sue Mallender.
Picture credit: Sue Mallender
Visualising Geological Time
In order to study the history of life, scientists need to locate important evolutionary events such as the development of animals with exoskeletons and the evolution of vertebrates within the geological time scale. Planet Earth was formed around 4.57 billion years ago. Geologists have divided the history of our planet into time intervals of varying duration. This time scale was devised in the 19th century, (although amendments to it and revisions continue to be made). The boundaries between the time intervals mark notable events such as dramatic changes in the type of fossils found in strata.
This remarkable knitted timescale provides a novel and very innovative way of demonstrating this fundamental aspect of geology.
Demonstrating deep geological time in knitted form. The geological time scale knitted. Picture credit: Sue Mallender.
Picture credit: Sue Mallender
This colourful visualisation of the age of our planet was created by dedicated knitter Helen Crowfoot.
The “Slow Burning Fuse” to Complex Life
The long interval of time from the origin of the Earth to the start of the Cambrian is referred to as the Cryptozoic Eon (meaning hidden life). This enormous time interval is also referred to as the Precambrian. Its length in comparison to the Phanerozoic Eon (visible life) – the time interval to the present day, is dramatically demonstrated in the knitted time scale by the burgundy-coloured strip.
Some palaeontologists have described the Cryptozoic Eon as the “slow burning fuse to complex life.”
A novel way of demonstrating the Cryptozoic Eon, informally known as the Precambrian – the immensely long period of time before complex life evolved on Earth. Picture credit: Sue Mallender
Picture credit: Sue Mallender
Cambrian Creatures
A spokesperson from Everything Dinosaur commented that they had been contacted about this innovative project and ask to recommend prehistoric animal models that could be placed along the time scale to depict the sort of creatures that evolved during the main geological periods.
The Everything Dinosaur spokesperson explained:
“We started with the Cambrian, suggesting some figures that could represent some of the first, large complex animals and then worked forwards from there recommending various models that could be used to populate the knitted time scale.”
The Safari Ltd Cambrian Toob models placed on the knitted time line. Picture credit: Sue Mallender.
“What a super idea! This is a fantastic way to visualise geological time and we congratulate Sue and the Learning and Engagement team for such an innovative and creative way of demonstrating how life on our planet has changed over millions of years.”
The award-winning Everything Dinosaur website: Dinosaur Toys.
One in five species of reptile is threatened with extinction. A team of international scientists including researchers from the Zoological Society of London, the University of Witwatersrand (Johannesburg, South Africa), Monash University (Victoria, Australia) and the Biodiversity Assessment Unit, IUCN-Conservation International based in Washington DC (USA), have conducted a comprehensive extinction-risk assessment of the class Reptilia. Writing in the academic journal “Natural” the team conclude that at least 1,829 out of 10,196 species of reptile (21.1%) are threatened. Twenty percent of extant reptiles threatened with extinction is astonishing.
An anterior view of the skull of an estuarine crocodile photographed in the Grant Museum, London. The largest reptile on Earth, the estuarine crocodile (Crocodylus porosus) from south-east Asia is also known as the saltwater crocodile or saltie. Picture credit: Everything Dinosaur.
Picture credit: Everything Dinosaur
According to the study turtles and crocodilians are particularly vulnerable to extinction.
Agriculture, Logging, Urban Development and Invasive Species
A global assessment of the risk of extinction to species of reptile has been lacking, although similar studies have been undertaken for the other tetrapods such as amphibians, mammals and birds. The researchers conclude that reptiles are threatened by the same major factors that threaten other tetrapods— agriculture, logging, urban development and invasive species, although the threat posed by climate change remains uncertain. Many species of reptile live in extremely arid or desert regions, this comprehensive study reveals that it is those reptiles that live in forests that face the greatest threat.
An Anolis lizard, note the long snout, large eyes and the jaw that extends under the orbit. Reptiles that live in forested areas are the most threatened according to a comprehensive study published in the journal Nature.
Reptiles Threatened with Extinction
The scientists discovered that birds, mammals and amphibians are unexpectedly good surrogates for the conservation of reptiles. The study revealed that efforts to conserve other threatened tetrapods (mammals, birds and amphibians) are more likely than expected to co-benefit many threatened species of reptile. Although reptiles are well known to inhabit arid habitats such as deserts and scrubland, most reptile species occur in forested habitats, where they and other vertebrate groups, suffer from threats such as logging and conversion of forest to agriculture. The study found that 30% of forest-dwelling reptiles are at risk of extinction, compared with 14% of reptiles in arid habitats.
The Radiated tortoise (Astrochelys radiata), native to Madagascar is critically endangered due to habitat loss and poaching. Picture credit: IUCN/Anders G. J. Rhodin.
Picture credit: IUCN/Anders G. J. Rhodin
An Urgent Multifaceted Plan is Needed
Neil Cox, co-leader of the study and Manager of the IUCN-Conservation International Biodiversity Assessment Unit in Washington DC stated:
“The results of the Global Reptile Assessment signal the need to ramp up global efforts to conserve them. Because reptiles are so diverse, they face a wide range of threats across a variety of habitats. A multifaceted action plan is necessary to protect these species, with all the evolutionary history they represent.”
The South American marked gecko (Homonota horrida) is found in Paraguay and Argentina. Reptile species face a significant extinction threat. Picture credit: IUCN/ Ignacio Roberto Hernández.
Picture credit: IUCN/ Ignacio Roberto Hernández
The report states that although some reptiles including most species of crocodiles and turtles require urgent, targeted action to prevent extinctions, efforts to protect other tetrapods, such as habitat preservation and control of trade and invasive species, will probably also benefit many reptiles. The conclusion from the study are stark. Twenty percent of all extant reptiles threatened with extinction is alarming. Conservations are demanding urgent action.
Everything Dinosaur acknowledges the assistance of a media release from the International Union for Conservation of Nature (IUCN) in the compilation of this article.
The scientific paper: “A global reptile assessment highlights shared conservation needs of tetrapods” by Neil Cox, Bruce E. Young, Philip Bowles, Miguel Fernandez, Julie Marin et al published in Nature.
At Everything Dinosaur, we are always amazed by the variety of prehistoric animal themed products that are available to fans of prehistoric life. Take for example, a new board game in development that has been inspired by palaeontology. We were contacted by Brett, one of the developers of “Holotype”, a fast-paced, worker placement game designed for 2-5 participants. Players get the chance to role play the life and work of a vertebrate palaeontologist.
“Holotype” an American designed board game for 2-5 players. Picture credit: Brexwerx Games.
A Kickstarter Project
This innovative, light-strategy board game has its own kickstarter funding page and the project has already received hundreds of backers.
Brett very kindly provided more details to Everything Dinosaur, commenting that the object of the game was to further the field of palaeontology by collecting specimens, undertaking research and getting findings published in scientific journals. “Holotype” focuses on the major fossil formations and prehistoric animals associated with North America, but other regional variations of this game, such as a version exploring the prehistoric animals of Europe, have been proposed.
The contents of the North American board game “Holotype”. Picture credit: Brexwerx Games.
Throughout the gameplay, players deploy their palaeontologist, graduate student and field assistant workers to perform various actions. Players can search for fossils by rolling fossil dice on field expeditions, conduct research at the university library and access museum collections to exchange fossils and to further their ambitions.
A Palaeontology Board Game – “Holotype”
By making discoveries and expanding scientific knowledge, players ultimately aim to have their research on holotypes published in prestigious scientific journals. Victory points are awarded as the player’s career in palaeontology advances.
As the game progresses, special milestones are unlocked to make each player’s gameplay unique. Semi-collaborative global objectives and private personal objectives ensure that every game will be different.
With a playing time estimated at around 1-2 hours, the winner is the person who has gained the most points through their research which resulted in published holotypes and the achievement of personal and global objectives.
The media release sent to Everything Dinosaur states:
“The goal of the developers was to create a game that would appeal to avid board gamers and palaeontology fans alike. The game features 60 unique dinosaurs and marine reptiles from the Mesozoic Era across North America, fossil-bearing geologic formations, and objectives referencing modern palaeontology concepts such as cladistics and taxonomy.”
Scientists from the University of Tel Aviv in collaboration with colleagues from the University of Napoli have published a study that suggests having a small brain relative to your body size predisposed Late Quaternary mammals to extinction. If you were a “smart” mammal, with a relatively big brain in proportion to your body size, you were less likely to become extinct.
A soft toy Megatherium. The newly published research suggests that mammals with relatively small brains in proportion to their large bodies for example, many members of the Order Pilosa such as the ground sloths, were more likely to go extinct in the Late Quaternary.
The Extinction of Megafauna
The Late Quaternary is marked by a drastic global extinction event, mainly of large-bodied, land mammals. Causes proposed for these extinctions include overhunting by an increasing human population, particularly in areas such as the Americas and Oceania where modern humans had been largely absent previously. Earlier papers had proposed that species with traits that make them less prone to human hunting (arboreal, nocturnal, or forest dwelling) were more likely to survive.
However, the rapid decline and extinction of large, terrestrial animals is linked to the end of the last glacial period (25,000 to 12,000 years ago) which saw dramatic climate change. The research team hypothesised that the large mammals that survived the extinctions might have been endowed with larger brain sizes than those that perished. Larger brains might have helped these animals to adapt better and to cope with the wild fluctuations in climate.
To test this idea, the scientists assembled data on the brain size of 291 living mammal species plus 50 more that went extinct during the Late Quaternary.
The team found that models that used brain size in addition to body size predicted extinction status better than models that used only body size. It was concluded that possessing a large brain was an important, yet so far neglected and rarely studied characteristic of surviving megafauna species.
The phylogenetic tree used in the brains size relative to body size paper. Terminal branches are colored according to residuals of endocast volume versus body mass regression with order as a random effect (large brains: green; small brains: gold). Large mammals with proportionately large brains such as monkeys record a lower level of extinction compared to other types of mammal. Picture credit: Dembitzer et al.
Picture credit: Dembitzer et al
Implications for Large Mammals Living Today
One prominent feature shared by many extinct taxa was their large body size. In mammals, body size is correlated with several traits, including low population density, small population size, long lifespans, extended gestation periods along with prolonged inter-birth intervals and low fecundity.
Brain size is strongly correlated with body size as well and yet, mammals of similar size can have greatly different brain sizes.
Members of small-brained orders may not have possessed the behavioural flexibility needed to cope with a changing climate and/or the arrival of Homo sapiens. Glyptodonts such as Doedicurus (order Cingulata), with their large bodies and small brains died out in the Late Quaternary. Picture credit: Everything Dinosaur.
Picture credit: Everything Dinosaur
In studies of modern birds and mammals, large brains have been found to improve survivability as these animals can modify their behaviour and adapt to rapidly changing environments and new threats such as an expanding human population.
When considering which animals around today might be under the most severe threat of extinction, brain-size should be considered when calculating the risk factors.
The paper published as an open access document in “Scientific Reports”
The scientific paper: “Small brains predisposed Late Quaternary mammals to extinction” by Jacob Dembitzer, Silvia Castiglione, Pasquale Raia and Shai Meiri published in Scientific Reports.
Today, Tuesday the 8th of March is International Women’s Day, a day that is celebrated across the world, recognising the achievements of women in business, the arts, politics and of course in the sciences. A movement that began in the early years of the 20th century has expanded to encompass all aspects of gender equality.
The theme for International Women’s Day 2022 is “breaking the bias”.
A collection of women scientists part of a poster montage spotted during a school visit. Celebrating International Women’s Day. Picture credit: Everything Dinosaur.
Picture credit: Everything Dinosaur
#BreakTheBias
Using the hashtag #BreaktheBias the official website states that whether deliberate or unconscious, bias makes it difficult for women to move ahead. Knowing that bias exists is not enough. Action is needed to level the playing field. Many academic institutions, museums and educational bodies are working to improve opportunities and to support gender equality.
Imagine a world with gender equality, collectively we can all #BreakTheBias.
Marvellous news for the start of 2022, the plans to locate a permanent statue commemorating the work of Mary Anning and her contribution to the Earth sciences have been approved by Dorset Council. The idea to erect a permanent memorial to the most famous former resident of Lyme Regis had been proposed in the past, but it was young, fossil fan Evie Swire and her mum who kick-started the project once more in 2018 with the launch of their charity Mary Anning Rocks.
Plans have been approved to erect a life-size bronze sculpture of Mary Anning. The memorial, designed by Denise Dutton, is likely to be unveiled in the late spring of 2022 and it will, in a small way, help to redress the great imbalance between statues of men and women in the UK. Approximately eighty-five percent of all the statues erected in Great Britain acknowledge the achievements of men. It is therefore fitting that a memorial to Mary Anning should be put on permanent display close to where she made some of her most important scientific discoveries.
Approval has been given for the erection of a permanent statue honouring Mary Anning. Picture credit: Denise Sutton/Mary Anning Rocks.
Picture credit: Denise Sutton/Mary Anning Rocks
Mary Anning Rocks
The charity, which team members at Everything Dinosaur have supported, has raised over £100,000 and plans are well advanced to place a statue of Mary Anning overlooking the beach to the east of the town of Lyme Regis. The charity wants to acknowledge and remember Mary Anning and her contribution to the nascent science of palaeontology. The statue will commemorate Mary and her dog Tray, which accompanied her on her fossil hunts. Unfortunately, the dog was killed in a landslide. The statue which will be within sight of Black Ven and Golden Cap will also provide a reminder to visitors of the dangers of straying too close to the cliffs as well as providing tourists with a focal point for remembrance and respect.
Part of the coastal defences at Lyme Regis. Picture credit: Everything Dinosaur.
Picture credit: Everything Dinosaur
Unveiled in May 2022
A spokesperson from Everything Dinosaur commented:
“This is fantastic news! We congratulate all those involved in helping to create this memorial to Mary Anning. The bronze, life-size statue will make a fitting tribute to one of the most influential figures in the early years of the science of palaeontology and perhaps help to inspire more girls to take up a career in the sciences.”
The grave of Mary and Joseph Anning. Picture credit: Everything Dinosaur.
Picture credit: Everything Dinosaur
A date for the unveiling ceremony has yet to be confirmed but it has been suggested that the unveiling will take place on Saturday 21st May (2022).
An exquisite dinosaur embryo from southern China has shed new light on the evolutionary link between the Dinosauria and modern birds. The beautifully preserved embryo of an oviraptorosaur has a posture inside the egg reminiscent of a late-stage modern bird embryo. This pre-hatching behaviour, previously considered unique to the Aves (birds), originated in the Theropoda.
Life reconstruction of a close-to-hatching oviraptorosaur dinosaur embryo, based on the new specimen “Baby Yingliang”. Picture credit: Lida Xing.
Picture credit: Lida Xing
“Baby Yingliang”
Writing in the journal “iScience”, the researchers who include Professor Lida Xing from the China University of Geosciences (Beijing), Professor Steve Brusatte (University of Edinburgh) and PhD student Fion Waisum Ma (University of Birmingham), describe the dinosaur embryo, nicknamed “Baby Yingliang”. Study of the fossilised remains preserved inside the egg (in-ovo), demonstrates that the head of the baby dinosaur lies ventral to the body, with the feet on either side and the back is curled along the blunt end of the egg. This posture had not been recorded in dinosaur embryos before. In modern birds, this posture is referred to as “tucking”. It is a behaviour controlled by the central nervous system and is critical for hatching success.
The oviraptorosaur embryo known as “Baby Yingliang”, one of the best-preserved dinosaur embryos ever reported. Picture credit: Xing et al.
Picture credit: Xing et al
An Oviraptorosaur Embryo
The fossil comes from Upper Cretaceous deposits from Ganzhou Province (southern China). It is believed to be between 72 and 66 million years old. Lead author of the study, Professor Lida Xing explained that the fossil was acquired by the director of Yingliang Group, Mr Liang Liu, during the construction of Yingliang Stone Nature History Museum.
The embryo is articulated in its life position without much disruption from fossilisation. It has been identified as an oviraptorosaur, a toothless theropod dinosaur and a member of the Maniraptora. It was closely related to the dinosaur lineage that led to modern birds. The elongatoolithid egg measures 17 cm in length and the embryo inside measures 27 cm long.
Joint first author of the scientific paper, Fion Waisum Ma stated:
“Dinosaur embryos are some of the rarest fossils and most of them are incomplete with the bones dislocated. We are very excited about the discovery of ‘Baby Yingliang’. It is preserved in a great condition and helps us answer a lot of questions about dinosaur growth and reproduction. It is interesting to see this dinosaur embryo and a chicken embryo pose in a similar way inside the egg, which possibly indicates similar prehatching behaviours.”
A line drawing of the oviraptorosaur embryo known as “Baby Yingliang”. Picture credit: Xing et al.
Picture credit: Xing et al
Plotting the Evolution of “Tucking” Behaviours
Birds develop this tucking posture, prior to hatching. Embryos that fail to adopt this posture have a higher chance of dying during the hatching process. By comparing this oviraptorosaur embryo with the embryos of other theropods, long-necked sauropod dinosaurs and birds, the researchers postulate that tucking behaviour, which was considered unique to birds, first evolved in theropod dinosaurs. Pinning down just when in geological time this behaviour evolved is dependent on the discovery of more dinosaur embryo fossils.
Co-author of the study, Steve Brusatte commented:
“This dinosaur embryo inside its egg is one of the most beautiful fossils I have ever seen. This little prenatal dinosaur looks just like a baby bird curled in its egg, which is yet more evidence that many features characteristic of today’s birds first evolved in their dinosaur ancestors.”
Everything Dinosaur acknowledges the assistance of a media release from the University of Birmingham in the compilation of this article.
The scientific paper: “An exquisitely preserved in-ovo theropod dinosaur embryo sheds light on avian-like prehatching postures” by Lida Xing, Kecheng Niu, Waisum Ma, Darla K. Zelenitsky, Tzu-Ruei Yang, Stephen L. Brusatte published in iScience.
An almost perfectly preserved specimen of the very bird-like theropod Caudipteryx has provided researchers with evidence of organic molecule preservation at a cellular and nuclear level. Writing in “Communications Biology”, scientists from the Institute of Vertebrate Palaeontology and Palaeoanthropology of the Chinese Academy of Sciences, in collaboration with colleagues from the Shandong Tianyu Museum of Nature (Shandong Province, eastern China), report on a study of fossilised cells from cartilage associated with a Caudipteryx thigh bone that reveal exquisite molecular preservation.
Photograph of the Caudipteryx specimen (A) with (B) a close-up of the femur showing the extracted fragment outlined in yellow. Illustrative line drawing (C). Picture credit: Xiaoting Zheng et al.
Fragments from a Femur
The specimen (number STM4-3), is in the Shandong Tianyu Museum of Nature vertebrate fossil collection, one of the largest collections of dinosaur fossils in the world. It was collected from the Yixian Formation near Chaoyang City, Dapingfang Town (Liaoning Province) and is almost complete and partially articulated. Gastroliths are preserved in the stomach cavity and the outline of some feathers can also be seen. A right femur, measuring 15 cm in length was examined, a fragment removed representing cartilage and divided into three portions to permit detailed scanning electron microscopy (SEM), histochemical staining, energy-dispersive X-ray spectroscopy (EDS) and transmission electron microscopy (TEM) along with chemical analysis.
The research team realised that some cells had been mineralised by silicification after the death of the animal. This silicification is most likely what permitted the excellent preservation of these cells.
A model of the theropod dinosaur Caudipteryx.
The picture (above) shows a Cauipteryx model produced by Safari Ltd.
Li Zhiheng, an Associate Professor at the Institute of Vertebrate Palaeontology and Palaeoanthropology and a co-author of the study commented that the discovery of cellular preservation in the cartilage was not unexpected stating:
“Geological data has accumulated over the years and shown that fossil preservation in the Jehol Biota was exceptional due to fine volcanic ashes that entombed the carcasses and preserved them down to the cellular level”.
Healthy Cells and Unhealthy, Dying Cells
The researchers discovered two main types of cells, cells that were healthy at the time of fossilisation, along with unhealthy cells that were porous and fossilised while in the process of dying.
Co-author Alida Bailleul (Institute of Vertebrate Palaeontology and Palaeoanthropology), explained:
“It is possible that these cells were already dying even before the animal died”.
Cell death is a process that occurs naturally throughout the lives of all organisms. But being able to identify a fossilised cell at a specific life stage within the cell cycle is quite new in palaeontology.
Staining the Nuclei of Dinosaur Cells
The team isolated some cells and stained them with a purple chemical used by biologists to identify nuclei material. This chemical, hematoxylin, is known to bind to the nuclei of cells. Cells from a chicken were also stained to provide an extant comparison. One dinosaur cell showed a purple nucleus with some darker purple threads. This provides strong evidence to support the idea that the 125-million-year-old dinosaur cell has a nucleus so well-preserved that it retains some original biomolecules and threads of chromatin.
Chromatin is found within the cells of all living organisms. It consists of tightly packed DNA molecules. The results of this study thus provide preliminary data suggesting that remnants of original dinosaur DNA may still be preserved.
Photographs of three cartilage cells from the femur of Caudipteryx. The purple chemical hematoxylin binds to the nuclei of cells. After the dinosaur cells were stained one cell showed a purple nucleus, this suggests that the 125-million-year-old fossil cell is so well preserved it has retained some original biomolecules and threads of chromatin. This cell replicated the reaction to hematoxylin expected from a cell of a living chicken. Picture credit: Alida Bailleul.
Much Further Work is Required
Whilst highlighting the significance of this study, after all discovering that 125-million-year-old dinosaur cells react to hematoxylin staining in the same way as living cells is remarkable, the researchers concede that a much more refined and precise approach will be required if dinosaur DNA is to be identified and recovered in any quantity.
The Jehol Biota approximately 125 million years ago. The corpse of the Caudipteryx lies on the lake shore whilst a pair of Psittacosaurus wander past and pterosaurs fly overhead. A Confuciusornis bird perches on a tree, undeterred by the erupting volcano nearby. Picture credit: Zheng Qiuyang.
In 2020, Everything Dinosaur reported upon the discovery of chromosome-like chromatin threads preserved in the fossilised cartilage of a 75-million-year-old hadrosaur (Hypacrosaurus stebingeri). This study identified nuclear and cellular preservation which was previously unknown in a Cretaceous fossil specimen. To read our article: Cartilage, Proteins and Potential Dinosaur DNA?
The scientific paper: “Nuclear preservation in the cartilage of the Jehol dinosaur Caudipteryx” by Xiaoting Zheng, Alida M. Bailleul, Zhiheng Li, Xiaoli Wang and Zhonghe Zhou published in Communications Biology.
New research published in the journal “Nature Communications” suggests that all extant snakes evolved from just a handful of species that survived the K-Pg extinction event 66 million years ago. The researchers conclude that this catastrophic extinction event, that wiped out the non-avian dinosaurs and something like 75% of all terrestrial life, was a form of “creative destruction” leading to a burst of evolutionary development within the Serpentes.
Snakes benefitted from the End-Cretaceous extinction event. It enabled them to evolve rapidly and to exploit new, ecological niches. Picture credit: Joschua Knüppe.
Snakes benefited from the extinction event, the loss of so many competitors allowed them to diversify rapidly and to occupy new niches in food chains.
The Snake Fossil Record
The fossil record of snakes is relatively poor because snake skeletons are typically small and fragile making the preservation of fossil material a rare event.
It is generally accepted that snakes (Suborder Serpentes), evolved from lizards. Snakes gradually losing their limbs, whether the first snakes were burrowers and evolved from burrowing lizards or whether the first snakes were adapted to a life in marine environments is an area of on-going debate between vertebrate palaeontologists. For example, in 2016 a team of scientists challenged the conclusions from the paper that described Tetrapodophis amplectus, a primitive snake-like animal from the Lower Cretaceous of Brazil. It had been suggested that T. amplectus, which had been described and named the year before, was adapted to a life underground, however, researchers from Canada and Australia challenged this view and proposed a marine habit for this 20 cm long animal that has been classified as being close to the base of the evolutionary lineage of true snakes.
The tiny limbs of Tetrapodophis may have been used to hold prey. Scientists are uncertain whether this animal was a burrower or adapted to a marine environment. Picture credit: Julius Csotonyi.
The research, led by scientists at the University of Bath in collaboration with researchers from Cambridge, Bristol and Germany, involved examining snake fossils and an analysis of the genomes of living snakes to pinpoint genetic differences permitting a picture of modern snake evolution to be built up.
The results indicate that despite the great variety of snakes alive today – cobras, vipers, pythons, boas, sea snakes and blind, burrowing snakes for example, all extant snakes can be traced back to a handful of species that survived the K-Pg extinction event that took place 66 million years ago.
Snake Survival Strategy
The authors postulate that the ability of snakes to shelter underground and go for long periods without food helped them survive the destructive effects of the bolide impact event. In the aftermath, the extinction of their competitors including Cretaceous snakes and small theropod dinosaurs, permitted snakes to move into new niches, new habitats and new parts of the world. Today, snakes are found in all but the highest latitudes and are present on every continent except Antarctica.
The researchers, which included lead author Dr Catherine Klein, a former graduate of Bath University but now based at the Alexander-Universität Erlangen-Nürnberg (FAU) in Germany, state that modern snake diversity – including tree snakes, sea snakes, venomous vipers and cobras, and huge constrictors like boas and pythons – emerged only after the non-avian dinosaur extinction.
Dr Klein commented:
“It’s remarkable, because not only are they surviving an extinction that wipes out so many other animals, but within a few million years they are innovating, using their habitats in new ways.”
A Change in Snake Vertebrae
Fossils also show a change in the shape of snake vertebrae in the aftermath, resulting from the extinction of Cretaceous lineages and the appearance of new groups, including giant sea snakes, such as Gigantophis garstini from the Eocene of northern Africa which may have reached a length of ten metres. Gigantophis was scientifically described in 1901, it was thought to have been the largest snake to have ever lived, until in 2009 when the giant, South American boa – Titanoboa cerrejonensis was described.
The Rebor Titanoboa Museum Class Maquette Monty Resurgent. A model of the largest snake known to science.
The picture (above) shows the Rebor Titanoboa Museum Class Maquette known as Monty Resurgent.
The research team also suggest that snakes began to spread rapidly around the globe. The “Greenhouse Earth” conditions that occurred close to the boundary between the Palaeocene and Eocene Epochs that led to the establishment of extensive tropical forests in the Northern Hemisphere, would have facilitated the geographical spread of cold-blooded animals such as snakes.
Although the ancestor of living snakes probably lived somewhere in the Southern Hemisphere, snakes first appear to have spread to Asia after the extinction event.
Corresponding author, Dr Nick Longrich, from the Milner Centre for Evolution (University of Bath), explained:
“Our research suggests that extinction acted as a form of “creative destruction”- by wiping out old species, it allowed survivors to exploit the gaps in the ecosystem, experimenting with new lifestyles and habitats. This seems to be a general feature of evolution – it’s the periods immediately after major extinctions where we see evolution at its most wildly experimental and innovative. The destruction of biodiversity makes room for new things to emerge and colonise new landmasses. Ultimately life becomes even more diverse than before.”
Further Serpentes Evolution Driven by Climate Change
The researchers also found evidence for a second major diversification event around the time that the world shifted from a warm and moist climate to a colder, more seasonal climate (Oligocene Epoch).
It seems, that for the snakes at least, global catastrophes can have their upsides. The patterns seen in snake evolution hint at the key role played by mass extinction events – they are the catalysts for driving rapid evolutionary changes.
The scientific paper: “Evolution and dispersal of snakes across the Cretaceous-Paleogene mass extinction” by Catherine G. Klein, Davide Pisani, Daniel J. Field, Rebecca Lakin, Matthew A. Wills and Nicholas R. Longrich published in Nature Communications.
