Newswise – A fossil find from Scotland has provided new information about the early evolution of lizards during the dinosaur age.
The tiny skeleton discovered on the Isle of Skye, dubbed Bellairsia gracilis, is only 6 cm long and dates from the Middle Jurassic 166 million years ago. The extraordinary new fossil consists of a nearly complete skeleton in lifelike articulation, missing only the snout and tail. This makes it the most complete fossil lizard of this age in the world.
Bellairsia exhibits a mix of ancestral and modern features in its skeleton, providing evidence of what the ancestor of modern-day lizards (which are part of the broader group of animals known as “squamates”) might have looked like.
The research, a joint project by researchers from the Universities of Warsaw, Oxford and UCL, is reported in the journal Nature. First author Dr. Mateusz Tałanda (University of Warsaw and UCL) said: “This little fossil lets us see evolution in action. It is rare in paleontology to work with such complete, well-preserved fossils from a time we know so little about.”
The fossil was found in 2016 by a team led by Oxford University and National Museums Scotland. It is one of several new fossil finds on the island, including early amphibians and mammals, that reveal the evolution of important animal groups that survive to this day.
dr Tałanda commented: “Bellairsia has some modern lizard traits, such as traits related to cranial kinesis – that is the movement of the skull bones in relation to one another. This is an important functional characteristic of many living squamates.’
co-author dr. Elsa Panciroli (Oxford University Museum of Natural History and National Museums Scotland), who discovered the fossil, said: “It was one of the first fossils I found when I started working on Skye. The small black skull poked out of the pale limestone, but it was small enough that I was lucky enough to see it. As I looked closer, I saw the tiny teeth and realized I had found something important, but we had no idea until later that almost the entire skeleton was inside.”
Squamates are the living group that includes lizards and snakes and today numbers more than 10,000 species, making them one of the most species-rich living vertebrate groups. This includes animals as diverse as snakes, chameleons and geckos, which can be found all over the world. The group is characterized by numerous special features of the skull and the rest of the skeleton.
Although we know that the earliest origins of squamates are 240 million years ago in the Triassic, a lack of Triassic and Jurassic fossils has made it difficult to trace their early evolution and anatomy.
Analysis of the new fossil along with living and extinct fossil squamates confirms this Bellairsia belongs to the ‘trunk’ of the Squamate family tree. This means that it split off from other lizards just before the emergence of modern groups. The research also supports the finding that geckos are a very early branching lineage and the enigmatic fossil Oculudentavis, previously thought to be a dinosaur, is also a tribe squamate.
To study the sample, the team used X-ray computed tomography (CT), which, like medical CT, allows for non-invasive 3D imaging. This allowed the researchers to image the entire fossil, although most of the specimen is still obscured by the surrounding rock. While medical scanners work in the millimeter range, the University of Oxford’s CT scanner revealed details down to tens of microns.
Parts of the skeleton were then imaged in more detail, including the skull, hind legs and pelvis, at the European Synchrotron (ESRF, Grenoble, France). The intensity of the synchrotron beam allows a resolution of 4 micrometers and shows details of the smallest bones of the skeleton.
Co-author Professor Roger Benson (Department of Earth Sciences, University of Oxford) said: “Fossils like this Bellairsia Samples have tremendous value in filling in gaps in our understanding of evolution and the history of life on Earth. It used to be almost impossible to study such tiny fossils as this one, but this study shows the power of new techniques, including CT scanning, to image them non-destructively and in great detail.’
Co-author Professor Susan Evans (UCL) who first described and named Bellairsia from some jaw and skull bones from Oxfordshire 25 years ago, added: “It’s wonderful to have a complete specimen of this tempting little lizard and see where it fits on the evolutionary tree. Through fossils like Bellairsia we gain a better understanding of early lizard anatomy. Angus Bellairs, the lizard embryologist, after that Bellairsia was originally named would have made me happy.”
The study was conducted by Dr. Mateusz Tałanda (University of Warsaw) and included researchers from the Department of Earth Sciences at Oxford University, the Oxford University Museum of Natural History, UCL (University College London), the European Synchrotron Radiation Facility, the Natural History Museum in London and the National Museums of Scotland.
Funding was provided by the Polish Ministry of Science and Higher Education. The John Muir Trust provided access to the Elgol Coast Site of Special Scientific Interest and NatureScot issued fossil collecting permits.
Notes for editors
The study appears in Nature. The DOI number for this paper is 10.1038/s41586-022-05332-6. Once published online, the paper will be available at the following URL: https://www.nature.com/articles/s41586-022-05332-6
About Oxford University
Oxford University has been ranked #1 in the Times Higher Education World University Rankings for the seventh year running and #2 in the QS World Rankings 2022. Central to this success are the two pillars of our groundbreaking research and innovation and our distinctive educational offering.
World-renowned for excellent research and teaching, Oxford is home to some of the most talented people from around the world. Our work helps the lives of millions by solving real-world problems through a vast network of partnerships and collaborations. The breadth and interdisciplinary nature of our research, as well as our personalized teaching approach, result in imaginative and inventive insights and solutions.
Through its research commercialization arm, Oxford University Innovation, Oxford is the UK’s highest university patent assignee and is the UK’s number one university spin-off company, having created more than 200 new companies since 1988. More than a third of these companies have been founded in the past three years. The university is a catalyst for prosperity in Oxfordshire and the UK, contributing £15.7 billion to the UK economy in 2018/19 and supporting more than 28,000 full-time jobs.
About UCL – London’s global university
UCL is a diverse global community of world-class academics, students, industry leaders, external partners and alumni. Our powerful collective of individuals and institutions work together to explore new possibilities.
Since 1826, we’ve championed independent thinking by attracting and nurturing the world’s brightest minds. Our community of more than 43,800 students from 150 countries and over 14,300 employees strives for academic excellence, breaks boundaries, and has a positive impact on real-world problems.
We are regularly ranked among the top 10 universities in the world and are one of only a handful of institutions with the strongest academic reputation and broadest research impact.
We pursue a progressive and integrated approach in teaching and research – we are committed to innovation, creativity and interdisciplinary work. We teach our students how to think, not what to think, and see them as partners, collaborators and contributors.
For almost 200 years, we’ve been proud to have opened higher education to students from all backgrounds and to transform the way we create and share knowledge.
We were the first in England to welcome women into university education and that bold attitude and disruptive spirit is still alive today. We are UCL.
www.ucl.ac.uk | consequences @uclnews on Twitter | Read the news at www.ucl.ac.uk/news/ | Listen to UCL Podcasts on SoundCloud | Find out what’s going on at UCL Minds
About the Natural History Museum
That Natural History Museum is both a world leading science research center and the most visited indoor attraction in the UK in the last year. With a vision of a future where both people and the planet thrive, the company is uniquely positioned to be a strong advocate for balancing the needs of humanity with those of the natural world. It is custodian of one of the world’s most important scientific collections with over 80 million specimens accessed by researchers from around the world both personally and through over 30 billion digital data downloads to date. The museum’s 350 scientists find solutions to planetary emergencies, from biodiversity loss to sustainable extraction of natural resources. The museum uses its global reach and influence to fulfill its mission to create advocates for the planet – to inform, inspire and empower everyone to make a difference for nature. We welcome millions of visitors through our doors each year, our website has been visited 17 million times in the last year and our traveling exhibitions have been seen by around 20 million people in the last 10 years.