Sunday, June 02, 2024

FOSSILS


Origins of Welsh dragons finally exposed by experts



Peer-Reviewed Publication

UNIVERSITY OF BRISTOL

Fig 1 

IMAGE: 

ARTIST’S DEPICTION OF A BRITISH ARCHIPELAGO DURING THE TRIASSIC

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CREDIT: GABRIEL UGUETO





A large fossil discovery has helped shed light on the history of dinosaurs in Wales.

Until recently, the land of the dragon didn’t have any dinosaurs. However, in the last ten years, several dinosaurs have been reported, but their life conditions were not well known. In a new study by a team from the University of Bristol and published in Proceedings of the Geologists’ Association, important details have been revealed for the first time.

They found that early Welsh dinosaurs from over 200 million year ago lived on a tropical lowland beside the sea. Dinosaur trackways are known from Barry and other sites nearby, showing that dinosaurs had walked across the warm lowlands.

The discovery was made at Lavernock Point, close to Cardiff and Penarth, where the cliffs of dark-coloured shales and limestones document ancient shallow seas. At several levels, there are accumulations of bones, including the remains of fish, sharks, marine reptiles and occasionally, dinosaurs.

Former student of the Bristol MSc in Palaeobiology Owain Evans led the study. He explained: “The bone bed paints the picture of a tropical archipelago, which was subjected to frequent storms, that washed material from around the surrounding area, both in land and out at sea, into a tidal zone. This means that from just one fossil horizon, we can reconstruct a complex ecological system, with a diverse array of marine reptiles like ichthyosaurs, plesiosaurs and placodonts in the water, and dinosaurs on land.

“I had visited the coast at Penarth all my life, growing up in Cardiff, but never noticed the fossils. Then, the more I read, the more amazing it became. Local geologists had been collecting bones since the 1870s, and most of these are in the National Museum of Wales in Cardiff.”

Cindy Howells, Curator of Palaeontology at the National Museum of Wales, adds: “The collections from Lavernock go all the way back to the 19th century, with many sections of the bone bed being collected over the years. The presence of dinosaur fossils at the site ensure that it remains one of the most significant localities for palaeontology in Wales.”

Two discoveries made by the team while conducting fieldwork at Lavernock were the fossilized remains of a placodont osteoderm, and a single coelacanth gular bone. Supervisor Dr Chris Duffin said: “The remains of coelacanths and placodonts are relatively rare in the UK, which makes these finds even more remarkable. These two fossils alone help build a broader picture of what the Rhaetian in the UK would have looked like.”

Professor Michael Benton from Bristol’s School of Earth Sciences, another project supervisor, adds: “The volume of dinosaur remains found at Lavernock is extremely exciting, and is a chance to study a complex, and often mysterious period in their evolutionary history. We have identified the remains of a large Plateosaurus like animal, along with several bones which likely belonged to a predatory theropod.”

A significant section of the paper is dedicated to the abundant microfossils found at the site, which include fish teeth, scales and bone fragments. By examining thousands of specimens, the team were able to identify the key species in the shallow seas and work out the relative importance of each.

The origins of the Welsh dragons have been pinned down at last.

The paper

Microvertebrates from the basal Rhaetian Bone Bed (Late Triassic) at Lavernock, South Wales’ by Owain Evans, Christopher J. Duffin, Claudia Hildebrandt, and Michael J. Benton, in Proceedings of the Geologists’ Association, doi: 10.1016/j.pgeola.2024.05.001.


Musankwa sanyatiensis, a new dinosaur 

from Zimbabwe


A new Late Triassic sauropodomorph dinosaur discovered in the Mid-Zambezi Basin, Zimbabwe


Peer-Reviewed Publication

UNIVERSITY OF THE WITWATERSRAND


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IMAGE: 

CAPTION: MAP SHOWING THE GEOGRAPHIC SETTING OF THE MID-ZAMBEZI BASIN AND SPURWING ISLAND IN NORTHWEST ZIMBABWE

CREDIT: LARA SCISCIO

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CREDIT: LARA SCISCIO

Fossils found on the shoreline of Lake Kariba in Zimbabwe represent a completely new dinosaur species. This remarkable find, named Musankwa sanyatiensis, marks only the fourth dinosaur species named from Zimbabwe. The research detailing this significant discovery is set to be published in the prestigious journal Acta Palaeontologica Polonica. The study was conducted by an international team of scientists from the University of the Witwatersrand (Wits) in South Africa, the Natural History Museum of Zimbabwe, Stony Brook University in New York and was led by Prof Paul Barrett from the Natural History Museum in London.

The discovery of Musankwa sanyatiensis is particularly significant as it is the first dinosaur to be named from the Mid-Zambezi Basin of northern Zimbabwe in over 50 years. Additionally, it is only the fourth dinosaur to be named from Zimbabwe, following the descriptions of “Syntarsus” rhodesiensis in 1969, Vulcanodon karibaensis in 1972, and, most recently, Mbiresaurus raathi in 2022.

The rocks yielding this new specimen date back to the Late Triassic period, approximately 210 million years ago. Musankwa sanyatiensis is represented by the remains of a single hind leg, including its thigh, shin, and ankle bones. “Despite the limited fossil material, these bones possess unique features that distinguish them from those of other dinosaurs living at the same time,” says Dr Kimberley ‘Kimi’ Chapelle, assistant professor at Stony Brook University and an honorary associate at the Evolutionary Studies Institute at Wits.

The discovery was named Musankwa sanyatiensis after the houseboat "Musankwa”. In the Tonga dialect, "Musankwa" means "boy close to marriage". This vessel served as the research team's home and mobile laboratory during two field expeditions to Lake Kariba in 2017 and 2018. The vessel was made available to the research team through the generosity of David and Julie Glynn, and the crew – Coster Katupu, Godfrey Swalika, Simbarashe Mangoroma, and Never Mapira – who provided essential logistic support.

Evolutionary analysis reveals that Musankwa sanyatiensis was a member of the Sauropodomorpha, a group of bipedal, long-necked dinosaurs that were widespread during the Late Triassic. Interestingly, this dinosaur appears to be closely related to contemporaries in South Africa and Argentina. Weighing in at around 390 kg, the plant-eating Musankwa sanyatiensis was one of the larger dinosaurs of its era.

Africa has a long history of dinosaur discovery, with the first dinosaur in the southern hemisphere found in South Africa just three years after the term "dinosaur" was coined by Sir Richard Owen in 1842. However, most known dinosaur fossils have been found in just 10 countries, particularly in the northern hemisphere, leading to a sparse representation of African dinosaur diversity in the global fossil record. “The main reason for the underrepresentation of African dinosaur fossils is ‘undersampling’,” says Barrett. “Put simply, there have been fewer people looking for and unearthing dinosaurs in comparison with other regions of the world,” he notes.

Despite the fewer discoveries in Africa, many of these fossils are historically and scientifically significant. These include some of the oldest dinosaurs like Nyasasaurus parringtoni from Tanzania and Mbiresaurus raathi from Zimbabwe, as well as rich dinosaur faunas from South Africa, Tanzania, Niger, and Morocco.

The Late Triassic-Early Jurassic sediments of Zimbabwe are crucial for understanding the End-Triassic extinction, a catastrophic event that dramatically reshaped Earth's biodiversity around 200 million years ago. These different layers provide insights into how different fossil-bearing sediments around the world correspond in age and help in piecing together the global picture of prehistoric life.

This new dinosaur species also highlights the untapped potential of the region for further paleontological discoveries. Barrett elaborates: “Over the last six years, many new fossil sites have been recorded in Zimbabwe, yielding a diverse array of prehistoric animals, including the first sub-Saharan mainland African phytosaurs (ancient crocodile-like reptiles), metoposaurid amphibians (giant armoured amphibians), lungfish, and other reptile remains”.

As more fossil sites are explored and excavated, there is hope for uncovering further significant finds that will shed light on the early evolution of dinosaurs and the ecosystems they inhabited. “Based on where it sits on the dinosaur family tree, Musanwka sanyantiensis is the first dinosaur of its kind from Zimbabwe,” Dr Kimi Chapelle excitedly explains. “It, therefore, highlights the potential of the region for further palaeontological discoveries,” she says.


Artist reconstruction of Musankwa sanyatiensis, walking in Triassic shallow waters past a metoposaur.

CREDIT

Atashni Moopen

Musankwa sanyatiensis leg bones as they were discovered in the ground on Spurwing Island, Lake Kariba, Zimbabwe

CREDIT

Paul Barrett

The international team composed of scientists from Zimbabwe, South Africa and the UK at the Musankwa sanyatiensis fossil locality on Spurwing Island, Lake Kariba, Zimbabwe.

CREDIT

Lara Sciscio


The house-boat “Musankwa”, the vessel that acted as the home and mobile laboratory during two field expeditions to Lake Kariba in 2017–2018, which was made available through the generosity of David and Julie Glynn, and whose crew, Coster Katupu, Godfrey Swalika, Simbarashe Mangoroma, and Never Mapira, provided essential logistic support.

CREDIT

Jonah Choiniere


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