PALEONTOLOGY
Fossil dung reveals clues to dinosaur success story
Uppsala University
image:
A duo of sauropodomorphs; one munching on the newly evolved plants in a wet Early Jurassic environment whilst the other is looking up as if there was something hiding in the vegetation. Illustration: Marcin Ambrozik.
view moreCredit: Marcin Ambrozik
In an international collaboration, researchers at Uppsala University have been able to identify undigested food remains, plants and prey in the fossilised faeces of dinosaurs. These analyses of hundreds of samples provide clues about the role dinosaurs played in the ecosystem around 200 million years ago. The findings have been published in the journal Nature.
“Piecing together ‘who ate whom’ in the past is true detective work,” says Martin Qvarnström, researcher at the Department of Organismal Biology and lead author of the study. “Being able to examine what animals ate and how they interacted with their environment helps us understand what enabled dinosaurs to be so successful.”
Palaeontologists from Uppsala University, in collaboration with researchers from Norway, Poland and Hungary, have examined hundreds of samples using advanced synchrotron imaging to visualise the hidden, internal parts of the fossilised faeces, known as coprolites, in detail. By identifying undigested food remains, plants and prey, they have recreated the structure of the ecosystems at the time when dinosaurs began their success story.
The study focused on a previously underexplored region, Polish Basin, located in the Late Triassic time in the in the northern parts of the then supercontinent Pangea. The researchers built up a comprehensive picture of the Triassic and Jurassic ecosystems (from about 230 to 200 million years ago) by combining the information from the coprolites with climate data and information from other fossils: plants, bite marks, vomit, footprints and bones.
“The research material was collected over a period of 25 years. It took us many years to piece everything together into a coherent picture,” says Grzegorz Niedźwiedzki, researcher at the Department of Organismal Biology and the study’s senior author. “Our research is innovative because we have chosen to understand the biology of early dinosaurs based on their dietary preferences. There were many surprising discoveries along the way.”
The coprolites contained remains of fish, insects, larger animals and plants, some of which were unusually well preserved, including small beetles and semi-complete fish. Other coprolites contained bones chewed up by predators that, like today’s hyenas, crushed bones to obtain salts and marrow. The contents of coprolites from the first large herbivorous dinosaurs, the long-necked sauropods, surprised the researchers. These contained large quantities of tree ferns, but also other types of plants, and charcoal. The palaeontologists hypothesise that charcoal was ingested to detoxify stomach contents, as ferns can be toxic to herbivores.
The research addresses a significant gap in current knowledge: the first 30 million years of dinosaur evolution during the Late Triassic period. Although much is known about their lives and extinction, the ecological and evolutionary processes that led to their rise are largely unexplored. The study results in a five-step model of dinosaur evolution that the researchers believe can explain global patterns.
The team emphasises that understanding how the first dinosaurs achieved their success can offer valuable insights into prehistoric ecosystems and evolutionary processes in general. The results show that dietary diversity and adaptability were crucial survival traits during the environmental changes of the Late Triassic.
“Unfortunately, climate change and mass extinctions are not just a thing of the past. By studying past ecosystems, we gain a better understanding of how life adapts and thrives under changing environmental conditions,” says Qvarnström.
“The way to avoid extinction is to eat a lot of plants, which is exactly what the early herbivorous dinosaurs did. The reason for their evolutionary success is a true love of green and fresh plant shoots,” Niedzwiedzki concludes.
s from a large fish with spiral gut (hence the spirals in the coprolite), showing fish scales indicative of diet. Illustration: Martin Qvarnström
CaptionLarge coprolite with fish remains: A coprolite fragment densely packed with fish bones, likely produced by the phytosaur Paleorhinus. Illustration: Martin Qvarnström
Fossil faeces of the bone-crushing archosaur Smok, with a Smok reconstruction in the background. (IMAGE)
Coprolite from Smok: Fossil faeces of the bone-crushing archosaur Smok, with a Smok reconstruction in the background. Illustration: Grzegorz Niedźwiedzki
Journal
Nature
Article Title
Digestive contents and food webs record the advent of dinosaur supremacy
Article Publication Date
27-Nov-2024
World’s oldest lizard wins fossil fight
University of Bristol
image:
Photo of the inside of the skull and lower jaw on the right and CT scan of the outside of the same bones on the left image. The images show the left side of the skull and lower jaw
view moreCredit: 3D imagery by Sofia Chambi Trowell, photograph by David Whiteside
A storeroom specimen that changed the origins of modern lizards by millions of years has had its identity confirmed.
The tiny skeleton, unearthed from Triassic-aged rocks in a quarry near Bristol, is at least 205 million years old and the oldest modern-type lizard on record.
Recently, the University of Bristol team’s findings came under question, but fresh analysis, published today in Royal Society Open Science, proves that the fossil is related to modern anguimorphs such as anguids and monitors. The discovery shifts the origin of the whole lizard-snake group, called Squamata, back by 35 million years.
In the original study, Dr David Whiteside, Dr Sofia Chambi-Trowell and Professor Mike Benton, named the little critter Cryptovaranoides microlanius, meaning ‘hidden lizard, small butcher’ because of its identification as a lizard and its sharp teeth, probably used for cutting up prey animals for food. The Bristol team identified many anatomical features of the skull and skeleton that allowed them to place it well within Squamata, and even close to the Anguimorpha.
“We knew our paper would be controversial,” explained Dr Whiteside. “But we were confident that we had looked at every possible feature and compared it with everything we could.”
Professor Benton said: “We were therefore surprised, perhaps even shocked, that in 2023 another team of academics suggested that Cryptovaranoides was not a lizard or even a lizard relative, but in fact an archosauromorph, more closely related to crocodilians and dinosaurs.”
In checking their original work, and the questions posed in the rival paper, the Bristol team explored all the data, including the original specimen as well as the X-ray scans that show the details hidden within the rock. “We had the marvellous images from those CT scans as well as further access to the fossil which enabled us to check all their suggestions,” said Dr Chambi-Trowell. “We found that most of the concerns raised were wrong.”
Professor Benton added: “All the details of the skull, the jaws, the teeth, and the limb bones confirm that Cryptovaranoides is a lizard, not an archosauromorph.
“In our new paper, we provide great detail of every criticism made and we provide more photographs of the specimen and 3D images from the scans, so everyone can check the detail.”
Dr Whiteside concluded: “The result of all this had to be tested by a phylogenetic analysis.
“This is where we code hundreds of anatomical features in Cryptovaranoides and other modern and fossil lizards, as well as various archosauromorphs.
“We ran the analysis time after time, and it gave our original result, that the little Bristol reptile is indeed the world’s oldest modern-type lizard.”
The paper
Whiteside DI, Chambi-Trowell SAV, Benton MJ. 2024 Late Triassic †Cryptovaranoides microlanius is a squamate, not an archosauromorph. R. Soc. Open Sci. 11: 231874. https://doi.org/10.1098/rsos.231874
Life restoration of the earliest lizard, Cryptovaranoides microlanius
Credit
Lavinia Gandolfi
Journal
Royal Society Open Science
Method of Research
Computational simulation/modeling
Subject of Research
Animals
Article Title
Cryptovaranoides microlanius is a squamate, not an archosauromorph
Article Publication Date
26-Nov-2024
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