Footprints discovered from the last dinosaurs to walk on UK soil
Footprints from at least six different species of dinosaur — the very last dinosaurs to walk on UK soil 110 million years ago — have been found in Kent, a new report has announced.
The discovery of dinosaur footprints by a curator from Hastings Museum and Art Gallery and a scientist from the University of Portsmouth is the last record of dinosaurs in Britain.
The footprints were discovered in the cliffs and on the foreshore in Folkestone, Kent, where stormy conditions affect the cliff and coastal waters, and are constantly revealing new fossils.
Professor of Palaeobiology, David Martill, said: “This is the first time dinosaur footprints have been found in strata known as the ‘Folkestone Formation’ and it’s quite an extraordinary discovery because these dinosaurs would have been the last to roam in this country before becoming extinct.
“They were walking around close to where the White Cliffs of Dover are now — next time you’re on a ferry and you see those magnificent cliffs just imagine that!”
The footprint fossils formed by sediment filling the impression left behind when a dinosaur’s foot pushes into the ground, which then preserves it.
The footprints are from a variety of dinosaurs, which shows there was a relatively high diversity of dinosaurs in southern England at the end of the Early Cretaceous period, 110 million years ago.
They are thought to be from ankylosaurs, rugged-looking armoured dinosaurs which were like living tanks; theropods, three-toed flesh-eating dinosaurs like the Tyrannosaurus rex; and ornithopods, plant-eating ‘bird-hipped’ dinosaurs so-called because of their pelvic structure being a little bit similar to birds.
Philip Hadland, Collections and Engagement Curator at the Hastings Museum and Art Gallery is lead author on the paper. He said: “Back in 2011, I came across unusual impressions in the rock formation at Folkestone. They seemed to be repeating and all I could think was they might be footprints.
“This was at odds with what most geologists say about the rocks here, but I went looking for more footprints and as the tides revealed more by erosion, I found even better ones. More work was needed to convince the scientific community of their validity, so I teamed up with experts at the University of Portsmouth to verify what I’d found.”
Most of the findings are isolated footprints, but one discovery comprises six footprints — making a ‘trackway’, which is more than one consecutive print from the same animal.
This trackway of prints are similar in size to an elephant footprint and have been identified as likely to be an Ornithopodichnus, of which similar, but smaller-sized footprints have also been found in China from the same time period.
The largest footprint found — measuring 80 cm in width and 65 cm in length — has been identified as belonging to an Iguanodon-like dinosaur. Iguanodons were also plant-eaters, grew up to 10 metres long and walked on both two legs or on all fours.
Professor Martill said: “To find such an array of species in one place is fascinating. These dinosaurs probably took advantage of the tidal exposures on coastal foreshores, perhaps foraging for food or taking advantage of clear migration routes.”
In the Late Cretaceous period, this part of Kent, and indeed much of the United Kingdom was beneath a shallow sea, but this study also shows unequivocally that the Folkestone Formation was inter-tidal.
Mr Hadland said: “Aside from finding that dinosaurs went to the seaside just like their modern relatives the birds, we have also found new evidence that changes the interpretation of the geology of the Folkestone Formation strata.
“It just goes to show that what has been previously published about the geology of an area isn’t always correct and new insights can be made. There is also the potential for almost anyone to make a discovery that adds to scientific knowledge from publicly accessible geological sites.”
Story Source:
Materials provided by University of Portsmouth. Note: Content may be edited for style and length.
Journal Reference:
- Philip T. Hadland, Steve Friedrich, Abdelouahed Lagnaoui, David M. Martill. The youngest dinosaur footprints from England and their palaeoenvironmental implications. Proceedings of the Geologists’ Association, 2021; DOI: 10.1016/j.pgeola.2021.04.005
Diverse fossil flora from 400 million year ago
The analysis of very old plant fossils discovered in South Africa and dating from the Lower Devonian period documents the transition from barren continents to the green planet we know today. Cyrille Prestianni, a palaeobotanist at the EDDy Lab at the University of Liège (Belgium), participated in this study, the results of which have just been published in the journal Scientific Reports.
The greening of continents — or terrestrialisation — is undoubtedly one of the most important processes that our planet has undergone. For most of the Earth’s history, the continents were devoid of macroscopic life, but from the Ordovician period (480 million years ago) green algae gradually adapted to life outside the aquatic environment. The conquest of land by plants was a very long process during which plants gradually acquired the ability to stand upright, breathe in the air or disperse their spores. Plant fossils that document these key transitions are very rare. In 2015, during the expansion of the Mpofu Dam (South Africa), researchers discovered numerous plant fossils in geological strata dated to the Lower Devonian (420 — 410 million years ago), making this a truly exceptional discovery.
Cyrille Prestianni, a palaeobotanist at the EDDy Lab (Evolution and Diversity Dynamics Lab) at the University of Liège, explains: “The discovery quickly proved to be extraordinary, since we are in the presence of the oldest fossil flora in Africa and it is very diversified and of exceptional quality. It is thanks to a collaboration between the University of Liège, the IRSNB (Royal Belgian Institute of Natural Sciences) and the New Albany Museum (South Africa) that this incredible discovery could be studied. The study, which has just been published in the journal Scientific Reports, describes this particularly diverse fossil flora with no less than fifteen species analysed, three of which are new to science. Dr. Prestianni adds : ” This flora is also particularly interesting because of the quantity of complete specimens that have been discovered,” says the researcher. These plants are small, with the largest specimens not exceeding 10 cm in height. They are simple plants, consisting of axes that divide two or three times and end in reproductive structures called sporangia. “
The fossil flora of Mpofu allows us today to imagine what the world might have been like when the largest plants were no taller than our ankle and almost no animals had yet been able to free themselves from the aquatic environment. It gives us a better understanding of how our Earth went from a red rock devoid of life to the green planet we know today. These plants, simple as they are, are a crucial step in the construction of the environments that hosted the first land animals, arthropods. They form the basis of the long history of life on Earth, which continues today from dense tropical forests to the arid tundra of the north.
Story Source:
Materials provided by University of Liege. Note: Content may be edited for style and length.
Journal Reference:
- Robert W. Gess, Cyrille Prestianni. An early Devonian flora from the Baviaanskloof Formation (Table Mountain Group) of South Africa. Scientific Reports, 2021; 11 (1) DOI: 10.1038/s41598-021-90180-z
School lesson gone wrong leads to new, bigger megalodon size estimate
A more reliable way of estimating the size of megalodon shows the extinct shark may have been bigger than previously thought, measuring up to 65 feet, nearly the length of two school buses. Earlier studies had ball-parked the massive predator at about 50 to 60 feet long.
The revised estimate is the result of new equations based on the width of megalodon’s teeth — and began with a high school lesson that went awry.
Victor Perez, then a doctoral student at the Florida Museum of Natural History, was guiding students through a math exercise that used 3D-printed replicas of fossil teeth from a real megalodon and a set of commonly used equations based on tooth height to estimate the shark’s size. But something was off: Students’ calculations ranged from about 40 to 148 feet for the same shark. Perez snapped into trouble-shooting mode.
“I was going around, checking, like, did you use the wrong equation? Did you forget to convert your units?” said Perez, the study’s lead author and now the assistant curator of paleontology at the Calvert Marine Museum in Maryland. “But it very quickly became clear that it was not the students that had made the error. It was simply that the equations were not as accurate as we had predicted.”
Although the equations have been widely used by scientists since their publication in 2002, the classroom exercise revealed they generate varying size estimates for a single shark, depending on which tooth is measured.
“I was really surprised,” Perez said. “I think a lot of people had seen that study and blindly accepted the equations.”
For more than a century, scientists have attempted to calculate the size of megalodon, whose name means “big tooth.” But the only known remains of the fearsome shark that dominated oceans from about 23 to 3.6 million years ago are fossilized teeth and a few, rare vertebrae. Like other sharks, the rest of megalodon’s skeleton, including its jaw, was composed of lightweight cartilage that decomposed quickly after death. Tooth enamel, however, “preserves really well,” Perez said. “It’s probably the most structurally stable thing in living organisms.” Megalodon sharks shed thousands of teeth over a lifetime, leaving abundant traces of the species in the fossil record.
The most accepted methods for estimating the length of megalodon have used great white sharks as a modern proxy, relying on the relationship between tooth size to total body length. While great white sharks and megalodon belong to different families, they share similar predatory lifestyles and broad, triangular teeth serrated like steak knives — ideal adaptations for hunting large, fleshy marine mammals such as whales and dolphins, Perez said.
But these methods also present a challenge: To generate body length estimates, they require the researcher to correctly identify a fossil tooth’s former position in a megalodon jaw. As in humans, the size and shape of shark teeth vary depending on where they’re located in the mouth, and megalodon teeth are most often found as standalone fossils.
So, Perez was ecstatic when fossil collector Gordon Hubbell donated a nearly complete set of teeth from the same megalodon shark to the Florida Museum in 2015, reducing the guesswork. After museum researchers CT scanned the teeth and made them available online, Perez collaborated with teacher Megan Higbee Hendrickson on a plan to incorporate them into her middle school curriculum at the Academy of the Holy Names school in Tampa.
“We decided to have the kids 3D-print the teeth, determine the size of the shark and build a replica of its jaw for our art show,” Hendrickson said.
Perez and Hendrickson co-designed a lesson for students based on the then-most popular method for estimating shark size: Match the tooth to its position in the shark jaw, look up the corresponding equation, measure the tooth from the tip of the crown to the line where root and crown meet and plug the number into the equation.
After a successful pilot test of a few teeth with Hendrickson’s students, he expanded the lesson plan to include the whole set of megalodon teeth for high school students at Delta Charter High School in Aptos, California. Perez expected a slight variability of a couple millimeters in their results, but this time, variations in students’ estimates shot to more than 100 feet. The farther a tooth position was from the front of the jaw, the larger the size estimate.
After Perez detailed the lesson’s results in a fossil community newsletter, he received an email from Teddy Badaut, an avocational paleontologist in France. Badaut suggested a different approach. Why not measure tooth width instead of height? Previous research had suggested tooth width was limited by the size of a shark’s jaw, which would be proportional to its body length.
Ronny Maik Leder, then a postdoctoral researcher at the Florida Museum, worked with Perez to develop a new set of equations based on tooth width.
By measuring the set of teeth from Hubbell, “we could actually sum up the width of the teeth and get an even better approximation of the jaw width,” Perez said.
The researchers analyzed sets of fossil teeth from 11 individual sharks, representing five species, including megalodon, its close relatives and modern great white sharks.
By measuring the combined width of each tooth in a row, they developed a model for how wide an individual tooth was in relation to the jaw for a given species. Now when a paleontologist unearths a lone megalodon tooth the size of their hand, they can compare its width to the average obtained in the study and get an accurate estimate of how big the shark was.
“I was quite surprised that indeed no one had thought of this before,” said Leder, now director of the Natural History Museum in Leipzig, Germany. “The simple beauty of this method must have been too obvious to be seen. Our model was much more stable than previous approaches. This collaboration was a wonderful example of why working with amateur and hobby paleontologists is so important.”
Perez cautioned that because individual sharks vary in size, the team’s methods still have a range of error of about 10 feet when applied to the largest individuals. It’s also unclear exactly how wide megalodon’s jaw was and difficult to guess based on teeth alone — some shark species have gaps between each tooth while the teeth in other species overlap.
“Even though this potentially advances our understanding, we haven’t really settled the question of how big megalodon was. There’s still more that could be done, but that would probably require finding a complete skeleton at this point,” he said.
Perez continues to teach the megalodon tooth lesson, but its focus has changed.
“Since then, we’ve used the lesson to talk about the nature of science — the fact that we don’t know everything. There are still unanswered questions,” he said.
For Hendrickson, the lesson sparked her students’ enthusiasm for science in ways that textbooks could not.
“Victor was an amazing role model for the kids. He is the personification of a young scientist that followed his childhood interest and made a career out of it. So many of these kids had never worked with or spoken to a scientist who respected their point of view and was willing to answer their questions.”
Leder and Badaut co-authored the study.
Story Source:
Materials provided by Florida Museum of Natural History. Original written by Natalie van Hoose and Jerald B Pinson. Note: Content may be edited for style and length.
Journal Reference:
- Victor Perez, Ronny Leder, Teddy Badaut. Body length estimation of Neogene macrophagous lamniform sharks (Carcharodon and Otodus) derived from associated fossil dentitions. Palaeontologia Electronica, 2021; DOI: 10.26879/1140