Oldest reptile tracks in Grand Canyon, USA


UNLV geologist Stephen Rowland discovered that a set of 28 footprints left behind by a reptile-like creature 310 million years ago are the oldest ever to be found in Grand Canyon National Park. Credit: Stephen Rowland

From the University of Nevada, Las Vegas in the USA:

Tiny footprints, big discovery: Reptile tracks oldest ever found in Grand Canyon

Geologist investigating 310 million-year-old fossil trackway from ancient reptilian creature

November 8, 2018

A geology professor at the University of Nevada, Las Vegas, has discovered that a set of 28 footprints left behind by a reptile-like creature 310 million years ago, are the oldest ever to be found in Grand Canyon National Park.

The fossil trackway covers a fallen boulder that now rests along the Bright Angel Trail in the national park. Rowland presented his findings at the recent annual meeting of the Society of Vertebrate Paleontology.

“It’s the oldest trackway ever discovered in the Grand Canyon in an interval of rocks that nobody thought would have trackways in it, and they’re among the earliest reptile tracks on earth”, said Rowland.

Rowland said he’s not prepared to say that they’re the oldest tracks of their kind ever discovered, but it’s a possibility, as he’s still researching the discovery.

“In terms of reptile tracks, this is really old,” he said, adding that the tracks were created as the supercontinent Pangaea was beginning to form.

Rowland was first alerted to the tracks in spring 2016 by a colleague who was hiking the trail with a group of students. The boulder ended up along the trail after the collapse of a cliff.

A year later, Rowland studied the footprints up close.

“My first impression was that it looked very bizarre because of the sideways motion”, Rowland said. “It appeared that two animals were walking side-by-side. But you wouldn’t expect two lizard-like animals to be walking side-by-side. It didn’t make any sense.”

When he arrived home, he made detailed drawings, and began hypothesizing about the “peculiar, line-dancing gait” left behind by the creature.

“One reason I’ve proposed is that the animal was walking in a very strong wind, and the wind was blowing it sideways”, he said.

Another possibility is that the slope was too steep, and the animal sidestepped as it climbed the sand dune. Or, Rowland said, the animal was fighting with another creature, or engaged in a mating ritual.

“I don’t know if we’ll be able to rigorously choose between those possibilities”, he said.

He plans to publish his findings along with geologist Mario Caputo of San Diego State University in January. Rowland also hopes that the boulder is soon placed in the geology museum at the Grand Canyon National Park for both scientific and interpretive purposes.

Meanwhile, Rowland said that the footprints could belong to a reptile species that has never yet been discovered.

“It absolutely could be that whoever was the trackmaker, his or her bones have never been recorded,” Rowland said.

Carboniferous-Permian plant extinction harmed amphibians, helped reptiles


This video says about itself:

30 March 2015

Dave and Palaeo After Dark’s James explore the Carboniferous forests in the ‘Carboniferous Forest Simulator‘!

This fantastic software is free for educational, museum or personal use. We really need to get our full support behind this project!

The programme, in its ‘alpha testing’ stage can be downloaded here.

Details of the development of the project can be found here.

From the University of Birmingham in England:

Rainforest collapse 307 million years ago impacted the evolution of early land vertebrates

February 7, 2018

Researchers at the University of Birmingham have discovered that the mass extinction seen in plant species caused by the onset of a drier climate 307 million years ago led to extinctions of some groups of tetrapods, the first vertebrates to live on land, but allowed others to expand across the globe. This research is published today (7th February 2018) in the journal Proceedings of the Royal Society B.

The Carboniferous and Permian periods (358 — 272 million years ago) were critical intervals in the evolution of life on land. During the Carboniferous Period North America and Europe lay in a single land mass at the equator which was covered by dense tropical rainforests. These rainforests flourished because of the warm humid climate, providing an ideal habitat for early tetrapods (vertebrates with four limbs), allowing them to diversify into a variety of species.

But towards the end of this period a major global environment change took place — just as the number of tetrapod species began to increase, the rainforests started to disappear. The climate became much drier causing the mass extinction of many species within the dominant plant groups, such as horsetails and club mosses. Despite this being a catastrophic event for plants, it has been unclear how this affected the early tetrapod community.

Previous attempts to estimate the diversity changes during this period have been hindered by the fossil record, which has not been sampled equally in different time intervals or geographic areas. To fill these gaps in the data, the Birmingham researchers compiled a new dataset from the Paleobiology Database and used advanced statistical methods to estimate diversity and biogeographic changes.

The results of the study show that tetrapod diversity decreased after the rainforest collapse and the onset of drier conditions, largely due to the reduction in suitable habitats for amphibians which needed wet environments to survive.

However they also found that after the rainforest collapse surviving tetrapod species began to disperse more freely across the globe, colonising new habitats further from the equator. Many of these survivors were early amniotes, such as early reptiles, whose generally larger size relative to early amphibians allowed them to travel longer distances, and their ability to lay eggs meant they were not confined to watery habitats.

Emma Dunne, from the University of Birmingham’s School of Geography, Earth and Environmental Sciences, said: ‘This is the most comprehensive survey ever undertaken on early tetrapod evolution, and uses many newly developed techniques for estimating diversity patterns of species from fossil records, allowing us greater insights into how early tetrapods responded to the changes in their environment.’

Dunne continued: ‘We now know that the rainiforest collapse was crucial in paving the way for amniotes, the group which ultimately gave rise to modern mammals, reptiles and birds, to become the dominant group of land vertebrates during the Permian period and beyond.’

Fish evolution, new discovery


Fukangichthys

By Viviane Callier, 2:17pm, September 18, 2017:

3-D scans of fossils suggest new fish family tree

Analysis of specimens from China implies ray-finned fishes are younger than previously thought

When it comes to some oddball fish, looks can be deceiving.

Polypterus, today found only in Africa, and its close kin have generally been considered some of the most primitive ray-finned fishes alive, thanks in part to skeletal features that resemble those on some ancient fish. Now a new analysis of fish fossils of an early polypterid relative called Fukangichthys [from the Triassic] unearthed in China suggests that those features aren’t so old. The finding shakes up the evolutionary tree of ray-finned fishes, making the group as a whole about 20 million to 40 million years younger than thought, researchers propose online August 30 in Nature.

Ray-finned fishes named for the spines, or rays, that support their fins — are the largest group of vertebrates, making up about half of all backboned animals. They include 30,000 living species, such as gars, bowfins and salmon. The group was thought to originate about 385 million years ago, in the Devonian Period. But the new research, using 3-D CT scans of the previously discovered fossils, shifts the fishes’ apparent origin to the start of the Carboniferous Period some 360 million years ago, says study coauthor Matt Friedman, a paleontologist at the University of Michigan in Ann Arbor.

One of the largest extinction events in Earth’s history marks the boundary between the Devonian and Carboniferous. “We know that many groups of backboned animals were hard hit by the event,” Friedman says. But after the massive die-off, ray-finned fishes popped up and, according to previous fossil evidence, their diversity exploded. The new finding “brings the origin of the modern ray-finned fish group in line with this conspicuous pattern that we see in the fossil record,” Friedman says. It suggests these vertebrates didn’t survive the event. They came after, then flourished.

Fish to amphibian evolution, new research


This video says about itself:

The Evolution of Amphibians

23 January 2016

The first major groups of amphibians developed in the Devonian period, around 370 million years ago, from lobe-finned fish which were similar to the modern coelacanth and lungfish.

These ancient lobe-finned fish had evolved multi-jointed leg-like fins with digits that enabled them to crawl along the sea bottom. Some fish had developed primitive lungs to help them breathe air when the stagnant pools of the Devonian swamps were low in oxygen. They could also use their strong fins to hoist themselves out of the water and onto dry land if circumstances so required.

Eventually, their bony fins would evolve into limbs and they would become the ancestors to all tetrapods, including modern amphibians, reptiles, birds, and mammals. Despite being able to crawl on land, many of these prehistoric tetrapodomorph fish still spent most of their time in the water. They had started to develop lungs, but still breathed predominantly with gills.

From the University of Calgary in Canada:

Fossil holds new insights into how fish evolved onto land

‘It’s like a snake on the outside, but a fish on the inside’

June 21, 2017

The fossil of an early snake-like animal — called Lethiscus stocki — has kept its evolutionary secrets for the last 340 million years.

Now, an international team of researchers, led by the University of Calgary, has revealed new insights into the ancient Scottish fossil that dramatically challenge our understanding of the early evolution of tetrapods, or four-limbed animals with backbones.

Their findings have just been published in the research journal Nature. “It forces a radical rethink of what evolution was capable of among the first tetrapods,” said project lead Jason Anderson, a paleontologist and Professor at the University of Calgary Faculty of Veterinary Medicine (UCVM).

Before this study, ancient tetrapods — the ancestors of humans and other modern-day vertebrates — were thought to have evolved very slowly from fish to animals with limbs.

“We used to think that the fin-to-limb transition was a slow evolution to becoming gradually less fish like,” he said. “But Lethiscus shows immediate, and dramatic, evolutionary experimentation. The lineage shrunk in size, and lost limbs almost immediately after they first evolved. It’s like a snake on the outside but a fish on the inside.”

Lethicus’ secrets revealed with 3D medical imaging

Using micro-computer tomography (CT) scanners and advanced computing software, Anderson and study lead author Jason Pardo, a doctoral student supervised by Anderson, got a close look at the internal anatomy of the fossilized Lethiscus. After reconstructing CT scans its entire skull was revealed, with extraordinary results.

“The anatomy didn’t fit with our expectations,” explains Pardo. “Many body structures didn’t make sense in the context of amphibian or reptile anatomy.” But the anatomy did make sense when it was compared to early fish.

“We could see the entirety of the skull. We could see where the brain was, the inner ear cavities. It was all extremely fish-like,” explains Pardo, outlining anatomy that’s common in fish but unknown in tetrapods except in the very first. The anatomy of the paddlefish, a modern fish with many primitive features, became a model for certain aspects of Lethiscus’ anatomy.

Changing position on the tetrapod ‘family tree’

When they included this new anatomical information into an analysis of its relationship to other animals, Lethiscus moved its position on the ‘family tree’, dropping into the earliest stages of the fin-to-limb transition. “It’s a very satisfying result, having them among other animals that lived at the same time,” says Anderson.

The results match better with the sequence of evolution implied by the geologic record. “Lethiscus also has broad impacts on evolutionary biology and people doing molecular clock reproductions of modern animals,” says Anderson. “They use fossils to calibrate the molecular clock. By removing Lethiscus from the immediate ancestry of modern tetrapods, it changes the calibration date used in those analyses.”

World’s oldest amphibian fossil in Scotland?


This video from the USA says about itself:

13 September 2016

In this lecture I will highlight five Devonian fossils that represent steps along the transition to a fully terrestrial tetrapod. You should be able to arrange a cladogram of Devonian tetrapods and illustrate the changes in anatomy that occurred during the transition toward living on land.

By Anna Buckley, BBC Science Radio Unit in Britain:

The most important fossil you’ve never heard of

10 April 2017

It’s not a household name, but an ancient creature found in the Scottish borders fills a crucial period in the evolutionary record. It sheds light on how four-limbed creatures became established on land.

An ancient animal found in rocks from the Scottish borders is thought to be the earliest known example of an animal with a backbone to live on land.

The fossilised remains of this highly significant creature, called Tiny, shed light on a key period in our evolutionary history.

Tiny has four limbs, a pair of lungs and up to five fingers (the fossil evidence is unclear exactly how many).

“It was one small step for Tiny, one giant leap for vertebrates,” said palaeontologist Dr Nick Fraser in an interview on the BBC Radio 4’s Life Scientific.

“Without Tiny, there would be no birds, no dinosaurs, no crocodiles, no mammals, no lizards and obviously we wouldn’t be around.”

“So that one step is crucial”, Fraser said. “And this fossil is right here on our doorstep in the Scottish Borders.”

There are infuriatingly few fossils from this important period in our evolutionary history, known as Romer’s Gap.

Previously, some palaeontologists had argued that this gap in the fossil record was due to lower than average oxygen levels in the earth’s atmosphere.

But the recent discovery of several four-limbed creatures like Tiny suggests many terrestrial tetrapods were thriving on land about 360 million years ago.

The late Stan Wood, a field collector, spent several decades looking for fossils to fill Romer’s gap, convinced that it didn’t really exist. In the late 2000s, he began to uncover a number of important fossils near the Whiteadder river in East Lothian.

He phoned Nick Fraser, director of natural sciences at the National Museums in Scotland, to alert him.

Members of the Tw:eed Project then collected rocks from this area and analysed them using CT scans.

Many ancient tetrapods were the size of dogs. So, with a skull just 4cm long, this one was dubbed Tiny.

So why isn’t this important fossil better-known? Perhaps because it is so small.

Or perhaps because, to this day, Tiny remains trapped in a rock and hidden from view.

305 million-year-old spider relative discovered


This video says about itself:

The ancient creature that was ‘nearly a spider’

30 March 2016

The ancient creature that was ‘nearly a spider’: 305-million-year-old arachnid had similar legs and jaw but couldn’t spin a web.

Spiders predate the dinosaurs, scurrying along 315 million years ago – but their precise origins remain a mystery.

Now scientists believe they have filled a ‘gap’ in the evolutionary story of arachnids, with the discovery of a fossil that’s the closest relative to spiders ever discovered.

The creature, dubbed Idmonarachne brasieri, measured less than one inch long and lived alongside the oldest known ancestors of modern spiders 305 million years ago.

From NPR in the USA:

305 Million-Year-Old Fossil A Glimpse Into The Origins Of Spiders

March 30, 20166:53 PM ET

Merrit Kennedy

Scientists have discovered a well-preserved 305 million-year-old arachnid that is “almost a spider” in France. In a new journal article, they say the fossil sheds some light on the origins of “true” spiders.

The main point of distinction: This newly discovered arachnid very likely could produce silk but lacked the spinnerets used by true spiders to, well, spin it, the scientists say. The researchers say it belongs to a “sister group” to the real-deal spiders.

The species, which they described in a new article in the journal Proceedings of the Royal Society B, is named Idmonarachne brasieri. That’s after Idmon, the father of Arachne in Greco-Roman mythology. Appropriately, Arachne was a master weaver who was transformed into a spider.

The paper says Idmonarachne “does not fit comfortably into the established orders.” National Geographic reports that it “acts as a bridge between early spider-like creatures brewing up blobs of silk and the skilled weavers that we see today.”

Here’s more from National Geographic on the comparatively clumsy beginnings of spiderly silk production:

“While delicately constructed webs seem synonymous with spiders, we know from the fossil record that the ability to secrete silk came before the ability to carefully control it. Spider relatives called uraraneids, which lived from 385 million years ago through the time of Idmonarachne, could produce silk but could not build webs.”

University of Manchester’s Russell Garwood, who was one of the article’s authors, told the BBC, “This fossil is the most closely related thing we have to a spider that isn’t a spider.”

The specimen was found in a deposit in Montceau-les-Mines in France and then included in what the article’s co-author described as a “box of fossils” borrowed by the University of Kansas, as the BBC reported. It had been sitting there for decades — the BBC says the box came from Paris’ Museum National d’Histoire Naturelle in the 1980s.

The scientists used laboratory and synchrotron scans of the fossil to produce digital 3-D imagery of Idmonarachne. The arachnid predated the first appearance of the dinosaurs by some 80 million years.

Carboniferous forest simulation on your computer?


This video is called The Carboniferous Period.

From the Carboniferous Forest Simulation site, where you can download this program:

Carboniferous Forest Simulation

Lost in the darkness of our coal mines for more than 300 millions of years, the swamps and forests of the ancient past of our planet now come to new life:

A free, interactive realtime simulation places you into a time machine and enables you to take a walk through the overgrown jungle of ferns, tree-like clubmosses and giant insects our modern civilization was founded on.

The application is currently in alpha state. This means, that the application is not complete both technical and content-wise (for example plant descriptions and sound are not complete, and animals are still missing) and it may contain errors. Nevertheless, we decided to release it as early as possible to share the development progress with you. You can also track and discuss the progress in the interesting “Making of”-thread in The Fossil Forum.

In its final version, the application will be free for personal, museum and educational use, in its current alpha version it is only free for personal use.

Any feedback, hints and reviews by paleontologists, fossil specialists, game/simulation developers and any interested persons are highly appreciated!

Please note, that you will need a pretty tough computer to run the simulation. The minimum requirement is a 2.4 GHz Core I5 processor or similar, 4 GB of RAM and a 1GB 3D graphics card (at least Geforce 560TI or similar).

Comparing a Late Carboniferous fossil locality in Portugal with its North American and European counterparts shows how plants dispersed and diversified during Pangaea’s early days: here.

Carboniferous fossil discoveries in England


This video is called The Carboniferous Period.

From Wildlife Extra:

Yorkshire‘s hidden fossil haven reveals an exotic past

A derelict mining tip in Doncaster has given up its 310-million-year-old secrets after a host of new fossils – including some fossilised plants and creatures that may even be new to science – were found. One of the most exciting finds was that of a fossilised shark egg case, hinting at Yorkshire’s more exotic history.

Also among the fossils were some horseshoe crabs and previously unrecorded seed pods, all of which were found in preserved rocks that formed within the coal and shale deposits in what is one of the few fossil locations of its kind left in the UK.

The tip, located in Edlington, southwest of Doncaster, has been identified as being the only tip in the borough where fossils could still potentially be collected. All others in the area have been landscaped, or turned into parks, leaving any fossils that may be lying beneath inaccessible.

Palaeontologist Dean Lomax, a visiting scientist at the University of Manchester’s School of Earth, Atmospheric and Environmental Sciences, described what the fossils indicate Yorkshire might have been like hundreds of millions of years ago: “The fossils unlock a window into a long distant past, buried deep beneath residents’ feet. They are proof that parts of Yorkshire were once a tropical water-logged forest, teeming with life that may have looked something similar to today’s Amazon delta, a mix of dense forest, lakes, swamps and lagoons.

“The shark egg case is particularly rare and significant, because it’s soft bodied and an unusual object to find fossilised. We hope that future organised collecting of the site may reveal further rare discoveries, such as dragonflies, beetles, spiders and further evidence of vertebrates. And who knows, maybe we will even find the actual shark.”

It is hoped that further fossil specimens unearthed at the site will continue to be found. Speaking from Doncaster Heritage Services, Peter Robinson said: “We hope this important discovery will encourage ex-miners from the borough to bring forward and donate fossil specimens from the now defunct collieries, which were collected whilst extracting coal from the pit face. We have heard many stories of some of the wonderful fossils that have been found.”

The fossils are being safely stored at Doncaster Museum and have been integrated into the museum’s fossil collection.

Prehistoric harvestman had extra eyes


This video says about itself:

10 April 2014

A 305-million-year-old harvestman fossil, ancestor of modern day arachnids, is more closely relates to the scorpions than spiders. Scientists discovered unusual features: it has 2 sets of eyes on the center and lateral sides of the body.

From Discovery News:

Ancient Daddy Longlegs Had Extra Eyes

APRIL 12, 2014 12:30 PM ET // BY PAUL HELTZEL

A 304-million-year-old fossil discovered in Eastern France shows primitive living harvestmen — more commonly called daddy longlegs — had one more pair of eyes than they do today.

The ancient harvestmen had a pair of eyes along the middle of the body — like their modern counterparts — but they also had a pair of eyes on the side of the body. The findings were reported by researchers from the American Museum of Natural History and the University of Manchester, in the journal Current Biology.

Scientists studied the fossil using high-resolution X-ray imaging at the Natural History Museum, London.

“Our X-ray techniques have allowed us to reveal this fossil in more detail than we would have dreamed possible two decades ago,” said Russell Garwood, a research fellow at the University of Manchester and a lead author on the study, in a release.

Though Harvestmen have eight legs and are categorized as arachnids, they’re not spiders. They’re more closely related to scorpions.

The scientists also examined the expression of an eye-stalk growing gene in harvestmen embryos. The embryos briefly express the gene for the second pair of eyes. But by the time they hatch, the daddy long legs’ second pair of eyes are long gone.

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How animals learned to eat plants


This 2016 video is called Tetrapod Evolution.

From the University of Lincoln in England:

Land animals kept fish-like jaws for millions of years

09 May 2013

Research has confirmed how early land vertebrates, which evolved from fish, developed weight-bearing limbs and other adaptations long before their feeding systems adjusted to a vegetation-based diet.

Now, for the first time, fossil jaw measurements have demonstrated this gap in evolutionary development.

Scientists from the University of Lincoln (UK), the University of Massachusetts, Amherst, and the University of Oxford (UK), examined the lower jaws of 89 fossils of early tetrapods (four-footed animals) and their fish-like predecessors.

The fossils ranged in age from about 300 to 400 million years old and the team were interested in how the mechanical properties of the jaws of these animals differed through time.

They used 10 biomechanical metrics to describe jaw differences. One of these, called mechanical advantage, measured how much force an animal can transfer to its bite.

Dr Marcello Ruta, from the School of Life Sciences, University of Lincoln, said: “Our study is the first of its kind to address changes in biomechanical properties of the lower jaw across the transition from fish to land vertebrates using a diverse range of extinct species. This work paves the way to in-depth analyses of the rates of evolutionary transformation in other anatomical structures during this major episode in vertebrate history. It also lays the foundations for integrative research that explores themes as diverse as the origin of the first terrestrial food webs, the impact of acquisition of new structures on the diversification of major animal groups, and patterns and processes of functional change.”

So it turns out that just moving into a new environment is not always enough to trigger functional adaptations.

The team discovered that the mechanical properties of tetrapod jaws did not show significant changes in patterns of terrestrial feeding until some 40 to 80 million years after the four-legged creatures initially came out of the water. Until then, tetrapod jaws were still very fish-like, even though their owners had weight-bearing limbs and the ability to walk on land.

In the paper, which has been published in an early online edition of the journal Integrative and Comparative Biology, the authors say the results may be explained by an earlier hypothesis: a shift from gilled to lung breathing in later four-footed animals was necessary before they could adapt their jaw structure to eating plants.

This finding suggests tetrapods may have shown a limited variety of feeding strategies in the early phases of their evolution on land.

Lead author Dr Phil Anderson, from the University of Massachusetts, said: “The basic result was that it took a while for these animals to adapt their jaws for a land-based diet. They stayed essentially fish-like for a long time.”

Dr Matt Friedman, lecturer in palaeobiology at the University of Oxford, said: “The thing that is really interesting is that the diversity of jaw function didn’t really take off until around the origin of amniotes – creatures that lay hard-shelled eggs on land rather than being tied to water for reproduction like fishes and amphibians. It is in amniotes and their closest relatives that we see the first evidence for dedicated herbivory – until that point tetrapods had basically been carnivores. So this means it took at least 50 million years of evolution after the origin of features like limbs, fingers and toes before tetrapods achieved dietary diversity that began to resemble what we see today.”

The statistical methods developed in this work could be used in future studies of more subtle biomechanical patterns in fossil animals that may not be initially clear.