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Fossil Friday: microbes discovered deep underground remain virtually unchanged since 175 million years ago

New research has identified what’s very likely the tiniest living fossils so far — a group of microbes that feed off radioactive decay.

Abandoned tin mine in Vredehoek, Cape Horn, South Africa. Image credits jbdodane / Flickr.

The team, led by the Bigelow Laboratory for Ocean Sciences, an independent, non-profit oceanography research institute, reports that the microbes have been frozen, evolutionary-speaking, for millions of years. Finding such a case could upturn our current understanding of how microbes evolve and why, and could potentially help guide biotechnology applications in the future (since you want these to not evolve/change over time).

We’re fine as we are

“This discovery shows that we must be careful when making assumptions about the speed of evolution and how we interpret the tree of life,” said Eric Becraft, the lead author on the paper. “It is possible that some organisms go into an evolutionary full-sprint, while others slow to a crawl, challenging the establishment of reliable molecular timelines.”

The microbe species is known as Candidatus Desulforudis audaxviator, and was first discovered in 2008 by a group of researchers led by Tullis Onstott, a co-author on the new study. They live in a gold mine in South Africa almost two miles beneath the surface, swimming merrily in the water-filled cavities inside the rock walls. They feed on chemical products formed by natural radioactive decay processes in minerals at the site, creating a completely independent ecosystem that doesn’t even rely on sunlight to function.

Given their very peculiar living arrangement, the team understandably wanted to know how the microbes evolved to where they are today. They checked other underground samples recovered from around the world and found the species in Siberia, California, and in several other mines in South Africa. Each of these environments was chemically different, the team explains, which spurred them to look for differences among the populations at each site. These groups were obviously separated, and have likely been separate for millions of years, and every one of them had unique conditions they lived in — which would make you think they evolved their own unique quirks.

“We wanted to use that information to understand how they evolved and what kind of environmental conditions lead to what kind of genetic adaptations,” said Bigelow Laboratory Senior Research Scientist Ramunas Stepanauskas, the corresponding author on the paper and Becraft’s postdoctoral advisor.

“We thought of the microbes as though they were inhabitants of isolated islands, like the finches that Darwin studied in the Galapagos.”

So they analyzed the genetic code of 126 individuals retrieved at sites on three different continents — and they were flabbergasted to find that all of them were almost completely identical.

They ruled out the possibility that these microbes could have traveled between the sites. The species is anaerobic and can’t live long in the presence of oxygen, they don’t survive well on the surface; the team also ruled out cross-contamination between these sites.

The best explanation they have so far, the team explains, is that these communities didn’t change all that much, genetically, since they first became separated about 175 million years ago as the supercontinent Pangaea split. In essence, they’re living fossils.

“They appear to be living fossils from those days. That sounds quite crazy and goes against the contemporary understanding of microbial evolution,” says Stepanauskas.

The findings offer a unique counterpoint to the much more accelerated rates of mutation and evolution seen in other microbial communities. Populations of bacteria such as E. coli have been noted to evolve (in response to environmental changes) in as little as a few years. The growing antibiotic resistance issue is an example of just how fast bacteria can evolve.

The team’s current hypothesis is that the species’ genetic freeze is due to powerful anti-mutation mechanisms in its genome. We don’t yet know whether that’s true, but if it is, we could have just discovered an extremely rare feature that we can copy and exploit. Developing this into a tool could pave the way towards more stable DNA polymerases (molecules that copy DNA strands), which are a key component of our biotechnology kit. Essentially, it would allow us to make the biological machinery that copies DNA much more stable over time, which sounds unimpressive but is actually a very big deal for the field.

But the findings also have deep implications for how we think about microbial genetics and the rate at which such microscopic organisms mutate.

“There’s a high demand for DNA polymerases that don’t make many mistakes,” Stepanauskas said. “Such enzymes may be useful for DNA sequencing, diagnostic tests, and gene therapy.”

“These findings are a powerful reminder that the various microbial branches we observe on the tree of life may differ vastly in the time since their last common ancestor,” Becraft said. “Understanding this is critical to understanding the history of life on Earth.”

The paper “Evolutionary stasis of a deep subsurface microbial lineage” has been published in The ISME Journal.

Fossil Friday: leg fragment points to huge, toothy bird with a wingspan of up to 21 feet

Fossils recovered from Antarctica four decades ago belonged to an ancient, massive toothed bird.

Photographs of the fossilized leg fragment. Image credits Peter A. Kloess, Ashley W. Poust, Thomas A. Stidham, Scientific Reports.

The bird belonged to a now-extinct group of birds called pelagornithids and boasted a wingspan of up to 21 feet. That easily makes it dwarf today’s largest bird, the wandering albatross, which can grow up to a 11½-foot wingspan.

It also kind of had teeth.

Biggest bird

The pelagornithids filled an ecological niche similar to that of albatrosses today — they would soar high above the Earth’s oceans feeding on fish and other marine wildlife. They seem to have been especially well-tailored to the task as the pelagornithids kept doing it for at least 60 million years.

We know of this family of birds from a (much smaller) pelagornithid fossil dating from around 62 million years ago. The new fossil however (a partial fossil of the bird’s food), is some 50 million years old and shows that much larger pelagornithids evolved following the mass extinction 65 million years ago when the dinosaurs went extinct. A second pelagornithid fossil, part of a jaw bone, dates from about 40 million years ago.

“Our fossil discovery, with its estimate of a 5-to-6-meter wingspan — nearly 20 feet — shows that birds evolved to a truly gigantic size relatively quickly after the extinction of the dinosaurs and ruled over the oceans for millions of years,” said first author Peter Kloess, a graduate student at the University of California (UC), Berkeley.

Pelagornithids are known as ‘bony-toothed’ birds. They don’t actually have teeth, but they do have bony protrusions (‘struts’) on their jaws that resemble teeth. They don’t have the internal structures that our teeth do, but they are covered in a layer of keratin (the same material in our fingernails and in animal horns). We call them pseudoteeth (lit. ‘false teeth’), and their purpose is to help the bird catch and hold onto slippery prey such as fish or squid on their week-long flights.

The fossilized jaw fragment. Pseudoteeth depicted as dashed outlines. Image credits Peter A. Kloess, Ashley W. Poust, Thomas A. Stidham, Scientific Reports.

Of course, what was most striking about this extinct bird is its sheer size. Large flying animals have made several appearances in the Earth’s past, with the largest known being the pterosaurs, dinosaurs with wingspans of up to 33 feet.

The newly-discovered pelagornithid grew even larger than teratorns — an extinct family of very large birds of prey native to North and South America, which included some of the largest flying birds ever found.

“[Teratorns] evolved wingspans close to what we see in these bony-toothed birds (pelagornithids),” said Poust. “However, in terms of time, teratorns come in second place with their giant size, having evolved 40 million years after these pelagornithids lived. The extreme, giant size of these extinct birds is unsurpassed in ocean habitats.”

The fossils were first discovered in the mid-1980s on Seymour Island, close to the Antarctic Peninsula by UC Riverside paleontologists. They were transferred to UC Museum of Paleontology, where Kloess stumbled upon them as a graduate student in 2015.

To the best of our knowledge, the last pelagornithid died off around 2.5 million years ago as the last Ice Age began.

The paper “Earliest fossils of giant-sized bony-toothed birds (Aves: Pelagornithidae) from the Eocene of Seymour Island, Antarctica” has been published in the journal Scientific Reports.

Fossil-ish Friday: researchers digitally unpack 3 Egyptian animal mummies

New research from the Egypt Centre at Swansea University in the UK is shedding light on the lives — and after-lives — of Egypt’s ancient pets.

A scan of the mummified snake.
Image credits Richard Johnston et al., (2020), Scientific Reports.

The team generated 3D models of a mummified snake, bird, and cat from the University’s collection. The method they employed — X-ray micro CT scanning — is extremely accurate, creating images with 100 times the resolution of a medical CT scan. The findings help us better piece together the lives and deaths of Egyptian animals, and offer us a glimpse into the culture of these ancient peoples.

Although these aren’t fossils, the techniques used here can be adapted to the study of fossils. The results also look spectacular — so I’m going to give them an honorary place on Fossil Friday.

Together forever

“Using micro CT we can effectively carry out a post-mortem on these animals, more than 2000 years after they died in ancient Egypt,” says co-author Dr. Carolyn Graves-Brown from the Egypt Centre at Swansea University.

“We were able to piece together new evidence of how they lived and died, revealing the conditions they were kept in, and possible causes of death. These are the very latest scientific imaging techniques. Our work shows how the hi-tech tools of today can shed new light on the distant past.”

Previous research has focused on the outside of these mummies as any direct intervention inside risked destroying them beyond repair. We knew which animals they likely were, but not much else. The digital approach allows us to investigate their insides without damaging them. Methods such as X-ray or CT scanning have been available for some time, but they are limited in usefulness: the first only returns 2D images, and the latter has comparatively poor resolution.

The team employed micro CT because it can produce high-quality, 3D images. The process is most commonly used in materials science and constructs the 3D image by layering multiple 2D scans.

They report that the mummified cat was no older than 5 months, as suggested by unerupted teeth in its jaw bone. Due to separation of vertebrae in its neck, they say that the most likely cause of death was strangulation. The bird is a close match for a Eurasian kestrel, and the snake was identified as a juvenile Egyptian Cobra.

Figure 2
Renderings of the cat’s head and jaw.
Image credits Richard Johnston et al., (2020), Scientific Reports.

The snake shows some signs of kidney damage and gout, probably due to lacking water during its life. It was likely killed by whipping (against a hard surface) as evidenced by bone fractures in its skull and neck. The team says this is the earliest evidence of a complex ritual (mummification) being performed on a snake.

The bird, meanwhile, seems “superficially intact”, the team notes. There is some evidence of damage to its beak and left leg, but this was likely caused after mummification.

So what did these poor animals do to deserve such a treatment? Well, ancient Egyptians had a habit of mummifying animals as well as people. Cats, ibis, hawks, snakes, dogs, and even whole crocodiles have been found mummified. Sometimes these were pets, but most often, they were messengers to the gods. These animals, it was believed, could act as intermediaries between mortals and their gods.

Not all of them were wild animals — most were in fact bred in captivity. It’s estimated that as many as 70 million animals were probably mummified this way.

The paper “Evidence of diet, deification, and death within ancient Egyptian mummified animals” has been published in the journal Scientific Reports.

Fossil Friday: mysterious, long-necked dinosaur species turns out to be two species that lived in the ocean

Researchers have finally made sense of a dinosaur first described in 1852. Called Tanystropheus, the dinosaur’s anatomy made it unclear whether it lived in the sea, or on land.

The fossil skull and its digital reconstruction.
Image credits Stephan Spiekman et al., (2020), Current Biology.

Now, computer tomography (CT) scans of the fossil reveals that the animal was indeed an ocean-dweller, according to the Fields Museum. More interestingly, it seems that the fossils they have found belong to not one but two very similar species, who nevertheless grew to vastly different sizes. They also likely hunted different prey and lived side-by-side.

Long-necked

“I’ve been studying Tanystropheus for over thirty years, so it’s extremely satisfying to see these creatures demystified,” says Olivier Rieppel, a paleontologist at the Field Museum in Chicago and one of the authors of a new paper detailing the discovery.

Because of its hollow bones and very long necks (which were initially mistaken for wings), Tanystropheus was first believed to have been a flying species, similar to a pterodactyl. Later on, we figured out that this 6-meter-long (20ft) animal actually had a 3-meter-long (10ft) neck.

Its weird proportions — the animal’s neck was three times as long as its torso — made it unclear as to where it lived. By scanning the crushed Tanystropheus skull and digitally reassembling the pieces, however, the team found it was very likely water-dwelling. The skull had telltale signs, including nostrils on top of the snouts (like a crocodile). Due to such features, it probably ambushed its prey, relying on long, curved teeth to keep them from escaping.

While it is possible that Tanystropheus came to land to lay eggs, it was overall a marine animal.

The species lived around 242 million years ago during the middle Triassic. Dinosaurs had just started to emerge on land, and Tanystropheus‘ strange body proportions certainly match such strange times. It was found in today’s Switzerland.

“Tanystropheus looked like a stubby crocodile with a very, very long neck,” says Rieppel.

The larger specimens were twenty feet long, with their necks making up ten feet of that length. Oddly for animals with such long necks, they only had thirteen neck vertebrae, just really elongated. (We see the same thing with giraffes, which have only seven neck bones, just like humans.) And their necks were rather inflexible, reinforced with extra bones called cervical ribs.

Smaller cousin

Smaller but strikingly similarly fossils were found in the same region as many of the big Tanystropheus fossils, which initially confounded researchers. These animals only grew to around 1 meter (4 ft) in length. The team’s analysis revealed that bones from both the large and small dinosaurs had large numbers of growth rings, suggesting that both were adults, despite their size.

“For many years now we have had our suspicions that there were two species of Tanystropheus, but until we were able to CT scan the larger specimens we had no definitive evidence. Now we do,” says Nick Fraser, Keeper of Natural Sciences at National Museums Scotland and a co-author of the paper.

“It is hugely significant to discover that there were two quite separate species of this bizarrely long-necked reptile who swam and lived alongside each other in the coastal waters of the great sea of Tethys approximately 240 million years ago.”

Their different size, and different teeth — cone-shaped teeth in the big species and crown-shaped teeth in the little species — points to them having different diets, so they were probably not competing for the same resources (a process called niche partitioning).

“These two closely related species had evolved to use different food sources in the same environment,” says Spiekman. “The small species likely fed on small shelled animals, like shrimp, in contrast to the fish and squid the large species ate.”

“This is really remarkable, because we expected the bizarre neck of Tanystropheus to be specialized for a single task, like the neck of a giraffe. But actually, it allowed for several lifestyles. This completely changes the way we look at this animal.”

While competition steals the limelight in discussions around evolution, processes like niche partitioning shows that species can live side-by-side, perhaps even cooperate. An important element that allowed for this to happen is likely that the Tethys Ocean was huge, so there were enough resources to go around for both species.

The paper “Aquatic Habits and Niche Partitioning in the Extraordinarily Long-Necked Triassic Reptile Tanystropheus” has been published in the journal Current Biology.

Fossil Friday: the UK’s first-ever pterodactyl fossil

Fossil hunters have discovered the UK’s first pterodactyl. This family of dinosaurs is more commonly found in China or Brazil.

The skeleton of Thalassodromeus sethi, a related tapejarid.
Image via Wikipedia.

A fragment of the fossilized skeleton was discovered by a fossil hunter while out walking his dog in Sandown Bay on the Isle of Wight. Unsure as to what exactly he had found, he passed the fragment over to Megan Jacobs of the University of Portsmouth Palaeontology department. Jacobs suspected it was a pterodactyl jaw — further research proved her right.

Ancient flier

“Although only a fragment of jaw, it has all the characteristics of a tapejarid jaw, including numerous tiny little holes that held minute sensory organs for detecting their food, and a downturned, finely pointed beak,” says Megan Jacobs.

“The crests were probably used in sexual display and may have been brightly colored.”

These dinosaurs are known from specimens recovered in China and Brazil and had never been found in the UK before. Tapejarids are on the smaller size as far as pterodactyl breeds go, although they do have a host of other distinguishable traits. Most have a bony crest on their snout, which supported an even larger crest of soft tissue in some species extending all the way across the skull.

Tapejarids also have a large, distinctive nasa antorbital fenestra, the opening in the skull birds show between their nose and their small, pear-shaped eye sockets. Judging from the ratios of their braincases, tapejarids likely had excellent sight and probably relied heavily on it for hunting, more-so than other pterosaur groups.

Finally, tapejarids had wings that protruded from nearer the belly than near the back due to shoulder girdles of smaller size compared to those of other pterosaurs.

The UK fossil lacked teeth, but was very similar in appearance and structures to tapejarid jawbones. The authors describing the finding christened it Wightia declivirostris, and explain that it’s likely more closely related to Chinese tapejarids than the Brazilian ones.

The finder donated the fossil to the Dinosaur Isle Museum at Sandown, so that it might go on display in the future.

The paper “First tapejarid pterosaur from the Wessex Formation (Wealden Group: Lower Cretaceous, Barremian) of the United Kingdom” has been published in the journal Cretaceous Research.

Fossil Friday: lizard foot trapped in amber helps us better understand fossilization

A new paper describing the foot of a lizard preserved in amber broadens our understanding of the fossilization processes.

The fossil seen under natural light (A, B) and false coloring (C, D).
Image credits H. Jonas Barthel et al., (2020), PLOS One.

The tiny foot belonged to a lizard in the genus Anolis which became trapped in resin around 15 to 20 million years ago. It is very well preserved, with every detail of the limb visible under the microscope.

However, this dandy exterior hides a very different core: the bone inside this foot is heavily decomposed and chemically transformed, with very little of the original structures still present.

Foot for thought

“This is surprising, because we assumed that the surrounding amber largely protects the fossil from environmental influences” says Jonas Barthel, a doctoral student at the Institute for Geosciences at the University of Bonn and first author of the paper.

Every fossil begins with a rapid embedding in a protective material — in this case plant resin, which turned into amber over time. This layer of material protects the biological material from scavengers and microorganisms. After the animal is encased in a protective layer of material, its tissues start being gradually replaced by mineral compounds as pressure from sediments on top compresses everything — in essence, it starts becoming a rock.

“That’s the theory,” says Barthel. “How exactly fossilization proceeds is currently the subject of intensive scientific investigation.”

The fossil described in this study is pretty rare; it’s usually small organisms such as insects that get trapped in resin (which over time becomes amber), not vertebrates (which are larger). It was analyzed as part of a larger research project between the University of Bonn and the German Research Foundation centered on fossilization processes, which has been ongoing since 2018.

The whole piece of amber than encases the limb is about two cubic centimeters in size and was recovered from the Dominican Republic. It belongs to a genus that is still alive today and was housed at the Stuttgart State Museum of Natural History.

For the study, the team asked the Institute for Evolutionary Biology at the University of Bonn to cut the amber down into thin sections to allow for investigation of the fossil inside. The claws and toes inside the amber were very well preserved, the team reports, suggesting that resin had dripped onto the limb. Further investigations at the university’s Institute for Geosciences using micro-computer tomography revealed that the forefoot had been broken in two places. The area around one showed slight swelling, indicative of a fracture that happened prior to fossilization

“This is an indication that the lizard had perhaps been injured by a predator,” says Barthel.

The other fracture, however, seems to have formed after fossilization, and coincides with a tiny crack running through the amber.

Analysis of the bone inside showed that the mineral hydroxyapatite in its tissues had been transformed into fluoroapatite, implying that fluorine penetrated the tissues. Additionally, they found that the collagen in the bones has largely degraded now. In other words, although the fossil seems very well-preserved at first glance, very little of the original tissues remain intact. So far, the researchers were unable to detect complex molecules such as proteins in the fossil.

The team believes that the tiny crack in the amber allowed mineral-rich solutions to filter through into the leg and destroy the organic matter.

“We have to expect that at least in amber from the Dominican Republic, macromolecules are no longer detectable,” says the supervisor of the study, Prof. Dr. Jes Rust from the Institute for Geosciences.

It was not possible to detect more complex molecules such as proteins, but final analyses are still pending. The degradation processes in this amber deposit are therefore very advanced, and there is very little left of the original substance.

Amber is generally considered to be an ideal preservative, as a fully-encased fossil will be completely isolated from the environment. However, in the case of this fossil, the team was surprised to see that the amber might have actually promoted the degradation of soft tissues. Acids in the original tree resin have probably reacted with apatite in the bones in a process similar to tooth decay, the researchers conclude.

The paper “Fluoridation of a lizard bone embedded in Dominican amber suggests open-system behavior” has been published in the journal PLOS One.

Burmanopetalum inexpectatum.

Fossil Friday: earliest known millipede found in piece of Burmese amber

Researchers have found the earliest-known millipede, tucked away in a piece of Burmese amber.

Burmanopetalum inexpectatum.

The newly described millipede (Burmanopetalum inexpectatum) seen in amber.
Image credits Leif Moritz.

Measuring a full 8.2 millimeters, the fossil millipede is the earliest discovered member of the entire order, a new paper reports. The new species, despite having lived alongside the Cretaceous megafauna, is smaller than any of the extant members of its group. Because of its extraordinary morphology, it is described as a new suborder.

Humble origins

“We were so lucky to find this specimen so well preserved in amber,” says lead author Prof. Pavel Stoev of the National Museum of Natural History (Bulgaria). “With the next-generation micro-computer tomography (micro-CT) and the associated image rendering and processing software, we are now able to reconstruct the whole animal and observe the tiniest morphological traits which are rarely preserved in fossils.”

“It came as a great surprise to us that this animal cannot be placed in the current millipede classification. Even though their general appearance have remained unchanged in the last 100 million years, as our planet underwent dramatic changes several times in this period, some morphological traits in Callipodida lineage have evolved significantly.”

The diminutive critter was recently found in a piece of 99-million-year-old amber in Myanmar. 3D X-ray microscopy revealed that it is the first fossil millipede of the order Callipodida to ever have been discovered, as well as the smallest among its relatives today. The team used this approach to generate cross-section ‘slices’ through the specimen and record every detail of its anatomy — which would normally not be preserved in fossils. A 3D model of the animal, christened Burmanopetalum inexpectatum, is also available in the research article.

This specimen provides the earliest evidence about the age of the order Callipodida, suggesting that this millipede group evolved at least some 100 million years ago. However, its morphology is drastically different from contemporary millipedes. As a result, Prof. Stoev together with his colleagues Dr. Thomas Wesener and Leif Moritz of the Zoological Research Museum Alexander Koenig (Germany) had to revise the current millipede classification and introduce a new suborder — one of only a handful of such cases in the last 50 years.

The anthropod was found amongst roughly 529 millipede specimens, but it was the only one of its order — its name reflects that. The generic epithet (Burmanopetalum) refers to the country of discovery (Myanmar, formerly Burma) and “inexpectatum” means “unexpected” in Latin.

C adds:

“We are grateful to Patrick Müller, who let us study his private collection of animals found in Burmese amber and dated from the Age of Dinosaurs,” says co-author Dr. Thomas Wesener. “His is the largest European and the third largest in the world collection of the kind. We had the opportunity to examine over 400 amber stones that contain millipedes.”

” Many of them are now deposited at the Museum Koenig in Bonn, so that scientists from all over the world can study them. Additionally, in our paper, we provide a high-resolution computer-tomography images of the newly described millipede. They are made public through MorphBank, which means anyone can now freely access and re-use our data without even leaving the desk.”

The paper “Dwarfs under dinosaur legs: a new millipede of the order Callipodida (Diplopoda) from Cretaceous amber of Burma” has been published in the journal ZooKeys.

Callichimaera perplexa.

Fossil Friday: newly-discovered Callichimaera perplexa is an adorable, weird crab

A newly-discovered ancient species is forcing scientists to rethink what exactly counts as a crab.

Callichimaera perplexa.

Image credits Oksana Vernygora / University of Alberta.

An international team led by paleontologists from the Yale University announced the discovery of a treasure trove of hundreds of well-preserved crab specimens. The fossils include species of true shrimp, comma shrimp and, most excitingly, a new branch of the evolutionary tree of crabs. The specimens were recovered from Colombia and the United States and date back to the mid-Cretaceous (around 90 to 95 million years ago).

Googly-eyed by design

“Callichimaera perplexa is so unique and strange that it can be considered the platypus of the crab world,” said Javier Luque, who led the research efforts.

“It hints at how novel forms evolve and become so disparate through time. Usually we think of crabs as big animals with broad carapaces, strong claws, small eyes in long eyestalks, and a small tail tucked under the body. Well, Callichimaera defies all of these ‘crabby’ features and forces a re-think of our definition of what makes a crab a crab.”

Reconstruction.

Reconstruction of Callichimaera perplexa.
Image credits J. Luque et al., 2019, Science Advances.

The team writes that Callichimaera perplexa is one of the earliest species of paddle-legged, swimming anthropods we’ve ever discovered, second only to the group of sea scorpions (which lived more than 250 million years ago). It was named for the chimera, a mythological creature whose body included features from several animals. Its full name translates to “perplexing beautiful chimera.”

The specimen, which Luque describes as “unusual and cute”, is definitely perplexing. The ancient crab was quite tiny, about the size of a quarter. It also had a striking pair of large, compound eyes — but no eye sockets. Bent claws, leg-like mouthparts, and a long body ending in an exposed tail completed its visage.

These latter features are typical of pelagic crab larvae to this day, the team writes. This suggests an evolutionary link tying them to the ancient species. The team believes that these traits were retained and amplified in ‘miniaturized adults’ through changes in the timing and rate of development. This process, called “heterochrony,” is one of the mechanisms through which species evolve novel body parts.

“It is very exciting that today we keep finding completely new branches in the tree of life from a distant past, especially from regions like the tropics, which, despite being hotspots of diversity today, are places we know the least about in terms of their past diversity,” Luque said.

The paper “Exceptional preservation of mid-Cretaceous marine arthropods and the evolution of novel forms via heterochrony,” has been published in the journal Science Advances.

Plaster fossil.

Fossil Friday: new study says Texas used to be a ‘veritable Serengeti’ 11 to 12 million years ago

 

A new study continues the work of amateur paleontologists from the Great Depression.

Actinopterygii teeth.

Actinopterygii teeth used in the study.
Image credits Steven R. May, (2019), P.E.

During the Miocene, the lone star state was a veritable Serengeti, one study reports, with rhinos, horses, antelopes, and elephant-like gomphotheres roaming all about. The fossils were discovered by unemployed Americans between 1939 and 1942. They took part in the State-Wide Paleontologic-Mineralogic Survey — a collaboration between the Works Progress Administration (WPA) and the University of Texas Bureau of Economic Geology — which gave unemployed people the chance to work on collecting fossils and minerals across Texas during the Great Depression.

Idle hands are the paleontologist’s tools

“It’s the most representative collection of life from this time period of Earth history along the Texas Coastal Plain,” said Steven May, the research associate at the UT Jackson School of Geosciences who studied the fossils and authored the paper.

Although those participating in the program were not trained paleontologists, they did manage to retrieve a treasure trove of fossils — tens of thousands of specimens strong. These fossils were then handed over to researchers at The University of Texas at Austin who, over the past 80 years, studied and stored them in various collections across the state. The majority of these fossils are now found in the Texas Vertebrate Paleontology Collections at the Jackson School Museum of Earth History.

WPA workers.

Pictured: not palaeontologists. The majority of these workers had no geological or paleontological experience and were paid $0.20/hour through the WPA.
Image credits Steven R. May, (2019), P.E. / The University of Texas at Austin.

The fossils point to a “Texas Serengeti” which developed on the Texas Gulf Coast 11 million to 12 million years ago, according to a new paper. The ecosystem at the time could boast at least 50 different species including elephant-like animals, rhinos, alligators, antelopes, camels, 12 types of horses and several species of carnivore. In addition to this, the study also reports some fossil firsts that include a new genus of gomphothere, an extinct relative of elephants with a shovel-like lower jaw, and the oldest fossils of the American alligator and an extinct relative of modern dogs.

Partial Shell.

Partial Trachemys shell used in the study.
Image credits Steven R. May, (2019), P.E.

The study worked with fossils recovered near Beeville, Texas, during the State-Wide Paleontologic-Mineralogic Survey. This study isn’t the first to work with fossils in this collection, but it is the first to look at the entire fauna of the time instead of individual species. The results are helping us understand what ancient Texas looked like, says Matthew Brown, director of the Jackson School Museum’s vertebrate paleontology collections. However, the collection itself did not provide a complete image.

“They collected the big, obvious stuff,” May said about the 1939-42 exavations. “But that doesn’t fully represent the incredible diversity of the Miocene environment along the Texas Coastal Plain.”

The fossil hunters, lacking training in paleontology, tended to go for the biggest, flashiest fossils they could find. This skewed the collections heavily towards big mammals — things like large tusks, teeth, and skulls are easier to spot and more exciting to find than bones left by small species, so they claimed the lion’s share of attention and effort.

Plaster fossil.

A fossil encased in plaster, being retrieved as part of the WPA program.
Image credits UT Austin.

To make up for this, May used aerial photography and field notes from the WPA program to track down one of the original dig sites, on a ranch near Beeville owned by John Blackburn. There, he screened the site for any tiny fossils that the original digs missed, such as rodent teeth, to help him flesh out the ancient ecosystems and fauna in Texas.

“We’re thrilled to be a part of something that was started in 1939,” Blackburn said. “It’s been a privilege to work with UT and the team involved, and we hope that the project can help bring additional research opportunities.”

Many of the WPA-era fossils are still in storage, safely ensconced in plaster jackets. May said that he plans to continue to study the fossils as more are prepared.

Alligator skull fragments.

Alligator mississippiensis skull fragments used in this study.
Image credits Steven R. May, (2019), P.E.

For more images of the fossils used in the study (they are quite pretty) and their descriptions, go here.

The paper “The Lapara Creek Fauna: Early Clarendonian of south Texas, USA” has been published in the journal Paleontologia Electronica.

Fossil Friday: the earliest known shells from 809 million years ago

The oldest evidence of biomineralization has been discovered 200 million years earlier than previously thought.

These structures might be the oldest known evidence of organisms building shells to defend themselves. They take many shapes, including this honeycomb pattern.
Image credits P. Cohen.

Talking at the Geological Society of America’s annual meeting on September 27, paleobiologist Phoebe Cohen described the oldest known fossilized eukaryotes. The “apatitic scale microfossils”, discovered in the Fifteenmile Group in Yukon, Canada, are layered out in armor-like sheets of mineral plates which formed about 809 million years ago — making them the oldest evidence we have of organisms using biomineralization for protection.

This new date of the shift towards biomineralization reflects changing ecosystems — there’s little point in building a shell if no one tries to eat you — coinciding with the end of a period known as the “boring billion” (the Mesoproterozoic era in science-speak). It also shows changing chemical conditions in the oceans at the time. Shelled creatures today trap a lot of carbon, forming an important part of the modern carbon cycle — as the critters die, their shells sink to the bottom of the ocean, removing this element from the atmosphere.

“We have been able to identify specific conditions that facilitated the evolution of the first eukaryote to biomineralize in Earth’s history,” Cohen, who studies ancient ecosystems at Williams College in Williamston, Mass, said.

“It paints a beautiful picture of the ecology and evolution and environmental conditions that led to this dramatic innovation.”

Previous evidence suggests eukaryote biomineralization appeared around 560 million years ago in primitive coral-like animals. But in those times, organisms built their shells very differently than how they organisms go about it today. The discovery of these fossils thus offers insight into how shell building first evolved, Cohen added.

The fossils were first retrieved in the late 1970s, and even then many paleontologists believed that they hinted at an earlier start for biomineralization. But the dating techniques of the day couldn’t pinpoint their age very accurately, and scientists couldn’t rule out the possibility that the minerals they were dating were there before the organisms died. Cohen and her team revisited the fossils — by dating shale rich in organic material a few meters below the fossil in the rocks, they determined their age at 809 million years old.

Using an electron microscope, they determined that each plate was weaved out of elongated mineral fibers. This structure is too orderly not to have been made by living organisms, Cohen said. They’re made of calcium phosphate, unlike modern shells which are built from calcium carbonate. Today, phosphate is scarce in the environment and it’s too valuable for microbes to waste it.

An electron microscope let researchers see that each plate is a weave of elongated mineral fibers. This intricate, orderly design had to have been purposefully built by life manipulating mineral formation, Cohen said. But 809 million years ago, oxygen levels in the water fluctuated wildly, an analysis of the surrounding rocks showed. This pulled phosphates from the sediment into the waters, so it was in plentiful supply.

Together with the emerging threat of predators, this abundance of phosphate drove eukaryotes to bunker up, Cohen said. Environmental changes eventually lead to these intrepid shell-builders going extinct.

 

Fossil Friday: the bug inside the lizard inside the snake

Forty-eight million years ago, a snake, a lizard, and an insect would unknowingly had a very, very bad day. But their Eocene tragedy would yield one of the most spectacular fossil finds of this year: the three animals fossilized together, one inside the other.

Yummy, yummy, get in my tummy. Forever!
Image credits Smith, K.T. & Scanferla A. / Palaeobio Palaeoenv (2016).

The fossil includes an unidentified insect ingested by a Geiseltaliellus maarius stem-basilisk (lizard,) which itself ended up as dinner for a juvenile Palaeopython fischeri snake. It was found in the Messel Pit, Germany, an area “renowned for the fidelity of preservation.” Today it’s a disused quarry but while these animals still lived, Messel was a volcanic lake with deep, toxic waters, and prone to belch out deadly clouds of carbon dioxide.

It’s unclear how the snake died, but no more than two days after eating the lizard it lay dead on the lake floor encased in fine sediment which would fossilize it, the lizard inside, and the insect inside both.

The fossil is the second of its kind ever found, and it preserves both the animals and a little piece of the day’s food chain. The other one was described in 2008 by a team led by the University of Vienna’s Jürgen Kriwet — it was a fossil of a shark that ate an amphibian with a spiny fish in its stomach.

It is, by all accounts, an astonishing find.

“It’s probably the kind of fossil that I will go the rest of my professional life without ever encountering again, such is the rarity of these things,” says Krister Smith, lead author of the paper describing the fossil.

“It was pure astonishment.”

The fossil will help define the range of Paleopython, which despite isn’t closely related to modern pythons.

“This fossil is amazing,” says Agustin Scafalera, co-author of the paper.

“We were lucky men to study this kind of specimen.”

Interpretive drawing of the fossil, overlaid on its photograph.
Image credits Smith, K.T. & Scanferla, A. / Palaeobio Palaeoenv (2016).

Maybe this is why my grandma told me not to swim after eating.

Fossil Friday: C. Megalodon, the true Jaws

Sharks are amazing animals, and they have been swimming the oceans for about 450 or 425 millions of years now. To put that into perspective, dinosaurs appeared some 230 million years ago, then largely died off. The first hominids (not actual humans, but human-like animals) date from around 4.5 million years ago. So sharks evolved some 200 million years before dinosaurs, and they’re still here — they’ve been around for 3 times as long as dinosaurs, and 100 times as long as hominids. Modern humans, who date back roughly 60,000 years, can’t even hold a candle to the sharks’ history.

And they’ve spent all that time becoming the best, most oiled killing machines you can imagine. Case in point: Carcharodon megalodon.

Famed fossil hunter Vito Bertucci with a megalodon jaw, measuring 3,4 m. (11 ft.) across and almost 2,8 m. (9 ft.) in height. It took her almost 20 years to reconstruct the jaw.

C. megalodon is an extinct species of shark that lived from the early Miocene to the end of the Pliocene, between 23 to 2.6 million years ago. And it was HUGE. While the exact length they could grow to is still a matter of debate, it’s generally agreed based on fossil records that the animal averaged around 18 meters (59 feet) in length, and most likely looked like a stocky great white shark.

A comparison between a megalodon (black) fossilized tooth and two great white shark teeth.
Image via Wikimedia.

Unfortunately, just like sharks today, megalodon was mostly built on cartilage, which usually decomposes before it has a chance to fossilize. What we did find is its jaws, however, and these are truly impressive.

Famed fossil hunter Vito Bertucci with a megalodon jaw, measuring 3,4 m. (11 ft.) across and almost 2,8 m. (9 ft.) in height. It took her almost 20 years to reconstruct the jaw.

For as long as it lived, it’s hard to imagine that C. megalodon had any natural predators — it’s the largest carnivorous fish to have ever lived, and it likely was the ultimate killer on the planet while it lived. It actively hunted whales and was so successful at it that researchers now believe its extinction is the only thing that allowed whales to grow as large as we see them today.

One thing is certain, though. I’m glad I’ll never have to come face to face with one.

Fossil Friday: Sciurumimus albersdoerferi, the single-fossil theropod

S. albersdoerferi fossil found in the Plattenkalk formation in Peinten, Germany.
Image credits to wikimedia user Toter Alter Mann

This fierce little guy is a Sciurumimus albersdoerferi. Well, it’s actually the only S. albersdoerferi we’ve ever found. He belongs to an extinct genus of coelurosaurian theropods that lived some 163 to 145 million years ago, in the Late Jurassic. Theropods were initially carnivorous, however, several groups are known to have evolved into other kinds of diets, from herbivorous to insectivore and omnivore. Based on the shape of his jaw and teeth, S. albersdoerferi was most likely a meat-eater (though we don’t know if he prayed on other dinosaurs, fish, or insects.)

And theropods have passed this wide diet to a very colorful part of life today — they’re the direct ancestors of modern birds. The link was established based on the fact that both theropods and birds have a wishbone and hollow skeletons. Some theropods even had feathers.

Now, this specimen is a fossil of a juvenile S. albersdoerferi so we don’t know what size an adult might grow to. As a group however, theropods tended to grow larger than any of the predators that came before them. To get an idea, think of the reconstructions of T-Rex you saw in Jurassic Park — also a theropod.

Do not want to be that guy.
Image credits wikimedia user Matt Martyniuk

 

 

Fossil friday: Platycrinus saffordi, the sea lily

Though they’re known as sea lilies, crinoids are animals not plants. Think of them as starfish-on-a-stick: they are filter-feeding sea floor echinoderms, and relatively common as fossils go. Crinoids as a group aren’t extinct, but are relatively uncommon in modern oceans.

Image via flickr user James St John.

Image via flickr user James St John.

Here you can see the crown of Platycrinus saffordi, part of the Crawfordsville fauna of Indiana. This fauna is well known for its abundance of excellently preserved, articulated crinoid fossils, and contains at least 63 different species. This specimen lived sometime during the upper Lower Mississippian or upper Lower Carboniferous period, around 330.9 to 346.7 million years ago.

The stem is made up of stalked columnals, small coin-like structures. Most crinoid fossils are found with the stem and columnal in good condition, but fully fossilized crinoid crowns or heads (the tentacle-like thing you can see in the picture) are rare, as they tend to break apart after the animal dies and starts decomposing.

 

Fossil Friday: Zaphrentis phrygia

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Zaphrentis phrygia
Image credits to flickr user James St. John

Kinda looks like the Sarlacc, doesn’t it? Well take your geek hat off cause it isn’t a Sarlacc. Now put your paleontology geek hats on because this is Fossil Friday and we’re talking about Zaphrentis phrygia.

Part of the prehistoric hexacoral family Zaphrentidae, this Z. phrygia specimen lived in the Middle Devonian, some 419 to 359 million years ago. Zaphrentis were solitary rugose (horn shaped) corals with calcitic skeletons. In the middle of the “cup” a single polyp (the animal that builds the coral) lived, feeding by filtering seawater for nutrients. The cone is 1.5 cm (0.196 inches) in diameter at its widest.

This fossil was found in the Jeffersonville Limestone, on the northern shore of the Ohio river. Part of fossils in this layer of rock (including the specimen pictured here) are silicified — meaning that the original carbonate material of the shell has been replaced with silica or quartz. Silica is much more resistant to weathering than the limestone formed by these reefs, so the fossils just stand out from the rock or are eroded completely free from it, as was the case with this specimen.

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Image credits to flickr user James St. John

Fossil Friday: Dicranurus monstrosus

Dicranurus monstrosus fossil, a balloon’s worst nightmare.
Image credits wikimedia user Daderot

When a species almost one hundred times bigger than you, who has access to nukes and can go to space, discovers your remains a few million years after you die and still decides to call you “monstrosus” you must be doing something very right survival-wise. Dicranurus (meaning “twin headtail”) was a genus of trilobites that lived in the lower Devonian, some 419 to 393 million years ago in a shallow sea, corresponding to today’s Oklahoma and Morocco.

The fossil you see here belongs to species known as Dicranurus monstrosus and for good reason – living in a time when fish started evolving solid jaws and took to preying upon trilobites, Dicranurus‘ answer was to go full out and grow 18 pairs of spikes to deter predators from any direction. The most impressive pair were the occipital spines on the animal’s head, the ones that resemble ram’s horns, for which the genus gets its name.

This specimen was found in Morocco and is currently housed at the Huston Museum of Natural Science.

 

Fossil Friday: Helicoprion

Helicoprion bessonovi fossil, housed at The Idaho Museum of Natural History’s Earth Science collection.
Image via imnh

Helicoprion is an extinct genus of shark-like, cartilaginous fish that lived from the early Permian (~290 m.y. ago) all through to the massive Permian-Triassic extinction episode (roughly 250 m.y. ago.)

Their most distinctive characteristic, the lower jaw, baffled scientists for over a hundred years. This “tooth-whorl” structure was the only bony tissue to be found in the animal’s body, and the only part of it that fossilizes under normal conditions — so for all this time, paleontologists didn’t have enough context to describe it beyond “round…thingy. With teeth!”

In 2011 IMNH researchers performed a CT scan on an exceptionally well preserved specimen that contained the elusive jaws. The research eventually led to the first accurate reconstruction of the shark as well as placing in its proper position on the great tree of life.

The CAT scans also allowed a partial reconstruction of the rest of the animal, estimated to have been 3-4 meters (9.8 to 13.1 feet) long, but some potentially grew to almost 7.5 meters (24.6 feet) long. As their jaws aren’t resilient enough to break shells, Helicoprion most likely dined on soft prey, such as mollusks.

Friday Round-up

Because of insufficient time and man power (if you want to help, just look at the banner in the right), we can’t tackle all the topics; but there’s so much going on in the world right now, something just had to be done. So I’m going to start this weekly round-up, in which I’ll just give you some more headlines from the current week and my 2 cents about it, with link to more details. This still doesn’t mean I’ll go over EVERYTHING, just what stands out to me, so please let me know if there’s anything I missed and we’ll damn sure publish it. Also, help me think of a better name for it :)

If you think Hiroshima was big, you should definitely take a look at this

Tech titans want to be more involved in ‘saving the planet’. I have no idea how this will work out, but it sounds really good.

The guys at environmental graffiti posted some pics of volcanoes + lightning, and it equals love. Rough love…

Scientists continue the search for habitable planets, although the mass isn’t quite right.

Ah yes, this was the week the true reason why biologists laugh at creationists was exposed.

We had Earth Day this week.

Stephen Hawking had some big health problems, but he’s getting better. We’re all keeping our fingers crossed.

A fertility expert shouted to the world: ‘I can clone a human being!!

Oh, and of course, men are no more promiscous than women. Makes sense.