Tag Archives: amber

Fossil Friday: Early-sprouting pine cone preserved in amber

A new fossil described by researchers at the Oregon State University captured a very rare occurrence in the distant past: an example of precocious germination when seeds sprout inside a living plant.

Image credits George Poinar Jr., Oregon State University.

The seed belonged to an ancient pine tree and sprouted while still inside its cone. The plant lived around 40 million years ago and was discovered preserved in a piece of Baltic amber. Several plant embryos are seen sprouting from the cone inside the amber.

A bit too early

“Crucial to the development of all plants, seed germination typically occurs in the ground after a seed has fallen,” said George Poinar Jr. of the Oregon State College of Science, an American entomologist and sole author of the paper. “We tend to associate viviparity – embryonic development while still inside the parent – with animals and forget that it does sometimes occur in plants.”

The findings are particularly interesting because the fossil belongs to a conifer — which belongs to the greater botanical family of gymnosperms. While precocious germination is rare, it is more commonly found in angiosperms, flowering plants which produce their seeds inside fruits. Gymnosperms, on the other hand, produce “naked” seeds; seeds that are not enclosed in mature fruits or ovaries. It’s pretty common to see gymnosperm producing cones, for example.

“Seed germination in fruits is fairly common in plants that lack seed dormancy, like tomatoes, peppers and grapefruit, and it happens for a variety of reasons,” Poinar adds. “But it’s rare in gymnosperms.”

In fact, examples of precocious germination in pine cones is so rare that only one such event (from 1965) has been described in scientific literature, he adds. Their rarity is part of what makes the current discovery so exciting. Added to that, this is the first time this phenomenon has been seen in a fossilized specimen.

Based on the structure of the sprout — the bundles of five needle clusters surrounding its tips in particular — Poinar attributed this specimen to the extinct pine species Pinus cembrifolia. This species has been previously described from other specimens of Baltic amber; examples of pines in Baltic amber are rare to begin with, he adds, despite the fact that the morphology of their cones makes them ideal for preservation in amber and keeps them virtually intact through this process.

Precocious germination is the more common of two types of viviparity, Poinar explains, the other being known as ‘vegetative viviparity’. In the case of this fossil, it’s very likely that some if not all the development of the sprout occurred before the cone fell from its mother tree into resin.

“Often some activity occurs after creatures are entombed in resin, such as entrapped insects depositing eggs,” Poinar said. “Also, insect parasites sometimes flee their hosts into the resin after the latter become trapped. In the case of the pine cone, the cuticle covering the exposed portions of the shoots could have protected them from rapid entrance of the resin’s natural fixatives.”

Beyond how spectacular this specimen itself is, the finding helps us gain a better idea of the environmental conditions in the Baltic region during the time of this pinecone. Previous research on viviparity occurrence in gymnosperms suggests that such events are linked to winter frosts. Light frosts would have been possible in the region if it had a humid, warm-temperate climate; this conclusion supports previous hypotheses regarding Baltic climates in the Eocene, the period when this pine cone grew and fell into amber.

The paper “Precocious germination of a pine cone in Eocene Baltic amber” has been published in the journal Historical Biology.

Fossil Friday: amphibian trapped in amber is the first known ‘tongue-thrower’

New research looking at some old fossils uncovers a novel species of amphibians. The animal belonged to the albanerpetontid family and provides the oldest known evidence of a slingshot-style tongue.

The skull encased in amber. Image credits Florida Museum / Edward Stanley.

The fossils had been previously analyzed and mistakenly interpreted as belonging to a species of ancient chameleons. However, the new study comes to show that despite having lizardlike claws, scales, and tails, albanerpetontids (or ‘albies’) were actually amphibians. They belonged to a lineage that’s distinct from modern frogs, salamanders, and caecilians. This lineage developed over some 165 million years and died out roughly 2 million years ago.

The fossils described in this study are roughly 99 million years old, and help showcase how the albies hunted: lying in wait for potential prey, then launching their tongue at them, similarly to modern chameleons. This fossil specimen (previously misidentified as an early chameleon) is the first albie discovered in modern-day Myanmar and the only known example in amber. The species was christened Yaksha perettii, after treasure-guarding spirits known as yakshas in Hindu literature and Adolf Peretti, who discovered the fossil.

Don’t judge a fossil by its tongue

“This discovery adds a super-cool piece to the puzzle of this obscure group of weird little animals,” said study co-author Edward Stanley, director of the Florida Museum of Natural History’s Digital Discovery and Dissemination Laboratory. “Knowing they had this ballistic tongue gives us a whole new understanding of this entire lineage.”

The initial misidentification of the species came down to the fossils it was described from: a juvenile individual with a hodgepodge of characteristics, including a specialized tongue bone. The paper describing them sparked an international collaboration to better correctly identify the fossils, after Susan Evans, professor of vertebrate morphology and paleontology at University College London and an albie expert, recognized some of the characteristics. Together with Peretti, the researchers sent the specimen together with similar amber-encased ones to the University of Texas at Austin for computer tomography (CT) scanning.

X-ray of albanerpetontid skull
An X-ray of the skull showing its long hyoid bone, which provided support for the tongue, jutting from the back. Image credits Florida Museum / Edward Stanley.
CT scan of albanerpetontid skull
CT scan of the skull. Preserved soft tissues are shown in pink. Image credits Florida Museum / Edward Stanley.

It was found that the amber-encased specimen was in “mint condition” (which tends to be rare for albies). It was also, luckily, an adult counterpart of the juvenile that has previously misidentified.

“Everything was where it was supposed to be. There was even some soft tissue,” says Evans.

The excellent quality of the specimen allowed the team to dispel some wrong assumptions about the species. Their reinforced skulls have led researchers to hypothesize that they were a species of digging salamanders. Several other shared features, most notably their claws, scales, and large eye sockets, were also reminiscent of reptiles. The albie also likely had a ballistic tongue similar to those of chameleons today.

Based on the skull, the researchers estimate that Y. perettii was about 2 inches long, not including the tail. The juvenile was a quarter that size. It relied on its fast tongue (the chameleon tongue can go from 0 to 60 mph in a hundredth of a second, being one of the fastest muscles in the animal kingdom) to hunt for insects, and would otherwise try to keep hidden among the brush, the team believes.

Its predatory nature and projectile tongue also help explain its other “weird and wonderful” features, including unusual jaw and neck joints and large, forward-looking eye sockets. It’s also likely they breathed through their skin like salamanders do, but this is still unconfirmed.

Although the specimens were in excellent condition, the team remains unsure where they fit in the amphibian family tree due to its unusual combination of features.

“In theory, albies could give us a clue as to what the ancestors of modern amphibians looked like,” Evan says. “Unfortunately, they’re so specialized and so weird in their own way that they’re not helping us all that much.”

No albies are known to have survived to modern times, but they only faded out about 2 million years ago — which means they might have crossed paths with our earlier hominid relatives.

“We only just missed them. I keep hoping they’re still alive somewhere,” Evan adds.

The paper “Enigmatic amphibians in mid-Cretaceous amber were chameleon-like ballistic feeders” has been published in the journal Science.

Researchers extract DNA from insects embedded in resin

For the first time, researchers have successfully extracted genetic material from insects embedded in resin samples. It’s not exactly Jurassic-age DNA but researchers say the technique could be used for older resin inclusions.

Resin with embedded ambrosia beetles. Image Credits: David Peris.

The idea of extracting DNA from resin-embedded organisns inevitably brings back memories of “Jurassic Park”. But despite being a globally acclaimed movie, Jurassic Park isn’t exactly scientific accurate — as you may have guessed.

For starters, DNA has a half life of 521 years. In 521 years, 50% of it is destroyed, in 1042 years, 75% of it is destroyed, and so on. Even if you had a perfectly preserved piece of DNA, it would be completely destroyed after 6.8 million years. In practical situations, the oldest DNA ever analyzed was under 2 million years. Finding the DNA of dinosaurs, which went extinct 65 million years ago, is not what you’d call realistic. But the DNA of insects trapped in amber may be accessible yet.

In the latest study, Senckenberg scientist Mónica Solórzano-Kraemer, together with lead authors David Peris and Kathrin Janssen of the University of Bonn and additional colleagues from Spain and Norway set much lower ambitions. They successfully extracted genetic material from insects embedded in two- and six-year-old resin samples. It may not be as exciting as Jurassic Park, but it’s the first time this has been done and it’s the first time researchers have demonstrated that DNA can be preserved in resin.

“We have no intention of raising dinosaurs,” says Dr. Mónica Solórzano-Kraemer of the Senckenberg Research Institute and Natural History Museum. “Rather, our current study is a structured attempt to determine how long the DNA of insects enclosed in resinous materials can be preserved.”

“Our study fundamentally aimed to clarify whether the DNA of insects embedded in resin continues to be preserved. Using the polymerase chain reaction (PCR) method, we were able to document that this is, indeed, the case in the six- and two-year-old resin samples we examined,” explains Solórzano-Kraemer.

Senckenberg researcher Mónica Solórzano-Kraemer with one of the examined resin samples. Image Credits: Xavier Delclòs.

It’s not uncommon to find insects trapped in amber from centuries, millennia, or even millions of years ago. However, all previous DNA tests of inclusions have failed, not only due to DNA decay, but also to the environmental impacts suffered by the DNA.

Now, at least, researchers know that when insects become embedded in resin, their DNA isn’t automatically destroyed.

“We are now able to show for the first time that, although it is very fragile, the DNA was still preserved in our samples. This leads to the conclusion that it is possible to study the genomics of organisms embedded in resin,” adds Solórzano-Kraemer.

It’s still not clear what the ‘shelf-life’ of resin-embedded DNA is, though. The best way to figure this out is to keep carrying out more and more experiments on resin-trapped insects of different ages.

The study was published in PLOS.

Amazing mold pigs trapped in 30-million-year-old amber

Amber is nature’s time capsule. Sometimes, tiny creatures and plants get trapped in a tree’s resin and, under the right condition, become preserved in minute details for millions of years. The picture below, for instance, shows a 30-million-year-old piece of amber containing microinvertebrates known as “mold pigs.”

A mold pig trapped in fossilized amber. Credit: Oregon State University.

You’ve likely heard about water bears, or tardigrades, before. These adorable-looking microscopic creatures are extremophiles that are able to withstand intense heat, cold, pressure, radiation, even the vacuum of space.

We don’t know if mold pigs were as resilient as water bears, but they sure look very similar. Technically, the species is called “Sialomorpha dominicana,” where “sialomorpha” is derived from the Greek words for “fat hog” and “shape.” Dominicana comes the Dominican Republic, where the amber was discovered not too long ago.

When a tree suffers a wound (like a broken branch) or if it is attacked by insects or fungi, it exudes thick resin that plugs up the injury and prevents further damage. It seals and sterilizes the injury.

When resin is secreted, it’s not certain that it will turn into amber. More often than not, it gets weathered away. First of all, the resin needs to be chemically stable and not degrade over time. It has to be resistant to sun, rain, extreme temperatures, and microorganisms like bacteria and fungi. There are two types of resin produced by plants that can fossilize. Terpenoids are produced by gymnosperms (conifers) and angiosperms (flowering plants). They are composed of ring structures made from isoprene (C5H8) units. Phenolic resins are only produced by angiosperms. An extinct type of tree called medullosans produced another unique type of resin.

The mold pig

George Poinar Jr. from Oregon State University recently published a paper in which he and colleagues closely examined the amber and the microscopic hogs trapped inside it, along with their fungal food source and other animals that lived in their habitat.  

“Every now and then we’ll find small, fragile, previously unknown fossil invertebrates in specialized habitats,” Poinar said. “And occasionally, as in the present case, a fragment of the original habitat from millions of years ago is preserved too. The mold pigs can’t be placed in any group of currently existing invertebrates – they share characteristics with both tardigrades, sometimes referred to as water bears or moss pigs, and mites but clearly belong to neither group.”

In total, the researchers have numbered several hundred individual fossils in the small piece of amber. Apart from mold pigs, the amber contains pseudoscorpions, nematodes, fungi, and protozoa.

Each mold pig is no longer than 100 micrometers and had flexible heads and four pairs of legs. The researchers assert that they must have grown by molting their exoskeleton and likely subsided on a diet of fungi and small invertebrates. Whereas mites and water bears have claws present at the end of their legs, mold pigs have none.

“The large number of fossils provided additional evidence of their biology, including reproductive behavior, developmental stages and food,” he said. “There is no extant group that these fossils fit into, and we have no knowledge of any of their descendants living today. This discovery shows that unique lineages were surviving in the mid-Tertiary.”

The researchers’ classification suggests that mold pigs represent a new phylum — a level of classification or taxonomic rank below kingdom and above class.

What researchers hope to answer in the future is when did this lineage originate and how long it lasted. Whether there are any living descendants to mold pigs is anyone’s guess at this moment.

Findings were published in the journal Invertebrate Biology.


Fossil Friday: bird encased in amber has an unique, “extreme” toe

The bird’s hyper-elongated third toe is longer than its whole lower leg, the authors report.

Bird in amber.

The fossilized bird, encased in amber. Image credits Linda Xing et al., (2019), Cell Biology.

Researchers in China have discovered a new species of ancient bird preserved in amber– and it’s packing one seriously impressive toe. The fossilized beast, which lived around 99 million years ago, likely used the appendage to draw food out of tree trunks. According to the team, it’s the first time such a food structure has been observed in either living or extinct birds.

Bigtoe

“I was very surprised when I saw the amber,” says first author Lida Xing at China University of Geosciences (Beijing). “It shows that ancient birds were way more diverse than we thought. They had evolved many different features to adapt to their environments.”

The fossils include two isolated wings, an isolated foot with wing fragment, and two partial skeletons, most of them from juvenile individuals. The fossils date back to the Cretaceous period and were found encased in amber in 2014 in the Hukawng Valley of Myanmar. It was christened Elektorornis chenguangi. The new species’ most distinctive feature is its very, very long third toe measuring 9.8 millimeters. It is a full 41% longer than its second toe and 20% longer than its tarsometatarsus, the main bone in the lower legs of birds. Comparison to 20 other extinct bird species from the same time and 62 living birds showed that, showed that Elektorornis chenguangi is the only species so far discovered to evolve this foot structure.

Elektorornis chenguangi is part of a group of extinct birds called Enantiornithes, the most abundant type of bird known from the Mesozoic era. To the best of our knowledge, the Enantiornithines became extinct during the Cretaceous-Paleogene extinction event about 66 million years ago (the one where all the dinosaurs died) and left no living descendants behind. Elektorornis means “amber bird”.

Bird leg.

A 3D reconstruction of the birds’ leg.
Image credits Linda Xing et al., (2019), Cell Biology.

Based on the measurements they’ve taken of the fossils, the team reports that Elektorornis was smaller than a sparrow and that it was arboreal (i.e. it liked trees as opposed to the ground or water surfaces). The bird’s foot measures 3.5 centimeters in length, and weighs 5.5 grams.

“Elongated toes are something you commonly see in arboreal animals because they need to be able to grip these branches and wrap their toes around them,” says co-author Jingmai O’Connor at the Chinese Academy of Sciences. “But this extreme difference in toe lengths, as far as we know, has never been seen before.”

During the Mesozoic area, the Hukawng Valley of Myanmar was heavily forested with trees that produced resin as a defensive mechanism. The area is famed for its amber and fossil-bearing amber bits to this day, all thanks to those trees. The oldest known bee and a feathered dinosaur tail, among many others, have been discovered in amber from this valley. The team obtained the amber from a local trader, who didn’t know what animal this weird foot belonged to.

“Some traders thought it’s a lizard foot, because lizards tend to have long toes,” Xing says. “Although I’ve never seen a bird claw that looks like this before, I know it’s a bird. Like most birds, this foot has four toes, while lizards have five.”

As to why the bird needed such a long leg, the team still can’t say for sure. The only animal today to sport similar digitation is the aye-aye, a lemur that uses its long middle fingers to fish larvae and insects out of tree trunks for food. The team suspects Elektorornis chenguangi used its toe in a similar way.

“This is the best guess we have,” O’Connor says. “There is no bird with a similar morphology that could be considered a modern analog for this fossil bird. A lot of ancient birds were probably doing completely different things than living birds. This fossil exposes a different ecological niche that these early birds were experimenting as they evolved.”

The paper “A New Enantiornithine Bird with Unusual Pedal Proportions Found in Amber” has been published in the journal Current Biology.

The unlikeliest catch: sea creatures found trapped in amber

You’ve seen insects, plants, and even small birds trapped in amber — but have you ever seen sea creatures?

Amber piece showing most large inclusions. Image credits: Yu et al, 2019.

The vast majority of creatures discovered in amber live in forests, and there’s a very good reason for that: amber is fossilized tree resin, and trees usually live, well, in forests. However, researchers working in Myanmar have found something completely unexpected: sea creatures and land dwellers, side by side, trapped in one of the most amazing pieces of amber you’ll ever see.

The 99-million-year-old amber from Northern Myanmar hosts a diverse assemblage of creatures — over 40 in total. The creatures include four sea snails, several isopods, 22 mites, a spider, beetles, flies, cockroaches, and several other yet-unidentified creatures. The highlight of the piece, however, is an ammonite: an extinct, exclusively marine creature.

Researchers are at a loss as to how all these creatures wound up together and got trapped in tree resin.

“It is rare to find aquatic organisms in amber, and it is extremely rare to find marine organisms in amber, let alone macroscopic marine organisms mixed with intertidal, terrestrial, and potentially freshwater aquatic organisms,” the researchers wrote in their paper.

There are some reliable assumptions to be made, however. Since the piece contains both aquatic and terrestrial creatures, particularly creatures that lived on the forest floor, it is believed that the amber formed in a coastal forest. Perhaps there was a flood or some other event that moved the ammonite and other marine creatures towards the tree, where they were engulfed in resin.

Image credits: Yu et al., PNAS, 2019.

All the shells from marine creatures are empty, so the organisms were long dead by the time they were engulfed; the outer shell of the ammonite is broken away and the entrance of the shell is full of sand. The amber also contains additional sand.

“There is a diverse assemblage (at least 40 individuals) of arthropods in this amber sample from both terrestrial and marine habitats, including Isopoda, Acari (mites), Araneae (spiders), Diplopoda (millipedes), and representatives of the insect orders Blattodea (cockroaches), Coleoptera (beetles), Diptera (true flies), and Hymenoptera (wasps). The incomplete preservation and lack of soft body of the ammonite and marine gastropods suggest that they were dead and underwent abrasion on the seashore before entombment,” researchers write.

The most plausible scenario is that the resin-producing tree lay on or right next to a sandy beach. The flying insects were trapped in amber while it was still on the tree, flying too close and getting stuck. As the resin slowly flowed down the tree trunk, it trapped more and more organisms. As it reached the floor, it finally encased some unfortunate marine creatures that were washed ashore.

Image credits: Yu et al., PNAS, 2019.

“The shells may record an exceptionally high, perhaps storm-generated tide, or even a tsunami or other high-energy event. Alternatively, and more likely, the resin fell to the beach from coastal trees, picking up terrestrial arthropods and beach shells and, exceptionally, surviving the high-energy beach environment to be preserved as amber,” researchers write.

At any rate, it was a spectacular chain of events that culminated with just the right conditions to preserve this stunning piece of amber for about a hundred million years.

It’s not exactly clear how old the piece of amber is. Researchers suspect it is 99 million years old since that is the date of the layer it was found in, but it could be even older.

(A) Lateral view under light microscopy. (B) Flattened sutures reconstructed by microtomography. (C) Microtomographic reconstruction, apparent view. (D) Microtomographic reconstruction, surface rendering; (E) Microtomographic reconstruction, virtual section. Image credits: Yu et al, 2019.

The team also used X-ray micro-computed tomography (micro-CT) to obtain high-resolution three-dimensional images of the ammonite including its convoluted shell sutures, which are very important for determining the species of ammonite.

The study “An ammonite trapped in Burmese amber” was published in Proceedings of the National Academy of Sciences

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.

Snake fossil.

First-ever baby snake fossil discovered beautifully encased in amber

Researchers have unearthed the very first baby snake fossil in history — and it’s teaching us a lot about how snakes’ biology and ecological role evolved.

Snake fossil.

The piece of amber encasing the fossil, alongside a synchrotron x-ray image of the snake skeleton within. Scale bar is 10 mm.
Image credits Lida Xing et al., 2018, Science Advances.

Scientists digging through the Angbamo site in the Kachin Province, Myanmar, have unearthed a 99 million-year-old baby snake, beautifully encased in amber. The fossil, dating back to the Late Cretaceous period, is the oldest baby snake fossil ever found to date, and the first snake we know of that lived in a forest.

Amber’d

The small Southeast Asian country of Myanmar is a known treasure trove of fossils. The area previously yielded the tail of a feathered dinosaur, their ticks, as well as a baby frog, all encased in the beautiful amber that the region is famed for. But Myanmar’s soil has yet to reveal all its treasures, judging by a recent discovery — that of a baby snake, similarly preserved in fossilized tree sap. Alongside this, the researchers also found a second snake fossil (also encased in amber) likely containing part of the shed skin of another, much larger snake. It is unclear so far if the two are members of the same species.

Snakes today are a very successful group. They’ve spread across all continents except Antarctica, and number roughly 2,900 different species. However, they weren’t always so pervasive; they only emerged on dry land during the Cretaceous period.

The new fossil shows us that by around 99 million years ago, snakes had found their way from swamps or sea shores to become fully-terrestrial in forested environments. The second fossil only consists of skin and scale fragments, but are still distinctly snake-like, its discoverers report. This second fossil shows dark and light patterns of coloration and likely formed from the remains of an older, larger individual.

Both are extremely similar to snake species living today, a testament to how well-adapted little these little, slithering predators are to their ecological niche.

Snake skin.

Photographs of snake shed skin. Scale bar, 5 mm, 1 mm, 1 mm, respectively.
Image credits

Using uranium-lead dating, a research team led by Lida Xing from the China University of Geosciences and Michael Caldwell from the University of Alberta dated the fossils to about 99 million years old. A technique called synchrotron x-ray micro–computed tomography allowed the researchers to get a close look at the tiny specimens inside the amber without having to break them apart.

The baby snake was just hatching when it died, the team report. It’s very tiny, at some 47.55 mm (1.8 inches) in length, but for reasons yet unknown it’s missing a head. Still, based on lab imaging, the team was able to document nearly 100 vertebrae, alongside bits of rib and other anatomical features. While very similar to other snakes from the Cretaceous, it’s distinct enough, the team argues, to warrant receiving its own name. They settled on Xiaophis myanmarensis, where “Xiao” is the Chinese word for “dawn,” “ophis” the Greek word for “snake”, and “myanmarensis” for the place of its discovery, Myanmar.

Neither of the snakes is significantly different from species today — the earliest direct evidence so far that the biology of snakes has remained relatively unchanged over the last 100-or-so million years.

The fossils are further relevant as they’re the earliest evidence of Mesozoic (the larger Era which includes the Cretaceous) snakes living in forests. This indicates “greater ecological diversity among early snakes than previously thought,” the study notes. The link was established by the remnants of insects and plant material found in association with the snake fossils.

The paper “A mid-Cretaceous embryonic-to-neonate snake in amber from Myanmar” has been published in the journal Science Advances.

A 99-million-year-old amber fossil preserved the earliest frog from tropical forests

These 99-million-year-old amber fossils provide the earliest direct evidence of frogs living in wet, tropical forests. Credit: Lida Xing/China University of Geosciences.

Millions of years ago, a juvenile frog was preparing to turn an unsuspecting beetle into a nice, juicy meal. Unfortunately for them, both frog and bug got trapped in sticky resin. Lucky for us, the sap turned to amber, beautifully preserving the fossil frog’s small bones and hints of its tropical environment. This is, in fact, the oldest frog we’ve ever found in a tropical environment — and the oldest frog trapped in amber, for that matter.

Nature’s time capsule

Although frogs have been around for at least 200 million years, being so small and mushy, scientists rarely find early fossils of them. The fossil record is skewed towards species from arid and seasonal environments, which are more robust. This is why the new 99-million-year-old amber fossils are so important to scientists — they provide a very rare insight into the lives of ancient frogs that used to live in wet environments. More than a third of the nearly 7,000 species of frogs live in these wet forests.

“Ask any kid what lives in a rainforest, and frogs are on the list,” said David Blackburn, study co-author and the associate curator of herpetology at the Florida Museum of Natural History, in a statement. “But surprisingly, we have almost nothing from the fossil record to say that’s a longstanding association.”

“These frogs were part of a tropical ecosystem that, in some ways, might not have been that different to what we find today—minus the dinosaurs,” he added.

The amber fossils were recovered from amber deposits in northern Myanmar, Southeast Asia, and have been dated to about 99 million years old. Besides ancient frog remains, the amber fossils also trapped plants, spiders, insects, and marine mollusks.

Amber is like nature’s time capsule. When the tree has a wound (like a broken branch) or if it is attacked by insects or fungi, it exudes the thick resin that plugs up the injury and prevents further damage. In certain conditions of pressure and temperature, typically after becoming covered in sediments, the resin can turn into a solid orange gem whose contents become preserved for millions of years.

For instance, the amber beautifully preserved the tiny frog, which is less than an inch long, visibly showing its skull, forelimbs, and part of its backbone and hind limb. Two other amber fossils contain two forelimbs and an imprint of a frog.

Frogs in amber are quite rare, with previous examples found in the Dominican Republic and Mexico and dating back to only about 40 million and 25 million years, respectively.

One of most well preserved amber fossils in the lot. It contains the skull, forelimbs, part of a backbone and a partial hind limb of an ancient juvenile frog.

One of the most well preserved amber fossils in the lot. It contains the skull, forelimbs, part of a backbone and a partial hind limb of an ancient juvenile frog. Credit: Lida Xing/China University of Geosciences.

The researchers performed a comparative analysis of the ancient frogs, which they dubbed Electrorana limoae, with similar species living today. They uncovered more common ground than differences, suggesting that frogs haven’t really changed that much across the eons. For instance, the ribs and a bone in the cartilaginous plate that supports the tongue suggest Electrorana l. closely resembled some of the species alive today, such as fire-bellied toads and midwife toads. But these are Eurasian species that live in temperate, not tropical, ecosystems.

What’s more puzzling is that the juvenile is missing or hadn’t yet had the chance to develop certain features that herpetologists usually look for in order to discern frog species. Features such as wrist bones, the pelvis, hip bones, the inner ear, the top of the backbone.

For now, Electrorana raises more questions than it answers but Blackburn and colleagues hope to find more specimens trapped in amber.

“We don’t have a lot of single-species frog communities in forests. It seems extremely unlikely that there’s only one. There could be a lot more fossils coming,” the authors wrote in the journal Scientific Reports. 

Scientific reference: Lida Xing et al, The earliest direct evidence of frogs in wet tropical forests from Cretaceous Burmese amber, Scientific Reports (2018). DOI: 10.1038/s41598-018-26848-w. 

New ancient tick.

Ancient amber reveals that ticks dined on feathered dinosaurs, too

Ticks are a much more ancient pain than you’d reckon — some 99 million years ago, they were bitting into (and annoying) feathered dinosaurs.

Tick and feather amber.

A tick grasping a dinosaur feather in Myanmar amber.
Image credits Peñalver et al., 2017, Nature Communications.

Dreaded today as vectors of Lime’s disease, ticks have been around for far longer than us humans. Being so ancient, scientists have long wondered what or who these insects dined on before mammals came to be. A recent discovery shows that even the mighty dinosaurs weren’t beyond the reach of this tiny, biting menace.

At least, not feathered dinosaurs.

Snapshot in time

The findings are partially based on amber specimens recovered from Myanmar. While forming, back in the Cretaceous, one of the pieces trapped a tick alongside a dinosaur feather in its hardening resin.

“Amber is fossilized resin, so it’s able to capture small bits of the ecosystem almost instantly,” says lead author Ricardo Pérez-de la Fuente, a research fellow at the Oxford University Museum of Natural History.

“Amber can actually preserve interactions between organisms. This is the case with the feather and the grasping tick.”

The fossilized interaction lends support to a theory that de la Fuente had been previously working on, largely based on other ticks trapped in amber during the same period. They didn’t get to endure the ages alongside feathers, but the bits of amber that enclosed them did contain little hairs, consistent with the type left behind by a type of beetle larva still seen today in birds’ nests.

New ancient tick.

A new species of ancient tick identified by the team.
Peñalver et al., 2017, Nature Communications

So there was evidence in favor of Pérez’s theory, but only of an indirect nature. Finding the feather-and-tick pair provided the link the team needed.

Until now, researchers assumed that ticks dined on early amphibians, reptiles, and the forefathers of modern mammals. Pérez’s theory doesn’t exclude these other types of animals from the menu, especially since feathered dinosaurs weren’t the only animals living in nests at the time, but it does expand on the menu.

Pérez says follow-up research needs to be done to understand how a new species of ancient tick identified in the study, Deinocroton draculi, fits into the bigger tick order Parasitiformes. Furthermore, the finding could help uncover the ancient origins of ticks and their blood-sucking behavior: one tick found in the amber is engorged with blood but the team couldn’t figure out how to analyze it — the tick was only partially encased in amber, so its original chemistry is altered.

The paper “Parasitised feathered dinosaurs as revealed by Cretaceous amber assemblages” has been published in the journal Nature Communications.

amber hatchling

Baby bird trapped in stunning pristine condition inside 100-million-year-old amber

amber hatchling

Credit: Lida Xing

Usually, it’s insects that get trapped in amber, like the Jurassic Park mosquitos which served to revive the dinosaurs. But sometimes we get lucky and come across something different — something that’s even more interesting that the best fiction. This time around, scientists were amazed to find a hatchling trapped in a 100-million-year-old amber collected from Myanmar. It looks like the most well preserved ancient bird ever. The footage below speaks for itself.

amber hatchling

This amber is 100 million years old. Credit: Xing Lida.

Amber first starts as a simple resin, a reddish, viscous liquid that flows out of a diseased or damaged tree. Not all trees produce the kind of resin that can eventually become amber. In the Dominican Republic, for example, an extinct leguminous tree is responsible for the area’s 16-million-year-old amber fossils.

When an animal comes along — whether an insect or even some larger animal — it gets stuck in the resin flow. Sometimes, if the animal is small enough, the flow or resin is large enough to engulf and eventually preserve the whole animal. For larger animals, most of the time, only parts of them may become preserved.

After the animal is trapped, the resin polymerizes and hardens through a chemistry that’s not completely understood yet. If the pressure and temperature are just right, the resin transforms into a semi-fossilized substance called copal and later some other process turns copal into amber. This takes at least two million years. Fraudsters on the streets of Morocco or Myanmar will often peddle copal as the older and far more valuable amber.

A closeup of the wing. Credit: Ming BAI.

A closeup of the wing. Credit: Ming BAI.

What makes amber fossils so amazing and valuable to science is that unlike mineralized — the kind you see at a natural history museum, dinosaur bones and so on — amber can preserve the soft tissue like the animal’s brain or other parts of the nervous system. For instance, we’ve found amber fossils like a flower caught right in the act of reproduction, ancient species of cockroaches, mammal blood or spiders locked in combat — and they’re all millions of years old, but here we are seeing them as if they were still alive. This is why amber is one of the most valuable time capsules out there, a golden tomb.

This 100-million-year-old trapped hatchling comes preserved in pristine condition. It contains the head, neck, wing, tail, and feet of the hatchling which couldn’t have been more than a couple days older when it got trapped in resin.

Zooming in on the tiny claws of this ancient hatchling. Credit: Xing Lida.

Zooming in on the tiny claws of this ancient hatchling. Credit: Xing Lida.

These images are striking. But we mustn’t be fooled, either. Though it might look like we’re seeing flesh, claws or skin, what we’re really seeing are their impressions. All that tissue has been broken down into carbon. It follows there’s no usable DNA either. That Jurassic Park DNA from dinosaur blood is just not gonna happen in the real world.

 

 

The hatchling, which the researchers named ‘Belone’ after a Burmese name for the amber-hued Oriental skylark, belonged to an extinct group of birds called enantiornithes, also known as ‘opposite birds’. These lived alongside the ancestors of modern birds but went extinct with the dinosaurs 66 million years ago. Previous fossil evidence suggested that opposite birds hatched with flight feathers, ready to take off from day 1. This present amber gem supports this hypothesis, as the images suggest it had flight feathers and growing tail feathers. And unlike modern day hatchlings, this ancient opposite bird youngster lacked body feathers. Ryan McKellar of the Royal Saskatchewan Museum, Regina, and one of the authors of the new study, says the birds likely hatched on the ground and later climbed into trees which also makes them predisposed to getting stuck in sap.

Artist impression of the hatchling's pose as preserved in the amber. Credit: CHUNG-TAT CHEUNG.

Artist impression of the hatchling’s pose as preserved in the amber. Credit: CHUNG-TAT CHEUNG.

Opposite birds were likely very similar in appearance to modern birds. The main difference between the two is that where modern birds have a ball-and-socket joint to connect their shoulders, opposite birds had a socked-and-ball joint. That’s where the name comes from. Some other notable differences include having jaws and teeth instead of the modern bird’s beak and the presence of claws on their wings.

It’s not clear why opposite birds went extinct along with the dinosaurs. Some speculate it’s because opposite birds didn’t seem to offer parental care whereas modern birds almost unanimously all do.

 

 

Insect courtship behavior trapped in 100-million-year-old amber

It’s Romeo and Juliet on steroids, with geology.

Reconstruction showing the courtship behavior. Image credits: Yang Dinghua.

We know a lot about the courtship of modern insects because we can observe them, but the rituals of ancient insects are pretty much a mystery — the fossil record almost never captures it… except this time, it did.

“Courtship behaviours, frequent among modern insects, have left extremely rare fossil traces. None are known previously for fossil (primitive winged insects),” said lead author Dr Daran Zheng.

Dr. Zhend Daran and Prof. Wang Bo from Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, have recently described a spectacular piece of amber dating from 100 million years ago. Inside it, it traps three male damselflies showing ancient courtship behavior, their legs beautifully extended to attract females and fend off other suitors.

The fossil features a new species researchers have called Yijenplatycnemis huangi, in the honor of Mr. Huang Yijen from Taiwan, who donated the specimen. It’s the oldest and one of the very few examples of fossils exhibiting this type of behavior, showing that courtship rituals go back to the time of the dinosaurs.

A damselfly was caught in the act of displaying to a female when he was trapped in amber. Image credits: Nanjing Institute of Geology and Paleontology.

Basically, what Y. huangi seems to do is spread its giant, well developed tibiae (legs), almost certainly to attract females and intimidate contenders. This is not an uncommon behavior today. A similar modern species, Platycypha caligata, also waves its six laterally enlarged tibiae at the females, but uses the posterior surface of the tibiae for intra-sexual signaling during territorial defense, something that the amber lovers don’t seem to do. Also, the tibiae of the modern species is not as well developed as that of the ancient ones. There are also some morphological differences. Aside from being larger, the tibiae of Y. huangi are nasymmetric and pod-shaped. While this would have made them more visible for females, it also made waving slower due to air friction. In other words, the modern species gave up sexiness for better flight speed.

Additionally, there is an eye-shaped spot in the middle of the hindleg, which researchers believe is used to intimidate vertebrate predators or protect the body by deflecting an attack to the wings. It’s also possible that these eye-spots emerged as yet another way to attract females. In case you haven’t figured it out by now, ancient damselflies were all about the ladies.

The fact that we can tell so much about a species that lived 100 million years ago is simply stunning. When these animals were trying to impress the ladies and were unfortunate enough to be trapped by amber, flowering plants were only starting to spread and dinosaurs were experiencing their most diverse period. T-Rex emerged 32 million years later.

Journal Reference: Daran Zheng, André Nel, Edmund A. Jarzembowski, Su-Chin Chang, Haichun Zhang, Fangyuan Xia, Haoying Liu & Bo Wang — Extreme adaptations for probable visual courtship behaviour in a Cretaceous dancing damselfly. doi:10.1038/srep44932

Amber reveals ancient insect that was literally scared out of its skin

Image credits George Poinar, Jr./Oregon State University

Image credits George Poinar, Jr./Oregon State University

It’s not uncommon for insects, plants and various other life forms to become trapped in amber deposits, but a recent discovery reveals a bit of a different story – a fifty-million-year-old exoskeleton of an ancient insect that was literally scared out of its skin.

The Baltic amber was retrieved from the coast of the Baltic Sea in Scandinavia and comes from a time when dinosaurs had recently died out and mammals were increasing in their diversity.

In addition to holding an insect exoskeleton, which is comparable to a modern-day “walking stick,” the amber also contains the first mushroom ever discovered in Baltic amber and a piece of mammalian hair. Taken together, these three remnants paint a picture of an ancient encounter between an insect and a rodent.

“From what we can see in this fossil, a tiny mushroom was bitten off, probably by a rodent, at the base of a tree,” said George Poinar, Jr., a researcher in in the College of Science at Oregon State University and author of the study. “An insect, similar to a walking stick, was probably also trying to feed on the mushroom. It appears to have immediately jumped out of its skin and escaped, just as tree sap flowed over the remaining exoskeleton and a hair left behind by the fleeing rodent.”

The ancient insect exoskeleton preserved in the amber was revealed to be a member of the Phasmatodea order, which are also referred to as stick insects due to their resemblance to sticks and leaves.

“It would have shed its skin repeatedly before reaching adulthood, in a short lifespan of a couple months,” Poinar said. “In this case, the ability to quickly get out of its skin, along with being smart enough to see a problem coming, saved its life.”

The presence of fine filaments in the exoskeleton suggest that the skin was extremely fresh when it was engulfed by the amber, supporting the idea that the insect jumped out of its skin just in the knick of time.

Journal Reference: A gilled mushroom, Gerontomyces lepidotus gen. et sp. nov. (Basidiomycota: Agaricales), in Baltic amber. 22 June 2016. 10.1016/j.funbio.2016.06.008

Fossil Friday: Diptera brachycera in amber

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Image via flickr user James St. John

Amber is the fossilized from of tree resins. While fresh and viscous, it often gulps up pollen, plant material and even insects — such as this Diptera brachycera.

The bug was discovered in the amber formations of Yantarnyi, western Russia, meaning it lived in the Lutetian (41.3-47.8 million years ago) stage of the Middle Eocene. The milky-white film that forms around the insect is decay coating, a good indicator of genuine Baltic amber.

Along with Diptera, the amber incorporated a lot of tiny things known as stellate trichomes — the fuzzy, spiny object in the left of the photo for example. They’re basically small pieces of ancient oaks, such as epidermal hairs on flowers or leaf buds that they shed and got caught in the resin.

Diptera specimens are still alive and kickin’ today, and some of them are getting coated in amber as we speak! A nice reminder that fossils are still being formed for future paleontologists to uncover.

Fly2

Image via flickr user James St. John

30 million year-old plants found in amber [awesome pics]

We’ve seen unfortunate insects trapped in amber time and time again, but this time it’s something else. This time, a new species of ancient flower was found preserved in amber. The fossil species are a representative of the asterids, one of the most diverse groups that also include sunflower, coffee, potatoes and mint.

 The new fossil flower Strychnos electri in its original Dominican amber piece of mid-Tertiary age. The whole flower is less than 20 mm long and is the first finding of an asterid flower in amber from the New World. Credit: George Poinar

The new fossil flower Strychnos electri in its original Dominican amber piece of mid-Tertiary age. The whole flower is less than 20 mm long and is the first finding of an asterid flower in amber from the New World.
Credit: George Poinar

Amber is fossilized tree resin (not sap), highly valued as a gemstone since Antiquity and even before. The oldest amber recovered dates to the Upper Carboniferous period (320 million years ago) and is also valued by paleontologists – for itself, but also for what it traps inside sometimes. Insects, spiders and even their webs, annelids, frogs and many more get trapped inside; this time, it was some flowers.

Caption: The flower of Strychnos electri, found in fossilized amber, shows a long fused petal tube, anthers that are visible in the mouth of the flower, and a long style that protrudes far. Credit: George Poinar

Caption: The flower of Strychnos electri, found in fossilized amber, shows a long fused petal tube, anthers that are visible in the mouth of the flower, and a long style that protrudes far.
Credit: George Poinar

George Poinar and Lena Struwe from Oregon State University and Rutgers University respectively discovered these two pieces of amber in the mountains in the Dominican republic. They managed to describe them biologically and realized that they’re completely new species – never before described in science. They name the new species Strychnos electri, after the Greek word for amber, elektron.

Strychnos electri is a newly found fossil flower in amber, and a closeup of the fossil shows the recurved petal lobes and small, tightly attached anthers with pollen in the mouth of the flower. Credit: George Poinar

Strychnos electri is a newly found fossil flower in amber, and a closeup of the fossil shows the recurved petal lobes and small, tightly attached anthers with pollen in the mouth of the flower.
Credit: George Poinar

Unfortunately, they weren’t really able to accurately date the amber. They are following two “trails” with dating, one that would put the amber back to 15-20 million years ago, while the other one would push them back to 30-45 million years. Putting things into perspective will help researchers better understand the biological evolution of the Caribbean environment.

Such fossils contribute to our understanding of the evolution and composition of the Caribbean forests, way before North and South America were connected by the Panama land bridge.

Flea trapped in amber for 20 million years might hold earliest evidence of bubonic plague

Paleontologists believe they have found the oldest evidence of the bubonic plague, embedded in a flea trapped in amber for the past 20 million years. This could provide insight onto how this devastating disease appeared and evolved.

Image credits: George Poinar.

Some 20 million years ago, this flea had a really bad day – not only was it infected with a nasty bacterium, but it got stuck in tree resin and never made it out. In time, the resin turned into amber, and the flea (as well as the embedded bacteria) got preserved inside it, for paleontologists to find it long after that.

The bacteria found a very creative way of reproducing; when a flea bites an infected creature, it absorbs the bacteria, which then multiplies and eventually blocks the flea’s stomach. Therefore, if it wants to feed again, the flea has to regurgitate the bacteria into a new host. Scientists believe it’s this kind of regurgitated bacteria that was found in the amber flea. However, they haven’t thoroughly identified the bacteria.

George Poinar, Jr, an entomology researcher in the College of Science at Oregon State University, said:

“Aside from physical characteristics of the fossil bacteria that are similar to plague bacteria, their location in the rectum of the flea is known to occur in modern plague bacteria. If this is an ancient strain of Yersinia, it would be extraordinary,” Poinar said. “It would show that plague is actually an ancient disease that no doubt was infecting and possibly causing some extinction of animals long before any humans existed. Plague may have played a larger role in the past than we imagined.”

Yernisia Pestis is this bacterium that can infect humans and animals, causing the bubonic plague. Y. pestis was discovered in 1894 by Alexandre Yersin, a Swiss/French physician and bacteriologist from the Pasteur Institute, during an epidemic of plague in Hong Kong, but most of the damage from disease came much earlier. In the 1340s, Europe had a severe disease outbreak that began in the southern port cities in Italy and thereafter steadily spread northward, killing millions in its path. It often emptied entire villages of people and created mass hysteria, killing about one third of the population.

Scientists find Salamander in Amber in the Caribbean

Finding insects, plants or even dinosaur feathers trapped in amber s rare and exciting. But finding a fossil salamander in amber… that’s something else – it’s actually unique. But the salamander’s unfortunate fate sparked immediate interest from researchers: not only is it a unique finding, but it’s from a never-before seen species of salamander, and it comes from the Caribbean – a place where there are no salamanders today.

GEORGE POINAR, JR., COURTESY OF OREGON STATE UNIVERSITY

The little creature suffered a most unfortunate fate. It was only a baby when it got into a skirmish of some kind and its back limb got torn off. Then, through a series of unknown events, it somehow got trapped in resin, where it remained stuck for the next 20-30 years. But one salamander’s misfortune is another paleontologist’s fortune.

“There are very few salamander fossils of any type, and no one has ever found a salamander preserved in amber,” said George Poinar, Jr., a professor emeritus in the OSU College of Science, in a press release. “And finding it in Dominican amber was especially unexpected, because today no salamanders, even living ones, have ever been found in that region.”

Salamander fossils of all types are rare. The amphibians with a lizard-like appearance are found in the Holarctic and Neotropical regions, though some researchers believe that they previously lived in other areas as well – and this is a fine piece of evidence.

The new species has been called Palaeoplethodon hispaniolae by the authors of the paper, and it adds more hint not only about the biology of the Caribbean area, but also about its geology and climate; salamanders require very specific conditions to be able to thrive, and finding a salamander basically ensures that those conditions were fulfilled at one point in time.

The family in which Palaeoplethodon belonged is fairly common in North America, especially in the Appalachian mountains, but this ancient species has some significant differences from the salamanders we see today. For starters, it didn’t have the distinctive “salamander legs”, and instead sported a kind of webbing that might have made it a worse climber.

But the species also raises some important questions: why is it that all salamanders went extinct in the Americas? Was there some predator that simply killed them all, some climatic event? Or did they simply drift with the tectonic movement of the Americas? We’re still far away from answering those questions, but this little guy might provide some valuable hints.

Predatory cockroach found in 100 million year old amber

Geologists have found a praying-mantis-like cockroach that lived at the side by side with the dinosaurs, 100 million years ago, during the mid Cretaceous. The insect was preserved in amber.

Peter Vršanský from the Geological Institute in Bratislava, Slovakia, and Günter Bechly from the State Museum of Natural History in Stuttgart found the insect at a mine in Noije Bum, Myanmar. The specimen was one of many found in the area, and is related to today’s praying mantises. Out of all the predatory cockroach lineages that evolved in the Cretaceous, only praying mantises survive today.

According to the two researchers, its long neck, which allows the head to rotate freely, and unusually long legs area a good indication that it actively hunted prey.

“The new species exemplifies the reverse trend to that observed in the mantodeans, namely an elongation of extremities, including palps. This elongation especially applies to the elongation of tibia. In addition to the pursuit predatory lifestyle, it can be inferred that these insect were autochthonous inhabitants of the Cretaceous Araucaria amber forest in Myanmar. This inference is mainly based on the fact that four additional specimens of this new taxon (with one early immature specimen) are known to us from traders of Myanmar amber inclusions,” the study reads.

The Cretaceous was a period with a relatively warm climate, resulting in high sea levels. It is the period when many new groups of mammals and birds, as well as flowering plants, appeared.

Journal reference: Geologica Carpathica, DOI: 10.1515/geoca-2015-0015

Dinosaurs lived in low-oxygen world, amber shows

An international team of researchers led by Ralf Tappert, from the University of Innsbruck, reconstructed the composition of Earth’s atmosphere of the last 220 million years by analyzing modern and fossil plant resins. Their results indicate that atmospheric oxygen was considerably lower in Earth’s geological past than previously assumed – providing valuable information about current climate models, and questioning some of the current theories about the evolution of climate and life, including the causes for the gigantism of dinosaurs.

Atmospheric oxygen and resin

Credit: Ryan C. McKellar

Credit: Ryan C. McKellar

Scientists face major challenges when reconstructing atmospheric compositions in Earth’s geological past because of the lack of sample material. Ice cores are very reliable, but they only go so far (usually tens or hundreds of thousands of years), and geologic phenomenona (such as volcanic ash, Stromatolite and Banded-iron Formation) offer only some approximations.

However, one of the few organic materials that may preserve reliable data of Earth’s geological history over millions of years are fossil resins (e.g. amber). They have been present in various forms for hundreds of millions of years and can offer valuable information.

“Compared to other organic matter, amber has the advantage that it remains chemically and isotopically almost unchanged over long periods of geological time,” explains Ralf Tappert from the Institute of Mineralogy and Petrography at the University of Innsbruck.

In order to fully analyze it and make the most of the samples, the team gathered researchers from several fields, including mineralogy, chemistry and paleontology. They mostly focused on the preserving properties of plant resins, caused by polymerization, for their study.

“During photosynthesis plants bind atmospheric carbon, whose isotopic composition is preserved in resins over millions of years, and from this, we can infer atmospheric oxygen concentrations,” explains Ralf Tappert

The information comes about oxygen concentration comes from the isotopic composition of carbon or rather from the ratio between the stable carbon isotopes 12C and 13C. The 12C/13C ratio is extremely important in studying the climate and atmospheric conditions in geologic times; a change in the ratio in the remains of plants indicates a change in the amount of photosynthetic activity, and thus in how favorable the environment was for the plants.

Oxygen, climate and life

The research team analyzed a total of 538 amber samples from well known deposits worldwide, with the oldest samples being approximately 220 million years, recovered from the Dolomites in Italy. The team also compared the resin samples with modern ones, to test the validity of their data. The results of this comprehensive study suggest that atmospheric oxygen during most of the past 220 was considerably lower than today’s 21 percent, raising major question marks about the data at the basis of most climate studies and models.

“We suggest numbers between 10 and 15 percent,” says Tappert. These oxygen concentrations are not only lower than today but also considerably lower than the majority of previous investigations propose for the same time period. For the Cretaceous period (65 — 145 million years ago), for example, up to 30 percent atmospheric oxygen has been suggested previously.

The team also confirmed some of the current theories, like for example the connection between high CO2 levels and high temperatures.

“We found that particularly low oxygen levels coincided with intervals of elevated global temperatures and high carbon dioxide concentrations,” explains Tappert.

He actually suggests that there may be a connection between oxygen and carbon levels, a ratio which is instrumental in our planet’s climate.

“Basically, we are dealing here with simple oxidation reactions that are amplified particularly during intervals of high temperatures such as during the Cretaceous period.”

Another interesting result of this study is the impact of the atmospheric oxygen on Earth’s life. Many theories on gigantism claim that as oxygen levels start to grow, so do animal sizes – but according to this study, this idea is invalid, as oxygen level during the Jurassic, for example, weren’t particularly high.

“We do not want to negate the influence of oxygen for the evolution of life in general with our study, but the gigantism of dinosaurs cannot be explained by those theories.

Journal Reference:

  1. Ralf Tappert, Ryan C. McKellar, Alexander P. Wolfe, Michelle C. Tappert, Jaime Ortega-Blanco, Karlis Muehlenbachs.Stable carbon isotopes of C3 plant resins and ambers record changes in atmospheric oxygen since the TriassicGeochimica et Cosmochimica Acta, 2013; 121: 240 DOI: 10.1016/j.gca.2013.07.011

First fossilized mosquito is still full of blood

Finding mosquitoes trapped in amber is truly exciting, but it’s not really unique – there have been several reported cases all around the world, and some people are even selling such samples (which I don’t think is a good thing, but that’s another discussion). But finding a fossilized mosquito in sediment… now that’s unique! It took a series of highly improbable events and a bit of luck for paleontologists to find this insect trapped in 46 million years old sedimentary rocks (dating from the the Eocene). But even more exciting, the mosquito still carries in its belly the blood from its last meal.

mosquito

The unique preservation of this well-fed mosquito is almost certainly bound to a pond or other lake-like environment.

“The insect had to take a blood meal, be blown to the water’s surface, and sink to the bottom of a pond or similar lacustrine [lake-like] structure to be quickly embedded in fine anaerobic sediment,” they write, “all without disruption of its fragile distended blood-filled abdomen.”

The result, discovered in a shale in Montana is the first fossil of a mosquito found still engorged with ancient blood. According to the study’s leader, Smithsonian Institution paleontologist Dale Greenwalt, this is only the fifth instance of blood-eating (hematophagy) fossilized ever found. Most likely candidates for such findings are midges, a kind of biting fly, which usually lived near lakes; mosquitoes, which typically prefer open air spaces, are less likely to be found in such a state. In addition, contrary to popular belief, most mosquitoes don’t really eat blood (most of them are pollinators), and even of those who do, it’s only the females which bite.

But don’t get your hopes up – whatever the mosquito bit, we won’t be able to find out. DNA molecules in blood couldn’t withstand fossilization; and if you were thinking dinosaurs, you’re way off the mark. This mosquito lived in the Eocene, some 19 million years after non-avian dinosaurs went extinct.

The results were published in the Proceedings of the National Academy of Sciences.