Earliest evidence of insect-angiosperm pollination found in Cretaceous Burmese amber

By: Thomas Schmitt Attorney on November 11, 2019 / comment : 0 Burma, Fossils, Palaeontology

Most of our food is from angiosperms, while more than 90% of angiosperms require insect pollination - making this pollination method hugely important. Nevertheless, scientists have long been unclear as to when insect pollination first appeared.

Artist's rendering of A. burmitina feeding on eudicot flowers [Credit: Ding-hau Yang]

Now, however, an international research group from China and the U.S. has provided the earliest evidence of insect-angiosperm pollination - by analyzing a sample of Cretaceous Burmese amber. The research was led by Prof. WANG Bo from the Nanjing Institute of Geology and Palaeontology (NIGPAS) of the Chinese Academy of Sciences. Results were published in Proceedings of the National Academy of Sciences.

Angiosperms, also known as flowering plants, originated in the Mesozoic and are the most diverse group of land plants, with approximately 300,000 known species. Their most distinguishing characteristic is the presence of true flowers. Angiosperms self-pollinate as well as use insects, animals, wind and water to achieve pollination, thus enhancing gene flow and increasing diversity.

A. burmitina in amber. The 99-million-year-old fossil, recovered from a mine in northern Myanmar, also contains 62 pollen grains from a eudicot flower. It is the earliest known physical evidence of insect pollination [Credit: Nanjing Institute of Geology and Palaeontology]

Angiosperms experienced rapid radiation by the mid-Cretaceous, which Darwin called an "abominable mystery." Since Darwin's time, numerous scholars have thought that insect pollination must be a key contributor to the Cretaceous radiation of angiosperms since insects and flowering plants were both common by this time. However, direct evidence of a Cretaceous insect-angiosperm pollination mode was missing and related theories remained hypothetical until now.

Working with Burmese amber dating to the mid-Cretaceous - 99 million years ago - the researchers discovered evidence of beetle pollination, thus confirming the hypothesis of Cretaceous insect-angiosperm interaction and offering the earliest evidence for entomophily.

Close up of A. burmitina in amber. The fossil also contains 62 pollen grains from a eudicot flower, which indicates the insect's role as a pollinator [Credit: Nanjing Institute of Geology and Palaeontology]

The beetle specimen in the amber sample is a new species within the family Mordellidae, named Angimordella burmitina. Extant Mordellidae beetles are a typical flower-visiting group. Commonly, they are known as "tumbling flower beetles" for the irregular movements they make when escaping predators, due to having an elongated pygidium (an external posterior body part or shield in arthropods).

A. burmitina is distinguished from most extant species by a poorly developed pygidium and enlarged, very well-developed hind legs. Based on these features, the scientists believe A. burmitina utilized a different movement mechanism than other species, preferring to jump or fly between corollas and plants. The mouth part of A. burmitina is also highly evolved for pollen collection, with enlargement of part of the maxillary palps, which are leg-like structures near the mouth.

Ecological reconstruction of the Cretaceous tumbling flower beetle [Credit: NIGPAS]

Numerous pollen grains were preserved on or near the A. burmitina specimen. To examine them closely, the research team performed high-precision grinding and polishing of the amber sample, then applied confocal laser scanning microscopy and optical photomicrography. Using these methods, the scientists identified the pollen grains as tricolpate, meaning they each have three pores and come from a type of flowering plant known as a eudicot. Their surface texture, size, and clumping also show that the pollen is zoophilous, making it more likely to be picked up by an animal such as a beetle.

Based on the entomological and palynological evidence, the research team believes this amber specimen proves a beetle-angiosperm pollination mode, supporting the hypothesis that specialized insect pollination modes were present in eudicots at least 99 million years ago. Previous evidence of insect pollination of flowering plants dates to the Middle Eocene, around 45-48 million years ago. Thus, the current finding extends the history of insect pollination of flowering plants by around 50 million years and suggests that such mutualism existed at least as far back as 99 million years ago.

Author: LI Yuan | Source: Chinese Academy of Science [November 11, 2019]

Paleontologists discover diversity of insect pollinators in 99-million-year-old amber

By: Thomas Schmitt Attorney on August 28, 2019 / comment : 0 Burma, Fossils, Palaeontology

A team of paleontologists from the Borissiak Paleontological Institute of Russian Academy of Sciences (Moscow) discovered four new species of extinct insects with sucking mouthparts in mid-Cretaceous Burmese amber. Researchers believe that they visited first angiosperm flowers, but eventually went extinct due to the inefficient design of the proboscis. According to the research, Paradoxosisyrinae, the group to which these creatures belong, is a kind of "Nature's failed experiment". The results of the study are published in the Cretaceous Research journal.

Buratina truncata, the new long-proboscid species of Paradoxosisyrinae  from Burmese amber [Credit: Alexander Khramov]

In recent years, Burmese amber makes headlines as a source of dinosaur remains, toothed birds and other incredible vertebrate findings. However, insects found there are often no less bizarre. This is especially true for Paradoxosisyrinae, a subfamily of Sisyridae, or spongeflies, which was described from Burmese amber based on a single specimen in 2016.

Neither living spongeflies nor any of their extant relatives from insect order Neuroptera, such as green lacewings and ant lions, have sucking mouthparts. In contrast, members of Paradoxosisyrinae were equipped with a well-developed proboscis -- which is a paradox indeed, as their name suggests.

Until now, functions of Paradoxosisyrinae's proboscis have remained unclear. It was hypothesized that Paradoxosisyrinae used their elongated mouthparts for piercing insect cuticle or frog skin. Contrary to this, the new research based on newly available specimens shows that in all probability these insects were not predators or bloodsuckers -- instead, they were harmless nectar feeders.

Scientists said that Paradoxosisyrinae simply could not pierce any dense substrates because of loosely coupled arrangement of the mouthparts, devoid of a supportive sheath, and the presence of long hairs at the mouthpart tips.

Artistic reconstruction of Buratina truncata gen. et sp. nov. feeding on Tropidogyne flowers, which are common in Burmese amber [Credit: Andrey Sochivko]

With the help of microscope examination and virtual 3D-models scientists came to a conclusion that proboscis of Paradoxosisyrinae, rather than having a common food canal, consists of two independent straws or tubes, each one formed by two halves loosely joined together without any special devices suitable to lock them tightly.

Since Paradoxosisyrinae could not seal their proboscis to produce a pressure gradient, as modern flies and moths do, they had to rely exclusively on capillary forces for nectar uptake, while other nectar feeders use also the muscular sucking pump. All this means that the proboscis of Paradoxosisyrinae, less than 1 mm in length, destined to be short forever, which undercut their ability to draw nectar from flowers with deep corolla tubes.

"These insects were a nature's unsuccessful attempt to make nectar feeding insects in response to the rise of the flowering plants in the Early Cretaceous period. Soon they were outcompeted by bees, flies and other nectar feeders with more cleverly designed mouthparts", said Alexander Khramov, study"s leading author and a senior researcher at the Borissiak Paleontological Institute.

Discovery of four new species of Paradoxosisyrinae, in addition to the only previously known member of this subfamily, dramatically expands our knowledge about diversity of these extinct nectar feeders.

One of the new species was named Buratina truncata after the long-nosed fiction character Buratino, the Russian analogue of Pinocchio. Body of Buratina truncata as well as of other newly described species was covered with dense hairs, the condition seen in modern pollinators, which allows them to carry pollen grains between plants. The researchers say that Paradoxosisyrinae could feed on small shallow flowers like Tropidogyne which are commonly occur in Burmese amber.

Source: AKSON Russian Science Communication Association [August 28, 2019]

Two tiny beetle fossils offer evolution and biogeography clues

By: Thomas Schmitt Attorney on January 17, 2019 / comment : 0 Burma, Fossils, Palaeontology

It is well-known that living fossils exhibit stasis over geologically long time scales. Examples are the panda and ginkgo. Now, two tiny beetles trapped in 99-million-year-old amber may join this group.

This is Sphaerothorax uenoi from mid-Cretaceous Burmese amber [Credit: NIGPAS]

Beetles are the most species-rich group of animals on our planet. Among four extant suborders of beetles, polyphaga is the largest and most diverse group. The origin and early evolutionary history of polyphagan beetles have been largely based on evidence from the derived and diverse 'core polyphaga', whereas little is known about the species-poor basal polyphagan lineages, which include Clambidae and four other extant families.

Recently, an international team led by Dr. CAI Chenyang, from the Nanjing Institute of Geology and Palaeontology of the Chinese Academy of Sciences, reported two new and rare species of the extant family Clambidae from Burmese amber: Acalyptomerus thayerae Cai and Lawrence, 2019, and Sphaerothorax uenoi Cai and Lawrence, 2019. They are important for understanding the early evolution and biogeography of the family and even for polyphagan beetles.

Geographical distribution of Acalyptomerus thayerae and Sphaerothorax uenoi and their related extant counterparts [Credit: NIGPAS]

Clambidae is a small group of small-sized (usually 0.7-2.0 mm long) polyphagan beetles distributed worldwide, with approximately 150 described species grouped in five extant genera. Most clambid adults occur in decaying vegetation, leaf litter and rotten wood and occasionally fly at dusk.

The two new species, represented by five well-preserved fossils, were discovered by Dr. CAI and colleagues from mid-Cretaceous Burmese amber. Both species are extremely morphologically close to their living counterparts, and can be placed in extant genera. Acalyptomerus thayerae (about 1.05-1.15 mm long) has a close affinity to A. herbertfranzi, a species currently occurring in Mesoamerica and northern South America. Sphaerothorax uenoi (about 0.71 mm long) is closely related to extant species of Sphaerothorax, which are usually collected in forests of Nothofagus in Australia, Chile and New Zealand.

This is Acalyptomerus thayerae from mid-Cretaceous Burmese amber [Credit: NIGPAS]

The discovery of two Cretaceous species from northern Myanmar indicates that both genera had lengthy evolutionary histories, originating at least by the earliest Cenomanian, and were probably more widespread than at present.

Remarkable morphological similarities between fossil and living species suggest that both genera changed little over long periods of geological time, which is usually considered to be a feature of living fossils. The long-term persistence of similar mesic microhabitats such as leaf litter may account for the 99-million-year morphological stasis in Acalyptomerus and Sphaerothorax.

The findings are published in Proceedings of the Royal Society B: Biological Sciences.

Source: Chinese Academy of Sciences [January 17, 2019]

Mosquitoes, other blood-sucking flies have been spreading malaria for up to 100 million years

By: Thomas Schmitt Attorney on November 27, 2018 / comment : 0 Burma, Canada, Dominican Republic, Fossils, Mexico, Palaeontology

The microorganisms that cause malaria, leishmaniasis and a variety of other illnesses today can be traced back at least to the time of dinosaurs, a study of amber-preserved blood-sucking insects and ticks show.

Fossilised black fly [Credit: Oregon State University]

In addition to demonstrating the antiquity of vectors and their long-term association with parasitic microorganisms, the findings are remarkable for several reasons.

First, bloodsuckers like mosquitoes, fleas, sand flies, ticks and biting midges aren't frequently found in amber, and rarer yet is evidence of any microorganisms they might have been carrying.

But a review by entomologist George Poinar of Oregon State University showed that amber from five regions around the world contained hematophagous arthropods carrying preserved, identifiable pathogens and parasites.

"Feeding on vertebrate blood evolved as an efficient way for certain insects and acarines to get protein for growth and reproduction," said Poinar, professor emeritus in the College of Science and an international expert on plant and animal life forms found preserved in amber. "It's likely that primitive mosquitoes and other arthropod vectors were present back in the Jurassic and were even transmitting pathogens at that period. This would have resulted in widely dispersed diseases, many of which were probably fatal to vertebrates when they first appeared."

Poinar looked at bloodsucking insects and ticks encased in Dominican, Mexican, Baltic, Canadian and Burmese amber dating back from 15 million to 100 million years.

Among the vectors were mosquitoes, sand flies, biting midges, bat flies, black flies, fleas, kissing bugs and ticks. They carry a cornucopia of microorganisms that today cause diseases such as filariasis, sleeping sickness, river blindness, typhus, Lyme disease and, perhaps most significantly, malaria.

Fossilised flea [Credit: Oregon State University]

Malaria remains a relentless public health concern, with multiple nations reporting increases in infections for 2018. In Venezuela alone, Poinar notes, more than 650,000 new cases of malaria have been reported this year.

"Numerous malaria species parasitize vertebrates today, and we now know that over the past 100 million years, malaria was being vectored by mosquitoes, biting midges, bat flies and ticks," Poinar said. "Obtaining fossil records of pathogens carried by biting arthropods establishes a timeline when and where various diseases appeared and how they could have affected the survival, extinction and distribution of vertebrates over time."

Poinar stresses, however, that while his research shows what parasites and pathogens specific bloodsuckers were transmitting at particular periods and locations in the past, "these fossils are not old enough to tell us when and how associations between vectors, pathogens and vertebrates originated."

Poinar believes that the microorganisms first infected blood-sucking arthropods and only after equilibria had been reached between them were the microorganisms then vectored to vertebrates.

"That topic has been and will continue to be under discussion for years to come," he said.

The findings are published in Historical Biology.

Author: Steve Lundeberg | Source: Oregon State University [November 27, 2018]

Tiny beetle trapped in amber might show how landmasses shifted

By: Thomas Schmitt Attorney on October 30, 2018 / comment : 0 Burma, Earth Science, Fossils, Palaeontology

In 2016, Shuhei Yamamoto obtained a penny-sized piece of Burmese amber from Hukawng Valley in northern Myanmar, near China's southern border. He had a hunch that the three-millimeter insect trapped inside the amber could help ansshow why our world today looks the way it does.

The fossil beetle in amber, with a pen tip for scale [Credit: (c) Field Museum]

After carefully cutting and polishing the amber, Yamamoto determined that the insect, smaller than the phone-end of an iPhone charger, was a new species to science. The beetle, which lived 99 million years ago, is a relative of insects alive today that live under tree bark, and it's giving scientists hints about how the Earth's landmasses were arranged millions of years ago.

"This is a very rare find," Yamamoto said, a Field Museum researcher and lead author of a paper in the Journal of Systematic Palaeontology describing the new species. The fossil beetle is one of the oldest known members of its family--its name, Propiestus archaicus, refers to the fact that it's an ancient relative of the flat rove beetles in the Piestus genus today of which now dominates the South America.

While dinosaurs roamed much of the Earth 99 million years ago during the Late Cretaceous era, Propiestus, with its flattened body and short legs, was busy conquering smaller turf underneath the bark of rotting trees. Its long, slender antennae were the clear giveaway to Yamamoto that Propiestus was lived in this environment--similar to today's flat rove beetles.

"The antennae probably had a highly sensitive ability as a sensory organ," Yamamoto said. Smaller hair-like structures attached perpendicular to the antennae would have increased its ability to feel out its surroundings. "There wouldn't have been a lot of space available in the beetle's habitat, so it was important to be able to detect everything," he explains.

Propiestus is just one of the hundreds of thousands of Burmese amber inclusions--another word for the objects trapped inside the amber--that scientists have extensively researched over the last 15 years. Many small insects that lived during the Cretaceous era met their maker at the hands of tree sap that engulfed the bugs and hardened into amber. The bugs trapped inside fossilized and remained frozen for millions of years, unaffected by the passage of time. The hardened amber, covered by soil, decayed leaves, and other organic material, eventually blended in with its surroundings.

Because of this, amber in nature doesn't look like it does in jewelry--in fact, it doesn't look like anything special at all. The small clumps of unpolished amber look like rocks, meaning only those experienced in amber identification, mostly local miners, are able to find them.

The fossil beetle, Propiestus archaicus, preserved in amber [Credit: (c) Field Museum, Shuhei Yamamoto]

After miners extract the amber, the clumps are either sold into the jewelry trade or to scientists like Yamamoto to study the inclusions. For Yamamoto's piece of amber, he used sandpaper to carefully polish the amber just enough to make Propiestus clearly visible.

"It was very exciting, because the cutting process is very sensitive," Yamamoto said. "If you cut too fast or apply too much pressure, you destroy the inclusion inside very quickly."

Once the amber was polished, the beetle was clearly visible, enabling Yamamoto and his colleagues to study the beetle and determine its closest living relatives. Propiestus's flat rove beetle cousins alive today are found mostly in South America, with the exception of one species in Southern Arizona. Myanmar, where Propiestus was found, is literally on the other side of the globe from these places. But it hasn't always been that way.

Millions of years ago, Myanmar and South America were actually quite close to each other, all fused together as part of the megacontinent Gondwanaland, which formed when the earlier megacontinent Pangea broke apart. Gondwanaland itself eventually broke apart, helping to form the continents we recognize on a map today.

Scientists have a clear sense of which of today's continents and subcontinents would have comprised Gondwanaland and which would have made up its sister continent, Laurasia. However, the detailed timing and pattern of Gondwanaland's split into smaller continents is disputable. Searching for supporting or contrasting evidence means analyzing fossils, some as small as Propiestus, to compare their similarities to other organisms discovered across the globe that might have inhabited the same space long ago.

"Like koalas and kangaroos today, certain animals that we think lived in Gondwanaland are only found in one part of the world. Although Propiestus went extinct long ago, our finding probably shows some amazing connections between Southern Hemisphere and Myanmar," Yamamoto said. "Our finding fits well with the hypothesis that, unlike today, Myanmar was once located in the Southern Hemisphere."

Many inclusions in Burmese amber that have been researched in the last 15 years, including Propiestus, show signs that show traits in common with insects from Gondwanaland. By studying these tiny creatures trapped in amber, we're finding answers to the questions surrounding Earth's structure and the life it supported millions of years ago.

"This fossil helps us understand life in the Mesozoic era," he said. "We need to think about everything from that time, both big and small."

Source: Field Museum [October 30, 2018]

Fossils reveal diverse Mesozoic pollinating lacewings

By: Thomas Schmitt Attorney on September 17, 2018 / comment : 0 Burma, China, Fossils, Palaeontology

Insect pollination played an important role in the evolution of angiosperms. Little is known, however, about ancient pollination insects and their niche diversity during the pre-angiosperm period due to the rarity of fossil evidence of plant-pollinator interactions.

(a) Jurassic kalligrammatids in the Daohugou forest; (b) Cretaceous kalligrammatids in the Burmese amber forest [Credit: Yang Dinghua]

Recently, a research group led by Prof. WANG Bo from the Nanjing Institute of Geology and Palaeontology of the Chinese Academy of Sciences (NIGPAS) has provided new insight into the niche diversity, chemical communication, and defense mechanisms of Mesozoic pollinating insects. Its findings were published in Nature Communications.

One of the most intensely investigated examples of pollination niches is the morphological match between insect proboscis and floral tube length, which Darwin described in a publication in 1877. Kalligrammatid lacewings are among the largest and most conspicuous Mesozoic insects with siphoning mouthparts.

The NIGPAS researchers reported 27 well-preserved kalligrammatids from late Cretaceous Burmese amber (99 Ma) and Chinese Early Cretaceous (125 Ma) and Middle Jurassic (165 Ma) compression rocks.

Jurassic and Cretaceous kalligrammatids from China [Credit: NIGPAS]

Kalligrammatid proboscides vary greatly in length, from 0.6 to 3.2 mm in amber inclusions and about 5 to 18 mm in compression fossils. The high diversity of kalligrammatids and large variation in proboscis length strongly suggest diverse plant hosts with different floral tube lengths. Therefore, pollination niche partitioning may have been present among some Mesozoic insects.

If pollination niches were partitioned, as in extant ecosystems, this likely increased pollination effectiveness and reduced the cost of pollination mutualism, thus contributing to the high diversity of pollinating insects and the success of pollinator-dependent plants during the Cretaceous period.

Kalligrammatid species diversification was potentially promoted by coevolution between pollinating kalligrammatids and their host plants under highly partitioned pollination niches.

Kalligrammatids in Burmese amber [Credit: NIGPAS]

Traits such as wing eyespots, which likely functioned as a defense in large-sized species, and sexually dimorphic antennae, which were likely used for pre-mating chemical communication, elucidate how kalligrammatids survived in the Mesozoic terrestrial ecosystem under intense competition.

However, such elaborate associations between kalligrammatids and their host plants (mostly confined to gymnosperms) could have been a key factor contributing to the extinction of kalligrammatids, which likely occurred during the late Cretaceous with the decline in gymnosperm diversity.

Source: Chinese Academy of Sciences [September 17, 2018]

Amber unveils evolution of ancient antlions

By: Thomas Schmitt Attorney on August 22, 2018 / comment : 0 Burma, China, Fossils, Palaeontology

Myrmeleontiformia (antlions and their relatives) are an ancient group of lacewing insects characterized by predatory larvae with unusual morphologies and behaviours.

This is a reconstruction of two lacewing larvae [Credit: YANG Dinghua]

An international team led by Prof. WANG Bo from the Nanjing Institute of Geology and Palaeontology of the Chinese Academy of Sciences (NIGPAS) and two Italian researchers found fossil Myrmeleontiformia fauna from mid-Cretaceous (approximately 100 million years ago) Burmese amber. The study was published in Nature Communications.

Their findings show that Myrmeleontiformia did not gain considerable morphological novelty during the subsequent 100 million years, and their diversity seemed to result from different combinations of a limited set of character traits in a complex trade-off.

This morphological stasis helped in reconstructing behaviours not preserved by a trace in the fossil record. Inference of these behaviors shed light on the ecological niche and lifestyle of extinct Myrmeleontiformia.

Diversity of lacewing larvae in mid-Cretaceous Burmese amber [Credit: NIGPAS]

Statistical correlation analysis strongly supported a correlation between a selection of morphological traits and two hunting strategies of these ambush predators - camouflaging and fossoriality - allowing us to reconstruct habits of extinct species.

The findings suggested that fossorial specializations evolved more than once across Myrmeleontiformia from arboreal ancestors. The fossorial lifestyle of antlions was certainly one of the factors leading to their success, allowing these insects to colonize and diversify in arid habitats where they survived considerable changes in terrestrial environments during the Cretaceous lineages.

The Burmese fossils showed that debris-carrying characterized this lineage for at least 100 million years. All of these camouflaging lacewings were equipped with elongate protuberances. The strong statistical correlation between the presence of these protuberances and camouflaging behavior demonstrated that this trait is an indicator of such behaviour, even when the debris covering is not directly preserved in the amber piece together with the larvae.

Phylogeny of Myrmeleontiformia based on larval morphology [Credit: NIGPAS]

This research also implies that camouflaging behaviour arose at least three times within Myrmeleontiformia. Camouflaging and fossoriality appear widespread across the lineage, and both behaviors allowed the predatory larvae to hide from their unsuspecting prey.

Source: Chinese Academy of Sciences [August 21, 2018]

99-million-year-old beetle trapped in amber served as pollinator to evergreen cycads

By: Thomas Schmitt Attorney on August 16, 2018 / comment : 0 Burma, Fossils, Palaeontology

Flowering plants are well known for their special relationship to the insects and other animals that serve as their pollinators. But, before the rise of angiosperms, another group of unusual evergreen gymnosperms, known as cycads, may have been the first insect-pollinated plants. Now, researchers reporting in the journal Current Biology have uncovered the earliest definitive fossil evidence of that intimate relationship between cycads and insects.

A dorsal view of the mid-Cretaceous beetle Cretoparacucujus cycadophilus with a 1mm scale bar [Credit: Chenyang Cai]

The discovery came in the form of an ancient boganiid beetle preserved in Burmese amber for an estimated 99 million years along with grains of cycad pollen. The beetle also shows special adaptations, including mandibular patches, for the transport of cycad pollen.

"Boganiid beetles have been ancient pollinators for cycads since the Age of Cycads and Dinosaurs," says Chenyang Cai, now a research fellow at the University of Bristol. "Our find indicates a probable ancient origin of beetle pollination of cycads at least in the Early Jurassic, long before angiosperm dominance and the radiation of flowering-plant pollinators, such as bees, later in the Cretaceous."

Cycad pollen grains associated with C. cycadophilus [Credit: NIGPAS]

When Cai's supervisor Diying Huang at the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, first showed him the beetle trapped in amber, he was immediately intrigued. He recognized that its large mandibles with bristly cavities might suggest the beetle was a pollinator of cycads.

After cutting, trimming, and polishing the specimen to get a better look under a microscope, Cai's excitement only grew. The beetle carried several clumps of tiny pollen grains. Cai consulted Liqin Li, an expert in ancient pollen at the Chinese Academy of Sciences, who confirmed that the pollen grains belonged to a cycad.

An ecological reconstruction of the mid-Cretaceous beetle Cretoparacucujus burmiticus [Credit: Chenyang Cai]

The researchers also conducted an extensive phylogenetic analysis to explore the beetle's family tree. Their analysis indicates the fossilized beetle belonged to a sister group to the extant Australian Paracucujus, which pollinate the relic cycad Macrozamia riedlei. The finding, along with the current disjunct distribution of related beetle-herbivore and cycad-host pairs in South Africa and Australia, support an ancient origin of beetle pollination of cycads, the researchers say.

Cai notes that the findings together with the distribution of modern boganiid beetles lead him to suspect that similar beetle pollinators of cycads are yet to be found. He's been looking for them for the last five years. The challenge, he says, is that older Jurassic beetles are generally found as compression fossils not trapped in amber.

Source: Cell Press [August 16, 2018]

Those fragrances you enjoy? Dinosaurs liked them first

By: Thomas Schmitt Attorney on August 07, 2018 / comment : 0 Burma, Dinosaurs, Fossils, Palaeontology

The compounds behind the perfumes and colognes you enjoy have been eliciting olfactory excitement since dinosaurs walked the Earth amid the first appearance of flowering plants, new research reveals.

Glandular laurel in amber [Credit: Oregon State University]

Oregon State University entomologist George Poinar Jr. and his son Greg, a fragrance collector, found evidence that floral scents originated in primitive flowers as far back as 100 million years ago as pollinator attractants -- a role they still play even though today's flowers also have colorful petals for luring pollinators.

"I bet some of the dinosaurs could have detected the scents of these early flowers," George Poinar said. "In fact, floral essences from these early flowers could even have attracted these giant reptiles."

The Poinars examined amber flowers from Burma, including the now extinct glandular laurel flower (Cascolaurus burmensis) and veined star flower (Tropidogyne pentaptera).

The research revealed that the flower-based chemical compounds that are the basis for the perfumes and colognes we use today have been providing olfactory excitement to pollinating insects and other animals since the mid-Cretaceous Period.

Without colorful petals, flowers from that period had to rely solely on scents to attract pollinators.

"You can't detect scents or analyze the chemical components of fossil flowers, but you can find the tissues responsible for the scents," said George Poinar, professor emeritus in the OSU College of Science.

Secretions in amber [Credit: Oregon State University]

The floral secretory tissues producing these scents include nectaries, glandular trichomes, eliaphores and osmophores.

Nectaries are glands that produce fragrances and sweet deposits that insects love. Glandular trichomes are hairs with cells that make and send out scented secretory products. Eliaphores are stalked aromatic oil glands. oOsmophores, also known as floral fragrance glands, are cell clusters specializing in scent emission.

The study also found that secretory tissues of these Cretaceous flowers are similar in structure to those of their modern descendants. That suggests modern and ancient flowers of the same lineages produced similar essences.

Some of flowers studied were even in the process of emitting compounds at the time they were engulfed by the tree resin that later became amber.

The study also included a milkweed flower (Discoflorus neotropicus) and an acacia flower (Senegalia eocaribbeansis) in 20- to 30-million-year-old Dominican Republic amber.

The anther glands on the fossil acacia flower were especially attractive to bees, one of which was fossilized while visiting the stamens. Today, honeybees are still visiting acacia flowers that have the same type of flora glands that existed in the ancient past.

"It's obvious flowers were producing scents to make themselves more attractive to pollinators long before humans began using perfumes to make themselves more appealing to other humans," George Poinar said.

The findings are published in Historical Biology.

Author: Steve Lundeber | Source: Oregon State University [August 07, 2018]

Tiny paragliding beetle that lived with dinosaurs discovered in amber

By: Thomas Schmitt Attorney on June 07, 2018 / comment : 0 Burma, Fossils, Palaeontology

Featherwing beetles are smaller than the period at the end of this sentence. They get their name from the feathery fringe on their wings that enables them to catch the air and float like dandelion seeds. And, it turns out, they go way back-- scientists discovered a 99-million-year-old featherwing beetle preserved in amber, and they named it "Jason."

The amber sample with the new beetle trapped inside - the beetle is the tiny speck indicated by the tip of a mechanical pencil for scale [Credit: Shuhei Yamamoto, Field Museum]

"This tiny beetle lived during the Cretaceous Period, it saw actual dinosaurs," says Shuhei Yamamoto, a researcher at the Field Museum in Chicago and co-lead author of a paper describing the beetle in Cretaceous Research. "The amber the beetle was found in is like a time capsule."

The new beetle, the earliest member of its family to get a scientific name, is called Kekveus jason. "Jason" is a reference to the Greek hero who sailed the world in search of the Golden Fleece; "Kekveus," meanwhile, doesn't mean anything--co-lead author Vasily Grebennikov of the Canadian Food Inspection Agency, picked it because new genus names for little-known fossils often wind up changing when the species is later reclassified as scientists learn more about it.

"From my perspective I always believe that an animal name should not have any meaning (except when named after a person), since if the authors are wrong, it might be odd to have later species 'chinensis' endemic to Europe, or something similarly absurd," says Grebennikov.

Yamamoto discovered the tiny sailing insect by poring over pieces of amber. Amber is made from fossilized resin, a sap-like substance produced by plants. When prehistoric insects got trapped in resin, their bodies would get incorporated into the amber that formed--think the mosquitos from Jurassic Park, minus the "resurrecting dinosaurs" part.

When Yamamoto spotted a tiny black speck in the amber, he was cautiously optimistic that he'd found a prehistoric insect. "I didn't have much confidence at first, but after cutting and polishing the amber so I could get a better look, I realized, oh, this is truly an amazing fossil," he says.

The beetle is only 0.536 millimeters long--it's dwarfed by the tip of a mechanical pencil. But under a microscope, Yamamoto was able to glean details of its anatomy that revealed it as a different species and genus from living featherwing beetles. For instance, it has three grooves running like pinstripes up its body, a feature not found on its modern cousins.

Overall, though, the researchers found that K. jason has a lot in common with featherwings alive today, meaning that the family of beetles evolved features like a tiny body size and fringed wings millions of years ago. According to Yamamoto, amber fossils yield a level of preservation rarely found in regular rock, especially for insects.

"There are many rock fossils from the Jurassic and Cretaceous periods, but they're limited to big animals like larger insects, mammals, dinosaurs, and birds, because small insects cannot be preserved in rock fossil very clearly. Only fossil insects in amber are preserved in fine detail, in three dimensions," says Yamamoto.

Yamamoto looks forward to further discoveries of prehistoric animals preserved in amber.

"It's likely that we'll find more in the future--Burmese amber is one of the hottest fossils in the world," he says. "There are so many great findings happening, literally day by day. Many important discoveries of insects will be made."

Source: Field Museum [June 07, 2018]

200-million-year-old insect color revealed by fossil scales

By: Thomas Schmitt Attorney on April 11, 2018 / comment : 0 Burma, Fossils, Palaeontology

Can researchers determine the color of a 200-million-year-old insect? Scientists from China, Germany and the U.K. have new evidence that reveals the true color of fossil insects. The research was recently published in Science Advances.

Ecological restoration of moths in the Cretaceous Burmese amber forest  [Credit: Yang Dinghua]

Structural colors have evolved in a myriad of animals and plants and result from the wavelength-selective scattering of incident light. Such colors are typically more vibrant and visually arresting than those produced via pigmentation and are often multifunctional, playing important roles in intraspecific sexual signaling, aposematism and crypsis.

Lepidoptera exhibit in their scales some of the most diverse structural colors produced by insects. This diversity undoubtedly contributed to the evolutionary success of the order. Despite sustained interest in the structure, development, and photonic and other biomimetic properties of lepidopteran scales in neontological studies, as well as recent research into structural colors in fossil beetles and feathers, the deep evolutionary history of scales and structural colors in lepidopterans is poorly understood.

Recently, researchers from the Nanjing Institute of Geology and Palaeontology (NIGP) of the Chinese Academy of Sciences and their colleagues from Germany and the UK reported scale architectures from Jurassic Lepidoptera from the U.K., Germany, Kazakhstan and China, along with Tarachoptera (a stem group of Amphiesmenoptera) from mid-Cretaceous Burmese amber.

They used optical microscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and confocal laser scanning microscopy (CLSM) to reveal the gross morphology and ultrastructure of the scales.

Tarachoptera from mid-Cretaceous Burmese amber  [Credit: ZHANG Qingqing et al.]

Using the ultrastructural parameters identified in Jurassic specimens, they demonstrated the use of optical modeling to describe the theoretical optical properties of the type-1 bilayer scale arrangement, thus providing the earliest evidence of structural colors in the insect fossil record.

The Jurassic lepidopterans exhibit a type 1 bilayer scale vestiture: an upper layer of large, fused cover scales and a lower layer of small, fused ground scales. This scale arrangement, plus preserved herringbone ornamentation on the cover scale surface, is almost identical to those of some extant Micropterigidae. Critically, the fossil scale ultrastructures possess periodicities measuring from 140-2000 nm and are therefore capable of scattering visible light.

Optical modeling confirms that diffraction-related scattering mechanisms dominate the photonic properties of the fossil cover scales, which would have displayed broadband metallic hues as in numerous extant Micropterigidae.

The fossil tarachopteran scales exhibit a unique suite of characteristics, including small size, elongate-spatulate shape, ridged ornamentation and irregular arrangement, providing novel insight into the early evolution of lepidopteran scales. Combined, these new results provide the earliest evidence for structural coloration in fossil lepidopterans and support the hypothesis that fused wing scales and the type?1 bilayer covering are fundamental features of the group.

Wings and scales of Jurassic Lepidoptera and extant Micropterigidae  [Credit: ZHANG Qingqing et al.]

"These findings have broader implications," said Prof. WANG Bo from NIGP, the leader of the research group. The widespread occurrence of wing scales in Jurassic lepidopterans and in tarachopterans strongly suggests that wing scales (including some possibly unknown morphotypes) were widespread in stem Amphiesmenoptera prior to their apogee in the Lepidoptera.

Given the presence of structural coloration in these basal fossil lepidopterans, the advent of major lepidopteran clades by the Cretaceous raises the possibility that this taxonomic radiation may have been accompanied by increased diversity in scale shape, microstructure and optical effects.

Future studies will characterize the optical response of scale nanostructures in other fossil specimens and will provide evidence for the presence of scale pigments in fossil lepidopterans in order to inform models of the evolution of structural colors in lepidopterans.

Source: Chinese Academy of Sciences [April 11, 2018]