WFS

Formation of sedimentary layers of white clay, Tamilnadu, India

Fossil site for wood fossils, Tamilnadu, India

Fossil site in Kerala, India

Fossil wood park maintained by geological survey of India at Tamilnadu

Cretaceous fossil sites india

Fossils in rack:-Cyad

Fossils in rack:-echiniderms

Fossils in rack:-Rastellum sp

Pre-historic seabed, Cretaceous period

WFS News: Birds of a Feather: Neanderthal Exploitation of Raptors and Corvids

June 29th, 2018

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@WFS,World Fossil Society,Riffin T Sajeev,Russel T Sajeev

Birds of a Feather: Neanderthal Exploitation of Raptors and Corvids

Citation: Finlayson C, Brown K, Blasco R, Rosell J, Negro JJ, Bortolotti GR, et al. (2012) Birds of a Feather: Neanderthal Exploitation of Raptors and Corvids. PLoS ONE 7(9): e45927. https://doi.org/10.1371/journal.pone.0045927

Editor: Michael D. Petraglia, University of Oxford, United Kingdom

Examples of cut-marks from Gibraltar sites.
a) distal diaphysis of Pyrrhocorax pyrrhocorax humerus (Gor’96 No. 87); b) proximal diaphysis of Pyrrhocorax pyrrhocorax humerus; c) proximal diaphysis of Pyrrhocorax pyrrhocorax humerus (GOR’96 NO. 299); d) distal diaphysis of Milvus milvus radius (GOR’00/B8/NIV/205); e) middle shaft of Pyrrhocorax pyrrhocorax tarsometatarsus (Ibex 94 No. 24); f) middle shaft of Pyrrhocorax pyrrhocorax femur (Ibex 94 No. 166); g) proximal diaphysis of Pyrrhocorax graculus ulna (GOR’00/B5/NIV/57); h) distal diaphysis of Gyps fulvus ulna (Van 96 No. 209A).

The hypothesis that Neanderthals exploited birds for the use of their feathers or claws as personal ornaments in symbolic behaviour is revolutionary as it assigns unprecedented cognitive abilities to these hominins. This inference, however, is based on modest faunal samples and thus may not represent a regular or systematic behaviour. Here we address this issue by looking for evidence of such behaviour across a large temporal and geographical framework. Our analyses try to answer four main questions: 1) does a Neanderthal to raptor-corvid connection exist at a large scale, thus avoiding associations that might be regarded as local in space or time?; 2) did Middle (associated with Neanderthals) and Upper Palaeolithic (associated with modern humans) sites contain a greater range of these species than Late Pleistocene paleontological sites?; 3) is there a taphonomic association between Neanderthals and corvids-raptors at Middle Palaeolithic sites on Gibraltar, specifically Gorham’s, Vanguard and Ibex Caves? and; 4) was the extraction of wing feathers a local phenomenon exclusive to the Neanderthals at these sites or was it a geographically wider phenomenon?. We compiled a database of 1699 Pleistocene Palearctic sites based on fossil bird sites. We also compiled a taphonomical database from the Middle Palaeolithic assemblages of Gibraltar. We establish a clear, previously unknown and widespread, association between Neanderthals, raptors and corvids. We show that the association involved the direct intervention of Neanderthals on the bones of these birds, which we interpret as evidence of extraction of large flight feathers. The large number of bones, the variety of species processed and the different temporal periods when the behaviour is observed, indicate that this was a systematic, geographically and temporally broad, activity that the Neanderthals undertook. Our results, providing clear evidence that Neanderthal cognitive capacities were comparable to those of Modern Humans, constitute a major advance in the study of human evolution.

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WFS News: Fossils of Pufferfish species unearthed in Germany

June 28th, 2018

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@WFS,World Fossil Society,Riffin T Sajeev,Russel T Sajeev

Scientists in southern Germany have discovered the fossilized remains of a previously unknown pufferfish.

A team from the Bamberg Museum of Natural History made the find in a stone quarry in nearby Wattendorf.

Matthias Mäuser, the head of the museum, said the pufferfish lived around 150 million years ago.Similar to pufferfish living today, the fossilized remains showed that the fish had teeth.

The previously unknown pufferfish species lived around 150 million years ago. A number of interesting finds have been unearthed at the same stone quarry in northern Bavaria.

Scientists from the museum regularly excavate the Wattendorf stone quarry and have unearthed many interesting finds to date.In 2011, they discovered the remains of a previously unknown flying dinosaur species known as pterosaurs.

The pufferfish find will be on display at the Bamberg Museum of Natural History before being sent to the Institute of

Palaeontology at the University of Vienna for further research.

@WFS,World Fossil Society,Riffin T Sajeev,Russel T Sajeev

WFS News: New species of sponge-like fossil from the Cambrian Period

June 24th, 2018

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@WFS,World Fossil Society,Riffin T Sajeev,Russel T Sajeev

Scientists have discovered the fossil of an unusual large-bodied sponge-like sea-creature from half a billion years ago.

The creature belongs to an obscure and mysterious group of animals known as the chancelloriids, and scientists are unclear about where they fit in the tree of life.They represent a lineage of spiny tube-shaped animals that arose during the Cambrian evolutionary “explosion” but went extinct soon afterwards. In some ways they resemble sponges, a group of simple filter-feeding animals, but many scientists have dismissed the similarities as superficial.

The new discovery by a team of scientists from the University of Leicester, the University of Oxford and Yunnan University, China, adds new evidence that could help solve the mystery.

The new species of fossil chancelloriid: an enigmatic animal from the Cambrian Period with a tube-like body, ‘minotaur-horn’ spines, and doughnut-shaped scars.Credit: Derek Siveter/Tom Harvey/Peiyun Cong

The researchers have published their findings in the Royal Society journal Proceedings of the Royal Society B. The Leicester authors are Tom Harvey, Mark Williams, David Siveter & Sarah Gabbott.The new species, named Allonnia nuda, was discovered in the Chengjiang deposits of Yunnan Province, China. It was surprisingly large in life (perhaps up to 50 cm or more) but had only a few very tiny spines. Its unusual “naked” appearance suggests that further specimens may be “hiding in plain sight” in fossil collections, and shows that this group was more diverse than previously thought.

Furthermore, the new species holds clues about the pattern of body growth, with clear links to modern sponges. It is too soon to say the mystery has been solved, but the discovery highlights the central role of sponge-like fossils in the debate over earliest animal evolution.

Dr Tom Harvey, from the University of Leicester’s School of Geography, Geology and the Environment, explained: “Fossil chancelloriids were first described around 100 years ago, but have resisted attempts to place them in the tree of life. We argue that their pattern of body growth supports a link to sponges, reinvigorating an old hypothesis. We’re not suggesting that it’s “case closed” for chancelloriids, but we hope our results will inspire new research into the nature of the earliest animals.”

Dr Peiyun Cong, from the Yunnan Key Laboratory for Palaeobiology, Kunming, China, and The Natural History Museum, UK, added: “The Chengjiang deposits of Yunnan Province continue to reveal surprising new fossils we could hardly have imagined. Together, they provide a crucial snapshot of life in the oceans during the Cambrian explosion.”

Pei-Yun Cong, Thomas H. P. Harvey, Mark Williams, David J. Siveter, Derek J. Siveter, Sarah E. Gabbott, Yu-Jing Li, Fan Wei, Xian-Guang Hou. Naked chancelloriids from the lower Cambrian of China show evidence for sponge-type growth. Proceedings of the Royal Society B: Biological Sciences, 2018; 285 (1881): 20180296 DOI: 10.1098/rspb.2018.0296

University of Leicester. “Strange sponge-like fossil creature from half a billion years ago.” ScienceDaily. ScienceDaily, 19 June 2018. <www.sciencedaily.com/releases/2018/06/180619230853.htm>.

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WFS News: A new Miocene pinniped Allodesmus from Japan

June 21st, 2018

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@WFS,World Fossil Society,Riffin T Sajeev,Russel T Sajeev

A new Miocene pinniped Allodesmus (Mammalia: Carnivora) from Hokkaido, northern Japan

Wataru Tonomori, , ,

Published 16 May 2018.DOI: 10.1098/rsos.172440

Reconstruction of Allodesmus skeleton. Blue parts indicate preserved bones of the holotype (AMP 25) of Allodesmus uraiporensis.

A nearly complete pinniped skeleton from the middle Miocene Okoppezawa Formation (ca 16.3–13.9 Ma), Hokkaido, northern Japan, is described as the holotype of Allodesmus uraiporensis sp. nov. The new species is distinguishable from other species of the genus by having the palatine fissure (incisive foramen) that is located anterior to the canine, an anteriorly located supraorbital process of the frontal, and by having the calcaneum with a developed peroneal tubercle. Our phylogenetic analysis suggests that the subfamily Allodesminae are represented by two genera, Atopotarus and Allodesmus, and the latter genus is represented by at least six species; Al. kernensis, Al. sinanoensis, Al. naorai, Al. packardi, Al. demerei and Al. uraiporensis sp. nov. Allodesmus uraiporensis sp. nov. is one of the oldest and the northernmost record of the genus in the western North Pacific, and it suggests that the diversification of the genus in the western North Pacific was synchronous to the time of their diversification in the eastern North Pacific.

Reconstruction of skull of the holotype (AMP 25) of Allodesmus uraiporensis. (a) dorsal, (b) ventral and (c) lateral views. Solid lines indicate those elements that are preserved on at least one side of the holotype, and other missing parts are represented by dashed lines.

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WFS News:Fossil Anemone Tracks Don’t Fit Evolution

June 18th, 2018

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@WFS,World Fossil Society,Riffin T Sajeev,Russel T Sajeev

Fossil Anemone Tracks Don’t Fit Evolution

Interesting markings were recently found on a rock in Newfoundland. A study concluded that they were trails left by seafloor-dwelling animals around 565 million years ago. But such a find is difficult to reconcile with the evolutionary teaching that muscles, and therefore animal locomotion, did not evolve until much later.

Before they could suggest that evolutionary history ought to be rewritten on this point, researchers first had to be quite certain that they were looking at some kind of animal track. They found over 70 tracks up to 13mm wide and 17cm long. At the end of some of the marks in siltstone was a circular kind of “footprint.” The traces cannot be scratch marks, because they show curves and “directional changes.”¹ Does any living animal make similar markings on today’s seafloors?

Fossil Anemone Tracks Don’t Fit Evolution

In their study published in the Geological Society of America’s journal Geology, British and Canadian paleontologists determined that the tracks were comparable to those made by certain modern sea anemones. They wrote, “Anemones are capable of crawling across sediment and can exhibit swimming and burrowing behavior.”¹ And anemones have a tubular body plan, which is consistent with the creature that made these tracks.

If correct, this extends muscular animal locomotion “five million years earlier”¹ than previous evolutionary thinking had held. Fossil finds consistently cause a rewriting of evolutionary history. There are often as many versions of it as there are scientists looking into the relevant fossils.

For example, a recent find of tracks made by a four-legged creature in Poland demonstrated that animals with fully operable legs were walking long before their supposed ancestors, such as Tiktaalik, “emerged.”² That highly debated fossil was initially hailed as one of the earliest creatures to make the evolutionary transition from water to land. Although the Polish tracks should erase Tiktaalik’s transitional status, the removal of its accompanying story from textbooks and museums promises to be painstakingly slow.

The Geology study’s authors concluded their report on the Newfoundland tracks with, “We consider that these impressions are consistent with locomotion traces produced by a cnidarian-like organism.”¹ Cnidarians are animals that include jellyfish and sea anemones. But how cnidarian-like was it? Since it was presumably able to live, reproduce, consume, metabolize, and move around enough to leave behind a trail, there is no empirical reason to believe that it was anything less than a real and complete sea anemone, perhaps like those living today.

If so, sea anemones may take the prize for the most stable animal life form over the longest evolutionary period of time. Though a body fossil found nearby―either horizontally or below―would provide higher quality evidence that these tracks were indeed made by sea anemones, the evidence at present is convincing.

That would mean that not only do anemones appear suddenly and fully formed in the fossil record, but they were able to leave behind prints of their characteristic circular footpad and have retained the same form since. The anemone has therefore not evolved significantly in “565 million years,” a wildly unlikely assertion in the context of macroevolution.³

The evidence may not fit the evolutionary story, but it does not conflict with biblical history. Ediacaran deposits like the one the tracks were found in can be thought of as remains from the pre-Flood ocean floor. Though in many places it would have been ripped up, reworked, and re-deposited by the great Flood, it appears that some of it was covered over and preserved by flood-borne sediments. Most often, this material lies far beneath vast fossil-bearing flood deposits, but it crops up in a few places around the globe.

In any case, the animal that made these tracks definitely had the ability to move. And moving animals today must use a fully intact suite of precisely specified muscle proteins, including actin, myosin, and a host of supporting enzymes for construction and operation. In jellyfish, which are often transparent, there are no muscle cells. They do have, however, the same muscle proteins as muscle cells have, although the protein suite resides in their skin cells.

Interdependent, complicated systems like these never spontaneously “emerge.” They are always intentionally constructed. And sea anemones, if they are indeed responsible for these tracks, were apparently constructed correctly from the start of creation only thousands, not billions, of years ago.⁴

References

Liu, A. G., D. McIlroy, D. and M. Brasier. 2010. First evidence for locomotion in the Ediacara biota from the 565 Ma Mistaken Point Formation, Newfoundland. Geology. 38 (2): 123-126.
Sherwin, F. Banner Fossil for Evolution Is Demoted. ICR News. Posted on icr.org January 27, 2010, accessed February 18, 2010.
The same problem is evident with the damselfly and other living fossils. See Thomas, B. New Population Found of Damselfly ‘Living Fossil.’ ICR News. Posted on icr.org January 19, 2010, accessed February 19, 2010.
DeYoung, D. 2005. Thousands, Not Billions. Green Forest, AR: Master Books.

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WFS News: Prehistoric frog in 99-million-year-old amber

June 16th, 2018

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@WFS,World Fossil Society,Riffin T Sajeev,Russel T Sajeev

In the film Jurassic Park, dinosaur DNA is extracted from mosquitoes which had been preserved in amber.

Now, scientists have discovered an amber fossil of a juvenile frog in present-day Myanmar dating back about 99 million years.Although the species is extinct, it has now been named Electrorana limoae and is one of four fossils that proves ancient frogs lived in wet tropical forests.

“It’s almost unheard of to get a fossil frog from this time period that is small, has preservation of small bones and is mostly three-dimensional. This is pretty special,” said Dr David Blackburn.

The best-preserved fossil of the group is of Electrorana limoae. Pic: Lida Xing/University of Geosciences

Dr Blackburn, who is the study’s co-author and the associate curator of herpetology at the Florida Museum of Natural History, added: “But what’s most exciting about this animal is its context.

“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.”

The findings and species description have been published in Nature’s Scientific Reports, alongside a CT scan of the amber fossil.They state that while frogs have been around for at least 200 million years, it’s difficult to know what their early evolutionary forms were like because their fossils do not tend to be well preserved.This means that the fossil record for frogs is skewed towards more robust species which live in arid and seasonal environments, despite the bulk of today’s frog species living in tropical forests.

“Ask any kid what lives in a rainforest, and frogs are on the list,” said Dr Blackburn, “but surprisingly, we have almost nothing from the fossil record to say that’s a longstanding association.”

Fortunately the amber deposits of northern Myanmar in southeast Asia provide a rare glimpse into the ecosystems of ancient forests.

Scientists have found fossil evidence of mosses as well as bamboo-like plants, and more complicated life including aquatic spiders and velvet worms in the amber.Electrorana and the other fossils are the first frogs to be recovered from these deposits and show how frogs inhabited wet, tropical forests during the Cretaceous period.

Although less than an inch long, Electrorana is the most well-preserved of this group of fossils.The frog’s skull is clearly visible through the amber, as are its forelimbs and part of its backbone, as well as a partial hind limb and the unidentified beetle.

But the fossil of the frog raises more questions than it answers, said Dr Blackburn.

Many of the characteristics which herpetologists use to analyse a frog’s evolutionary and life history – the wrist bones, the pelvis, hip bones, the inner ear, and the top of the backbone – are either missing from the fossil or were not yet fully developed in the juvenile frog.

Although the bones that the team are able to see do provide some clues about Electrorana’s possible living relatives, the results are puzzling.Dr Blackburn said that species which have similar features include fire-bellied toads and midwife toads – Eurasian species that live in temperate and not tropical ecosystems.

Gathering CT skeletal data for both living and extinct frogs, one of Dr Blackburn’s long-term projects, is intended to reveal their ancient evolutionary relationships.

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WFS News: A new therocephalian from Russia

June 13th, 2018

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A new therocephalian (Gorynychus masyutinae gen. et sp. nov.) from the Permian Kotelnich locality, Kirov Region, Russia

Kammerer CF, Masyutin V. (2018) A new therocephalian (Gorynychus masyutinae gen. et sp. nov.) from the Permian Kotelnich locality, Kirov Region, Russia. PeerJ 6:e4933https://doi.org/10.7717/peerj.4933

A new therocephalian taxon (Gorynychus masyutinae gen. et sp. nov.) is described based on a nearly complete skull and partial postcranium from the Permian Kotelnich locality of Russia. Gorynychus displays an unusual mixture of primitive (“pristerosaurian”) and derived (eutherocephalian) characters. Primitive features of Gorynychus include extensive dentition on the palatal boss and transverse process of the pterygoid, paired vomers, and a prominent dentary angle; derived features include the absence of the postfrontal. Gorynychus can be distinguished from all other therocephalians by its autapomorphic dental morphology, with roughly denticulated incisors and postcanines. Phylogenetic analysis recovers Gorynychus as a non-lycosuchid, non-scylacosaurid therocephalian situated as sister-taxon to Eutherocephalia. The identification of Gorynychus as the largest predator from Kotelnich indicates that therocephalians acted as apex predators in middle–late Permian transition ecosystems in Russia, corroborating a pattern observed in South African faunas. However, other aspects of the Kotelnich fauna, and Permian Russian tetrapod faunas in general, differ markedly from those of South Africa and suggest that Karoo faunas are not necessarily representative of global patterns.

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Holotype of Gorynychus masyutinae.

Recent expeditions by the Vyatka Paleontological Museum have collected a wealth of spectacularly-preserved Permian fossils near the town of Kotelnich along the Vyatka River in European Russia. These fossil discoveries include the remains of two previously unknown species of predatory protomammals, newly described in the journal PeerJ by Christian Kammerer of the North Carolina Museum of Natural Sciences and Vladimir Masyutin of the Vyatka Paleontological Museum. The first of the two new species, Gorynychus masyutinae, was a wolf-sized carnivore representing the largest predator in the Kotelnich fauna. The second new species, Nochnitsa geminidens, was a smaller, long-snouted carnivore with needle-like teeth. Gorynychus belongs to a subgroup of protomammals called therocephalians (“beast heads”), whereas Nochnitsa belongs to a different subgroup called gorgonopsians (“gorgon faces”).

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Anterior snout and dentition of Gorynychus masyutinae.
(A) Photograph and (B) interpretive drawing of the skull (KPM 346) in anterior view. (C) Disarticulated incisor (KPM 348) associated with skull in presumed anterior or anterolateral view. Abbreviations: apc, anterior premaxillary channel; mx, maxilla; na, nasal; nr, naris; pmx, premaxilla; smx, septomaxilla. Gray coloration indicates matrix. Scale bars equal 1 cm. Photographs and drawing by Christian F. Kammerer.

Both new species are named after legendary monsters from Russian folklore, befitting their menacing appearances. Gorynychus is named after Zmey Gorynych, a three-headed dragon, and Nochnitsa is named after a malevolent nocturnal spirit. (Based on their relatively large eye sockets, it is likely that Nochnitsa and its relatives were nocturnal.)

Gorynychus and Nochnitsa improve scientists’ understanding of ecosystem reorganization after the mid-Permian extinction (260 mya). Although not as well-known as the more devastating end-Permian mass extinction (252 mya, which nearly wiped out protomammals), the mid-Permian mass extinction also played a major role in shaping the course of protomammal evolution. In typical late Permian ecosystems, the top predators were giant (tiger-sized), saber-toothed gorgonopsians and therocephalians were generally small insectivores. In mid-Permian ecosystems, by contrast, these roles are reversed. At Kotelnich, the saber-toothed top predator Gorynychus is a therocephalian and the only gorgonopsians are much smaller animals.

“In between these extinctions, there was a complete flip-flop in what roles these carnivores were playing in their ecosystems — as if bears suddenly became weasel-sized and weasels became bear-sized in their place,” says Kammerer. The new species from Russia provide the first evidence that there was a worldwide turnover in predators after the mid-Permian extinction, and not just a localized turnover in South Africa.

Kammerer adds, “Kotelnich is one of the most important localities worldwide for finding therapsid fossils — not only because they are amazingly complete and well-preserved there, but also because they provide an all-too-rare window into mammal ancestry in the Northern Hemisphere during the Permian.”

@ WFS,World Fosssil Society,Riffin T Sajeev,Russel T Sajeev

WFS News: First seismic evidence for mantle exhumation at an ultraslow-spreading center

June 10th, 2018

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@WFS,World Fossil Society,Riffin T Sajeev,Russel T Sajeev

Episodic magmatism and serpentinized mantle exhumation at an ultraslow-spreading centre

A mountain range with a total length of 65,000 kilometers runs through all the oceans. It marks the boundaries of tectonic plates. Through the gap between the plates material from the Earth’s interior emerges, forming new seafloor, building up the submarine mountains and spreading the plates apart. Very often, these mid-ocean ridges are described as a huge, elongated volcano. But this image is only partly correct, because the material forming the new seafloor is not always magmatic. At some spreading centres material from the Earth’s mantle reaches the surface without being melted. The proportion of seabed formed this has been previously unknown.

This is the area of investigation at the Cayman Trough in the Caribbean.
Credit: Ingo Grevemeyer/GEOMAR

Scientists from the Universities of Kiel (Germany), Austin (Texas, USA) and Durham (Great Britain) have now published data in the international journal Nature Geoscience that, for the first time, allow a detailed estimation on how much seafloor is formed by mantle material without magmatic processes. “This phenomenon occurs especially where the seabed spreads at paces of less than two centimeters per year,” explains Prof. Dr. Ingo Grevemeyer from the GEOMAR Helmholtz Centre for Ocean Research Kiel, lead author of the study.

One of these zones is located in the Cayman Trough south of the island of Grand Cayman in the Caribbean. In 2015, the researchers used the German research vessel METEOR to investigate the seafloor seismically, i.e. by using sound waves. Sound signals sent through different rocks or sediment layers, are being reflected and refracted in different ways by each layer. Rock, which has been melted and solidified on the seabed, has a different signature in the seismic signal than rock from the Earth’s mantle, which has not been melted.

But scientists had a problem so far: The contact with the seawater changes the mantle rocks. “After this process called serpentinisation mantle rocks are barely distinguishable from magmatic rocks in seismic data,” says Professor Grevemeyer. Until now, mantle rock on the seabed could only be detected by taking samples directly from the seafloor and analyzing them in the laboratory. “But that way you only get information about a tiny spot. A large-scale or even in-depth information on the composition of the seabed cannot be achieved,” says Grevemeyer.

However, during the expedition in 2015, the team not only used the energy of ordinary sound waves — it also detected so-called shear waves, which occur only in solid materials. They could be recorded very clearly thanks to a clever selection of measuring points.

From the ratio of the speed of both types of waves, the scientists were able to differentiate mantle material from magmatic material. “So we could prove for the first time with seismic methods that up to 25 percent of the young ocean floor is not magmatic at the ultra-slow spreading centre in the Cayman trough,” says Ingo Grevemeyer.

Since there are similar spreading centres in other regions, such as the Arctic or Indian Ocean, these results are of great importance for the general idea about the global composition of the seabed. “This is relevant, if we want to create global models on the interactions between seabed and seawater or on processes of plate tectonics,” summarizes Professor Grevemeyer.

Ingo Grevemeyer, Nicholas W. Hayman, Christine Peirce, Michaela Schwardt, Harm J. A. Van Avendonk, Anke Dannowski, Cord Papenberg. Episodic magmatism and serpentinized mantle exhumation at an ultraslow-spreading centre. Nature Geoscience, 2018; DOI: 10.1038/s41561-018-0124-6

Helmholtz Centre for Ocean Research Kiel (GEOMAR). “Cold production of new seafloor: First seismic evidence for mantle exhumation at an ultraslow-spreading center.” ScienceDaily. ScienceDaily, 24 May 2018. <www.sciencedaily.com/releases/2018/05/180524112401.htm>

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WFS News: A new insight into the mechanism of biosilicification

June 9th, 2018

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@WFS,World Fossil Society,Riffin T Sajeev,Russel T Sajeev

Formation of Asymmetrical Structured Silica Controlled by
a Phase Separation Process and Implication for Biosilicification

Citation: Shi J-Y, Yao Q-Z, Li X-M, Zhou G-T, Fu S-Q (2013) Formation of Asymmetrical Structured Silica Controlled by a Phase Separation Process and Implication for Biosilicification. PLoS ONE 8(4): e61164. https://doi.org/10.1371/journal.pone.0061164

Editor: Vipul Bansal, RMIT University, Australia

Biogenetic silica displays intricate patterns assembling from nano- to microsize level and interesting non-spherical structures differentiating in specific directions. Several model systems have been proposed to explain the formation of biosilica nanostructures. Of them, phase separation based on the physicochemical properties of organic amines was considered to be responsible for the pattern formation of biosilica. In this paper, using tetraethyl orthosilicate (TEOS, Si(OCH₂CH₃)₄) as silica precursor, phospholipid (PL) and dodecylamine (DA) were introduced to initiate phase separation of organic components and influence silica precipitation. Morphology, structure and composition of the mineralized products were characterized using a range of techniques including field emission scanning electron microscopy (FESEM), transmission electron microscope (TEM), X-ray diffraction (XRD), thermogravimetric and differential thermal analysis (TG-DTA), infrared spectra (IR), and nitrogen physisorption. The results demonstrate that the phase separation process of the organic components leads to the formation of asymmetrically non-spherical silica structures, and the aspect ratios of the asymmetrical structures can be well controlled by varying the concentration of PL and DA. On the basis of the time-dependent experiments, a tentative mechanism is also proposed to illustrate the asymmetrical morphogenesis. Therefore, our results imply that in addition to explaining the hierarchical porous nanopatterning of biosilica, the phase separation process may also be responsible for the growth differentiation of siliceous structures in specific directions. Because organic amine (e.g., long-chair polyamines), phospholipids (e.g., silicalemma) and the phase separation process are associated with the biosilicification of diatoms, our results may provide a new insight into the mechanism of biosilicification.

SEM images of discus-like silica particles (sample L5): low magnification (a), the side- (b) and front-view (c) observations of individual particles.

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WFS News: Study On prehistoric diets

June 8th, 2018

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@WFS,World Fossil Society,Riffin T Sajeev,Russel T Sajeev

Whenever we think about extinct animals we often imagine them eating their favourite meals, whether it be plants, other animals or a combination of both.

But are our ideas about extinct diets grounded within scientific reasoning, or are they actually little more than conjecture and speculation?

New research, published in Biological Reviews and led by a team of palaeobiologists from the University of Leicester, has revealed that the diets of pterosaurs are largely based on ideas that have been uncritically accepted for decades, or even centuries — and may often be wrong.The study shows that one group of extinct animals where our dietary knowledge is lacking are the pterosaurs; extinct flying reptiles who lived in the Mesozoic Period 215-66 million years ago.

Restoration of the giant azhdarchid pterosaur Hatzegopteryx catching an unsuspecting dinosaur for supper. In addition to carnivory, azhdarchids have been hypothesized to have eaten fish, insects, fruits, hard-shelled organisms or a combination of them all.Credit: Mark P. Witton/CC BY 4.0

The research involved a comprehensive analysis of the scientific literature, summarising over 300 statements from 126 studies about the diets of pterosaurs, and the types of evidence used to support ideas of what they ate.

The research shows the vast majority of ideas about pterosaur diet are based on inferences drawn from modern organisms and/or the environments in which pterosaur fossils are preserved. These are not always reliable.

Jordan Bestwick, a PhD student from the School of Geography, Geology and the Environment, and lead author of the study, said: “Working out the diets of extinct animals is vitally important for understanding how they fitted within their respective ecosystems, which can tell us about how present ecosystems function and may change in the future.

“Being able to robustly test ideas is a key attribute of the scientific process, and helps us fully understand what we can know about the lifestyles of extinct animals, and what we can never know.”

Analysis reveals that over sixty percent of all hypotheses of pterosaur diet are based on simplistic anatomical comparisons between pterosaurs and modern organisms, particularly of the skulls and teeth. A key problem with this is that many of these interpretations are difficult, if not impossible, to test.

Jordan explained: “The potential range of pterosaur diets has been reviewed in the past but little attention has been paid to the evidence, if any, that support dietary interpretations. We realised that not only was it important to discover what we know about pterosaur diets, but to also find out how we know what we know about pterosaur diets.

“We find for some pterosaurs there is strong agreement among researchers as to their likely diet. Pteranodontids for example, which include one of the best known pterosaurs, Pteranodon, are almost unanimously agreed to have been fish feeders, an idea that is independently supported by multiple lines of evidence.

“In contrast, there is far less agreement as to what the giant azhdarchid pterosaurs ate. Azhdarchids can reach sizes of up to 10 metres or more in wingspan, like Hatzegopteryx, and there have been at least six different diets argued for these pterosaurs.”

This is not to say there are no methods or techniques that yield reliable evidence for understanding diets in these extinct animals. Biomechanical analysis of how hard pterosaurs could bite, and flight modelling that predicts how pterosaurs may have foraged for food have proven useful for understanding what some pterosaurs may or may not have eaten.

However techniques like these are employed in a small minority of studies and as such, it is currently not possible to identify the biological reasons that might explain the range and diversity of pterosaurs diets.

Dr David Hone from the Queen Mary University of London, who was not involved in the study, commented: “This is an important summary of what we know (and what we don’t) about what these animals fed on. This gives pterosaur researchers an excellent and critical starting point and a roadmap for future research on the diets of pterosaurs, and more broadly for all extinct animals.”

Jordan Bestwick, David M. Unwin, Richard J. Butler, Donald M. Henderson, Mark A. Purnell. Pterosaur dietary hypotheses: a review of ideas and approaches. Biological Reviews, 2018; DOI: 10.1111/brv.12431

University of Leicester. “Jurassic diet: Why our knowledge of what ancient pterosaurs ate might be wrong: Research reveals knowledge of prehistoric diets is often based on outdated ideas and could be inaccurate.” ScienceDaily. ScienceDaily, 7 June 2018. <www.sciencedaily.com/releases/2018/06/180607112805.htm>.

@WFS,World Fossil Society,Riffin T Sajeev,Russel T Sajeev