WFS News: An Extraordinary Gobioid Fish Fossil from Southern France

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

An Extraordinary Gobioid Fish Fossil from Southern France

Abstract

Background

The classification of gobioid fishes is still under discussion. Several lineages, including the Eleotridae and Butidae, remain difficult to characterize because synapomorphies are rare (Eleotridae) or have not yet been determined (Butidae). Moreover, the fossil record of these groups is scarce.

Results

Exceptionally well-preserved fish fossils with otoliths in situ from uppermost Oligocene sediments (≈23–24 Mio. y. ago) in Southern France provide the most in-depth description of a fossil gobioid to date. The species was initially described as Cottus aries Agassiz, then transferred to †Lepidocottus Sauvage, and subsequently assigned to Gobius. Based on a comparative analysis of meristic, osteological and otolith data, this species most likely is a member of the family Butidae. This discovery is important because it represents the first record of a fossil butid fish based on articulated skeletons from Europe.

Significance

The Butidae and Eleotridae are currently distributed in W-Africa, Madagascar, Asia and Australia, but they do not appear in Europe and also not in the Mediterranean Sea. The new results indicate that several species of the Butidae thrived in Europe during the Oligocene and Early Miocene. Similar to the recent Butidae and Eleotridae, these fishes were adapted to a wide range of salinities and thrived in freshwater, brackish and marginal marine habitats. The fossil Butidae disappeared from Europe and the Mediterranean and Paratethys areas during the Early Miocene, due probably to their lack of competitiveness compared to other Gobioidei that radiated during this period of time. In addition, this study documents the great value of otoliths for gobioid systematics.

Osteology, scales and otolith of †Lepidocottus aries (Agassiz). A: Specimen MC-P-2011-01-TF1. B: Specimen MC-P-2011-01-TF2. A1. General overview. Head displays right premaxilla (Pmx) and frontal (Fr) in lateral view, and several bones from the left head side in medial view (dentary (Dent), quadrate (Q), anterior ceratohyal (Chy), posterior ceratohyal (epihyal, Ehy)). The elongate parasphenoid (Psph) is also visible. The girdle exposes both pelvic fins (Pelv), the left supracleithrum (SCl), and imprints of the left pectoralis (Pect) and the uppermost part of the left cleithrum (Cl). The predorsal scales (PrSc) are well preserved. A2. Close-up of right premaxilla (isolated from skeleton) showing alveoles for the teeth and a complete processus articularis.

Osteology, scales and otolith of †Lepidocottus aries (Agassiz).
A: Specimen MC-P-2011-01-TF1. B: Specimen MC-P-2011-01-TF2. A1. General overview. Head displays right premaxilla (Pmx) and frontal (Fr) in lateral view, and several bones from the left head side in medial view (dentary (Dent), quadrate (Q), anterior ceratohyal (Chy), posterior ceratohyal (epihyal, Ehy)). The elongate parasphenoid (Psph) is also visible. The girdle exposes both pelvic fins (Pelv), the left supracleithrum (SCl), and imprints of the left pectoralis (Pect) and the uppermost part of the left cleithrum (Cl). The predorsal scales (PrSc) are well preserved. A2. Close-up of right premaxilla (isolated from skeleton) showing alveoles for the teeth and a complete processus articularis.

Citation: Gierl C, Reichenbacher B, Gaudant J, Erpenbeck D, Pharisat A (2013) An Extraordinary Gobioid Fish Fossil from Southern France. PLoS ONE 8(5): e64117. https://doi.org/10.1371/journal.pone.0064117

Editor: Laurent Viriot, Team ‘Evo-Devo of Vertebrate Dentition’, France

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

WFS News: A Time-Lapse Bathymetry Study of the Kick-‘em-Jenny Volcano

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

Researchers got a rare opportunity to study an underwater volcano in the Caribbean when it erupted while they were surveying the area.

The research, published today in the journal Geochemistry, Geophysics, Geosystems, provides new insight into the little-studied world of underwater volcanoes. It investigated a volcano named Kick-’em-Jenny (KeJ), which is thought to be named after the turbulent waters nearby.

The team from Imperial College London, Southampton and Liverpool universities, in collaboration with The University of the West Indies Seismic Research Centre (SRC), were collecting ocean-bottom seismometers aboard the NERC research ship R.R.S. James Cook as part of a larger experiment when they were alerted to the volcano erupting.

Direct observation of submarine eruptions are very rare, but having the ship nearby allowed them to get to the volcano in time to record the immediate aftermath of the eruption.

Underwater bathymetric view with gas venting captured in April 2017. Credit: Imperial College London

Underwater bathymetric view with gas venting captured in April 2017.                                                                        Credit: Imperial College London

Using ship-based imaging technology, the team was able to survey the volcano, observing gas coming from the central cone. The data was then combined with previous surveys going back more than 30 years to reveal the long-term pattern of activity.

Kick-’em-Jenny is one of the Caribbean’s most active volcanoes. It sits eight kilometres off the northern coast of the island of Grenada, and was first discovered in 1939 when a 300-metre column of ash and dust was spotted rising from the ocean.

However, volcanic activity at KeJ is usually detected by accompanying seismic activity picked up on land-based seismometers. These recordings show that the volcano is active on a decadal timescale.

Lead author PhD student Robert Allen, from the Department of Earth Science & Engineering at Imperial, said: “There are surveys of the Kick-’em-Jenny area going back 30 years, but our survey in April 2017 is unique in that it immediately followed an eruption. This gave us unprecedented data on what this volcanic activity actually looks like, rather than relying on interpreting seismic signals.”

The team found that the volcano has frequent cycles of lava ‘dome’ growth followed by collapse through landslides. Similar cycles have been recently witnessed on the nearby volcanic island of Montserrat.

Co-author Dr Jenny Collier, from the Department of Earth Science & Engineering at Imperial, said: “Kick-’em-Jenny is a very active volcano but because it is submarine is less well studied than other volcanoes in the Caribbean. Our research shows that whilst it has quite regular cycles, it is on a relatively small scale, which will help inform future monitoring strategies.”

SRC Director Professor Richard Robertson said: “This study has confirmed very useful recent insights on the activity and evolution of Kick-’em-Jenny volcano. For us, the agency with responsibility for monitoring this volcano, the results of this collaborative research project enable us to better quantify our existing model of this volcano and help in developing strategies for managing future eruptions.”

Any volcano on land which was as lively as KeJ would be constantly monitored by satellites and an array of local instruments looking for the slightest change in behaviour that could precede a major volcanic eruption.

Under the ocean this job is much more difficult, as the electromagnetic energy emitted by satellites cannot penetrate the sea surface and instruments are much more difficult to set up on the volcano itself. Scientists therefore know comparatively little about the growth and long-term behaviour of a fully submerged volcanic cone like KeJ.

The most famous submarine volcanoes are those that lead to the formation of new islands, such as the eruption of Surtsey in Iceland in the 1960s. However, rather than a growing cone, the surveys show significant mass loss from KeJ due to frequent landslides in recent decades.

Comparison with recent studies elsewhere has shown that similar, frequent, small volume landslides may be a fundamental mechanism in the long-term evolution of active submarine volcanoes.

  1. R. W. Allen, C. Berry, T. J. Henstock, J. S. Collier, F. J-Y. Dondin, A. Rietbrock, J. L. Latchman, R. E. A. Robertson. 30 Years in the Life of an Active Submarine Volcano: A Time-Lapse Bathymetry Study of the Kick-‘em-Jenny Volcano, Lesser AntillesGeochemistry, Geophysics, Geosystems, 2018; DOI: 10.1002/2017GC007270
Imperial College London. “Underwater volcano behavior captured by timely scientific expedition.” ScienceDaily. ScienceDaily, 14 March 2018. <www.sciencedaily.com/releases/2018/03/180314102021.htm>.

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

WFS News: Correlative microscopy of the constituents of a dinosaur rib fossil and hosting mudstone: Implications on diagenesis and fossil preservation

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

Citation: Kim J-K, Kwon Y-E, Lee S-G, Kim C-Y, Kim J-G, Huh M, et al. (2017) Correlative microscopy of the constituents of a dinosaur rib fossil and hosting mudstone: Implications on diagenesis and fossil preservation. PLoS ONE 12(10): e0186600. https://doi.org/10.1371/journal.pone.0186600

Editor: Dong Hoon Shin, Seoul National University College of Medicine, REPUBLIC OF KOREA

The Boseong fossil site is a rich Upper Cretaceous fossil site from South Korea based on the discovery of abundant dinosaur eggs and egg clutches [13], post-cranial skeletal remains of the small basal ornithopod Koreanosaurus boseongenesis [4], and partial skeletal remains of the large anguimorph lizard Asprosaurus bibongriensis [5]. While it has been presumed that rapid burial took a key role in preserving the fossils from the local region based on large-scale depositional features [2], deeper insights in specific factors that may have contributed to bone preservation has not been thoroughly explored. Analytical studies on both skeletal fossil material and the hosting geological matrix provide insights into the interaction and relationship of composing elements [6,7]. Chemical analysis on a microscopic scale of fossil bone allows further evaluation of elements that have native and/or external origins [712]. Although the general nanostructure of fossilized bone can be investigated through novel X-ray techniques [13], transmission electron microscopy (TEM) analysis directly provides information on the morphology, arrangement, and chemistry of fossil apatite nanocrystals [9,1418]. Such data are crucial for understanding how these apatitic crystalline phases have originated and also how the bone structure was maintained during fossilization. It should be noted that TEM data is based on an extremely small and localized scale, and such shortcomings of TEM investigation can be mitigated through correlative microscopy [1719]. We have previously investigated structural and chemical features at micro- to nanoscale of a dorsal rib portion from Koreanosaurus [17] obtained from the holotype specimen (referred to as KDRC-BB2: Korea Dinosaur Research Center-Boseong Bibong 2) which consist mainly the “torso” region discovered in an articulated state in a large mudstone block that may have originated directly from the main outcrop of Site 5 [4]. In this study, the distal region of a fully preserved seventh left dorsal rib bone was obtained from KDRC-BB2, and we have specifically selected it based on the following reasons; i) information on exact original position, ii) simple morphology, and iii) intact hosting mudstone (S1 Fig).

The section was divided into three regions–hosting mudstone (yellow arrow), boundary (red arrow), and rib bone (blue arrow). Clusters of calcite microcrystals can be directly observed in all regions. The mudstone and boundary region primarily contains detrital clasts of quartz and feldspars. Due to the compressed nature of the bone matrix, specific osteohistological features were not discernible from the rib bone besides the vascularization pattern.

The section was divided into three regions–hosting mudstone (yellow arrow), boundary (red arrow), and rib bone (blue arrow). Clusters of calcite microcrystals can be directly observed in all regions. The mudstone and boundary region primarily contains detrital clasts of quartz and feldspars. Due to the compressed nature of the bone matrix, specific osteohistological features were not discernible from the rib bone besides the vascularization pattern.

Here, through correlative microscopy techniques, we aimed to investigate the microstructure and chemistry of key constituting phases of the fossil rib bone, hosting mudstone, and the boundary in-between. We evaluated the distribution and interaction of the key phases between these regions with focus on unraveling features involved in diagenesis and bone preservation. The frequent occurrence of “platy phases” within the rib bone matrix from our initial study was a compelling feature [17], and we intended to fully reveal the identity and origin of these phases and their presumed role in bone preservation. These phases may have affected the arrangement of apatite crystals from the rib bone, and without TEM investigation, such assumptions cannot be thoroughly assessed. Although our research sample represents only a small fraction of the entire skeletal fossil and fossil site, the preservation of the brittle and highly porous dorsal rib bones of Koreanosaurus was intriguing. We also considered it as an ideal research material without inflicting considerable damage to the holotype specimen. Due to the small size and fractured state of the rib bones, correlating microstructural and nanostructural preservation of osteohistological features were mainly performed on the larger and more intact femoral bones from the paratype specimens [4,18].

Correlative microscopy is a technique for performing progressive structure and chemical analyses on specimens from macro- to nanoscale and involves the use of optical and electron microscopes. The key importance of this technique is that a specific region of interest observed from the optical thin section should be reexamined in detail by electron microscopes in higher resolution. A crucial step in correlative microscopy is the use of proper and effective sample preparation methods for the corresponding analytical procedures. Typically, two types of samples—optical thin sections and nanopowders—are prepared directly from the bulk specimen. As conventional powder preparation methods result in an inevitable loss of spatial information, in this study we employed an ultrasonic drilling device (S2A Fig) which allowed us to acquire very small amounts of powders (in ng range) from predetermined specific regions either from the bulk specimen or optical thin section. We also designed an ultrasonic spraying device (S2B Fig) that is capable of dispersing powder samples on a TEM grid via a masking tool. This device is derived from a previously developed multi-sample loading device by our research team [20], which can load up to four samples on a single TEM grid using more conventional methods. We also utilized half-masking techniques on TEM grids by coating Au nanoparticles as a standard on half of the grid. For acquiring TEM samples from optical thin sections, we employed focused ion beam (FIB) milling. The biggest advantages are its precision and capability in preparing TEM samples from various directions [21]. The following methods were used in this study. 1) Initially, we used a stereoscopic zoom microscope to observe the bulk sample before carrying out specific preparation procedures. We also used the microscope to evaluate the overall sample quality after preparation using reflected light. 2) We used a polarizing optical microscope to identify mineral constituents of the hosting mudstone, and to discern the microstructural features of the rib bone. 3) We carried out initial phase identification by X-ray diffraction (XRD) analysis on both the optical thin sections and powder samples. 4) An electron probe microanalyzer (EPMA) equipped with wavelength dispersive spectroscopy (WDS) was primarily used for chemical mapping of optical thin sections to characterize the distribution of distinctive and common elements from the rib bone, hosting mudstone, and boundary region. 5) Scanning electron microscopy (SEM) imaging and chemical analysis with energy dispersive spectroscopy (EDS) was performed for investigating microstructures and elemental distributions from both thin sections and powder samples in general, and for characterizing the constituting phases. 6) We used TEM as the main technique for evaluating the specific structure and chemistry of the identified phases. For electron crystallographic analysis, we obtained and analyzed selected area electron diffraction (SAED) patterns and high-resolution TEM (HRTEM) images along with corresponding fast Fourier transform (FFT) data. We mainly carried out TEM–EDS analysis to identify the distribution of specific clay phases from the FIB-milled samples. All microscopes were equipped with charge-coupled device (CCD) cameras, and we captured and stored the micrographs directly using the respective software of each CCD camera.

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

 

WFS News: Patterns of divergence in the morphology of ceratopsian dinosaurs: sympatry is not a driver of ornament evolution

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

The elaborate frills and horns of a group of dinosaurs including Triceratops and Styracosaurus did not evolve to help species recognise each other, according to researchers at Queen Mary University of London.

It has been suggested that different species that live in the same location may evolve features in order to distinguish one another to help avoid problems such as hybridisation, where two individuals of different species produce infertile or unfit offspring.

Line drawings of ceratopsian skulls in simplified phylogeny to illustrate morphological diversity of cranial ornaments within the clade. (a) Liaoceratops yangzigouensis; (b) Protoceratops andrewsi; (c) Centrosaurus apertus; (d) Achelousaurus horneri; (e) Pachyrhinosaurus canadensis; (f) Chasmosaurus belli; (g) Triceratops horridus. Node 1 represents the clade Coronosauria, containing all taxa with enlarged frills. Node 2 represents the clade Ceratopsoidea, encompassing Centrosaurinae (orange branch) and Chasmosaurinae (blue branch), within which the majority of cranial ornamental diversity, and all horned taxa, are found. Lower image: full-body illustration of Styracosaurus albertensis (Centrosaurinae) with highlighted examples of the three different character classes used in this study (refer to the electronic supplementary material for full list of characters).

Line drawings of ceratopsian skulls in simplified phylogeny to illustrate morphological diversity of cranial ornaments within the clade. (a) Liaoceratops yangzigouensis; (b) Protoceratops andrewsi; (c) Centrosaurus apertus; (d) Achelousaurus horneri; (e) Pachyrhinosaurus canadensis; (f) Chasmosaurus belli; (g) Triceratops horridus. Node 1 represents the clade Coronosauria, containing all taxa with enlarged frills. Node 2 represents the clade Ceratopsoidea, encompassing Centrosaurinae (orange branch) and Chasmosaurinae (blue branch), within which the majority of cranial ornamental diversity, and all horned taxa, are found. Lower image: full-body illustration of Styracosaurus albertensis (Centrosaurinae) with highlighted examples of the three different character classes used in this study (refer to the electronic supplementary material for full list of characters).

To test this hypothesis the researchers examined patterns of diversity in the ornamentation of 46 species of ceratopsians, the horned dinosaurs, but found no difference between species that lived together and those that lived separately.

A previous research paper from Queen Mary found that the frill in one ceratopsian species, Protoceratops, may have evolved under sexual selection. These new findings appear to add evidence to this across the entire group.

The researchers also found evidence that ornamental traits seemed to evolve at a much faster rate than other traits. As these structures are costly to grow and maintain, this finding similarly points to a strong selective pressure on these traits.

The study was published in Proceedings of the Royal Society B.

Andrew Knapp, PhD candidate from the School of Biological and Chemical Sciences and lead author of the study, said: “This resolves a long-standing and hitherto untested hypothesis concerning the origin and function of ornamental traits in ceratopsian dinosaurs. Many general discussions of ceratopsian ornaments in museum signage and popular literature often include examples of what they might have been for, but these tend to be rather speculative.

“We have shown that species recognition, one of the commonest explanations, is unlikely to be responsible for the diversity or origin of ornamentation in this group.”

The researchers believe the implications extend beyond the scope of ceratopsians and have consequences for the study of evolutionary theory over vast stretches of time.

The fossil record offers an opportunity to see evolution in action over much longer time periods than can be achieved with living organisms, but it is difficult to assign explanations to unusual features such as ceratopsian ornaments with the limited information that fossils provide.

The researchers have now largely ruled out one explanation, species recognition, and provided some evidence for another, sexual selection.

Mr Knapp said: “If sexual selection is indeed the driver of ornament evolution in ceratopsians, as we are increasingly confident it is, demonstrating it through different lines of evidence can provide a crucial window into tracing its effects over potentially huge timescales.”

He added: “Modern computer models have suggested that sexual selection can promote rapid speciation, adaptation, and extinction. In our world of increasing pressure on the natural world, these predictions may have important consequences for conservation and the fate of living things everywhere.”

To test these predictions the researchers hope to look at changes in the fossil record and gather further evidence to first identify sexual selection in a fossil group.

The study was conducted in collaboration with the Raymond M. Alf Museum of Paleontology in California and Natural History Museum of Utah. It was funded by a Natural Environment Research Council (NERC) doctoral training partnerships (DTP) grant through the London DTP programme.

  1. Andrew Knapp, Robert J. Knell, Andrew A. Farke, Mark A. Loewen, David W. E. Hone. Patterns of divergence in the morphology of ceratopsian dinosaurs: sympatry is not a driver of ornament evolutionProceedings of the Royal Society B: Biological Sciences, 2018; 285 (1875): 20180312 DOI: 10.1098/rspb.2018.0312

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

WFS News: A method for rapid 3D scanning and replication of large paleontological specimens

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

Citation: Das AJ, Murmann DC, Cohrn K, Raskar R (2017) A method for rapid 3D scanning and replication of large paleontological specimens. PLoS ONE 12(7): e0179264. https://doi.org/10.1371/journal.pone.0179264

Editor: Pasquale Raia, Seconda Universita degli Studi di Napoli, ITALY

Scanning technique. (a) Small section, high resolution scanning. The user holds a monopod mounted Kinect at close range (0.5–1.5 m) from the target. (b) Large section or complete 360° scanning. The user mounts Kinect on a body supported rig and walks around the artifact (1.5–4.5 m from target) to complete the scan. Sketch by Francis Goeltner.

Scanning technique.(a) Small section, high resolution scanning. The user holds a monopod mounted Kinect at close range (0.5–1.5 m) from the target. (b) Large section or complete 360° scanning. The user mounts Kinect on a body supported rig and walks around the artifact (1.5–4.5 m from target) to complete the scan. Sketch by Francis Goeltner.

The field of paleontology has transformed in the last few years as a result of the developments in 3D scanning technology and rendering software that have enhanced the quality of virtual models [14]. Conventionally, a photograph is utilized for research purposes which has its benefits but also has limited application. A two dimensional (2D) image is easy to capture, interpret and is still a useful method of analysis in paleontology research [57]. However, a 2D image cannot capture the details regarding depth of the scene. Recent studies have shown that 3D scanning and analysis of specimens can provide rich information which can be beneficial in a range of studies [8]. These techniques are increasingly seen in museums and research labs due to the compact nature of some of the imaging devices [34]. 3D scanning can provide depth maps in a non-invasive, non-contact manner which is attractive for studying paleontological specimens due to their delicate physical properties. For instance, it has been used to estimate the mass of dinosaurs by combining it with computer modeling [9]. It has also been used to create virtual skeletons for different fauna for comparative purposes [10]. Other examples of 3D scanning in related fields include typology [11], pottery studies [12] and footprint analysis in archaeology [13].

At the heart of 3D imaging technology is the 3D scanner itself. There are several approaches to perform 3D scanning from structured light scanners to computed tomography (CT). However, most of these scanners are industrial or clinical grade instruments and are generally very expensive and bulky. Structured light scanners need calibration and are inherently expensive due to the requirement of a laser projector and a high end camera to capture the images. There are reports of using structured light based 3D scanning for fossils of the size of several tens of centimeters [14] but not large specimens like T.rex skulls [10]. Several other reports have demonstrated the use of CT imaging due to its ability to study internal details of specimens. However, CT scanners are expensive and the imaging is done at a clinical facility [1516]. Additionally, most studies have used these techniques on small specimens due to the complexity of the scanner and also restriction of the data size that can be handled by the software for large specimens. For instance, a high resolution dental scanner would not be able to handle the large data size when scanning the jaw of a T.rex. Hence, there are limitations in the volume of the object that can be scanned with these methods, the ease of setup and processing the data. Furthermore, the software for these industrial scanners is proprietary making it inaccessible to researchers and museums. Although there have been some reports on the use of free open source photogrammetric software for 3D imaging, the process is cumbersome requiring a large amount of data to reconstruct the models [17]. Hence there is a need for a technique that is accurate, low-cost, easy to implement, has open source software capability and can be adapted for large scale paleontological scanning.

We propose a new technique that provides high quality 3D reconstructions of large specimens with relative ease. We used the Kinect v2 TOF sensor to perform 3D scanning of large paleontological specimens for the first time. Kinect has traditionally been used in gesture recognition [1820] in gaming, computer graphics [21] and more recently in 3D scanning [2224]. There has been one earlier report that used Kinect v1 for paleontological specimens but the reconstructions were noisy and smoothing the data resulted in loss of features [14]. Kinect v1 uses structured light imaging in contrast to Kinect v2 that is based on TOF imaging which has significantly improved since the report by Falkingham [14]. The sensor technology in Kinect v2 is not only superior to Kinect v1 but also the computation aspect has improved providing real-time high quality reconstructions. The Kinect has shown to be a promising tool for full body scanning with improvements in registration and alignment techniques [25]. Most of the earlier demonstrations have been performed on rotating objects where the Kinect is stationary. However, this may not be possible for large paleontological specimens that are housed in enclosures that cannot be modified.

In this report, we present a method for 3D scanning that is well suited for paleontology and has the following advantages; a) It has an short acquisition time of 60-120s even for large specimens, b) Since the scanner is compact so it can be moved around the specimen on a tripod or adapted to a body-mounted wearable geometry; c) The entire set-up being low-cost and the availability of free scanning and post-processing software.

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

 

WFS News: Two-billion-year-old evaporites capture Earth’s great oxidation.

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

A 2-billion-year-old chunk of sea salt provides new evidence for the transformation of Earth’s atmosphere into an oxygenated environment capable of supporting life as we know it.

The study by an international team of institutions including Princeton University found that the rise in oxygen that occurred about 2.3 billion years ago, known as the Great Oxidation Event, was much more substantial than previously indicated.

“Instead of a trickle, it was more like a firehose,” said Clara Blättler, a postdoctoral research fellow in the Department of Geosciences at Princeton and first author on the study, which was published online by the journal Science on Thursday, March 22. “It was a major change in the production of oxygen.”

A sample of 2-billion-year-old salt (pink-white recrystallized halite) with embedded fragments of calcium sulfate from a geological drill core in Russian Karelia. Credit: Photo by Aivo Lepland, Geological Survey of Norway; courtesy of Science/AAAS

A sample of 2-billion-year-old salt (pink-white recrystallized halite) with embedded fragments of calcium sulfate from a geological drill core in Russian Karelia.
Credit: Photo by Aivo Lepland, Geological Survey of Norway; courtesy of Science/AAAS

The evidence for the profound upswing in oxygen comes from crystalized salt rocks extracted from a 1.2-mile-deep hole in the region of Karelia in northwest Russia. These salt crystals were left behind when ancient seawater evaporated, and they give geologists unprecedented clues to the composition of the oceans and atmosphere on Earth more than 2 billion years ago.

The key indication of the increase in oxygen production came from finding that the mineral deposits contained a surprisingly large amount of a component of seawater known as sulfate, which was created when sulfur reacted with oxygen.

“This is the strongest ever evidence that the ancient seawater from which those minerals precipitated had high sulfate concentrations reaching at least 30 percent of present-day oceanic sulfate as our estimations indicate,” said Aivo Lepland, a researcher at the Geological Survey of Norway, a geology specialist at Tallinn University of Technology, and senior author on the study. “This is much higher than previously thought and will require considerable rethinking of the magnitude of oxygenation of Earth’s 2-billion year old atmosphere-ocean system.”

Oxygen makes up about 20 percent of air and is essential for life as we know it. According to geological evidence, oxygen began to show up in the Earth’s atmosphere between 2.4 and 2.3 billion years ago.

Until the new study, however, geologists were uncertain whether this buildup in oxygen — caused by the growth of cyanobacteria capable of photosynthesis, which involves taking in carbon dioxide and giving off oxygen — was a slow event that took millions of years or a more rapid event.

“It has been hard to test these ideas because we didn’t have evidence from that era to tell us about the composition of the atmosphere,” Blättler said.

The recently discovered crystals provide that evidence. The salt crystals collected in Russia are over a billion years older than any previously discovered salt deposits. The deposits contain halite, which is called rock salt and is chemically identical to table salt or sodium chloride, as well as other salts of calcium, magnesium and potassium.

Normally these minerals dissolve easily and would be washed away over time, but in this case they were exceptionally well preserved deep within the Earth. Geologists from the Geological Survey of Norway in collaboration with the Karelian Research Center in Petrozavodsk, Russia, recovered the salts from a drilling site called the Onega Parametric Hole (OPH) on the western shores of Lake Onega.

The unique qualities of the sample make them very valuable in piecing together the history of what happened after the Great Oxidation Event, said John Higgins, assistant professor of geosciences at Princeton, who provided interpretation of the geochemical analysis along with other co-authors.

“This is a pretty special class of geologic deposits,” Higgins said. “There has been a lot of debate as to whether the Great Oxidation Event, which is tied to increase and decrease in various chemical signals, represents a big change in oxygen production, or just a threshold that was crossed. The bottom line is that this paper provides evidence that the oxygenation of the Earth across this time period involved a lot of oxygen production.”

The research will spur the development of new models to explain what happened after the Great Oxidation Event to cause the accumulation of oxygen in the atmosphere, Blättler said. “There may have been important changes in feedback cycles on land or in the oceans, or a large increase in oxygen production by microbes, but either way it was much more dramatic than we had an understanding of before.”

  1. C. L. Blättler, M. W. Claire, A. R. Prave, K. Kirsimäe, J.A. Higgins, P. V. Medvedev, A. E. Romashkin, D. V. Rychanchik, A. L. Zerkle, K. Paiste, T. Kreitsmann, I. L. Millar, J. A. Hayles, H. Bao, A. V. Turchyn, M. R. Warke, A. Lepland. Two-billion-year-old evaporites capture Earth’s great oxidationScience, 2018; eaar2687 DOI: 10.1126/science.aar2687
Princeton University. “Two-billion-year-old salt rock reveals rise of oxygen in ancient atmosphere.” ScienceDaily. ScienceDaily, 22 March 2018. <www.sciencedaily.com/releases/2018/03/180322150306.htm>.

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

WFS News: Baby tyrannosaur fossil unearthed in Montana

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

For now, there are just a few things researchers and students at the University of Kansas want people to dig about the new dinosaur they recently excavated in Montana’s Hell Creek Formation.

Back at the lab, the researchers found the fossil glowed under a black light. Credit: University of Kansas Read more at: https://phys.org/news/2018-03-baby-tyrannosaur-fossil-unearthed-montana.html#jCp

Back at the lab, the researchers found the fossil glowed under a black light. Credit: University of Kansas
Read more at: https://phys.org/news/2018-03-baby-tyrannosaur-fossil-unearthed-montana.html#jCp

Careful, microscopic preparation of its fragile bones is beginning to reveal important information that will help unravel the life history of Tyrannosaurus rex.

Other young tyrannosaur specimens have been recovered over the years, but since animal skeletons change shape as they grow, some confusion as to their evolutionary relationships has ensued. Some paleontologists think the young ones may represent different species, while other workers have suggested they all represent different growth stages of one species—Tyrannosaurus rex.

KU’s new specimen has the information that may provide the deciding factor of which theory is correct.

Researchers believe the specimen is a young Tyrannosaurus rex but are still conducting their analysis to be sure. They expect to publish their findings in the coming months.

“The teeth suggest it’s a Tyrannosaurus rex; however, there is still more work to be done,” said David Burnham, preparator of vertebrate paleontology at the KU Biodiversity Institute. “Because a young T. rex is so rare, there are only a few that have been found over the years, so it’s difficult to discern what are changes due to growth or if the differences in the bones reflect different species. Fortunately, KU has an older T. rex to compare with and another young T. rex on loan to help decipher this problem.”

One possibility is the specimen represents another carnivorous dinosaur dubbed a Nanotyrannus that likewise was discovered in the Hell Creek Formation and described by other scientists. The Nanotyrannus is a subject of controversy because it may represent a separate species, or it may be a juvenile Tyrannosaurus rex.

“Confusing the issue here is age,” Burnham said. “Ontogeny, that’s the process of growth—and during that process we change. Adult dinosaur bones, especially in the skull, don’t look the same as their younger selves. So, if someone finds a baby or juvenile fossil they may think it’s a new species, but we have to be careful since it may represent a younger growth stage of an existing . It’s reasonable to assume Nanotyrannus could be valid—but we must show it’s not just a stage in the life history of T. rex.”

Source: Article By  Brendan M. Lynch, University of Kansas

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

 

 

WFS News: EVIDENCE OF NEOTECTONIC ACTIVITY ALONG THE EAST COAST OF INDIAN PENINSULA

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

EVIDENCE OF NEOTECTONIC ACTIVITY ALONG THE EAST COAST OF INDIAN PENINSULA ( Riffin T Sajeev

Geological Society of America Abstracts with Programs.doi: 10.1130/abs/2017AM-293786,Volume 49,Issue 6,Pages
388 T219. Challenges in Tectonics:Publisher:Geological Society of America (GSA) :https://gsa.confex.com/gsa/2017AM/meetingapp.cgi/Paper/293786
Abstract:

The eastern coastal plains of the Indian peninsula are studied meagerly based on its tectonic aspects. In the previous ventures, the author reported the paleochronological existence of a large estuary, on the basis of fossils of Crassostrea Sp. Dating back to the mio-pliocene Epoch. The author suggests that the paleo-estuary ceased in existence due to a marine regression caused by a regional uplift in between the present day trajectories of the rivers Thamirabharani and Nambiar. The natures of structural characteristics seen in the regional outcrops of the basin indicate a dominant neotectonic feature. Brittle slip faults are abundant in these rocky outcrops containing Khondalite beds. Shearing is visible almost anywhere. This may be caused by the near proximity of the study area with the Achankovil Shear Zone (AKSZ). A second look at the trajectories of the rivers and drainage mentioned above and the structural features on the outcrops indicate that the uplift is neotectonically induced rather than shear induced.During site exploration, the author found rocks of volcanic origin distributed randomly over the study area. Till this date, the geological community had approached volcanic/ neo tectonic activities in this area only through speculations without any physical, visible evidence. The presences of chunks of volcanic rocks are an acute visual evidence of an event of volcanic nature. Through this study, the author aims to analyze the extent of uplift and its impact on the drainage systems of the rivers on its either side and their divide migration possibilities. The neotectonic aspects of the region are analyzed and any solid evidence of active volcanism is collected and studied. The study is primarily aimed to report the existence of neotectonic activity in the south eastern coast of India.

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

 

 

WFS facts: dating of fossils

Radioactive dating

Radioactive dating

For example if you have a fossil trilobite and it was found in the Wheeler Formation. The Wheeler Formation has been previously dated to approximately 507 million year old, so we know the trilobite is also about 507 million years old. But, how can we determine how old a rock formation is, if it hasn’t previously been dated?

Scientists can use certain types of fossils referred to as index fossils to assist in relative dating via correlation. Index fossils are fossils that are known to only occur within a very specific age range. Typically commonly occurring fossils that had a widespread geographic distribution such as brachiopods, trilobites, and ammonites work best as index fossils. If the fossil you are trying to date occurs alongside one of these index fossils, then the fossil you are dating must fall into the age range of the index fossil.

Sometimes multiple index fossils can be used. In a hypothetical example, a rock formation contains fossils of a type of brachiopod known to occur between 410 and 420 million years. The same rock formation also contains a type of trilobite that was known to live 415 to 425 million years ago. Since the rock formation contains both types of fossils the ago of the rock formation must be in the overlapping date range of 415 to 420 million years.

Studying the layers of rock or strata can also be useful. Layers of rock are deposited sequentially. If a layer of rock containing the fossil is higher up in the sequence that another layer, you know that layer must be younger in age. If it is lower in sequence it’s of a younger age. This can often be complicated by the fact that geological forces can cause faulting and tilting of rocks.

Absolute dating is used to determine a precise age of a rock or fossil through radiometric dating methods. This uses radioactive minerals that occur in rocks and fossils almost like a geological clock. It’s often much easier to date volcanic rocks than the fossils themselves or the sedimentary rocks they are found in. So, often layers of volcanic rocks above and below the layers containing fossils can be dated to provide a date range for the fossil containing rocks.

The atoms in some chemical elements have different forms, called isotopes. These isotopes break down at a constant rate over time through radioactive decay. By measuring the ratio of the amount of the original (parent) isotope to the amount of the (daughter) isotopes that it breaks down into an age can be determined.

We define the rate of this radioactive decay in half-lives. If a radioactive isotope is said to have a half-life of 5,000 years that means after 5,000 years exactly half of it will have decayed from the parent isotope into the daughter isotopes. Then after another 5,000 years half of the remaining parent isotope will have decayed.

While people are most familiar with carbon dating, carbon dating is rarely applicable to fossils. Carbon-14, the radioactive isotope of carbon used in carbon dating has a half-life of 5730 years, so it decays too fast. It can only be used to date fossils younger than about 75,000 years. Potassium-40 on the other hand has a half like of 1.25 billion years and is common in rocks and minerals. This makes it ideal for dating much older rocks and fossils.

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

WFS News:60-year-old paleontological mystery of a ‘phantom’ dicynodont

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

A new study has re-discovered fossil collections from a 19th century hermit that validate ‘phantom’ fossil footprints collected in the 1950s showing dicynodonts coexisting with dinosaurs.

Before the dinosaurs, around 260 million years ago, a group of early mammal relatives called dicynodonts were the most abundant vertebrate land animals. These bizarre plant-eaters with tusks and turtle-like beaks were thought to have gone extinct by the Late Triassic Period, 210 million years ago, when dinosaurs first started to proliferate. However, in the 1950s, suspiciously dicynodont-like footprints were found alongside dinosaur prints in southern Africa, suggesting the presence of a late-surviving phantom dicynodont unknown in the skeletal record. These “phantom” prints were so out-of-place that they were disregarded as evidence for dicynodont survival by paleontologists. A new study has re-discovered fossil collections from a 19th century hermit that validate these “phantom” prints and show that dicynodonts coexisted with early plant-eating dinosaurs. While this research enhances our knowledge of ancient ecosystems, it also emphasizes the often-overlooked importance of trace fossils, like footprints, and the work of amateur scientists.

This is a skeleton of the dicynodont Placerias, a close relative of the newly-discovered Pentasaurus, with dicynodont trackways (Pentasauropus). Credit: Christian Kammerer

This is a skeleton of the dicynodont Placerias, a close relative of the newly-discovered Pentasaurus, with dicynodont trackways (Pentasauropus).Credit: Christian Kammerer

“Although we tend to think of paleontological discoveries coming from new field work, many of our most important conclusions come from specimens already in museums,” says Dr. Christian Kammerer, Research Curator of Paleontology at the North Carolina Museum of Natural Sciences and author of the new study.

The re-discovered fossils that solved this mystery were originally collected in South Africa in the 1870s by Alfred “Gogga” Brown. Brown was an amateur paleontologist and hermit who spent years trying, with little success, to interest European researchers in his discoveries. Brown had shipped these specimens to the Natural History Museum in Vienna in 1876, where they were deposited in the museum’s collection but never described.

“I knew the Brown collections in Vienna were largely unstudied, but there was general agreement that his Late Triassic collections were made up only of dinosaur fossils. To my great surprise, I immediately noticed clear dicynodont jaw and arm bones among these supposed ‘dinosaur’ fossils,” says Kammerer. “As I went through this collection I found more and more bones matching a dicynodont instead of a dinosaur, representing parts of the skull, limbs, and spinal column.” This was exciting — despite over a century of extensive collection, no skeletal evidence of a dicynodont had ever been recognized in the Late Triassic of South Africa.

Before this point, the only evidence of dicynodonts in the southern African Late Triassic was from questionable footprints: a short-toed, five-fingered track named Pentasauropus incredibilis (meaning the “incredible five-toed lizard foot”). In recognition of the importance of these tracks for suggesting the existence of Late Triassic dicynodonts and the contributions of “Gogga” Brown in collecting the actual fossil bones, the re-discovered and newly described dicynodont has been named Pentasaurus goggai (“Gogga’s five-[toed] lizard”).

“The case of Pentasaurus illustrates the importance of various underappreciated sources of data in understanding prehistory,” says Kammerer. “You have the contributions of amateur researchers like ‘Gogga’ Brown, who was largely ignored in his 19th century heyday, the evidence from footprints, which some paleontologists disbelieved because they conflicted with the skeletal evidence, and of course the importance of well-curated museum collections that provide scientists today an opportunity to study specimens collected 140 years ago.”

A video about this new research can be found here: https://savetubevideo.com/?v=BrdwIQKPCHY

 

Journal reference:Christian F. Kammerer. The first skeletal evidence of a dicynodont from the lower Elliot Formation of South Africa. Palaeontologia Africana, 2018

North Carolina Museum of Natural Sciences. “60-year-old paleontological mystery of a ‘phantom’ dicynodont.” ScienceDaily. ScienceDaily, 14 March 2018. <www.sciencedaily.com/releases/2018/03/180314092330.htm>.

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