WFS News: 3-Billion-Year- fossilized Old Bubbles found

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

Citation: Djokic, T. et al. Earliest signs of life on land preserved in ca. 3.5 Ga hot spring deposits. Nat. Commun. 8, 15263 doi: 10.1038/ncomms15263 (2017).

Scale bar measurements indicated. (a) Dresser terracettes (red arrows) with preserved primary porosity (green arrow) and a horizon containing Dresser stratiform geyserite (black arrow). Scale bar, 1 cm. Inset box of c. displays palisade fabric. (b) >1,800-year-old sinter terracettes (red arrows) with preserved primary porosity (green arrow) from a sinter buttress at Te Kopia, New Zealand. Scale bar, 1 cm. Micrographs in XPL of (c) Dresser palisade fabric oriented vertical to bedding (scale bar, 1 mm) and (d) close-up (scale bar, 250 μm). (e) Sinter with preserved palisade fabric, Te Kopia, New Zealand. Scale bar, 1 mm.

Scale bar measurements indicated. (a) Dresser terracettes (red arrows) with preserved primary porosity (green arrow) and a horizon containing Dresser stratiform geyserite (black arrow). Scale bar, 1 cm. Inset box of c. displays palisade fabric. (b) >1,800-year-old sinter terracettes (red arrows) with preserved primary porosity (green arrow) from a sinter buttress at Te Kopia, New Zealand. Scale bar, 1 cm. Micrographs in XPL of (c) Dresser palisade fabric oriented vertical to bedding (scale bar, 1 mm) and (d) close-up (scale bar, 250 μm). (e) Sinter with preserved palisade fabric, Te Kopia, New Zealand. Scale bar, 1 mm.

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

The ca. 3.48 Ga Dresser Formation, Pilbara Craton, Western Australia, is well known for hosting some of Earth’s earliest convincing evidence of life (stromatolites, fractionated sulfur/carbon isotopes, microfossils) within a dynamic, low-eruptive volcanic caldera affected by voluminous hydrothermal fluid circulation. However, missing from the caldera model were surface manifestations of the volcanic-hydrothermal system (hot springs, geysers) and their unequivocal link with life. Here we present new discoveries of hot spring deposits including geyserite, sinter terracettes and mineralized remnants of hot spring pools/vents, all of which preserve a suite of microbial biosignatures indicative of the earliest life on land. These include stromatolites, newly observed microbial palisade fabric and gas bubbles preserved in inferred mineralized, exopolymeric substance. These findings extend the known geological record of inhabited terrestrial hot springs on Earth by 3 billion years and offer an analogue in the search for potential fossil life in ancient Martian hot springs.

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

 

(a) Proximal to distal hot spring facies, with spring vent fed by subsurface hydrothermal fluids. (b) Preserved sequence of hot spring facies deposits, geographically patchy in nature, with spring vent infilled by late-stage crystallization of barite.

(a) Proximal to distal hot spring facies, with spring vent fed by subsurface hydrothermal fluids. (b) Preserved sequence of hot spring facies deposits, geographically patchy in nature, with spring vent infilled by late-stage crystallization of barite.

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

Scale bar measurements indicated. (a) High resolution gigapan image of Dresser geyserite. Inset boxes are figure parts (b,c,d). Laminae overgrowth stages; s1 and s2 represented by white dashed lines. Ferruginous material (red arrows) contains inferred gas bubbles; see Fig. 5. Scale bar, 2 mm. Micrographs in PPL (b–f). (b) Botryoidal textures display laminae onlap/offlap (red arrow), separated by siliceous equigranular troughs (white arrow) overlain by fine, planar laminae (scale bar, 1 mm). (c) Botryoidal–columnar textures overlain by planar (black dashes), slumped (red arrow) laminae. Scale bar, 1 mm. (d) Overgrowth (e1) with outward and downward facing botryoids (white arrows). Quartz (Qz) and barite (B), infill and cross-cut laminae (scale bar, 1 mm). (e) Close-up of light/dark microlaminae in Dresser geyserite. Inset box of figure part (i). Scale bar, 50 μm. (f) Modern geyserite with botryoidal microlaminae (red arrow), Geysir, Iceland. Analogous to (b). Scale bar, 1 mm. (g) Slumped laminae of <100-year-old geyserite, Geyser Valley, New Zealand. Analogous to c. Scale bar, 1 cm. (h) Pool rim overgrowth of geyserite with outward facing botryoids (arrows), Geyser Valley, New Zealand. Analogous to d. Scale bar, 2 cm. (i) SEM-EDS element maps showing light bands enriched in K–Al alternating with dark bands enriched in Ti, identified as kaolinite+illite and anatase, respectively, from Raman spectroscopy and XRD analysis; see Supplementary Figs 2–6 (scale bar, 50 μm).

Scale bar measurements indicated. (a) High resolution gigapan image of Dresser geyserite. Inset boxes are figure parts (b,c,d). Laminae overgrowth stages; s1 and s2 represented by white dashed lines. Ferruginous material (red arrows) contains inferred gas bubbles; see Fig. 5. Scale bar, 2 mm. Micrographs in PPL (b–f). (b) Botryoidal textures display laminae onlap/offlap (red arrow), separated by siliceous equigranular troughs (white arrow) overlain by fine, planar laminae (scale bar, 1 mm). (c) Botryoidal–columnar textures overlain by planar (black dashes), slumped (red arrow) laminae. Scale bar, 1 mm. (d) Overgrowth (e1) with outward and downward facing botryoids (white arrows). Quartz (Qz) and barite (B), infill and cross-cut laminae (scale bar, 1 mm). (e) Close-up of light/dark microlaminae in Dresser geyserite. Inset box of figure part (i). Scale bar, 50 μm. (f) Modern geyserite with botryoidal microlaminae (red arrow), Geysir, Iceland. Analogous to (b). Scale bar, 1 mm. (g) Slumped laminae of<100-year-old geyserite, Geyser Valley, New Zealand. Analogous to c. Scale bar, 1 cm. (h) Pool rim overgrowth of geyserite with outward facing botryoids (arrows), Geyser Valley, New Zealand. Analogous to d. Scale bar, 2 cm. (i) SEM-EDS element maps showing light bands enriched in K–Al alternating with dark bands enriched in Ti, identified as kaolinite+illite and anatase, respectively, from Raman spectroscopy and XRD analysis; see Supplementary Figs 2–6 (scale bar, 50 μm).                                                                                                         

3.3 Million-Year-Old Fossil Sheds Light On How Spines Evolved

A remarkably complete fossil of a young child suggests that key elements of the human spinal structure were already in place in an ancient human relative 3.3 million years ago.

The child, about three years old, likely died suddenly and quickly drifted into a body of water, where she was covered in sediment that eventually hardened to sandstone, Zeray Alemseged of the University of Chicago tells The Two-Way.

His team found the well-preserved fossil in 2000 in Dikika, Ethiopia, and for years they have been painstakingly excavating it, revealing what they say is the only known backbone with completely preserved bones of the middle and upper back dated prior to 60,000 years ago. Their findings were recently published in the Proceedings of the National Academy of Science.

Now, Alemseged says this shows “that the human type of segmentation and numbering of our backbone emerged 3.3 million years ago, and this fossil provides us for the first time the hard evidence, the fossil evidence, to confirm that indeed the structure is as ancient as we’re claiming it now to be.”

The fossil is nicknamed Selam, which means “peace” in Ethiopian Amharic. She is from an early human relative species called Australopithecus afarensis. The famous Lucy fossil is also from this species.

 This is a vertebrae of the Selam skeleton. Zeray Alemseged, University of Chicago

       This is a vertebrae of the Selam skeleton.
         Zeray Alemseged, University of Chicago

The spines of our early ancestors have been mysterious. They are not well preserved in the fossil record, Alemseged explains, because they are much more fragile than other parts of the animal, like teeth.

This specimen is particularly unique, because it belongs to a child whose individual vertebrae are “still in the process of fusing and forming.” He says that’s why “the data is so unique, shedding light on one of the key milestone events in human evolution and that is the transition from the more ape-like arrangement of the backbone to the more humanlike arrangement of the backbone.”

The specimen has the same number of neck (seven) and mid-back vertebrae (12) as modern humans, while African apes have 13 mid-back vertebrae.

 The full skeleton of Selam, including the spinal column. Zeray Alemseged, University of Chicago

The full skeleton of Selam, including the spinal column.
Zeray Alemseged, University of Chicago

It is well-established that this species walked upright on two legs (though there’s some debate about how much time they spent climbing). But this backbone sheds more light on how they moved.

“The specimen says yes, they had the ability to walk like we do today, like humans, but there are some minor differences,” Alemseged says. “Particularly the transition from the middle part of the backbones to lower part of the backbone, showing that they may have been good walkers, upright like us, but they were clearly not the runners and the endurance walkers that humans are today.”

That’s because they “don’t seem to have the ability to rotate their backbone, even though they had the ability to extend and flex their backbone,” he says.

Scientists spent 13 years working on the fossil at Ethiopia’s National Museum; it later traveled to Grenoble, France, for high-resolution imaging.

“It’s a good example of how much effort you have to put in to get high-quality and reliable information,” says Bernard Wood, a paleoanthropologist at George Washington University who was not involved in the research. “It’s an excellent piece of science.”

He described the fossil found at Dikika as the “gift that keeps on giving,” because its completeness allows researchers to be quite sure about their conclusions. It’s high praise for research on ancient fossils, where findings are often highly controversial.

Richard Potts, the director of Smithsonian’s Human Origins Program, echoed the sentiment, calling it an “excellent job of analysis and interpretation.” At the same time, he stressed that other, less-complete vertebrae, such as fossils found in Sterkfontein, South Africa, have previously suggested that a humanlike species more than 2 million years old had some of the same spinal features.

WFS News: The first reported ceratopsid dinosaur from eastern North America

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

A chance discovery in Mississippi provides the first evidence of an animal closely related to Triceratops in eastern North America. The fossil, a tooth from rocks between 68 and 66 million years old, shows that two halves of the continent previously thought to be separated by seaway were probably connected before the end of the Age of Dinosaurs.

“The fossil is small, only the size of a quarter, but it packs a ton of information,” said Andrew Farke, a paleontologist at the Raymond M. Alf Museum of Paleontology at The Webb Schools in Claremont, California, and one of the authors of the paper announcing the discovery in the journal PeerJ.

Marine macrofossils collected in loose association with ceratopsian tooth (from Table 1), most consistent with a Maastrichtian age. (A) Striaticostatum cf. S. sparsum Sohl, MMNS IP-8648; (B) Liopistha protexta (Conrad), MMNS IP-6116; (C) Discoscaphites iris (Conrad), microconch, MMNS IP-8646; (D) Costacopluma grayi Feldmann & Portell, larger Maastrichtian variety (Martínez-Díaz et al., 2016), MMNS IP-8647 (distinct from the smaller Danian variety); (E) Discoscaphites iris (Conrad), macroconch, MMNS IP-494; (F) Cretalamna appendiculata (Agassiz), variant of a lower posterior tooth, MMNS VP-8041; (G) Branchiocarcinus flectus (Rathbun), MMNS IP-6115.3; (H) Mosasaurus hoffmani Mantell, MMNS VP-6803; and (I) Peritresius ornatus (Leidy), costal carapace fragment, MMNS VP-4407.

Marine macrofossils collected in loose association with ceratopsian tooth (from Table 1), most consistent with a Maastrichtian age.
(A) Striaticostatum cf. S. sparsum Sohl, MMNS IP-8648; (B) Liopistha protexta (Conrad), MMNS IP-6116; (C) Discoscaphites iris (Conrad), microconch, MMNS IP-8646; (D) Costacopluma grayi Feldmann & Portell, larger Maastrichtian variety (Martínez-Díaz et al., 2016), MMNS IP-8647 (distinct from the smaller Danian variety); (E) Discoscaphites iris (Conrad), macroconch, MMNS IP-494; (F) Cretalamna appendiculata (Agassiz), variant of a lower posterior tooth, MMNS VP-8041; (G) Branchiocarcinus flectus (Rathbun), MMNS IP-6115.3; (H) Mosasaurus hoffmani Mantell, MMNS VP-6803; and (I) Peritresius ornatus (Leidy), costal carapace fragment, MMNS VP-4407.

“The shape of this tooth, with its distinctive split root, is absolutely unique among dinosaurs,” Farke continued. “We only have the one fossil, but it’s more than enough to show that an animal very similar to Triceratops-perhaps even Triceratops itself-made it into eastern North America.”

Horned dinosaurs, or ceratopsids, had previously only been found in western North America and Asia. A seaway down the middle of North America, which linked the Arctic Ocean and Gulf of Mexico, split the continent into eastern and western halves during much of the Late Cretaceous (around 95 to 66 million years ago). This means that animals that evolved in western North America after the split-including ceratopsids-were prevented from traveling east.

Right dentary tooth of ceratopsid dinosaur, MMNS VP-7969. Digital renderings and photographs in (A, B) mesial (posterior); (C, D) lingual (medial); (E, F) distal (anterior); (G, H) apical (dorsal); (I, J) labial (lateral); (K, L) root (ventral) views. Scale bar equals 10 mm. Directional abbreviations: api, apical; dist, distal; mes, mesial; lab, labial; ling, lingual.

Right dentary tooth of ceratopsid dinosaur, MMNS VP-7969.
Digital renderings and photographs in (A, B) mesial (posterior); (C, D) lingual (medial); (E, F) distal (anterior); (G, H) apical (dorsal); (I, J) labial (lateral); (K, L) root (ventral) views. Scale bar equals 10 mm. Directional abbreviations: api, apical; dist, distal; mes, mesial; lab, labial; ling, lingual.

Due to a lack of preserved rock and fossils, scientists weren’t sure precisely when the seaway disappeared and animals could once again walk freely across North America. The newly described fossil strongly suggests that this happened when large dinosaurs such as Tyrannosaurus and Triceratops were still around, before the major global extinction 66 million years ago.

George Phillips, paleontology curator at the Mississippi Department of Wildlife, Fisheries, and Parks’ Museum of Natural Science and co-author of the paper, discovered the fossil in the Owl Creek Formation in northern Mississippi.

Phillips described the moment of discovery: “I was excited because I knew it was a dinosaur tooth, and dinosaur fossils are rare discoveries east of the Mississippi River. I called my volunteer, Michael Estes, over to share in the discovery, and he was beside me in seconds. I knew it wasn’t a duck-billed dinosaur, and within 30 minutes of having found it, I posted on Facebook that I’d collected some rare plant-eating dinosaur tooth. It was none other than my colleague Lynn Harrell who made the suggestion, within minutes of my post, that it looked like a ceratopsian tooth.”

Although previously known fragments indicated horned dinosaurs in Maryland and North Carolina, those fossils were of more “primitive” species that likely lived in the area well before it was separated from western North America.

“The discovery is shocking because fossils of ceratopsid horned dinosaurs had never been discovered previously from eastern North America. It’s certainly the most unique and important vertebrate fossil discovery I’ve ever made,” said Phillips.

The ceratopsid tooth, from the lower jaw of the animal, was found in the Owl Creek Formation in northern Mississippi. Although that part of the state was under water at the time, it was fairly close to land. Farke and Phillips speculate that the tooth probably washed out to sea from a horned dinosaur living along the coastline in that area.The fossil is housed at the Mississippi Museum of Natural Sciences.

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

Citation:Andrew A. Farke, George E. Phillips. The first reported ceratopsid dinosaur from eastern North America (Owl Creek Formation, Upper Cretaceous, Mississippi, USA). PeerJ, 2017; 5: e3342 DOI: 10.7717/peerj.3342

WFS News: Galeamopus pabsti , A new sauropod species

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Researchers from Italy and Portugal describe yet another new sauropod species from 150 million years ago, from Wyoming, USA.

The new species, Galeamopus pabsti, is the most recent dinosaur to be described by paleontologists from the Department of Earth Sciences of the University of Turin, Italy; the Faculty of Science and Technology, Universidade Nova de Lisboa, and the Museum of Lourinhã in Portugal. This Jurassic dinosaur was originally excavated in 1995 by a Swiss team, led by Hans-Jakob “Kirby” Siber and Ben Pabst, in Wyoming, in the United States and is the latest in a series of new discoveries by the paleontologists Emanuel Tschopp and Octávio Mateus, which started in 2012 with Kaatedocus siberi. The paper describing the new species was published online in the open access scientific journal PeerJ on Tuesday, May 2.

Quarry map of SMA 0011. Note the separation of the cervical series and the skull from the dorsal column and the appendicular skeleton, and the articulated block of dorsal vertebrae that do not belong to SMA 0011 (see arrowhead between horizontal lines 15 and 16). Abb.: bc, braincase; co, coracoid; CR, cervical rib; CV, cervical vertebra; DR, dorsal ribs; DV, dorsal vertebra; fe, femur; fi, fibula; fl, forelimb; h, humerus; hl, hindlimb; il, ilium; is, ischium; ma, manus; pcg, pectoral girdle; pe, pes; pu, pubis; pvg, pelvic girdle; r, radius; sc, scapula; SR, sternal ribs; SV, sacral vertebrae; ti, tibia; u, ulna. Map drawn by Esther Premru, copyright by Sauriermuseum Aathal, modified with permission.

Quarry map of SMA 0011.Note the separation of the cervical series and the skull from the dorsal column and the appendicular skeleton, and the articulated block of dorsal vertebrae that do not belong to SMA 0011 (see arrowhead between horizontal lines 15 and 16). Abb.: bc, braincase; co, coracoid; CR, cervical rib; CV, cervical vertebra; DR, dorsal ribs; DV, dorsal vertebra; fe, femur; fi, fibula; fl, forelimb; h, humerus; hl, hindlimb; il, ilium; is, ischium; ma, manus; pcg, pectoral girdle; pe, pes; pu, pubis; pvg, pelvic girdle; r, radius; sc, scapula; SR, sternal ribs; SV, sacral vertebrae; ti, tibia; u, ulna. Map drawn by Esther Premru, copyright by Sauriermuseum Aathal, modified with permission.

Galeamopus pabsti is similar to the famous dinosaur Diplodocus, but with more massive legs, and a particularly high and triangular neck close to the head. It is the second species of the genus Galeamopus to be shown to be different to Diplodocus by the same researchers (the first being published in 2015, in a paper which also reinstated the brontosaurus as a distinct genus). The new species is dedicated to Ben Pabst, who found the skeleton, and prepared it for mounting at the Sauriermuseum Aathal in Switzerland, where it is one of the main attractions of the permanent exhibit.

Skull bones of Galeamopus pabsti SMA 0011 before mounting. Gray elements were lacking and reconstructed for the mounted skull. Abb.: an, angular; aof, antorbital fenestra; d, dentary; f, frontal; j, jugal; la, lacrimal; m, maxilla; na, nasal; oc, occipital condyle; p, parietal; pf, prefrontal; pm, premaxilla; popr, paroccipital process; pra, proatlas; q, quadrate; qj, quadratojugal; sa, surangular; so, supraoccipital; sq, squamosal; t, teeth. Scale bar = 10 cm. Photo by Urs Möckli and copyright by Sauriermuseum Aathal, modified with permission.

Skull bones of Galeamopus pabsti SMA 0011 before mounting.
Gray elements were lacking and reconstructed for the mounted skull. Abb.: an, angular; aof, antorbital fenestra; d, dentary; f, frontal; j, jugal; la, lacrimal; m, maxilla; na, nasal; oc, occipital condyle; p, parietal; pf, prefrontal; pm, premaxilla; popr, paroccipital process; pra, proatlas; q, quadrate; qj, quadratojugal; sa, surangular; so, supraoccipital; sq, squamosal; t, teeth. Scale bar = 10 cm. Photo by Urs Möckli and copyright by Sauriermuseum Aathal, modified with permission.

Diplodocid sauropods are among the most iconic dinosaurs. With their greatly elongated necks and tails, they represent the typical body shape of sauropods. Species of this group occur also in Africa, South America, and Europe, but the highest diversity is known from the USA: more than 15 species of these gigantic animals are known from there, also including the famous Brontosaurus. Researchers are still baffled by this high diversity of giants, and are continuing their studies to understand how such a diversity could be maintained by the ecosystem in which they lived.

Skull of Galeamopus pabsti SMA 0011 as usually figured. The skull is shown as usually figured in dorsal (A), posterior (B), right lateral (C), and anterior views (D), following our terminology section. Dark, uniformely colored elements were lacking and reconstructed for the mounted skull. Note the shallow groove on the premaxilla, extending from the lateral margin anteromedially (1). Abb.: an, angular; aof, antorbital fenestra; bo, basioccipital; bpr, basipterygoid process; d, dentary; ex, exoccipital; f, frontal; j, jugal; ltf, laterotemporal fenestra; m, maxilla; n, external nares; na, nasal; o, orbit; os, orbitosphenoid; p, parietal; paof, preantorbital fossa; pf, prefrontal; pm, premaxilla; po, postorbital; popr, paroccipital process; pro, prootic; q, quadrate; qj, quadratojugal; sa, surangular; so, supraoccipital; sq, squamosal; stf, supratemporal fenestra. Scale bar =10 cm.

Skull of Galeamopus pabsti SMA 0011 as usually figured.
The skull is shown as usually figured in dorsal (A), posterior (B), right lateral (C), and anterior views (D), following our terminology section. Dark, uniformely colored elements were lacking and reconstructed for the mounted skull. Note the shallow groove on the premaxilla, extending from the lateral margin anteromedially (1). Abb.: an, angular; aof, antorbital fenestra; bo, basioccipital; bpr, basipterygoid process; d, dentary; ex, exoccipital; f, frontal; j, jugal; ltf, laterotemporal fenestra; m, maxilla; n, external nares; na, nasal; o, orbit; os, orbitosphenoid; p, parietal; paof, preantorbital fossa; pf, prefrontal; pm, premaxilla; po, postorbital; popr, paroccipital process; pro, prootic; q, quadrate; qj, quadratojugal; sa, surangular; so, supraoccipital; sq, squamosal; stf, supratemporal fenestra. Scale bar =10 cm.

Skull reconstruction of Galeamopus pabsti. The reconstruction is in dorsal (A) and lateral view (B), and was created by Simão Mateus (ML), and based on the holotypic skull of SMA 0011. Lacking bones were reconstructed after Diplodocus (Whitlock, 2011b). Only the bones preserved in the skull of SMA 0011 are labeled. Abb.: an, angular; bpr, basipterygoid process; d, dentary; f, frontal; j, jugal; la, lacrimal; m, maxilla; n, nasal; p, parietal; pf, prefrontal; pm, premaxilla; po, postorbital; popr, paroccipital process; q, quadrate; qj, quadratojugal; sa, surangular; sq, squamosal.

Skull reconstruction of Galeamopus pabsti.
The reconstruction is in dorsal (A) and lateral view (B), and was created by Simão Mateus (ML), and based on the holotypic skull of SMA 0011. Lacking bones were reconstructed after Diplodocus (Whitlock, 2011b). Only the bones preserved in the skull of SMA 0011 are labeled. Abb.: an, angular; bpr, basipterygoid process; d, dentary; f, frontal; j, jugal; la, lacrimal; m, maxilla; n, nasal; p, parietal; pf, prefrontal; pm, premaxilla; po, postorbital; popr, paroccipital process; q, quadrate; qj, quadratojugal; sa, surangular; sq, squamosal.

Citation: PeerJ. “New species of dinosaur increases the already unexpected diversity of ‘whiplash dinosaurs’: Researchers from Italy and Portugal describe yet another new sauropod species from 150 million years ago, from Wyoming, USA.” ScienceDaily. ScienceDaily, 2 May 2017. <www.sciencedaily.com/releases/2017/05/170502084129.htm>.

Key: WFS,World Fossil Society,Riffin T Sajeev,Russel T Sajeev

WFS News: Parvancorina fossil suggests Life in the Precambrian may have been much livelier

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

The Garden of the Ediacaran was a period in the ancient past when Earth’s shallow seas were populated with a bewildering variety of enigmatic, soft-bodied creatures. Scientists have pictured it as a tranquil, almost idyllic interlude that lasted from 635 to 540 million years ago. But a new interdisciplinary study suggests that the organisms living at the time may have been much more dynamic than experts have thought.

Artist’s conception of a scene from the Garden of the Ediacaran. The new study suggests a number of these strange species which predate animals may have been capable of moving about (Franz Anthony / Studio 252MYA)

Artist’s conception of a scene from the Garden of the Ediacaran. The new study suggests a number of these strange species which predate animals may have been capable of moving about (Franz Anthony / Studio 252MYA)

Scientists have found It extremely difficult to fit these Precambrian species into the tree of life. That is because they lived in a time before organisms developed the ability to make shells or bones. As a result, they didn’t leave much fossil evidence of their existence behind, and even less evidence that they moved around. So, experts have generally concluded that virtually all of the Ediacarans—with the possible exception of a few organisms similar to jellyfish that floated about—were stationary and lived out their adult lives fixed in one place on the sea floor.

Fossil imprint of Parvancorina, which may have been the first species capable of orienting itself to face into an ocean current. (Masahiro Miyasaka / Wikimedia Commons)

Fossil imprint of Parvancorina, which may have been the first species capable of orienting itself to face into an ocean current. (Masahiro Miyasaka / Wikimedia Commons)

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The new findings concern one of the most enigmatic of the Ediacaran genera, a penny-sized organism called Parvancorina, which is characterized by a series of ridges on its back that form the shape of a tiny anchor. By analyzing the way in which water flows around Parvancorina’s body, an international team of researchers has concluded that these ancient creatures must have been mobile: specifically, they must have had the ability to orient themselves to face into the current flowing around them. That would make them the oldest species known to possess this capability, which scientists call rheotaxis.

“Our analysis shows that the amount of drag produced with the current flowing from front to back is substantially less than that flowing from side to side,” said Simon Darroch, assistant professor of earth and environmental sciences at Vanderbilt University, who headed the study. “In the strong currents characteristic of shallow ocean environments, that means Parvancorina would have benefited greatly from adjusting its position to face the direction of the flow.”

Top and side views produced by computer simulations show how water flows around the body of Parvancorina when the current is coming from the front (a), side (b) and rear (c). The arrows show the direction of the water flow and the colors represent its velocity (red and yellow are fast, blue and green are slow). It demonstrates that the flow patterns differ dramatically with each orientation. This implies that the organism had to have been mobile to feed effectively. (Simon Darroch / Vanderbilt)

Top and side views produced by computer simulations show how water flows around the body of Parvancorina when the current is coming from the front (a), side (b) and rear (c). The arrows show the direction of the water flow and the colors represent its velocity (red and yellow are fast, blue and green are slow). It demonstrates that the flow patterns differ dramatically with each orientation. This implies that the organism had to have been mobile to feed effectively. (Simon Darroch / Vanderbilt)

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

The analysis, which used a technique borrowed from engineering called computational fluid dynamics (CFD), also showed that when Parvancorina faced into the current, its shape created eddy currents that were directed to several specific locations on its body. “This would be very beneficial to Parvancorina if it was a suspension feeder as we suspect because it would have concentrated the suspended organic material making it easier to consume,” Darroch said.

Details of the analysis are described in a paper titled “Inference of facultative mobility in the enigmatic Ediacaran organismParvancorina” published online May 17 by the Royal Society journal Biology Letters.

Model of a Parvancorina organism. (Matteo De Stefano/MUSE/Wikimedia Commons)

Model of a Parvancorina organism. (Matteo De Stefano/MUSE/Wikimedia Commons)

These conclusions are reinforced by an independent study performed by a team of Australian researchers published March 30 in the journal Scientific Reports. Analyzing an Ediacaran site in South Australia, they found that the Parvancorina fossils were preferentially aligned in the direction of the prevailing current and determined that this alignment was not passive but represented a rheotactic response at some point in the organism’s life history.

This is only the second time that CFD has been applied to study Ediacarans. In 2015, the same team of researchers applied this technique to analyze flow patterns around an organism called Tribrachidium heraldicum. This is a disk-shaped organism characterized by three spiraling ridges on its back. In this case, their analysis supported the conclusion that it was the oldest known suspension feeder, dating back to 555 million years.

“We decided to stop trying to figure out where these species fit in the tree of life and to try to determine how they were shaped by evolutionary forces,” said Darroch. “We wanted to understand how their weird architectures affected how they ate, reproduced and moved. Because they lived in a shallow sea environment, strong currents must have played a major role in their evolution. So computational fluid dynamics is the perfect tool for addressing this question.”

Simon Darroch (Steve Green / Vanderbilt)

Simon Darroch (Steve Green / Vanderbilt)

According to team member Imran Rahman, research fellow at the Oxford University Museum of Natural History, CFD has been used to analyze the design and optimize the performance of a wide variety of structures and machines, ranging from nuclear reactors to aircraft, but it is only in the last few years that they have begun applying it to study the fossil record: “CFD has the potential to transform our understanding of how ancient organisms fed and moved, so I would anticipate that many more paleontologists will start making use of the method in coming years.”

“When you sit back and think about it, we are virtually recreating ancient oceans, and populating them with digital representations of long extinct organisms that have defied our understanding for over 50 years in order to gain insight on how they lived their day to day lives,” added co-author Marc Laflamme, assistant professor of earth science at the University of Toronto Mississauga. “This kind of work would not have been feasible even a decade ago, and I believe it represents the direction that modern paleontology is forging.”

“The fact that we have now established that one Ediacaran species could move around suggests that our picture of this period may be fundamentally wrong,” said Darroch. “There may have been a lot more movement going on than we thought and we intend to apply this technique to other Ediacaran fossils to determine if that was the case.”

Vanderbilt graduate student Brandt Gibson and Rachel Racicot at the Natural History Museum of Los Angeles County also contributed to the study.

The research was supported by National Science Foundation grants DEB 1331980 and PLR 134175 and by National Science and Engineering Research Council of Canada grant RGPIN 435402.

Courtesy:Article by by

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WFS News:The Biomechanics Behind strong bites of Tyrannosaurus rex

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The giant Tyrannosaurus rex pulverized bones by biting down with forces equaling the weight of three small cars while simultaneously generating world record tooth pressures, according to a new study by a Florida State University-Oklahoma State University research team.

Left ilium of Triceratops sp. (MOR 799) in ventrolateral view with ~80 bite marks attributed to Tyrannosaurus rex. A large portion (~17%) of the iliac crest was removed (bracketed) by repetitive, localized biting.

Left ilium of Triceratops sp. (MOR 799) in ventrolateral view with ~80 bite marks attributed to Tyrannosaurus rex. A large portion (~17%) of the iliac crest was removed (bracketed) by repetitive, localized biting.

In a study published today in Scientific Reports, Florida State University Professor of Biological Science Gregory Erickson and Paul Gignac, assistant professor of Anatomy and Vertebrate Paleontology at Oklahoma State University Center for Health Sciences, explain how T. rex could pulverize bones — a capacity known as extreme osteophagy that is typically seen in living carnivorous mammals such as wolves and hyenas, but not reptiles whose teeth do not allow for chewing up bones.

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Jaw adductor muscle model for Tyrannosaurus rex (BHI 3033) in (A) dorsal, (C) left lateral, and (D) posterior views. Muscles in anatomical position are figured in (B) (lateral view is on left; anterior view is on right), textures and shades based on Alligator mississippiensis 32. Abbreviations: mamem, Musculus adductor mandibulae externus medialis; mames, M. adductor mandibulae externus superficialis; mamep, M. adductor mandibulae externus profundus; mptd, M. pterygoideus dorsalis; mps, M. pseudotemporalis complex; mamp, M. adductor mandibulae posterior; mptv, M. pterygoideus ventralis; mint, M. intramandibularis.

Jaw adductor muscle model for Tyrannosaurus rex (BHI 3033) in (A) dorsal, (C) left lateral, and (D) posterior views. Muscles in anatomical position are figured in (B) (lateral view is on left; anterior view is on right), textures and shades based on Alligator mississippiensis 32. Abbreviations: mamem, Musculus adductor mandibulae externus medialis; mames, M. adductor mandibulae externus superficialis; mamep, M. adductor mandibulae externus profundus; mptd, M. pterygoideus dorsalis; mps, M. pseudotemporalis complex; mamp, M. adductor mandibulae posterior; mptv, M. pterygoideus ventralis; mint, M. intramandibularis.

Erickson and Gignac found that this prehistoric reptile could chow down with nearly 8,000 pounds of force, which is more than two times greater than the bite force of the largest living crocodiles — today’s bite force champions. At the same time, their long, conical teeth generated an astounding 431,000 pounds per square inch of bone-failing tooth pressures.

This allowed T. rex to drive open cracks in bone during repetitive, mammal-like biting and produce high-pressure fracture arcades, leading to a catastrophic explosion of some bones.

“It was this bone-crunching acumen that helped T. rex to more fully exploit the carcasses of large horned-dinosaurs and duck-billed hadrosaurids whose bones, rich in mineral salts and marrow, were unavailable to smaller, less equipped carnivorous dinosaurs,” Gignac said.

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Tyrannosaurus rex dental functional morphology. (A) Exemplar tooth pressures along the distal 37 mm of the left M5 of BHI 3033 (warmer colours indicate higher pressures), illustrating bone-penetrating shear stresses (>65 MPa4, 39) for almost 25 mm of indentation depth. (B) Mesial and distal facing carinae (white arrows) helped direct pathways of bone fracture towards adjacent maxillary teeth (C) (ventral view of BHI 3033) that were also engaged during indentation, illustrating how the most procumbent maxillary tooth crowns collectively form a fracture arcade (pink arrows) due to pressures generated when biting. (Figure element in (A) derived from digital scan by Virtual Surfaces, Inc).

Tyrannosaurus rex dental functional morphology. (A) Exemplar tooth pressures along the distal 37 mm of the left M5 of BHI 3033 (warmer colours indicate higher pressures), illustrating bone-penetrating shear stresses (>65 MPa4, 39) for almost 25 mm of indentation depth. (B) Mesial and distal facing carinae (white arrows) helped direct pathways of bone fracture towards adjacent maxillary teeth (C) (ventral view of BHI 3033) that were also engaged during indentation, illustrating how the most procumbent maxillary tooth crowns collectively form a fracture arcade (pink arrows) due to pressures generated when biting. (Figure element in (A) derived from digital scan by Virtual Surfaces, Inc).

The researchers built on their extensive experience testing and modeling how the musculature of living crocodilians, which are close relatives of dinosaurs, contribute to bite forces. They then compared the results with birds, which are modern-day dinosaurs, and generated a model for T. rex.

From their work on crocodilians, they realized that high bite forces were only part of the story. To understand how the giant dinosaur consumed bone, Erickson and Gignac also needed to understand how those forces were transmitted through the teeth, a measurement they call tooth pressure.

“Having high bite force doesn’t necessarily mean an animal can puncture hide or pulverize bone, tooth pressure is the biomechanically more relevant parameter,” Erickson said. “It is like assuming a 600 horsepower engine guarantees speed. In a Ferrari, sure, but not for a dump truck.”

Jaw models of Tyrannosaurus rex paired with idealized beam diagrams, illustrating three- (A) (lateral view), (B) (anterior view) and four-point ((C), anterior view) loading configurations that allowed T. rex to promote failure stresses and fracture rigid structures (e.g., bone) without the aid of occluding dentitions. Teeth (cones) and the osseus palate, composed of the right and left maxillae and an anterior expansion of the vomer (rectangle), are shown as contact points in pink; original beam shapes are dark blue; and idealized plastic deformations (exaggerated) are light blue.

Jaw models of Tyrannosaurus rex paired with idealized beam diagrams, illustrating three- (A) (lateral view), (B) (anterior view) and four-point ((C), anterior view) loading configurations that allowed T. rex to promote failure stresses and fracture rigid structures (e.g., bone) without the aid of occluding dentitions. Teeth (cones) and the osseus palate, composed of the right and left maxillae and an anterior expansion of the vomer (rectangle), are shown as contact points in pink; original beam shapes are dark blue; and idealized plastic deformations (exaggerated) are light blue.

In current day, well-known bone crunchers like spotted hyenas and gray wolves have occluding teeth that are used to finely fragment long bones for access to the marrow inside — a hallmark feature of mammalian osteophagy. Tyrannosaurus rex appears to be unique among reptiles for achieving this mammal-like ability but without specialized, occluding dentition.

The new study is one of several by the authors and their colleagues that now show how sophisticated feeding abilities, most like those of modern mammals and their immediate ancestors, actually first appeared in reptiles during the Age of the Dinosaurs.

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

Citation:Paul M. Gignac, Gregory M. Erickson. The Biomechanics Behind Extreme Osteophagy in Tyrannosaurus rex. Scientific Reports, 2017; 7 (1) DOI: 10.1038/s41598-017-02161-w

WFS News: Arctostrea Oyster fossils found in India

WFS News: Arctostrea Oyster fossils found in India

 Arctostrea fossil from dalmiapuram,India.( Photo Courtesy: (C)World Fossil Society.Photo by Riffin T Sajeev ,Russel T Sajeev

Arctostrea fossil from dalmiapuram,India.( Photo Courtesy: (C)World Fossil Society.Photo by Riffin T Sajeev ,Russel T Sajeev

 Arctostrea fossil from dalmiapuram,India.( Photo Courtesy: (C)World Fossil Society.Photo by Riffin T Sajeev ,Russel T Sajeev

Arctostrea fossil from dalmiapuram,India.( Photo Courtesy: (C)World Fossil Society.Photo by Riffin T Sajeev ,Russel T Sajeev

The fossil of Arcostrea from Dalmiapuram formation has a well defined high zigzag commissure. The problem of oxygen and food supply is particularly important to the development of oysters. Passive mode of life on the basin floors of muddy and often turbid waters and gregarious occurrence did not create good living conditions. In response to difficult environmental regime the oysters have developed highly advanced functional adaptations which are reflected first of all in structural peculiarities of the shell. These are: arcuate shape, zigzag commissure, lobe-like enlarged posterior edge of umbo, promyal chamber and also marginal denticles and pedal retractor muscle scar .

Part of Arctostrea fossil from dalmiapuram,India.( Photo Courtesy: (C)World Fossil Society.Photo by Riffin T Sajeev ,Russel T Sajeev

Part of Arctostrea fossil from dalmiapuram,India.( Photo Courtesy: (C)World Fossil Society.Photo by Riffin T Sajeev ,Russel T Sajeev

 

 Arctostrea fossil from dalmiapuram,India.( Photo Courtesy: (C)World Fossil Society.Photo by Riffin T Sajeev ,Russel T Sajeev

Arctostrea fossil from dalmiapuram,India.( Photo Courtesy: (C)World Fossil Society.Photo by Riffin T Sajeev ,Russel T Sajeev

Pervinquiere (1910) proposed to separate from Alectryonia new genus, Arctostrea, with type species Ostrea carinata Lamarck, comprising strongly elongated, slender, arcuate forms with high zigzag commissure. These genera differ in a number of features in external and inner structures, but some representatives of genus Alectryonia (e.g., AL rastellaris or AL gregarea) are rather elongated and arched. Probably the Arctostrea originated from such forms.

 Arctostrea fossil from dalmiapuram,India.( Photo Courtesy: (C)World Fossil Society.Photo by Riffin T Sajeev ,Russel T Sajeev

Arctostrea fossil from dalmiapuram,India.( Photo Courtesy: (C)World Fossil Society.Photo by Riffin T Sajeev ,Russel T Sajeev

 Arctostrea fossil from dalmiapuram,India.( Photo Courtesy: (C)World Fossil Society.Photo by Riffin T Sajeev ,Russel T Sajeev

Arctostrea fossil from dalmiapuram,India.( Photo Courtesy: (C)World Fossil Society.Photo by Riffin T Sajeev ,Russel T Sajeev

 

 Arctostrea fossil from dalmiapuram,India.Commisures are visible( Photo Courtesy: (C)World Fossil Society.Photo by Riffin T Sajeev ,Russel T Sajeev

Arctostrea fossil from dalmiapuram,India.Commisures are visible( Photo Courtesy: (C)World Fossil Society.Photo by Riffin T Sajeev ,Russel T Sajeev

I proposed The Rastellum (Arcostrea) genus in cavery basin geological area may have originated in late Jurassic with adaptive modifications like high toothed commissure. The reason for such adaptation is the existence of high energy environment with heavy sedimentation. Hence the possibility of various adaptations on the alectryonia cannot be ruled out. The functional importance of high toothed commissure was broadly discussed by Carter (1968) on the Cretaceous representatives of Arctostrea.

 Arctostrea fossil from dalmiapuram,India.( Photo Courtesy: (C)World Fossil Society.Photo by Riffin T Sajeev ,Russel T Sajeev

Arctostrea fossil from dalmiapuram,India.( Photo Courtesy: (C)World Fossil Society.Photo by Riffin T Sajeev ,Russel T Sajeev

  • Riffin T Sajeev (2013) “Occurrence of Arctostrea: Existence of high energy Paleoenvironment in Cauvery basin, India during Late Cretaceous.” International Journal of Scientific & Engineering Research Volume 4, Issue 12, December-2013,ISSN 2229-5518

WFS News: fossilized flowers found in Argentina

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Around 66 million years ago, at the end of the Cretaceous period, a giant asteroid crashed into the present-day Gulf of Mexico, leading to the extinction of the non-avian dinosaurs. How plants were affected is less understood, but fossil records show that ferns were the first plants to recover many thousands of years afterward.

Two fossilized flowers next to each were discovered in shales of the Salamanca Formation in Chubut Province, Patagonia, Argentina. Credit: Nathan Jud, Cornell University

Two fossilized flowers next to each were discovered in shales of the Salamanca Formation in Chubut Province, Patagonia, Argentina.Credit: Nathan Jud, Cornell University

Now, a team including Cornell researchers reports the discovery of the first fossilized flowers from South America, and perhaps the entire Southern Hemisphere, following the extinction event. The fossils date back to the early Paleocene epoch, less than one million years after the asteroid struck. They were discovered in shales of the Salamanca Formation in Chubut Province, Patagonia, Argentina.

The researchers identified the fossilized flowers as belonging to the buckthorn family (Rhamnaceae). Today, the family is found worldwide.

Notiantha grandensis Jud, Gandolfo, Iglesias & Wilf, gen et sp. nov. (A) Flower in transverse view showing pentamerous structure, sepals triangular with a distinct keel, cucullate petals alternating with sepals, stamens antepetalous, and floral disk surrounding a coalified gynoecium. MPEF-Pb 8548a. (B) Counterpart of specimen in ‘A’ showing a sepal with a central keel and two marginal veins converging toward the apex (at arrow) MPEF-Pb 8548b. (C) Composite digital illustration of the flower created from ‘A’ and ‘B’. (D) Flower in longitudinal view showing slender pedicel, floral cup (at arrow), three preserved sepals, and a cucullate petal (at arrowhead). MPEF-Pb 8549. (E) Close-up of the petal in ‘D’ showing clawed structure and the longitudinally folded distal portion of the petal; the overlapping lobes are marked with arrows. MPEF-Pb 8549. (F) Flower in longitudinal view showing slender pedicel and three sepals. MPEF-Pb 8551. (G) Close-up of flower in ‘A’ showing the keeled sepal (at arrowhead), and the notched petal apex (at arrow). MPEF-Pb 8548a. (H) Close-up of flower in ‘A’ showing an anther opposite a petal, and a line suggesting where the anther filament adnate to the petal at its base (at arrow). MPEF-Pb 8548a. Scale bars: A-D, F = 2 mm; E = 0.5 mm; G, H = 1 mm.

Notiantha grandensis Jud, Gandolfo, Iglesias & Wilf, gen et sp. nov.
(A) Flower in transverse view showing pentamerous structure, sepals triangular with a distinct keel, cucullate petals alternating with sepals, stamens antepetalous, and floral disk surrounding a coalified gynoecium. MPEF-Pb 8548a. (B) Counterpart of specimen in ‘A’ showing a sepal with a central keel and two marginal veins converging toward the apex (at arrow) MPEF-Pb 8548b. (C) Composite digital illustration of the flower created from ‘A’ and ‘B’. (D) Flower in longitudinal view showing slender pedicel, floral cup (at arrow), three preserved sepals, and a cucullate petal (at arrowhead). MPEF-Pb 8549. (E) Close-up of the petal in ‘D’ showing clawed structure and the longitudinally folded distal portion of the petal; the overlapping lobes are marked with arrows. MPEF-Pb 8549. (F) Flower in longitudinal view showing slender pedicel and three sepals. MPEF-Pb 8551. (G) Close-up of flower in ‘A’ showing the keeled sepal (at arrowhead), and the notched petal apex (at arrow). MPEF-Pb 8548a. (H) Close-up of flower in ‘A’ showing an anther opposite a petal, and a line suggesting where the anther filament adnate to the petal at its base (at arrow). MPEF-Pb 8548a. Scale bars: A-D, F = 2 mm; E = 0.5 mm; G, H = 1 mm.

The study was published May 10 in the online journal PLOS One. “The fossilized flowers provide a new window into the earliest Paleocene communities in South America, and they are giving us the opportunity to compare the response to the extinction event on different continents,” said Nathan Jud, the paper’s first author and a postdoctoral researcher in Maria Gandolfo’s lab, a senior research associate at the L.H. Bailey Hortorium and a co-author of the paper.

The finding also helps resolve an ongoing debate in the field of paleobotany on the origin of the Rhamnaceae plant family. Scientists have argued about whether early buckthorns originated in an ancient supercontinent called Gondwana, which later split and includes most of the Southern Hemisphere landmasses today; or whether the family originated in another supercontinent called Laurasia that accounts for most of today’s Northern Hemisphere landmasses.

“This, and a handful of other recently-discovered fossils from the Southern Hemisphere, supports a Gondwanan origin for Rhamnaceae in spite of the relative scarcity of fossils in the Southern Hemisphere relative to the Northern Hemisphere,” Jud said.

Fossils found in Colombia and Southern Mexico offer evidence that plants from the Rhamnaceae family first appeared in the Late Cretaceous epoch shortly before the extinction event, Jud said.

Comparison of fossil (A-F) and modern Rhamnaceae leaves (G-J). (A) S. grandensis MPEF-Pb 8553 showing overall shape, stout petiole, acute base (at arrow), serrate margin, and acrodromous primary veins. (B) S. grandensis MPEF-Pb 8560 showing its shape, acute to attenuate apex (at arrow), serrate margin, and acrodromous primary veins. (C) S. grandensis MPEF-Pb 8555 showing overall shape, petiole, acute base, serrate margin, and acrodromous primary veins. (D) Close-up of the leaf blade (MPEF-Pb 8552) showing mixed percurrent epimedial tertiary veins running between the medial primary vein (mp) and the lateral primary vein (lp). Note that they form an acute angle to the medial primary vein. (E). S. grandensis MPEF 8563 overall shape, petiole, acute base, serrate margin, and acrodromous primary veins, and an asymmetric, obtuse apex. (F) Close-up of the margin in ‘E’ showing exterior tertiary veins that are looped or terminating at the margin; note the glandular tooth apex (at arrow). (G) Leaf of Sarcomphalus saeri (Pittier) Hauenschild US 2045934 showing ovate blade, petiole, rounded base, acute apex, serrate margin, three acrodromous primary veins, and alternate percurrent epimedial tertiary veins. (H) Leaf of S. saeri US 3554997 showing ovate blade, petiole, rounded base, acute apex, serrate margin with apically oriented teeth, three acrodromous primary veins, distal major secondary veins, and alternate percurrent epimedial tertiary veins. (I) Cleared leaf of Ziziphus sativa Gaertn. (junior synonym of Z. jujuba Miller) NCLC-H 1791 showing ovate to elliptic blade, acute base, acute apex, serrate margin with apically oriented teeth, three acrodromous primary veins. (J) Close-up of the leaf in ‘I’ showing the apically oriented glandular teeth. Note the similarity to ‘F.’ Scale bars: A, B, H = 10 mm; C, E = 5 mm; D = 3 mm; F, J = 2 mm; G = 15 mm; I = 40 mm

Comparison of fossil (A-F) and modern Rhamnaceae leaves (G-J).
(A) S. grandensis MPEF-Pb 8553 showing overall shape, stout petiole, acute base (at arrow), serrate margin, and acrodromous primary veins. (B) S. grandensis MPEF-Pb 8560 showing its shape, acute to attenuate apex (at arrow), serrate margin, and acrodromous primary veins. (C) S. grandensis MPEF-Pb 8555 showing overall shape, petiole, acute base, serrate margin, and acrodromous primary veins. (D) Close-up of the leaf blade (MPEF-Pb 8552) showing mixed percurrent epimedial tertiary veins running between the medial primary vein (mp) and the lateral primary vein (lp). Note that they form an acute angle to the medial primary vein. (E). S. grandensis MPEF 8563 overall shape, petiole, acute base, serrate margin, and acrodromous primary veins, and an asymmetric, obtuse apex. (F) Close-up of the margin in ‘E’ showing exterior tertiary veins that are looped or terminating at the margin; note the glandular tooth apex (at arrow). (G) Leaf of Sarcomphalus saeri (Pittier) Hauenschild US 2045934 showing ovate blade, petiole, rounded base, acute apex, serrate margin, three acrodromous primary veins, and alternate percurrent epimedial tertiary veins. (H) Leaf of S. saeri US 3554997 showing ovate blade, petiole, rounded base, acute apex, serrate margin with apically oriented teeth, three acrodromous primary veins, distal major secondary veins, and alternate percurrent epimedial tertiary veins. (I) Cleared leaf of Ziziphus sativa Gaertn. (junior synonym of Z. jujuba Miller) NCLC-H 1791 showing ovate to elliptic blade, acute base, acute apex, serrate margin with apically oriented teeth, three acrodromous primary veins. (J) Close-up of the leaf in ‘I’ showing the apically oriented glandular teeth. Note the similarity to ‘F.’ Scale bars: A, B, H = 10 mm; C, E = 5 mm; D = 3 mm; F, J = 2 mm; G = 15 mm; I = 40 mm

Though there was likely some extinction when the asteroid struck, especially near the crater where everything was destroyed by impact-generated wildfires, he added.

One scenario is that Rhamnaceae first appeared in the tropics of Gondwana, but survived the extinction in Patagonia, and then spread from there after the extinction event as plants re-colonized the most affected areas, Jud said.

The Salamanca Formation is among the most precisely-dated sites from that era in the world. The age of the fossils was corroborated by radiometric dating (using radioactive isotopes), the global paleomagnetic sequence (signatures of reversals of Earth’s magnetic field found in the samples), and fossil correlations (age of other fossils).

“These are the only flowers of Danian age [an age that accounts for about 5 million years following the extinction event] for which we have good age control,” said Jud. Researchers have discovered other fossilized flowers in India and China from around the Danian age, but their dates are not as precise, he said.

To determine that the fossilized flowers from Argentina belonged to the Rhamnaceae family, the authors noticed that the organization of the petals and stamens in the fossil is found in Rhamnaceae and a few other families. They found examples of 10 of the 11 living Rhamnaceae tribes in the L.H. Bailey Hortorium Herbarium at Cornell University, which then were compared with morphological features in the fossil flowers to identify them.

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

Citation:Nathan A. Jud, Maria A. Gandolfo, Ari Iglesias, Peter Wilf. Flowering after disaster: Early Danian buckthorn (Rhamnaceae) flowers and leaves from Patagonia. PLOS ONE

WFS News: Nodosaur,The Amazing Dinosaur Accidentally Found

Some 110 million years ago, this armored plant-eater lumbered through what is now western Canada, until a flooded river swept it into open sea. The dinosaur’s undersea burial preserved its armor in exquisite detail. Its skull still bears tile-like plates and a gray patina of fossilized skins.

On the afternoon of March 21, 2011, a heavy-equipment operator named Shawn Funk was carving his way through the earth, unaware that he would soon meet a dragon.
Nodosaur,a type of Ankylosaur

                                                                           Nodosaur,a type of Ankylosaur

That Monday had started like any other at the Millennium Mine, a vast pit some 17 miles north of Fort McMurray, Alberta, operated by energy company Suncor. Hour after hour Funk’s towering excavator gobbled its way down to sands laced with bitumen—the transmogrified remains of marine plants and creatures that lived and died more than 110 million years ago. It was the only ancient life he regularly saw. In 12 years of digging he had stumbled across fossilized wood and the occasional petrified tree stump, but never the remains of an animal—and certainly no dinosaurs.

 In life this imposing herbivore—called a nodosaur—stretched 18 feet long and weighed nearly 3,000 pounds. Researchers suspect it initially fossilized whole, but when it was found in 2011, only the front half, from the snout to the hips, was intact enough to recover. The specimen is the best fossil of a nodosaur ever found.  COMPOSITE OF EIGHT IMAGES PHOTOGRAPHED AT ROYAL TYRRELL MUSEUM OF PALAEONTOLOGY, DRUMHELLER, ALBERTA (ALL)

In life this imposing herbivore—called a nodosaur—stretched 18 feet long and weighed nearly 3,000 pounds. Researchers suspect it initially fossilized whole, but when it was found in 2011, only the front half, from the snout to the hips, was intact enough to recover. The specimen is the best fossil of a nodosaur ever found.COMPOSITE OF EIGHT IMAGES PHOTOGRAPHED AT ROYAL TYRRELL MUSEUM OF PALAEONTOLOGY, DRUMHELLER, ALBERTA (ALL)

But around 1:30, Funk’s bucket clipped something much harder than the surrounding rock. Oddly colored lumps tumbled out of the till, sliding down onto the bank below. Within minutes Funk and his supervisor, Mike Gratton, began puzzling over the walnut brown rocks. Were they strips of fossilized wood, or were they ribs? And then they turned over one of the lumps and revealed a bizarre pattern: row after row of sandy brown disks, each ringed in gunmetal gray stone.

“Right away, Mike was like, ‘We gotta get this checked out,’ ” Funk said in a 2011 interview. “It was definitely nothing we had ever seen before.”

A cluster of pebble-like masses may be remnants of the nodosaur's last meal.

                                             A cluster of pebble-like masses may be remnants of the nodosaur’s last meal.

Nearly six years later, I’m visiting the fossil prep lab at the Royal Tyrrell Museum in the windswept badlands of Alberta. The cavernous warehouse swells with the hum of ventilation and the buzz of technicians scraping rock from bone with needle-tipped tools resembling miniature jackhammers. But my focus rests on a 2,500-pound mass of stone in the corner.

At first glance the reassembled gray blocks look like a nine-foot-long sculpture of a dinosaur. A bony mosaic of armor coats its neck and back, and gray circles outline individual scales. Its neck gracefully curves to the left, as if reaching toward some tasty plant. But this is no lifelike sculpture. It’s an actual dinosaur, petrified from the snout to the hips.

The more I look at it, the more mind-boggling it becomes. Fossilized remnants of skin still cover the bumpy armor plates dotting the animal’s skull. Its right forefoot lies by its side, its five digits splayed upward. I can count the scales on its sole. Caleb Brown, a postdoctoral researcher at the museum, grins at my astonishment. “We don’t just have a skeleton,” he tells me later. “We have a dinosaur as it would have been.”

During its burial at sea, the nodosaur settled onto its back, pressing the dinosaur’s skeleton into the armor and embossing it with the outlines of some bones. One ripple in the armor traces the animal’s right shoulder blade.

During its burial at sea, the nodosaur settled onto its back, pressing the dinosaur’s skeleton into the armor and embossing it with the outlines of some bones. One ripple in the armor traces the animal’s right shoulder blade.

For paleontologists the dinosaur’s amazing level of fossilization—caused by its rapid undersea burial—is as rare as winning the lottery. Usually just the bones and teeth are preserved, and only rarely do minerals replace soft tissues before they rot away. There’s also no guarantee that a fossil will keep its true-to-life shape. Feathered dinosaurs found in China, for example, were squished flat, and North America’s “mummified” duck-billed dinosaurs, among the most complete ever found, look withered and sun dried.

Paleobiologist Jakob Vinther, an expert on animal coloration from the U.K.’s University of Bristol, has studied some of the world’s best fossils for signs of the pigment melanin. But after four days of working on this one—delicately scraping off samples smaller than flecks of grated Parmesan—even he is astounded. The dinosaur is so well preserved that it “might have been walking around a couple of weeks ago,” Vinther says. “I’ve never seen anything like this.”

A poster for the movie Night at the Museum hangs on the wall behind Vinther. On it a dinosaur skeleton emerges from the shadows, magically brought back to life.

The remarkable fossil is a newfound species (and genus) of nodosaur, a type of ankylosaur often overshadowed by its cereal box–famous cousins in the subgroup Ankylosauridae. Unlike ankylosaurs, nodosaurs had no shin-splitting tail clubs, but they too wielded thorny armor to deter predators. As it lumbered across the landscape between 110 million and 112 million years ago, almost midway through the Cretaceous period, the 18-foot-long, nearly 3,000-pound behemoth was the rhinoceros of its day, a grumpy herbivore that largely kept to itself. And if something did come calling—perhaps the fearsome Acrocanthosaurus—the nodosaur had just the trick: two 20-inch-long spikes jutting out of its shoulders like a misplaced pair of bull’s horns.

Courtesy:Article in nat Geo

Key:WFS,World Fossil Society,Riffin T Sajeev,Russel T Sajeev

WFS News: Sponges Ruled the World After Second-Largest Mass Extinction

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

Sponges may be simple creatures, but they basically ruled the world some 445 million years ago, after the Ordovician mass extinction, a new study finds.

Roughly 85 percent of all species died in the Ordovician mass extinction, the first of the world’s five known mass extinctions. (The other mass extinctions are the Late Devonian, End Permian, End Triassic and End Cretaceous.) However, while the Ordovician mass extinction wiped out many of these ancient creatures, one group actually prospered: sponges.

“We think the sponges thrived because they can tolerate changes in temperature and low oxygen levels, while their food source (organic particles in the water) would have been increased enormously by the death and destruction all around them,” lead study author Joe Botting, a paleontologist at Nanjing Institute of Geology and Palaeontology in China, said in a statement.

Chinese and British researchers discovered the fossils of some of these sponges in the newfound Anji Biota, a fossil deposit in the bamboo forests of Zhejiang province, in eastern China. The scientists uncovered nearly 100 species during their first excavation at Anji, and 75 of these species were sponges, many with preserved soft tissues, they said. [Wipe Out: History’s Most Mysterious Extinctions]

The diversity of sponges is impressive given that the end-Ordovician event is the second-largest mass extinction on record, the researchers said.

Fossils of 444-million-year-old sponges from the Anji Biota in China that thrived after the mass extinction. Credit: J.P. Botting

Fossils of 444-million-year-old sponges from the Anji Biota in China that thrived after the mass extinction.
Credit: J.P. Botting

The extinction occurred when a sudden, intense ice age was followed by an equally rapid warming period, which changed the ocean’s chemistry and circulation, the researchers said. Earlier studies show that plankton quickly recovered after the extinction, but there are few fossils from that time period that show how other organisms fared, they said. In fact, until the discovery of the Anji Biota, the only known, well-preserved fossil deposit from that era was South Africa’s Soom Shale.

Usually, mass extinctions decimate animal life, with the surviving ecosystems holding only small, stunted species that somehow managed to survive. In contrast, thousands of fossils indicate that the sponges in the Anji Biota were large and complex. Moreover, while some sponge species lived only in certain areas, others were so plentiful, they formed forests on the seafloor, the fossils show.

In addition, the researchers uncovered several mollusks known as nautiloids, as well as a rare find: a single fossil sea scorpion that still had its legs.

It’s possible that the vast abundance of sponges in ancient China helped the post-extinction ecosystem recover “by stabilizing the sediment surface [and] allowing sessile [immobile] suspension feeders such as brachiopods, corals and bryozoans to recover rapidly,” the researchers wrote in the study.

What’s more, other scientists have discovered numerous sponge remains dating to periods following other mass extinction events, suggesting that it’s not uncommon for sponges to take over following a major ecological collapse, the researchers said.

The findings were published online Feb. 9 in the journal Current Biology.

Courtesy: Article by Laura Geggel, Senior Writer ,Live science.

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