Romer's Gap Plugged: 5 new Tetrapods From Tournaisian Mississippian Carboniferous Scotland

Phylogenetic and environmental context of a Tournaisian tetrapod fauna

Authors:

Clack et al

Abstract:

The end-Devonian to mid-Mississippian time interval has long been known for its depauperate palaeontological record, especially for tetrapods. This interval encapsulates the time of increasing terrestriality among tetrapods, but only two Tournaisian localities previously produced tetrapod fossils. Here we describe five new Tournaisian tetrapods (Perittodus apsconditus, Koilops herma, Ossirarus kierani, Diploradus austiumensis and Aytonerpeton microps) from two localities in their environmental context. A phylogenetic analysis retrieved three taxa as stem tetrapods, interspersed among Devonian and Carboniferous forms, and two as stem amphibians, suggesting a deep split among crown tetrapods. We also illustrate new tetrapod specimens from these and additional localities in the Scottish Borders region. The new taxa and specimens suggest that tetrapod diversification was well established by the Tournaisian. Sedimentary evidence indicates that the tetrapod fossils are usually associated with sandy siltstones overlying wetland palaeosols. Tetrapods were probably living on vegetated surfaces that were subsequently flooded. We show that atmospheric oxygen levels were stable across the Devonian/Carboniferous boundary, and did not inhibit the evolution of terrestriality. This wealth of tetrapods from Tournaisian localities highlights the potential for discoveries elsewhere.

pop sci write up.

Subduction or sagduction in Scotland's Archean ultramafic–mafic bodies

Subduction or sagduction? Ambiguity in constraining the origin of ultramafic–mafic bodies in the Archean crust of NW Scotland

Authors:

Johnson et al

Abstract:

The Lewisian Complex of NW Scotland is a fragment of the North Atlantic Craton. It comprises mostly Archean tonalite–trondhjemite–granodiorite (TTG) orthogneisses that were variably metamorphosed and reworked in the late Neoarchean to Palaeoproterozoic. Within the granulite facies central region of the mainland Lewisian Complex, discontinuous belts composed of ultramafic–mafic rocks and structurally overlying garnet–biotite gneiss (brown gneiss) are spatially associated with steeply-inclined amphibolite facies shear zones that have been interpreted as terrane boundaries. Interpretation of the primary chemical composition of these rocks is complicated by partial melting and melt loss during granulite facies metamorphism, and contamination with melts derived from the adjacent migmatitic TTG host rocks. Notwithstanding, the composition of the layered ultramafic–mafic rocks is suggestive of a protolith formed by differentiation of tholeiitic magma, where the ultramafic portions of these bodies represent the metamorphosed cumulates and the mafic portions the metamorphosed fractionated liquids. Although the composition of the brown gneiss does not clearly discriminate the protolith, it most likely represents a metamorphosed sedimentary or volcano-sedimentary sequence. For Archean rocks, particularly those metamorphosed to granulite facies, the geochemical characteristics typically used for discrimination of paleotectonic environments are neither strictly appropriate nor clearly diagnostic. Many of the rocks in the Lewisian Complex have ‘arc-like’ trace element signatures. These signatures are interpreted to reflect derivation from hydrated enriched mantle and, in the case of the TTG gneisses, partial melting of amphibolite source rocks containing garnet and a Ti-rich phase, probably rutile. However, it is becoming increasingly recognized that in Archean rocks such signatures may not be unique to a subduction environment but may relate to processes such as delamination and dripping. Consequently, it is unclear whether the Lewisian ultramafic–mafic rocks and brown gneisses represent products of plate margin or intraplate magmatism. Although a subduction-related origin is possible, we propose that an intraplate origin is equally plausible. If the second alternative is correct, the ultramafic–mafic rocks and brown gneisses may represent the remnants of intracratonic greenstone belts that sank into the deep crust due to their density contrast with the underlying partially molten low viscosity TTG orthogneisses.

Tournaisian Mississipian Tetrapods of Scotland Lived in a Seasonal Mosaic Tropical Forest

The terrestrial landscapes of tetrapod evolution in earliest Carboniferous seasonal wetlands of SE Scotland

Authors:

Kearsey et al

Abstract:

The Lower Mississippian (Tournaisian) Ballagan Formation in SE Scotland yields tetrapod fossils that provide fresh insights into the critical period when these animals first moved onto land. The key to understanding the palaeoenvironments where they lived is a detailed analysis of the sedimentary architecture of this formation, one of the thickest and most completely documented examples of a coastal floodplain and marginal marine succession from this important transitional time anywhere in the world. Palaeosols are abundant, providing a unique insight into the early Carboniferous habitats and climate.

More than 200 separate palaeosols are described from three sections through the formation. The palaeosols range in thickness from 0.02 to 1.85 m and are diverse: most are Entisols and Inceptisols (63%), indicating relatively brief periods of soil development. Gleyed Inseptisols and Vertisols are less common (37%). Vertisols are the thickest palaeosols (up to 185 cm) in the Ballagan Formation and have common vertic cracks. Roots are abundant through all the palaeosols, from shallow mats and thin hair-like traces to sporadic thicker root traces typical of arborescent lycopods.

Geochemical, isotope and clay mineralogical analyses of the palaeosols indicate a range in soil alkalinity and amount of water logging. Estimates of mean annual rainfall from palaeosol compositions are 1000–1500 mm per year. The high mean annual rainfall and variable soil alkalinities contrast markedly with dry periods that developed deep penetrating cracks and evaporite deposits. It is concluded that during the early Carboniferous, this region experienced a sharply contrasting seasonal climate and that the floodplain hosted a mosaic of closely juxtaposed but distinct habitats in which the tetrapods lived. The diversification of coastal floodplain environments identified here may link to the evolution and movement of tetrapods into the terrestrial realm.

Neolithic People Purposefully Introduced Red Deer to the Scottish Islands

Colonization of the Scottish islands via long-distance Neolithic transport of red deer (Cervus elaphus)

Authors:

Stanton et al

Abstract:

Red deer (Cervus elaphus) have played a key role in human societies throughout history, with important cultural significance and as a source of food and materials. This relationship can be traced back to the earliest human cultures and continues to the present day. Humans are thought to be responsible for the movement of a considerable number of deer throughout history, although the majority of these movements are poorly described or understood. Studying such translocations allows us to better understand ancient human–wildlife interactions, and in the case of island colonizations, informs us about ancient human maritime practices. This study uses DNA sequences to characterise red deer genetic diversity across the Scottish islands (Inner and Outer Hebrides and Orkney) and mainland using ancient deer samples, and attempts to infer historical colonization events. We show that deer from the Outer Hebrides and Orkney are unlikely to have originated from mainland Scotland, implying that humans introduced red deer from a greater distance. Our results are also inconsistent with an origin from Ireland or Norway, suggesting long-distance maritime travel by Neolithic people to the outer Scottish Isles from an unknown source. Common haplotypes and low genetic differentiation between the Outer Hebrides and Orkney imply common ancestry and/or gene flow across these islands. Close genetic proximity between the Inner Hebrides and Ireland, however, corroborates previous studies identifying mainland Britain as a source for red deer introductions into Ireland. This study provides important information on the processes that led to the current distribution of the largest surviving indigenous land mammal in the British Isles.

Consider Romer's Gap Plugged! New Floodplain Siltstone Deposit From Scotland Preserves Tetrapods From Tournaisian Carboniferous

Early Mississippian sandy siltstones preserve rare vertebrate fossils in seasonal flooding episodes

Authors:

Bennett et al

Abstract:

Flood-generated sandy siltstones are under-recognised deposits that preserve key vertebrate (actinopterygians, rhizodonts, and rarer lungfish, chondrichthyans and tetrapods), invertebrate and plant fossils. Recorded for the first time from the Lower Mississippian Ballagan Formation of Scotland, more than 140 beds occur throughout a 490 m thick core succession characterised by fluvial sandstones, palaeosols, siltstones, dolostone ‘cementstones’ and gypsum from a coastal–alluvial plain setting. Sandy siltstones are described as a unique taphofacies of the Ballagan Formation. They are matrix-supported siltstones with millimetre-sized siltstone and very fine sandstone lithic clasts. Common bioclasts include plants and megaspores, fish, ostracods, eurypterids and bivalves. Fossils have a high degree of articulation compared with those found in other fossil-bearing deposits such as conglomerate lags at the base of fluvial channel sandstones. Bed thickness and distribution varies throughout the formation, with no stratigraphic trend. The matrix sediment and clasts are sourced from the reworking of floodplain sediments including desiccated surfaces and palaeosols. Secondary pedogenic modification affects 30% of the sandy siltstone beds and most (71%) overlie palaeosols or desiccation cracks. Sandy siltstones are interpreted as cohesive debris flow deposits that originated by the overbank flooding of rivers and due to localised floodplain sediment transport at times of high rainfall; their association with palaeosols and desiccation cracks indicates seasonally wet to dry cycles throughout the Tournaisian. Tetrapod and fish fossils derived from floodplain lakes and land surfaces are concentrated by local erosion and reworking and are preserved by deposition into temporary lakes on the floodplain; their distribution indicates a local origin, with sediment distributed across the floodplain in seasonal rainfall episodes. These deposits are significant new sites that can be explored for the preservation of rare non-marine fossil material and provide unique insights into the evolution of early terrestrial ecosystems.

Heterolithic Meandering-channel Deposits From Neoproterozoic Scotland may Give Insight to Martian Riverbeds

Heterolithic meandering-channel deposits from the Neoproterozoic of NW Scotland: Implications for palaeogeographic reconstructions of Precambrian sedimentary environments

Authors:

Santos et al

Abstract:

Pre-Silurian fine-grained meandering river deposits are apparently rare in the rock record. Most modern-day river dynamics are influenced by vegetation through bank stabilization, fine-grained sediment production and retention, and runoff control, leading to the development of highly sinuous, single-channel systems. In contrast, pre-vegetation river dynamics are poorly understood, in part because there are no modern-day analogues for completely non-vegetated meandering river systems, particularly under humid climates. Some models attribute the paucity of fine-grained sediments described from studies of pre-vegetation fluvial deposits to lower rates of chemical weathering in the absence of land plants. The architecture of precambrian, fine-grained meandering stream deposits is here described for the first time.

The Allt na Béiste Member at the base of the Applecross Formation of the Torridon Group (Neoproterozoic, NW Scotland) is characterized by heterolithic deposits, preserving a varied suite of fluvial forms including inclined heterolithic strata, lateral-accretion sets, up to 8 m-thick muddy floodplain deposits with preserved crevasse-splays. Successions of laterally-accreting strata are interbedded with metre-scale channel-fill sandstones, in a succession up to 190 m-thick related to the early stages of the Applecross Formation fluvial system, as large-scale rivers buried the Lewisian palaeovalleys over which fluvial and lacustrine sediments of the Diabaig Formation had been deposited. The lacustrine fine-grained sediments, coupled with relatively low gradients of the shallow lacustrine environments and denuded, highly weathered Lewisian basement, apparently provided considerable amounts of fine-grained sediment which added sufficient cohesion to this fluvial system to induce the adoption of laterally-migrating, meandering channel planforms at the expense of multi-thread braided channels.

Our data suggest that, given appropriate conditions, pre-vegetation meandering channel planforms were indeed able to develop, without the buffering effects of land plants. The paucity of fine-grained sediments in the pre-vegetation rock record may be more a consequence of preservation-related issues than the actual paucity of such sediments. These results provide novel insights into the characteristics of Earth's landscape prior to the Silurian, and provide potential analogues for meandering channels interpreted from satellite imagery of Mars.

More Threats From Scotland to Seek Independence

Scotland's First Minister on Friday warned that a united Britain was "on borrowed time" unless Prime Minister David Cameron devolved more powers to Edinburgh, on the first anniversary of a historic independence referendum.

Scottish voters decided to stay part of the United Kingdom by 55 percent to 45 percent on September 18 last year, but First Minister Nicola Sturgeon told supporters that she would favour another referendum if polls showed renewed public demand.

"Only the people can decide if we will have another referendum," the Scottish National Party (SNP) leader said in the anniversary address.

"Only the people can decide when that will be. And only the people can decide if Scotland will become independent."

Recent polls have shown an increased support for independence.

"Right now, what people see at Westminster is a Tory government failing to fully deliver on the vow it made on more powers for our parliament," she said in the speech in a conference hall in Edinburgh.

link.

New Scottish Independence Vote on its way...AGAIN

Scottish nationalists will propose holding a new referendum on independence from the rest of Britain, Scotland's First Minister Nicola Sturgeon said on Sunday.

Sturgeon said her pro-independence Scottish National Party (SNP) would set out a timescale for a referendum in its manifesto ahead of regional elections next year.

"Our manifesto will set out what we consider are the circumstances and the timescale on which a second referendum might be appropriate," Sturgeon told the Press Association news agency.

The manifesto is due to be unveiled at the SNP's annual conference next month.

link.

I guess that was NOT settled for a generation.

Evidence of a Stenian MesoProterozoic Impact Discovered in Scotland

Precambrian reidite discovered in shocked zircon from the Stac Fada impactite, Scotland

Authors:

Reddy et al

Abstract:

Terrestrial impact events have had a profound influence on Earth's geological, geochemical, and biological evolution. However, the record of Precambrian impacts is poorly constrained due to the dynamic nature of plate tectonics, erosion, and deposition of younger rocks that may destroy or cover the evidence. Here we report the first Precambrian occurrence of the rare mineral reidite (ZrSiO4) within grains of shocked zircon in the ca. 1.18 Ga Stac Fada Member (Stoer Group), northwestern Scotland. The reidite, preserved as less than 2-μm-wide lamellae, is unambiguous evidence of shock pressures in excess of ∼30 GPa and confirms the impact origin for the Stac Fada deposit. The reidite lamellae are locally deformed, and sites of deformation record its decomposition to baddeleyite (ZrO2) and amorphous silica, the first natural example of this transformation. The findings demonstrate that reidite and baddeleyite may form and be transported in high-energy ejecta without physical or chemical breakdown and are stable during sedimentary diagenesis and low-grade metamorphism. Thus, reidite may be preserved over time scales exceeding 1 b.y., establishing the use of reidite within detrital shocked zircon from Precambrian strata as a viable and valuable means of recognizing and characterizing ancient terrestrial impact events.

Salmond Says Second Scottish Independence Referendum Inevitable

Former Scottish nationalist leader Alex Salmond said Sunday that another referendum on independence from the United Kingdom was "inevitable" because of policies pursued by Prime Minister David Cameron's government in London.

"I think a second independence referendum is inevitable," Salmond told the BBC, although he would not say when.

Salmond resigned as leader of the Scottish National Party (SNP) and first minister of the devolved government in Edinburgh after Scots voted "no" to independence by 55 to 45 percent in September.

But nationalist feeling has soared in Scotland since then, and in May's general election the SNP won 56 out of 59 Scottish seats in the House of Commons, making them the third largest party after the main opposition Labour party.

link.

Whoa-Awesome Level: Fossil Ripple Marks Indicate Middle Devonian Wind Direction During dry Season (April to July)

Ripple marks indicate Mid-Devonian palaeo-wind directions in the Orcadian Basin (Orkney Isles, Scotland)

Authors:

De Vleeschouwer et al

Abstract:

Few climate proxies provide information on palaeo-wind directions. However, fossilized bedform elements can provide insight into the direction of flow that formed them. Wave-formed ripple marks, for example, which developed in shallow waters, extend transverse to the wind direction. In this study, Middle Devonian palaeo-wind directions are reconstructed by measuring the orientation of 511 fossilized wave ripple marks in the Rousay Flagstone Formation on the island of Westray, Orkney, Scotland. The orientation of ripple marks was measured in four different localities on the island. A chi-squared test demonstrates that these four ripple-mark subsets show the same distribution of ripple mark orientation and thus indicates that the studied ripple marks display the same distribution of palaeo-winds. Two dominant ripple mark orientations were observed at all studied localities. The most abundant ripple mark orientation suggests palaeo-winds from the present-day North or South. Second most abundant are ripple marks that suggest palaeo-winds from the present-day ENE or WSW (70° or 250°). When a 40° clockwise rotation of Orkney since the Middle Devonian is taken into account, the ripple marks suggest that the dominant wind directions were south-southeast (SSE) and north-northeast (NNE) in the tropical setting of the Orcadian basin. The SSE wind-direction is represented by the abundant ripple marks, with a present-day near N-S orientation of the line perpendicular to the crests. These ripple marks are also characterized by the largest wavelengths. The abundance of the latter ripple marks with long wavelengths is the result of a lower water level and thus a larger wave-exposed surface during the dry winter season, from April to July, which was mainly characterized by SSE palaeo-trade winds.

Dearcmhara shawcrossi: a new Toarcian/Bajocian Jurassic Ichthyosaur From Scotland

Ichthyosaurs from the Jurassic of Skye, Scotland

Authors:

Brusatte et al

Abstract:

Fossils of Mesozoic vertebrates are rare in Scotland, particularly specimens of marine reptiles such as plesiosaurs and ichthyosaurs. We describe a suite of ichthyosaur fossils from the Early to Middle Jurassic of Skye, which to our knowledge are the first ichthyosaurs from Scotland to be described and figured in detail. These fossils span approximately 30 million years, from the Sinemurian to the Bathonian, and indicate that ichthyosaurs were a major component of Scottish marine faunas during this time. The specimens include isolated teeth that could represent the most northerly known occurrences of the widespread Sinemurian species Ichthyosaurus communis, a characteristic component of the famous Lyme Regis faunas of England, suggesting that such faunas were also present in Scotland during the Early Jurassic. An associated humerus and vertebrae from Toarcian–Bajocian-aged deposits are named as a new genus and species of basal neoichthyosaurian, Dearcmhara shawcrossi. The taxonomic affinities of this taxon, which comes from a critical but poorly sampled interval in the fossil record, suggest that non-ophthalmosaurid neoichthyosaurians dominated European assemblages around the Early–Middle Jurassic boundary, and were later replaced by ophthalmosaurids, whose radiation likely took place outside Europe. Many of these specimens were collected by amateurs and donated to museum collections, a co-operative relationship essential to the preservation of Scotland’s fossil heritage.

Scotland Will Seek new Independence Referendum if Britain Fails to Keep Devo Max Promise

Scotland may seek another independence vote if Britain's rulers fail to honor their pledge to grant it further autonomy, outgoing Scottish National Party leader Alex Salmond warned on Friday, less than two months after Scots spurned independence.

Salmond, in his final speech as party leader, told members that Scotland would eventually secure his dream of independence from London. He also delivered a warning to British Prime Minister David Cameron:

"Let the message be very clear from this hall and from this country ... Prime Minister - delay, prevaricate, block or obstruct the implementation of what Scotland was promised, and Scotland will take matters into our own, democratic, hands."

link.

The First Pterosaur From Kimmeridgian Jurassic Scotland

A Scottish pterosaur in London: the first record of Pterosauria from the Upper Jurassic (Kimmeridgian) of Eathie (Ross and Cromarty), Scotland

Authors:

Steel et al

Abstract:

A pterosaur wing phalange from the Kimmeridgian of Eathie (Ross and Cromarty) is identified as the first pterosaur to have been collected in Scotland. The specimen was acquired by the British Museum (Natural History) in 1888, but an old collector's label gives the date of collection as 1850. The handwriting matches that of Charles W. Peach (1800–1886), who later became better known for his fossil fish and plant collections, which still exist in the Natural History Museum, London, and other museums. Peach collected this pterosaur specimen during his first year of working in Scotland, and it was probably one of his earliest finds of north of the border. Pterosaur remains are exceptionally rare in Scotland and otherwise unknown from this particular site, so this newly recognised specimen is a significant addition to the Scottish fossil record. It is also among the earliest UK pterosaur finds, post-dating Mary Anning's discovery of Dimorphodon by just over two decades.

British Government Lays out Path Forward for Scottish Devolution

The British government on Monday formally outlined a timetable to grant more autonomy to Scotland, following accusations that it would not deliver on promises made in the run-up to last month's independence referendum.

In a report, ministers promised "the publication of draft clauses in January 2015" for new legislation that would grant the devolved parliament in Edinburgh far greater powers on taxation and social welfare.

The powers were offered in the final days of the referendum campaign to persuade Scots to vote against independence, after opinion polls indicated the nationalists might win. Scottish voters ultimately opted to stay in Great Britain.

"The government is meeting the first step in the further devolution process," Scotland minister Alistair Carmichael told the British parliament, where he presented the report.

link.

Despite Independence's Defeat in Scotland, Catalonia is Undetered

Despite Scotland's decision to reject independence, lawmakers in Spain's Catalonia region voted overwhelmingly Friday to give their leader the power to call a secession referendum that the central government in Madrid has denounced as illegal.

The prospect of an independent Scotland had captivated European separatists. Besides the Catalans, their ranks include pro-independence Basques in northern Spain; Corsicans who want to break away from France; Italians from several northern regions; and Flemish speakers in Belgium demanding more autonomy, independence or union with the Netherlands.

Catalonia's regional president, Artur Mas, supported a Yes vote in Scotland, but stressed Catalans simply wanted the same chance as the Scots. Spanish Prime Minister Mariano Rajoy has said he will block a planned Nov. 9 vote in the wealthy northeastern region of 7.5 million people.

"What happened in Scotland and the United Kingdom is not a setback for us because what we really want in Catalonia is to have the chance to vote, the same possibility," Mas said.

Later Friday, the Catalan parliament voted 106-28 to give him the power to call a referendum. Mas didn't say when he would sign the decree to set the vote date.

link.

Obviously the Song for Scotland's Vote Tonight is...

Scotland: The Results are...?

Barring a radical change, I'd say the UK survives intact: right now its about 55/45.  Edinburgh and Glasgow have not reported in though.  From the sounds of things, some SNP strongholds - or supposedly strongholds - voted to stay.  This may be as big a setback from Scottish Independence as 1995 was for Quebec.

Best quote I saw for tonight:

"Not so fast--according to Karl Rove there are still a few precincts in Glasgow yet to report."

In Honor of the Scottish Independence Referendum, a theme song

I'm guessing the polls ought to be opening about this time.   Good luck and make the right choice.

Little Scotlander Chief: This is the Only Referendum on Independence for a Generation

Alex Salmond has said the independence vote is a "once in a generation" opportunity as he pledged not to quickly bring back another referendum if Scots choose to remain in the UK.

Commentators have been predicting a "neverendum" if the No campaign wins on Thursday by a narrow margin, with nationalists calling for a new independence poll within a few years.

As a series of polls indicate the vote remains too close to call, Mr Salmond was asked if he could pledge not to bring back another referendum if the Yes campaign does not win on Thursday, he said: "That's my view. My view is this is a once in a generation, perhaps even a once in a lifetime, opportunity for Scotland."

link.