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Brittle-star mass occurrence on a Late Cretaceous methane seep from South Dakota, USA
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Ben Thuy1,
Neil H. Landman2,
Neal L. Larson3 &
Lea D. Numberger-Thuy1
Scientific Reports volume 8, Article number: 9617 (2018) Cite this article
Palaeoecology
Articulated brittle stars are rare fossils because the skeleton rapidly disintegrates after death and only fossilises intact under special conditions. Here, we describe an extraordinary mass occurrence of the ophiacanthid ophiuroid Brezinacantha tolis gen. et sp. nov., preserved as articulated skeletons from an upper Campanian (Late Cretaceous) methane seep of South Dakota. It is uniquely the first fossil case of a seep-associated ophiuroid. The articulated skeletons overlie centimeter-thick accumulations of dissociated skeletal parts, suggesting lifetime densities of approximately 1000 individuals per m2, persisting at that particular location for several generations. The ophiuroid skeletons on top of the occurrence were preserved intact most probably because of increased methane seepage, killing the individuals and inducing rapid cementation, rather than due to storm-induced burial or slumping. The mass occurrence described herein is an unambiguous case of an autochthonous, dense ophiuroid community that persisted at a particular spot for some time. Thus, it represents a true fossil equivalent of a recent ophiuroid dense bed, unlike other cases that were used in the past to substantiate the claim of a mid-Mesozoic predation-induced decline of ophiuroid dense beds.
Brittle stars, or ophiuroids, are among the most abundant and widespread components of the marine benthos, occurring at all depths and latitudes of the world oceans1. Most of the time, however, ophiuroids tend to live a cryptic life hidden under rocks, inside sponges, epizoic on corals or buried in the mud (e.g.2) to such a point that their real abundance is rarely appreciated at first sight.
As a result, openly visible mass occurrences of brittle stars raise attention and often incite scientific studies to explore the ecological factors explaining the alleged aberrant abundance (e.g.3,4,5,6,7,8). One of the most remarkable examples of a recent ophiuroid mass occurrence was discovered on the Macquarie Ridge chain of Seamounts in 2008 as part of the Census of Marine Life initiative: dubbed "Brittle star city", the spectacular mass aggregation of ophiuroids was met with wide academic and public interest. That same year, the flanks of the Admiralty Seamount in Antarctica yielded a similarly impressive but smaller ophiuroid mass occurrence, consequently called "Brittle star village"9.
Interest in dense ophiuroid aggregations has gone far beyond the mere ecological background of the occurrences. Assumed fossil equivalents (e.g.10,11,12,13,14,15) have shaped the hypothesis that dense ophiuroid populations were common in shallow waters until the Jurassic and then significantly declined by the end of the Mesozoic (e.g.16). In combination with an assumed lower predation pressure in the Jurassic16, ophiuroid mass aggregations gained key witness status for the so-called Marine Mesozoic Revolution: a hypothesised causal connection between the evolution of durophagous predators and the Mesozoic decline of epifaunal suspension-feeder communities17,18. Although recent studies suggest that ophiuroid mass aggregations in modern oceans are neither rare nor restricted to low-predation areas (e.g.8,19), such communities are still commonly considered archaic benthic assemblages20.
We here describe an extraordinary fossil ophiuroid occurrence from the Late Cretaceous of South Dakota. The material is outstanding in several aspects. First, it represents one of the very few seep-associated ophiuroids known to date (e.g.21) and the first from the fossil record. Second, it is an unambiguous case of an autochthonous, dense ophiuroid community that persisted at a particular spot during several generations, thus representing a true fossil equivalent of a recent ophiuroid dense bed. As such, it casts doubt on several other cases of assumed fossil ophiuroid dense beds used in the past to substantiate the predation-induced decline of ophiuroid dense beds during the mid-Mesozoic (e.g.22). Finally, it significantly adds to the very sparse Mesozoic ophiuroid fossil record of the United States and the Western Interior Seaway in particular, currently counting as few as 9 species in total23,24,25,26,27,28,29. Apart from the systematic assessment of the material, we elucidate its intriguing taphonomy and discuss its significance for the interpretation of other fossil ophiuroid mass aggregations.
Geological Context
Methane seep deposits have been recognized in the Upper Cretaceous marine sediments (shales) of the U.S. Western Interior since the late 1800 s and have been extensively studied over the last several decades30,31,32,33,34,35. The structures usually appear as conical mounds with their "core" or micritic bodies that were formed by the erosion of the surrounding, less consolidated sediments. These conical structures have been documented since the late 19th century and are frequently referred to as "tepee buttes"36.
Around the Black Hills, these deposits were formed from methane enriched fluids escaping from underlying layers of the Pierre, Niobrara, Belle Fourche, Mowery and Greenhorn Formations35,37. The presence of methane was confirmed through isotopic analyses of the carbonate cements35,37,38,39. Methane gas probably migrated along faults and fractures that developed in the Late Cretaceous prior to the uplift of the Black Hills during the Laramide Orogeny34,35. Dewatering of the thick, black shales (hundreds of meters thick) due to the weight of the water and sediments also, most likely, contributed to this process35.
Carbonate by-products precipitated out of solution as a result of anaerobic oxidation of methane thus allowing carbonate cementation to occur below the sediment water interface and in and around the fauna at the seeps that might have formed small, elevated mounds on the seafloor, creating refuges in an otherwise less than friendly environment37,40,41. Seeps may have represented semi-permanent self-sustaining habitats that were inhabited by a unique group of animals that lived on the nutrients provided by symbiotic, sulfur-oxidizing chemosynthetic bacteria34,35,42.
Echinoderms seem more common in the Didymoceras cheyennense and Baculites compressus zones around the Black Hills but are still mostly rare at seeps. Both regular and irregular echinoids have been found along with stalked crinoids41, feather stars (in preparation), asteroids42 and ophiuroids (this paper). An abundant food source and a hard substrate in an otherwise soft, muddy ocean bottom were most likely the key factors for echinoderms to habitat the seeps.
The material consists of 147 fragments of a carbonate plates yielding articulated ophiuroids, partially articulated arm fragments and fully dissociated skeletal plates. The ophiuroid locality is AMNH locality 3509A (WPT 130a) (Fig. 1), Didymoceras cheyennense Zone, upper Campanian, Late Cretaceous (Fig. 2), Pierre Shale, Pennington County, South Dakota. It is one of two closely associated seeps (WPT 130a & b) separated by approximately 25 m. Seep AMNH 3509A looks similar to many of the other highly weathered 'teepee buttes' while AMNH 3509B is almost indistinguishable. Ophiuroids have only been discovered from Seep AMNH 3509A.
Site map of the ophiuroid-yielding seep site (AMNH locality 3509A) showing the location of the fossil ophiuroids, with three individuals near the large micritic body and a brittle-star mass aggregation (dubbed 'brittle star village') at some distance of it. The seep site is covered with seep associated carbonate concretions across the entire map area except for the ravine. Map courtesy of Jamie Brezina.
New ophiuroid Brezinacantha tolis gen. et sp. nov. from Upper Cretaceous (Didymoceras cheyennense Zone, upper Campanian) methane seep deposits of Pennington County, South Dakota. (a) AMNH 113563 (holotype), articulated skeleton exposing ventral side. (b) Detail of (a) showing mouth plating. (c) MnhnL OPH039 (paratype), articulated skeleton showing ventral side. (d) AMNH 113564 (paratype), detail of an articulated skeleton fragment exposing the dorsal side shown in (e), with dorso-lateral view of three dental plates with teeth. (e) AMNH 113564 (paratype), articulated skeleton fragment exposing the dorsal side. (f) interpretative drawing of the articulated skeleton fragment shown in (f). Abbreviations: AOS: adoral shield; APa: apical oral papilla; AS: arm spine; DAP: dorsal arm plate; DP: dental plate; IS: interradial disc scales; LAP: lateral arm plate; LPa: lateral oral papilla; OP: oral plate; OS: oral shield; RS: radial shield; T: tooth; 1VAP: first ventral arm plate. Scale bars equal 1 mm.
Seep AMNH 3509A seems to have four different micritic masses. One is large and well exposed while the three others to the west are much smaller, meaning there was less methane seepage and thus less carbonate precipitation. There are no obvious carbonate structures exactly where the brittle stars were found on the seep (Fig. 1). While there are abundant seep associated carbonate concretions (SACS) all over the seep, the closest micritic mass is about 1.8 to 2 meters away. These carbonate concretions, burrows and pipes were probably precipitating just at or beneath the sediment/water interface.
AMNH 3509A has a rich, varied fauna that contains: ammonites (Placenticeras meeki (Böhm, 1898), Hoploscaphites brevis (Meek, 1876), H. nodosus (Owen, 1852), Didymoceras cheyennense (Meek and Hayden, 1856), Spiroxybeloceras meekanum (Whitfield, 1877) and Baculites corrugatus (Elias, 1933)), nautilus (Eutrephoceras nebrascense (Meek and Hayden, 1862)), ghost shrimp (Callianassa sp.), crabs (undescribed - Nyborg et al. in preparation), oysters, lucinids, inoceramids and other miscellaneous bivalves, gastropods, crinoids (Lakotacrinus brezinai Hunter et al.41), echinoids (regular), ophiuroid (this paper), tube worms, radiolarians, foraminifera, dinoflagellates, a mosasaur vertebra (Plioplatecarpus) along with a few miscellaneous fish vertebrae.
Selected ophiuroid skeletal plates were mechanically removed from one slab, mounted on a stub and gold-coated for Scanning Electron Microscopy using a Jeol Neoscope JMC-5000. Terminology follows Stöhr et al.1 and Thuy and Stöhr43. Ophiuroid classification is adopted from O'Hara et al.44. All types and additional specimens were deposited in the collections of the American Museum of Natural History (AMNH) and the Natural History Museum Luxembourg (MnhnL).
The electronic edition of this article conforms to the requirements of the amended International Code of Zoological Nomenclature, and hence the new names contained herein are available under that Code from the electronic edition of this article. This published work and the nomenclatural acts it contains have been registered in ZooBank, the online registration system for the ICZN. The ZooBank LSIDs (Life Science Identifiers) can be resolved and the associated information viewed through any standard web browser by appending the LSID to the prefix "http://zoobank.org/". The LSID for this publication is: urn:lsid:zoobank.org:pub:3A98CFE8-7F81-4906-9D41-072CF02D61C5; for Brezinacantha: urn:lsid:zoobank.org:act:621CED39-46AF-4B98-B531-0CC362AAEE3E; for Brezinacantha tolis: urn:lsid:zoobank.org:act:BABFCFB5-F991-44EF-8DB6-A1A701187BCB. The electronic edition of this work was published in a journal with an ISSN, and has been archived and is available from the following digital repositories: PubMed Central, LOCKSS.
Systematic Palaeontology
Class: Ophiuroidea Gray, 1840
Subclass: Myophiuroidea Matsumoto, 1915
Infraclass: Metophiurida Matsumoto, 1915
Superorder: Ophintegrida O'Hara et al., 2017
Order Ophiacanthida O'Hara et al., 2017
Suborder: Ophiacanthina O'Hara et al., 2017
Family: Ophiacanthidae Ljungman, 1867
Genus: Brezinacantha gen. nov.
Diagnosis: as for species
Type and only known species: Brezinacantha tolis™
Etymology: Genus named after Jamie Brezina (Rapid City, South Dakota) who discovered the ophiuroid specimens described herein, to honour his indefatigable commitment to the study of seep deposits and their fossil content in the Western Interior Seaway; suffix derived from 'Acantha', a Greek nymph whose name literally translates into "thorny"; gender feminine.
Brezinacantha tolis sp. nov.
Etymology: Species named after Sakis and Themis Tolis, founding members of a Greek Black Metal band, to honour their unorthodox yet powerful approach to music. The ophiuroids described herein merit in many ways a Black-Metal-referenced name: they gathered in great numbers in a spooky, toxic environment on top of their dead predecessors' remains. The species name is entirely the responsibility of the lead author, Ben Thuy.
Holotype: AMNH 113563
Type locality and stratum: AMNH locality 3495 (WPT 130a), Didymoceras cheyennense Zone, upper Campanian, Late Cretaceous, Pierre Shale, Pennington County, South Dakota.
Diagnosis: Ophiacanthid with very large triangular radial shields accounting for three quarters of the disc radius, interradially separated by a narrow band of tiny, radially elongate scales; interradii not indented; two to three apical oral papillae; small, narrow adoral shields; distal portion of lateral arm plates strongly elevated, separated from remaining outer surface by a poorly defined, wavy ridge; up to five arm spines as long as one and a half arm segments, round in cross section, devoid of thorns.
Paratypes: AMNH 113564–113568, MnhnL OPH039 - 040
Other material examined: AMNH 113569–113585, AMNH 82689–82691, MnhnL OPH041 - 043.
Description of holotype: AMNH 113563 (Fig. 2a,b) is an articulated skeleton exposing the ventral side of three radii with associated proximal to median arm segments; reconstructed disc diameter 8.8 mm; ventral interradii straight to slightly concave, covered by few round scales, no granules or spines discernible; distal edges of radial shields visible, suggesting very large radial shields; oral shields as long as one quarter of the disc radius, rounded triangular, approximately as wide as long, with pointed proximal tip, slightly concave latero-proximal edges and convex distal edge; adoral shields narrow, inconspicuous; jaws moderately elongate and slender, with at least four small, conical, pointed lateral oral papillae in a single row and one or two similarly small, conical, pointed but shorter apical oral papillae; second oral tentacle pore opening within mouth slit.
Arms moderately wide, with first two segments covered by disc; first ventral arm plate wider than long, oval; following ventral arm plates nearly two times larger, nearly as wide as long, widest distally, with convex distal edge, deeply concave lateral edges and obtuse proximal angle; ventral arm plates separated by lateral arm plates from first arm segments onwards; no spurs or conspicuous ornamentation discernible. Lateral arm plates with conspicuously bulging distal portion sharply offset with respect to proximal portion of plate; elevated distal portion with at least four large, freestanding, ear-shaped spine articulations; stereom of lateral arm plate outer surface with slightly protruding trabecular intersections arranged in faint vertical rows; ventral portion of lateral arm plate not protruding ventro-proximalwards; spine articulations composed of narrow and strongly arched dorsal and ventral lobes proximally merged to form a circle around a large muscle opening, separated from much smaller nerve opening by sigmoidal fold; spine articulations increasing in size dorsalwards; large, conical, pointed arm spines at least as long as one arm segment. Tentacle openings small, covered by single oval tentacle scale.
Paratypes: MnhnL OPH039 (Fig. 2c) is a fragment of an articulated skeleton exposing the ventral side and preserving proximal to median portions of three arms; reconstructed disc diameter 8.7 mm; generally in agreement with holotype but with better preserved oral shields and lateral oral papillae; distal portion of oral shields with slighty concave latero-distal edges; at least four small, conical, pointed lateral oral papillae in a single row, proximalmost longest, almost spine-like.
AMNH 113564 (Fig. 2d–f) is a fragment of an articulated skeleton exposing the dorsal side and preserving a proximal arm portion; reconstructed disc diameter 10.9 mm; Interradius slightly concave but not indented; radial shields thick, isosceles triangular with slightly concave distal edges, accounting for three quarters of the disc radius, contiguous along the entire radial midline, separated interradially by numerous tiny, radially elongate scales; no scales or plates discernible in the centre of the disc; preservation too poor to ascertain the presence or absence of disc granules or spines. Centre of disc exposing non-fragmented, ventralwards widening dental plate with teeth preserved in place; five dorsalmost teeth pointed, dorsoventrally compressed, tetrahedral, in a single row with ventralward widening of the teeth; three ventralmost teeth smaller than dorsal ones, forming an irregular cluster. Arm segments higher than long; dorsal arm plates separated by lateral arm plates, lozenge-shaped with slightly obtuse distal and proximal edges and slightly pointed lateral edges, wider than long, devoid of conspicuous outer surface ornamentation; arm spines round in cross section, hollow, devoid of thorns or scale-like external ornamentation, as long as one and a half arm segments.
MnhnL OPH040 (Fig. 3a,c) is a dissociated proximal lateral arm plate on a slab exposing the outer surface, approximately two times higher than long, with convex dorsal edge, wavy proximal edge and convex distal edge; ventral portion not protruding ventro-distalwards; poorly defined, small, horizontally elongate spur in the centre of the ventralmost third of the proximal edge; outer surface stereom with knobs slightly larger than surrounding pores and vertically elongate to form a faint, irregular striation especially in the central part of the outer surface; distal portion of lateral arm plate strongly elevated, dorsally fading into non-elevated dorsal portion of lateral arm plate, and proximally bordered by poorly defined, thin, wavy ridge; four large spine articulations freestanding on elevated distal portion of lateral arm plate; spine articulations with very large muscle opening encompassed by thin ventral and dorsal lobes proximally merged to form an almost perfect circle; much smaller nerve opening on ventro-distal edge of circle and separated from muscle opening by sigmoidal lobe; dorsalward increase in size of spine articulations, in size of gaps separating them and in the distance between the spine articulations and the distal plate edge.
New ophiuroid Brezinacantha tolis gen. et sp. nov. from Upper Cretaceous (Didymoceras cheyennense Zone, upper Campanian) methane seep deposits of Pennington County, South Dakota. (a) MnhnL OPH040 (paratype), dissociated proximal lateral arm plate in external view, with dorsal side pointing upwards. (b) AMNH 113565 (paratype), median arm segments in lateral view, with dorsal side pointing downwards. (c) detail of (a) showing spine articulation. (d) AMNH 113566 (paratype), dissociated oral plate in adradial view. (e) AMNH 113567 (paratype), dissociated proximal vertebra in distal view, with dorsal side pointing upwards. (f) AMNH 113568 (paratype), dissociated arm spines, with proximal tip pointing downwards. Abbreviations: MO: muscle opening; NO: nerve opening. Scale bars equal 0.5 mm in (a,b) and (d–f), and 0.1 mm in (c).
AMNH 113565 (Fig. 3b) is a dissociated arm fragment composed of three median arm segments exposing the ventro-lateral side; lateral arm plate of middle arm segment well preserved, outer surface stereom as in MnhnL OPH040 but with slightly better developed vertical striation especially; elevated distal portion of the lateral arm plates extending over the entire height of the plate; four arm spine articulations similar to those of MnhnL OPH040.
AMNH 113566 (Fig. 3d) is a dissociated oral plate on a slab exposing the adradial face; oral plate slightly longer than high; adradial muscle attachment area small, in ventral position lining ventro-distal edge of articulation area.
AMNH 113567 (Fig. 3e) is a dissociated vertebra on a slab exposing the distal face, with strongly oblique, dorsalwards converging zygocondyles; zygosphene projecting beyond ventral edge of zygocondyles with projecting part almost as long as zygocondyles; dorso-distal muscular fossae not transformed into distalwards projecting process.
AMNH 113568 (Fig. 3f) are two dissociated arm spines, evenly tapering, conical, pointed, outer surface stereom coarse but devoid of thorns.
Remarks: The shape of the spine articulations and their dorsalward increase in size clearly place the present specimens in the ophiacanthid suborder Ophiacanthina. Within this group, the single row of lateral oral papillae, the absence of a ventral tooth cluster, the non-fragmented dental plate, the ornamentation of the outer lateral arm plate surface and the non-protruding ventral portion of the lateral arm plates suggest closest affinities with the family Ophiacanthidae. The excessively large radial shields in combination with the strongly elevated distal portion of the lateral arm plates and the relatively long arm spines place the present ophiuroids close to extant Ophioplinthaca Verrill, 1899. In this genus, however, the interradii are strongly indented and the radial shields are interradially bordered by a series of large, crescent-shaped scales (e.g.45).
Remarkable similarities are shared with the genus Ophiosternle crinitum (Quenstedt, 1876) from the Late Jurassic of Germany46, especially with respect to the size and position of the radial shields that are interradially separated by tiny scales. In the present specimens, however, the ventral tips of the jaws lack a well-defined cluster of apical papillae, the adoral shields are much narrower, the dorsal arm plates are smaller and not overlapping, and the arm spines are smaller and less numerous, thus precluding assignment to Ophiosternle. We thus suggest the new taxon Brezinacantha tolis to accommodate the ophiuroids described herein. With respect to the relevant morphological similarities, Brezinacantha seems the most closely related to Ophioplinthaca and Ophiosternle, and we anticipate close phylogenetic ties between the three.
Taphonomy and Palaeoecology
The state of articulation of the ophiuroids mostly varies between the two extremes of the spectrum: fully dissociated skeletal plates on the one hand and fully articulated skeletons with no or little sign of post-mortem decay. The most likely mechanism to preserve an ophiuroid skeleton in its original anatomical disposition is rapid and effective burial either by storm-induced currents or by slumping (e.g.47). Yet, the site of discovery shows no sedimentary evidence for such an obrution event. Microbial and bacterial mats are a common feature of cold methane seeps and were highlighted as a possible factor in the preservation of partially articulated crinoids at neighboring seep locations41. Another very likely factor to explain the exceptional preservation of the ophiuroid skeletons is rapid carbonate cementation related to anaerobic oxidation of methane, known to enable exceptional fossil preservation in seeps (e.g.48,49). Considering the speed of post-mortem disarticulation of the ophiuroid skeleton, however, trapping and overgrowth by microbial mats and rapid cementation alone might not be sufficient to explain the here-described occurrence of fully articulated ophiuroid skeletons.
Interestingly, intact ophiuroid skeletons are known from sediments that lack obrution-related features but instead show signs of low oxygen levels at the time of deposition (e.g.11,50). These occurrences suggest that the otherwise rapid post-mortem decay of the ophiuroid skeleton can be significantly delayed by a lack of oxygen, an assumption corroborated by yet unpublished experiments on decay of dead ophiuroids exposed to high concentrations of methane or hydrogen sulfide (Y. Ishida, personal communication). We thus speculate that the ophiuroids described herein were killed by an increase in methane seepage, delaying skeletal decomposition and allowing microbial mats and rapid cementation to fossilise the skeletons intact.
With respect to the mode of occurrence, the limestone slabs yielding the ophiuroids all follow a striking pattern: the lower half of the slab is largely composed of an accumulation of dissociated skeletal plates, up to three centimeters thick and densely packed, often to an almost rock-forming extent, overlain, in the upper half of the slab, by densely packed, fully articulated skeletons, piled to layers up to 2.5 centimeters thick (Fig. 4). The dissociated skeletal plates mostly comprise vertebrae, lateral arm plates, oral plates and genital plates. Remarkably, arm spines are clearly underrepresented in most of the accumulations, in spite of being the most numerous component of the ophiuroid arm. Dissociated arm spines only occur in greater numbers underneath or inside bivalve and ammonite shell fragments. Long and hollow arm spines are among the first skeletal components of a disintegrated ophiuroid to be swept away by water movements (Thuy personal observation). We thus assume that the dissociated skeletal parts of the ophiuroid material described herein were size-sorted by weak bottom currents just strong enough to selectively wash away the arm spines except in protected spots, e.g. inside or underneath shell fragments.
Slab with Brezinacantha tolis gen. et sp. nov. from Upper Cretaceous (Didymoceras cheyennense Zone, upper Campanian) methane seep deposits of Pennington County, South Dakota, AMNH 113563, in lateral view to show the densely packed articulated skeletons (top right detail: upside of slab) overlying an accumulation of dissociated skeletal plates (bottom right detail: underside of slab). Note the round arm sections in the lateral view.
Assuming the individuals preserved intact are a snapshot of the original mode of occurrence, the ophiuroids must have lived in a very dense aggregation with arms touching or even individuals overlapping, with an extrapolated density of approximately 1000 individuals per m2. Given the thickness of the ossicle accumulations underlying the articulated skeletons, and depending on the lifespan of the species, the dense ophiuroid aggregation must have persisted at that particular spot at least for several decades.
Judging from the distribution of the ophiuroid fossils at the site of discovery, the dense ophiuroid aggregation covered an area of at least 3 to 4 m, representing a fossil case of a brittle-star mass aggregation. It was found in an area with bivalve and ammonite shell hash and numerous seep-associated microbialite nodules at approximately 10 m distance from the central core of the seep (Fig. 1). Three small slabs with articulated remains of Brezinacantha tolis were found in the immediate vicinity of the central carbonate core, at some distance of the brittle-star mass aggregation. In analogy with modern relatives (e.g.8), Brezinacantha probably lifted its spinose arms in the water column to suspension feed, probably benefitting from a weak bottom water current (see above). The seep created a nutrient-rich environment with vast amounts of organic matter and thus provided abundant sources of food to sustain an extremely dense aggregation of suspension-feeding ophiuroids for several generations.
Dense Ophiuroid Aggregations in the Fossil Record
Proponents of the Marine Mesozoic Revolution postulate that dominance within communities of suspension-feeding invertebrates was pushed to more cryptic, active, or heavily armoured species by increased predation pressure in the course of the Mesozoic (e.g.17,18). In the same logic, a Mesozoic decline of brittle-star beds visible in the fossil record was postulated, in association with the diversification of durophagous predators22, except in areas with anomalously low predation (e.g.5), e.g. at high latitudes (e.g.15).
In an attempt to understand the ophiuroid mass occurrence described herein in a broader evolutionary context, we noticed that the compilation of fossil ophiuroid beds used to substantiate the assumed mid-Mesozoic decline of such occurrences22 vary considerably in their taphonomic and palaeo-ecological context. Critical re-evaluation of the occurrences compiled by Aronson22, including direct examination of the specimens in several cases, suggests that some might, in fact, not represent fossil equivalents of recent shallow-water ophiuroid beds. Some consist of a series of articulated ophiuroids collected at the same locality but probably not forming a dense bed originally (Early Cretaceous of Alexander Island, Mid-Jurassic of Weymouth, Late Devonian of Velbert and Angerbachtal). Others are the result of storm-induced obrution, implying that the ophiuroids might not be autochthonous but instead washed together before burial (Early and Mid-Triassic records). Finally, the Mid-Jurassic occurrence from La-Voulte-sur-Rhône, while probably representing a true fossil ophiuroid mass occurrence, originates from a bathyal rather than shallow-water setting51. Furthermore, from a methodological point of view, it should be noted that the Late Devonian records of Velbert and Angerbachtal and the Mid-Triassic records of Nordwürttemberg, Weimar and Mergentheim originate from the same depositional settings respectively, implying that they should possibly be considered as a single Late Devonian and a single Mid-Triassic occurrence.
With so many dubious, if not invalid, fossil occurrences in the original compilation, and with the number of true fossil ophiuroid dense beds described since including the present one, the hypothesis of the mid-Mesozoic decline of ophiuroid dense beds should be revisited.
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Aronson, R. B., & H.-D. Sues. The fossil record of brittlestar beds. In: Echinoderm biology. Proceedings of the Sixth International Echinoderm Conference. (Burke, R. D., Mladenov, P. V., Lambert, P. & Parsley, R. L., edis). A. A. Balkema, Rotterdam, The Netherlands, 147–148 (1988).
Aronson, R. B. & Blake, D. B. Evolutionary paleoecology of dense ophiuroid populations. Paleontological Society Papers 3, 107–119 (1997).
Aronson, R. B., Blake, D. B. & Oji, T. Retrograde community structure in the late Eocene of Antarctica. Geology 25, 903–906 (1997).
Aronson, R. B. Predation, physical disturbance, and sublethal arm damage in ophiuroids: a Jurassic–Recent comparison. Mar. Ecol. Prog. Ser. 74, 91–97 (1991).
Vermeij, G. J. The Mesozoic marine revolution: evidence from snails, predators and grazers. Paleobiology 3, 245–258 (1977).
Vermeij, G. J. Unsuccessful predation and evolution. Am. Nat. 120, 701–720 (1982).
Woolsey, E. et al. Ophiopsila pantherina beds on subaqueous dunes off the Great Barrier Reef. In: Echinoderms in a Changing World (Johnson, C. ed.), Taylor & Francis, 175–179 (2013).
Bowden, D. A., Schiaparelli, S., Clark, M. R. & Rickard, G. J. A lost world? Archaic crinoid-dominated assemblages on an Antarctic seamount. Deep-Sea Res. II 58, 119–127 (2011).
Stöhr, S. & Ségonzac, M. Two New Genera and Species of Ophiuroid (Echinodermata) from Hydrothermal Vents in the East Pacific. Species Diversity 11, 7–32 (2006).
Aronson, R. B. Biology of a scale-independent predator– prey interaction. Mar. Ecol. Prog. Ser. 89, 1–13 (1992).
Clark, W. B. Mesozoic Echinodermata of the United States. U.S. Geological Survey Bulletin 97, 1–207 (1892).
Alexander, C. J. A new Lower Cretaceous ophiuroid. J. Paleontol. 5, 152–153 (1931).
Berry, C. T. Cretaceous ophiurans from Texas. J. Paleontol. 15, 61–67 (1941).
Clark, D. L. Texas Cretaceous ophiuroids. J. Paleontol. 33, 1126–1127 (1959).
Cornell, W. C., Lemone, D. V. & Norland, W. D. Albian ophiuroids from Cerro de Cristo Rey, Dona Ana County, New Mexico. J. Paleontol. 65, 1009–1013 (1991).
Thuy, B., Gale, A. S., Stöhr, S. & Wiese, F. Shallow-water brittle-star (Echinodermata: Ophiuroidea) assemblages from the Aptian (Early Cretaceous) of the NorthAtlantic: first insights into bathymetric distribution patterns. Göttingen Contributions to Geoscience 77, 163–182 (2014).
Thuy, B. & Stöhr, S. Lateral arm plate morphology in brittle stars (Echinodermata: Ophiuroidea): new perspectives for ophiuroid micropalaeontology and classification. Zootaxa 3013, 1–47 (2011).
Howe, B. Tepee Buttes: a petrological, paleontological, and paleoenvironmental study of Cretaceous submarine spring deposits. (University of Colorado at Boulder, 1987).
Bishop, G. A. & Williams, A. B. Fossil crabs from Tepee Buttes, submarine seeps of the late Cretaceous Pierre Shale, South Dakota and Colorado, USA. J. Crustacean Biol. 20(2), 286–300 (2000).
Metz, C. L. The paleobiogeography of the Late Cretaceous Western Interior Basin Tepee Butte Mounds (hydrocarbon seeps) of North America and possible tectonic factors controlling their distribution. GSA 40, 250–251 (2008).
Metz, C. L. Tectonic controls on the genesis and distribution of Late Cretaceous, Western Interior Basin hydrocarbon seep mounds (Tepee Buttes) of North America. J. Geol. 118, 201–213 (2010).
Landman, N. H. et al. Methane seeps as ammonite habitats in the US Western Interior Seaway revealed by isotopic analyses of well-preserved shell material. Geology 40, 507–510 (2012).
Larson, N. L., Brezina, J., Landman, N. H., Garb, M. P. & Handle, K. C. Hydrocarbon seeps: unique habitats that preserved the diversity of fauna in the Late Cretaceous Western Interior Seaway. Academia http://academia.edu/4641897/Hydrocarbon_seeps_unique_habitats (2014).
Gilbert, G. K. & Gulliver, F. R. Tepee Buttes. GSA Bulletin 6, 333–342 (1895).
Kauffman, E. G., Arthur, M. A., Howe, B. & Scholle, P. A. Widespread venting of methane-rich fluids in Late Cretaceous (Campanian) submarine springs (Tepee Buttes), Western Interior seaway, USA. Geology 24, 799–802 (1996).
Cochran, J. K., Landman, N. H., Larson, N. L. & Meehan, K. C. Geochemical evidence (C and Sr isotopes) for methane seeps as ammonite habitats in the Late Cretaceous (Campanian) Western Interior Seaway. Swiss J. Paleontol. 134, 153–165 (2015).
Kato, M., Tatsuo, O. & Shirai, K. Paleoecology of Echinoderms in cold seep environments revealed by isotope analysis in the Late Cretaceous Western Interior Seaway. Palaios 32, 218–230 (2017).
Hendricks, J. K. et al. Depositional model for the tepee buttes methane seeps-zoned and conical, or flat and patchy? GSA Abstracts with Programs 43, 95 (2011).
Hunter, A. W., Larson, N. L., Landman, N. H. & Oji, T. Lakotacrinus brezinai n. gen. n. sp., a new stalked crinoid from cold methane seeps in the Upper Cretaceous (Campanian) Pierre Shale, South Dakota, United States. Journal of Paleontology 90, 506–524 (2016).
Blake, D. B., Halligan, W. & Larson, N. L. A new species of the asteroid (Echinodermata) genus Betelgeusia from methane seep settings, Late Cretaceous of South Dakota. J. Paleontol. https://doi.org/10.1017/jpa.2017.96 (2018).
Thuy, B. & Stöhr, S. A New Morphological Phylogeny of the Ophiuroidea (Echinodermata) Accords with Molecular Evidence and Renders Microfossils Accessible for Cladistics. PLoS ONE 11(5), e0156140 (2016).
O'Hara, T. D., Hugall, A. F., Thuy, B., Stöhr, S. & Martynov, A. Restructuring higher taxonomy using broad-scale phylogenomics: The living Ophiuroidea. Mol. Phylogenet. Evol. 107, 415–430 (2017).
O'Hara, T. D. & Stöhr, S. Deep water Ophiuroidea (Echinodermata) of New Caledonia: Ophiacanthidae and Hemieuryalidae. In: Tropical Deep-Sea Benthos (Richer de Forges, B. et al. Eds) Mémoires du Muséum national d'Histoire naturelle 24(193), 33–141 (2006).
Thuy, B. & Schulz, H. The oldest representative of a modern deep-sea ophiacanthid brittle-star clade from Jurassic shallow-water coral reef sediments. Acta Pal. Pol. 58(3), 525–531 (2012).
Ausich, W. I. Echinoderm taphonomy. In: Echinoderm studies 6 (Jangoux, M. & Lawrence, J. M. Eds). Rotterdam, Balkema, 171–227 (2001).
Hikida, Y., Suzuki, S., Togo, Y. & Ijiri, A. An exceptionally well-preserved fossil seep community from the Cretaceous Yezo Group in the Nakagawa area, Hokkaido, northern Japan. Paleontological Research 7, 329–342 (2003).
Kiel, S., Peckmann, J. & Simon, K. Catshark egg capsules from a Late Eocene deep-water methane-seep deposit in western Washington State, USA. Acta Palaeontol. Pol. 58, 77–84 (2013).
Hess, H. Neue Schlangensterne aus dem Toarcium und Aalenium des Schwäbischen Jura (Baden-Württemberg). Stutt. Beitr. Naturkd., B. 180, 1–11 (1991).
Charbonnier, S., Vannier, J., Gaillard, C., Bourseau, J.-P. & Hantzpergue, P. The La Voulte Lagerstätte (Callovian): Evidence for a deep water setting from sponge and crinoid communities. Palaeogeography, Palaeoclimatology, Palaeoecology 250, 216–236 (2007).
We thank Yoshiaki Ishida (Tokyo, Japan) who provided observations on decay of dead ophiuroids exposed to high concentrations of methane or hydrogen sulfide, and Guy Marson (Luxembourg) who helped with the photographs of the specimens. Barbara Beasley for arranging collection permits in the Buffalo Gap Grasslands Unit and Jamie Brezina for locating and donating all specimens for research.
Natural History Museum Luxembourg, Department of Palaeontology, 25, rue Münster, 2160, Luxembourg-city, Luxembourg
Ben Thuy & Lea D. Numberger-Thuy
American Museum of Natural History, Division of Paleontology (Invertebrates), New York, New York, 10024, USA
Neil H. Landman
Larson Paleontology, Keystone, South Dakota, 57751, USA
Neal L. Larson
Ben Thuy
Lea D. Numberger-Thuy
B.T. and L.D.N.-T. designed the research, N.H.L. and N.L.L. compiled the geological context of the material, B.T. and L.D.N.-T. described and interpreted the specimens and took the scanning electron microscope images, all authors contributed to writing and approved the final manuscript.
Correspondence to Ben Thuy.
Thuy, B., Landman, N.H., Larson, N.L. et al. Brittle-star mass occurrence on a Late Cretaceous methane seep from South Dakota, USA. Sci Rep 8, 9617 (2018). https://doi.org/10.1038/s41598-018-27326-z
DOI: https://doi.org/10.1038/s41598-018-27326-z
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Dr. Farokhnia received his PhD degree in Civil Engineering from University of Colorado Boulder in 2013 and his dissertation focused on performance based earthquake engineering and rapid regional level seismic risk assessment. He has conducted two postdoctoral research work at Virginia Tech and at the Center for Risk-Based Community Resilience Planning at Colorado State University. His work is focused on applying the science of Artificial Intelligence in resilience-based planning for infrastructural network, and regional level natural hazards risk assessment.
Dr. Farokhnia is also the founder of a research-based startup company NHRC, LLC (Natural Hazards Research and Consulting Center). His work at NHRC is dedicated to study indirect early consequences or precursors of earthquake occurrence, such as disruption in the earth electromagnetic field, gravity field, early rock fracture infrasound detection, groundwater flow and pore water pressure variation, radon gas emission, displacement field, heat gradient, and air ions emissions. This is a comprehensive study on all the already developed prediction models of earthquake induced precursors, and to develop a collective algorithm utilizing all of them interactively to avoid single precursor model noises or malfunction.
Last updated Jan 30, 2019.


Center and Spread of the Quantitative Data – Collect 10-20 pieces of quantitative data and find the mean, variance, standard deviation, and five number summary.
Explain the importance of this data, what you find interesting about the data, and why the public should know.
Then graph the data (dotplot, stemplot, histogram, frequency polygon, scatterplot, time series graph, pie graph, and Pareto chart).
-pick one graph that bests shows the data.


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The awesome and alluring RPS Advent Calendar 2017
Feature by RPS Hivemind
Published on 1 Dec, 2017
We like to have our eyes fixed on the future here at RPS, celebrating those games and creators that push things forward, but from time to time, tradition can be a fine thing and the RPS Advent Calendar is our grandest tradition. Here's how it works.
As December begins, we round up our favourite games of the year and trap them behind the doors of a giant calendar/dungeon. Every day, we open a door and allow the game behind it to emerge, bewildered, into the cold of winter. Don't worry - there's plenty to keep them occupied while they're locked inside the calendar, including a bottle of pop, a half-completed Witcher colouring book and a cracked snowglobe. The final game to leave is our absolute favourite game of the year, but they're all great games so do greet their emergence with applause, cheers and kind words. Perhaps you could bring them a warm blanket and a cup of cocoa?
Now is the time to bookmark this page because it is where you will find the calendar. Every day, a new door will unlock, allowing you to click on it and discover the bounty inside. Don't try to open any of the doors before they're unlocked though. The calendar is a living thing and has been known to bite.
We've done this many times before, including in 2007 when the calendar was a photo of a fairtrade advent calendar, and then again in 2009, 2010, 2011, 2012 and 2013. In 2014 we did the RPS Bestest Bests which were the exact same only it wasn't based around a calendar. This was clearly inferior, and so the Horatian calendar returned in 2015 and last year's edition was a roaring success.
All entries should be considered equally brilliant, though the later a game appears the more of our writers voted for it. And, yes, the game behind door number 24 is the best game of the year. No arguments. If you think we're missing some other, excellent games, you are certainly right. Twenty four doors could not contain all of 2017's greats, so do let us know about your favourites below.
And now, settle back, join us for the big reveal at 5pm UK time every day from now until Christmas Eve, and enjoy the countdown.
RPS Advent Calendar 2017
Hivemind
The all-seeing eye of Rock, Paper, Shotgun, the voice of many-as-one.
Nvidia DLDSR tested: better visuals and better performance than DSR
How Deep Learning Dynamic Super Resolution looks and runs on RTX graphics cards
James Archer 6 hours ago
When will video games give me their sad murder mums?
It's complex, Oedipus
Alice Bell 12 hours ago
The Sunday Papers
Ed Thorn 1 day ago

redpajama_set_name: RedPajamaCommonCrawl


It used to be that getting a quote on life insurance felt like you were pre-determining your life expectancy. Sure, they called it a life insurance quote, but it seemed more like a death insurance quote. After answering each question, the insurance salesperson would give you that look that says, "How could you do that? Don't you know it cuts ten years off your life?"
Well it's not that bad today. Life insurance quotes are now easier than ever, thanks to the time saving technology from the online world. You can get a term life insurance quote from several companies and compare them without ever talking to a representative. Get a whole life insurance quote in a matter of seconds instead of days. And you can do it all from the comfort of home.
1. Be Accurate: The more accurate your information is, the more accurate your life quote will be. Never hide information like whether or not you smoke. Remember, this would set life insurance companies free from their obligations in the event of your death?so it wouldn?t even make sense to have insurance if you?re not as accurate as possible.
2. Never Base Your Choices on Price Alone: Low prices are always attractive, but find out for sure that a policy will suit your needs. Ask for the details involved in term life insurance and whole life insurance plans. Don?t take anything for granted. And research the insurance companies. Find out how long they?ve been in business and how fast their usual turn around is for pay-offs.
3. Compare from at Least Three Companies: There is no reason to limit yourself to one or two quotes?not when obtaining a quote is so easy. Shop around and find out what insurance companies have to offer.
4. To Compare Life Insurance Quotes, Start with the Same Set of Answers: If you?re comparing different quotes, make sure they?re not for different policies. Type of life insurance policy, time periods for term policies, and the insured amount can all have a huge impact on a quote?so make sure the answers to questionnaires are the same from company to company.
For the most part, there are two kinds of life insurance: whole life insurance and term life insurance. While there are variations of both of these, the biggest difference between the two is that one is for long term coverage and one is for short term coverage?and your life insurance quotes will be very different for each one.
Whole Life Insurance (generally for long term coverage) has a set premium and doesn?t change (except for some variations) throughout the policy term. You pay your premiums, and when you die, your beneficiary receives the pay-off. Your whole life insurance quote will specify the premium amount. As you pay into the policy, it builds equity, which you can withdraw or borrow against.
Term Life Insurance (usually used for short term coverage) only lasts for a certain amount of time. That time is defined in the term life insurance quote. At the end of this term, the policy ends and the policy is re-evaluated for a new quote.
Use a website that connects you to several life insurance companies. Add them to your favorites menu so you can find them again. As you receive your quotes, print them out for easy comparison. In no time at all, you?ll find the perfect company for your life insurance needs without ever feeling like you?re the one being examined.


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Serbia SEE Energy Mining News|SEE Energy News|Hungary: MOL made yet another gas discovery in Pakistan
Hungary: MOL made yet another gas discovery in Pakistan
Published on 11. July 2016. , SEE Energy News
Hungarian oil and gas company MOL announced that it has made yet another natural gas discovery in TAL block in Pakistan.
An exploration well in TAL block yielded gas flow rate of 2,300 barrels of oil equivalent per day during the test phase. Currently, total gas production at TAL block stands at about 80,000 barrels of oil equivalent per day.
Earlier this week, MOL announced another hydrocarbons discovery at the same block, stating that an exploration well flowed at the rate of 2,020 barrels of oil per day and 900 barrels of oil equivalent per day during the testing period.
MOL's partners in TAL block are OGDC, PPL, POL and GHPL. This discovery is MOL's ninth in the TAL block and 13th in Pakistan. In late March, the company announced the discovery of new hydrocarbons deposit in Karak block, which was the third one in this block.
MOL is present in Pakistan for 17 years already and has equity stakes in five blocks in the country. Last year, average daily hydrocarbons production of all MOL's blocks in Pakistan reached 103,900 barrels of oil equivalent per day, transmits Serbia-energy.eu
Previous Article : Greece: Gas interconnection agreement between Greece and Bulgaria signed
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Forty years of progress for the Commercial Division
To explain the dramatic changes that have occurred in the Winnipeg real estate industry, Bill Burns tells people how things were 40 years ago. "In January 1960, when I went to get my real estate licence at the Norqu...
Wild West shootout in Winnipeg — murderer Gribbon flees justice and the chase is on
by Bruce Cherney It had all the hallmarks of an old-time Western movie — a drunken brawl in a brothel, gun play on the street, a murder leading to a flight from the authorities, a posse in hot pursuit, a reward offered for the ...
When politicians sing
Once a year, Earth Day rolls around and again a flurry of announcements come from every conceivable source. "Going green" is the new phrase of the 2000s, and nearly everyone is jumping on the bandwagon. Of course, t...
Bank of Canada cuts interest rate
This spring Winnipeg has witnessed a 28 per cent increase in new listings over the same period last year. Just under 900 new MLS® listings were entered on WinnipegREALTORS® MLS® during the first half of April. This ...
New Titanic Theory
Years ago, I met an Englishman who had made a pilgrimage to Neepawa to see for the first time the grave of his great-uncle who perished in the 1912 Titanic tragedy. The man related that his great-uncle had embarked on the Titanic to s...
Elephants in Manitoba — new research suggests extinction linked to arrival of first humans
by Bruce Cherney In his Narrative of the Canadian Red River Exploring Expedition of 1857, Henry Youle Hind related the finding of "great bones" along Shell Creek in Manitoba. Hind said the bones "ha...
More than a needle in a haystack
WinnipegREALTORS® tagline The tools. The team. The trust. is representative of REALTORS®' commitment to their customers. They have literally helped thousands of buyers and sellers meet their residential and commercial real est...
Politics and Olympics
If people believe that the Olympic Games and its symbols cannot be turned into a propaganda machine for the world's great tyrannies, consider the lesson of 1936. American Esther Myers Wenzel, reporting for the Douglas Tribu...
MP wants to improve Home Buyers' Plan
Winnipeg MP (NDP) Pat Martin was pleased this week to hear his private members bill, introduced on April 2, gained momentum as a result of backbench Tory MP Rick Dykstra's support. The Tory MP's backing made the Hou...
Broadway Bridge damaged during spring break-up — occurred just four days after grand opening
by Bruce Cherney At one time, Broadway didn't abruptly end at Main Street but continued on to the Red River. Where Broadway met the Red a bridge was built connecting the picturesque avenue with Provencher Boulevard on the St. B...


The project is new distributed ecosystem for Machine Learning and AI, based on new consensus Algorithm; It's an augmented Blockchain technology. It provides a decentralized artificial intelligence (AI) and machine learning (ML) mechanism for any real life and business purpose. The validation mechanism is based on Bots (robots animated by AI algorithms) installed on a decentralized network. They are elected on a scientific protocol called Proof of Involvement and Integrity (PII) so as to validate transactions on NeuroChain network.
Who is the team behind NeuroChain?
Billal CHOULI: a Ph.D. in Nuclear Fusion physics who strive at applying his knowledge on uncharted fields. Billal is the author of the Blockchains, a reference book on blockchain in France.
Frederic GOUJON: an entrepreneur, expert in IT architecture with strong knowledge how to run a business and an IT project. He is also an expert on blockchain and the co-author of Blockchains.
What are the key differences between NeuroChain and Ethereum?
Ethereum is a blockchain where Turing completeness was introduced (Smart contracts).
What is the role of Bots in NeuroChain?
Why do bots need to be elected and what is that process to do so?
They start looking at the ledger and compute the Proof of Involvement and Integrity algorithm (to reach the consensus) of each Bot on the network. This is a score that measures the activity in the network, and the power of this activity, also known as entropy and enthalpy.
The top scored Bots are elected among an arbitrary number of 577 Bots (which evolve according to the network).
They receive the transaction of the community of other Bots.
The elected Bots create Blocks and validate them.
The elected Bot receives a given amount of NCCs, to compensate for the validation work.
The elected Bots send the validated Blocks to the other Bots.
A block received is always controlled: was the Bot who sent the Block was able to validate or not. If so, make a copy of it in your local ledger.
Who will operate these Bots and what are the requirements and incentives to do so?
Anyone can operate a simple Bot. It must at least be installed and connected to the network. The best performers are more likely to be elected as validators. Hence, the network quality, speed and power of the Bot are all incentivized in exchange of NCC (NeuroChain Clausius) forging.
It can be installed on a VM, a container or anything alike.
Can the Bot operators alter bot behaviour?
Yes, it can. If doing so, their PII score will be altered. If the alteration is positive (e.g., better speed), its PII score will increase, hence the probability to forge NCC. If altering negatively, the probability of being elected shrinks significantly.
A bot counterfeiting a program is highly unlikely, thanks to the Proof of Workflow. A program was validated as not behaving as a malware.
What are the elected bots using NeuroChain tokens for?
They can be used, by selling them, as a mean to pay for the operations. It can be used otherwise on other programs or Bots to process a given computation. And they use them to operate the Intelligent applications.
Can tokens be issued on NeuroChain?
No. They are forged by the Bots. The first NCC (tokens) are created by the genesis block however.
What are some practical use cases for NeuroChain?
What are the key dates on the NeuroChain roadmap?
What are the key dates for the ICO?
How will the ICO funds be distributed?
The NeuroChain is a scientific applied project. Anything you can do with artificial intelligence and machine learning can be done through NeuroChain.
Granted that most business issues can be tackled with AI and ML, then pretty much everything you can think of can be dealt with NeuroChain.
We are looking for entrepreneurs, engineers, believers and new ways to exploit our project.
The code is open source. You can fork, but we would prefer a community work than a quick segregation of seed projects.
Previous articleLocalCoinSwap Review: The Most Most Inclusive Cryptocurrency Marketplace.
Next articleA History Of Gold Confiscation.
ICOVend: Easy Way To Invest In ICOs.


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Startup Grind Hosts Oğuz Alper Öktem (Martı)
Kolektif House Maslak - Maslak, Maslak Mah Ahi Evran cad 34485, Ahi Evran Cd. No:6 D:3, 34398 Sarıyer/İstanbul Istanbul, 34398 - View Map Istanbul
Tue, Feb 18, 2020, 6:00 PM (GMT+3)
About 40% of all car trips around the world are for distances of less than 5 km. On average, only 2% of the fuel spent on car journeys is used to transport passengers. Throw everything to wind, the e-scooters are both eco-friendly, modern, fun and e-scooter businesses have presented themselves as a lost gem we totally forgot about.
Our fireside chat guest is none other than Oğuz Alper Öktem who is the Co-founder and CEO of the new solution for Istanbul's traffic: Martı. Launched in October 2018 with a passionate team, Martı is growing rapidly and continues to expand the e-scooter market in Turkey.
Come to Startup Grind Istanbul on February 18th at Kolektif House Maslak, where Oğuz Alper Öktem will share his experiences as an entrepreneur and investor, also share his thoughts about the future of e-scooter business in Turkey. You can get inspired from his success story, meet the brilliant minds behind our startup ecosystem and get awards from our partners at this event.
Oğuz Alper Öktem
Martı
Oğuz Alper Öktem graduated from VKV Koç Private Primary School in 2005. Due to his success in High School Entrance Exam held in the same year, he was entitled to study at VKV Koç Private High School with a full boarding scholarship. Since then, the financial dimension of his education has been financed by Kıraca Foundation and Vehbi Koç Foundation. Throughout his high school years, he focused …
Oğuz Alper Öktem graduated from VKV Koç Private Primary School in 2005. Due to his success in High School Entrance Exam held in the same year, he was entitled to study at VKV Koç Private High School with a full boarding scholarship. Since then, the financial dimension of his education has been financed by Kıraca Foundation and Vehbi Koç Foundation. Throughout his high school years, he focused on mathematics lessons. At the same time, he was closely interested in the student union, won several elections and chaired the term. In addition, it has the highest average in the 11th grade in the field of mathematics at Koç High School.
His great interest in the economy started while he was studying at Koç High School. He spent all his free time in high school, reading books and articles about economics and following the markets. After deciding to pursue his undergraduate education in his field of interest, he applied to the University of Chicago and he was accepted. He completed the four-year undergraduate program of the University of Chicago with honors in three years.
After his graduation, he got his master's degree in Political Economy from London School of Economics. During his master's degree in London, he served as chairman of the LSE Turkish Society. After receiving his diploma, he briefly worked on nuclear energy companies in Deutsche Bank's London office. He returned to Istanbul in 2014. He completed his undergraduate and graduate education in two educational institutions that are accepted as the best in the world. After returning to Turkey, he worked as Chief Operating Officer at BLUTV. He also worked in companies such as McKinsey & Company, and received proposals to advise senior politicians on economic advice.
In November 2018, together with his sister Seher Sena Öktem, he founded the domestic and national Marti Teknoloji company in the micro mobility sector.
6:00 PM - 9:00 PM (+03)
Kolektif House Maslak
Maslak, Maslak Mah Ahi Evran cad 34485, Ahi Evran Cd. No:6 D:3, 34398 Sarıyer/İstanbul Istanbul, 34398
Can Kagitcibasi
Mevsimi
Istanbul Director
Can Tecim
Startup Grind Istanbul
Sinem Eser
Mixpanel is a leading product analytics software company, currently helping the world answer 81 million product questions every year. Our pioneering event-based tracking solution gives product teams the ability to gain insights into how to best acquire, convert, and retain their users across web and mobile platforms.
Kolektif House
One of the most impressive working spaces of İstanbul.
Girişimciye Dönüş
Girisimciye Donus is the online workshop tool for entrepreneurs and entrepreneur candidates. They can develop all skills about startup ecosystem starting with validating the problem till pitching presentation.
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Galaxy Rasbora (Fireworks Rasbora)
Decrease quantity for Galaxy Rasbora (Fireworks Rasbora)
Increase quantity for Galaxy Rasbora (Fireworks Rasbora)
Common name: Galaxy rasbora, Fireworks rasbora, Rasbora toei, Celestial pearl danio, Chilli rasbora
Scientific name: Microrasbora sp. "Galaxy". Currently being described and due to be placed in a new genus shortly.
Origin: Myanmar. The supplier wanted to keep the exact collection locality under wraps for commercial reasons. It was eventually discovered to be a micro-habitat wetland area east of Inle Lake.
Habitat: According to the exporter, his species lives among dense vegetation in a cool, high-altitude wetland region in a marsh area fed by a spring. It lives in sympatry with Danio sondhii and the undescribed Rosy loach, Yunnanilus sp.
Due to its tiny size, this beautiful little cyprinid would be best in a small aquarium, away from larger fish that might look upon it as a tasty snack. You could keep an impressive little shoal of these in a tiny desktop aquarium such as the AquaCube we gave away with last month's Practical Fishkeeping subscription. No details on the habitat are available, however, aquarium observations seem to suggest that the fish likes well-aerated or flowing water. Most fishkeepers are keeping theirs in small planted aquariums, in which the species is the only inhabitant.
Early reports suggested that the fish might only consume tiny live foods, so most people have been feeding theirs with live Daphnia, brineshrimp or microworms. However, most have reported that these will also accept small dried foods such including Tetra Mini Granules and crumbled flakes, as well as live Tubifex.