Paleontology

Over the past few weeks, Jacob and I were out doing some scouting and excavation in the lower Niobrara chalk in western Kansas. With the recent drought in the area, not much erosion has happened and so specimens were a bit tough to come by. Though we were blessed with instructions to just record fish localities, secure them, and move on, sometimes the fish are just too good to pass up.Enchodus palatine fang eroding outOne of our long term goals is to expand our 3 dimensional fish reproductions from Kansas. We've completed 4 so far (Xiphactinus, Ichthyodectes, Saurodon, Pachyrhizodus) and we're working on Megalocoelacanthus as our 5th. Enchodus has always been on our wish list (one of the most common fish in the WIS, and those fangs... people love pointy parts), however the large specimens of Enchodus petrosus are very rare, especially anything resembling a complete skeleton and not just isolated palatine bones with fangs.RMDRC 13-001 fanf after prepJacob struck first with a very large Enchodus fang protruding from the grey chalk between MU 7 and 8 He took down the overburden and exposed a sizable disarticulated skull with pectoral fins and vertebrae. We prepared a good portion of it in the lab and have decided that this specimen is where we will mold the majority of the individual elements from.RMDRC 13-001 digsiteA few days later I was working an outcrop slightly lower (just above MU 6) and was shocked to find an articulated skull weathering out of some seriously soft chalk. I hoped it was attached to the rest of an Enchodus.RMDRC 13-005 as foundOriginally we were going to "Sternberg" the specimen (pouring plaster directly over the exposed bones to stabilize everything in the jacket) assuming that there was more resent at the site. Unfortunately, sometimes all you get is a head. In this case a giant one (lower jaw 25cm long) indicating an overall length of about 1.25m. This will be the basis for our overall reconstruction.RMDRC 13-005, bottom side preparedWe're hoping for the prototype to be completed and ready for SVP at the end of October. Fingers crossed.

Trophic cascade alters ecosystem carbon exchangeAuthors:1. Michael S. Strickland (a,b)2. Dror Hawlena (c)3. Aspen Reese (a,d)4. Mark A. Bradford (a)5. Oswald J. Schmitz (a)Affiliations:a. School of Forestry and Environmental Studies, Yale University, New Haven, CT 06511b. Department of Biological Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061c. Department of Ecology, Evolution and Behavior, The Alexander Silberman Institute of Life Sciences, Hebrew University of Jerusalem, Givat-Ram, Jerusalem 91904, Israeld. Department of Biology, Duke University, Durham, NC 27708Abstract:Trophic cascades—the indirect effects of carnivores on plants mediated by herbivores—are common across ecosystems, but their influence on biogeochemical cycles, particularly the terrestrial carbon cycle, are largely unexplored. Here, using a 13C pulse-chase experiment, we demonstrate how trophic structure influences ecosystem carbon dynamics in a meadow system. By manipulating the presence of herbivores and predators, we show that even without an initial change in total plant or herbivore biomass, the cascading effects of predators in this system begin to affect carbon cycling through enhanced carbon fixation by plants. Prolonged cascading effects on plant biomass lead to slowing of carbon loss via ecosystem respiration and reallocation of carbon among plant aboveground and belowground tissues. Consequently, up to 1.4-fold more carbon is retained in plant biomass when carnivores are present compared with when they are absent, owing primarily to greater carbon storage in grass and belowground plant biomass driven largely by predator nonconsumptive (fear) effects on herbivores. Our data highlight the influence that the mere presence of predators, as opposed to direct consumption of herbivores, can have on carbon uptake, allocation, and retention in terrestrial ecosystems.

Title link as always, but note the list has power consumption on it. Tianhe-2 consumes at least 17 MW of power...I'm willing to bet that does NOT include cooling.

Cambrian lobopodians: A review of recent progress in our understanding of their morphology and evolutionAuthors:1. Jianni Liu (a)2. Jason A. Dunlop (b)Affiliations:a. Early Life Institute, The Key Laboratory of Continental Dynamics, Northwest University, Xi’an, 710069, Chinab. Museum für Naturkunde, Leibniz Institute for Research on Evolution, and Biodiversity at the Humboldt University Berlin, D-10115 Berlin, GermanyAbstract:Lobopodians are an important group of organisms which appeared during the Cambrian Explosion. The underlying morphology is invariably a worm-like body bearing multiple pairs of legs. Yet in detail these animals preserve a range of morphologies and have attracted much palaeontological attention; particularly since this assemblage probably includes the ancestors of living velvet worms (Onychophora), water bear (Tardigrada) and arthropods (Arthropoda). In recent years, knowledge of Cambrian lobopodians has increased dramatically based on numerous new records. However, there have been few comprehensive reviews of these animals since Ramsköld & Chen's study in 1998. In the present paper, new insights into Cambrian lobopodians are presented. The legs of Aysheaia pedunculata have a strong attachment with the body, like those of lobopodians in the Chengjiang Fauna. Hallucigenia fortis has a pair of eyes, two pairs of tentacles are observed in the 'neck' region while a bivalved head shield is unequivocally lacking. Some new characters for, and the orientation of, Hallucigenia sparsa are discussed. Longitudinal wrinkles on the body of Xenusion auerswalde are regarded here as putative muscles. Cardiodictyon sinicum bears doublure structures at the anterior margin of head and a pair of eye spots; the shape of dorsal plates is also reinterpreted. Onychodictyon has a pair of anterior appendages, but no sclerotized head shield. The affinities of Miraluolishania haikouensis are clarified and the proposal that M. haikouensis is a junior synonym of Luolishania longicruris is refuted. The large lobopodians, Kerygmachela, Jianshanopodia and Megadictyon – all with frontal appendages, gill-like limbs and tree-like or lamellate-like branches – may be swimming predators.

Hemichordata (Pterobranchia, Enteropneusta) and the fossil recordAuthor:1. Jörg Maletz (a)Affiliation:a. FU Berlin, Institut für Geologische Wissenschaften, Malteser Str. 74–100, Haus B 322, D- 12247 Berlin, GermanyAbstract:The Hemichordata are generally interpreted as early deuterostomes, closely related to the chordates, a notion important for modern analyses of the origin of the deuterostomes. Because their fossil record is quite scanty, modern phylogenetic interpretations largely rely on analysis of DNA of the available extant taxa. The tripartite body plan of the group of worm-like hemichordates, the Enteropneusta, may be traced back in deep time to a few poorly known Middle Cambrian (Series 3, Stage 5) taxa from the Burgess Shale biota. The derived small, colonial or pseudocolonial Pterobranchia (Cephalodiscida and Graptolithina) have a more complete fossil record due to their preservable housing construction, the tubarium. The relationships of fossil taxa, putatively identified as early deuterostomes and possible hemichordates or even as pterobranchs of Lower to Middle Cambrian age (e.g. Galeaplumosus, Herpetogaster), cannot be substantiated. The Pterobranchia and their housing construction is first seen in the Middle Cambrian Series 3, Stage 5 but a clonal, colonial organization of the tubaria can only be recognized in the basal Drumian. The fossil enteropneust Mazoglossus ramsdelli Bardack, 1997 from the Carboniferous Mazon Creek Biota is re-described, its lectotype designated and illustrated for the first time.

I know I’ve written about this before, but Richard Poynder’s new post reminds me that we Brits really do need to be up in arms over the abject behaviour of our supposed representatives, the research councils (RCUK). As a direct result of this policy, the publisher Emerald has now introduced 24-month embargoes on RCUK-funded papers, where before it had none. The scandal here is that when RCUK first published their draft open-access policy in March 2012, it was exemplary. Its front page summarised its key points as follows: Specifically stating that Open Access includes unrestricted use of manual and automated text and data mining tools; and unrestricted reuse of content with proper attribution. Requiring publication in journals that meet Research Council ‘standards’ for Open Access. No support for publisher embargoes of longer than six months from the date of publication (12 months for research funded by the Arts and Humanities Research Council (AHRC) and the Economic and Social Research Council (ESRC)). Subsequent revisions of this policy have systematically removed all three of these policies: Green-OA papers may now be encumbered by commercial clauses, RCUK has said it will not enforce its journal standards, and the maximum six-month embargo for STM publication has quadrupled to 24 months. As a matter of fact, it looks uncannily as though they read my comments and deliberately did the exact opposite. (No, I am not seriously suggesting that’s what happened. I’m not paranoid. What actually happened is less conspiracy-flavoured: I want what’s good for the world; publishers want what’s good for publishers, which is the opposite. They got what they wanted.) How the hell did this happen? The irony here is that the House of Lords select committee criticised RCUK for “lack of consultation” when in fact it had circulated its initial policy for comments. It was after this that RCUK threw out all its progressive promises without consultation — except, evidently, with the publishers to whom it so cravenly capitulated. Where was the consultation on the 24-month embargoes now being exploited by “publishers” like Emerald? There was none: suddenly, from out of the blue, the Publishers Association’s “decision tree” appeared bearing the shameful legend “endorsed by BIS and RCUK”. On whose mandate? BIS and RCUK both exist to spend taxpayers’ money: when did taxpayers give their consent to quadrupling embargoes? The whole thing makes me want to weep. By this stage in the proceedings, we expect barrier-based publishers to act against the interests of every other party. What we don’t expect it for our elected representatives to collude. Could we at least have the courtesy of some kind of explanation for RCUK?

I recently attempted a new drawing and experimented with adding a bit more detail than I normally do. I find that every drawing is a learning process, and I try to challenge myself by learning new techniques and styles every time I put a pencil to paper. Until about a year ago, I had never really used anything other than a #2 pencil - which is a relatively soft lead. More recently I have started using somewhat harder pencils, including a 3H - which remains sharper for longer, and can be sharpened more finely - allowing for much more detailed work. Skull and mandible of Delphinapterus leucas from the MNHN, borrowed from Wikipedia. Occasionally I'll see a photograph that speaks to me and looks like it would be fun (or challenging) to illustrate. A few weeks ago I found a neat looking photo of a beluga (Delphinapterus leucas) skull and mandible from the MNHN in Paris (shown above). It's a rather old mount as can be gathered from the nails and wires securing the teeth. This one was of sufficiently high resolution to elaborate minute details of the bone texture, and was an excellent candidate for an experiment in substantially more detailed illustration than what I've previously attempted. The completed illustration, measuring about ~14" wide or so. This illustration took about 20 or so hours to complete - perhaps double the time I've invested in similar sized illustrations previously. I spent about 6 hours just on the temporal region of the skull. Altogether, I am really pleased with the end result. Come to think about it, I should probably post some illustrating tutorials at some point in the future. Close up of the temporal region. I went a bit crazy here.