Daily Archives: March 10, 2009

Cosmic Science News

The basic fabric of the universe is heterogeneous and lumpy. Why? Cosmologists fight over that. Recent theoretical work may be pushing the pendulum towards a string-related explanation (after a period of time when this seemed less likely).

A network of ‘cosmic strings’ criss-crossing the Universe could be responsible for a mysterious flux of antimatter particles which has been puzzling astronomers. … theoretical astrophysicist Tanmay Vachaspati at Case Western Reserve University in Ohio, suggests that space may be threaded … with a network of much lighter strings – too lightweight to be directly responsible for galaxy formation – that could have formed during phase transitions in the Universe’s unseen dark matter…

At the other end of the size spectrum, the immutable atom (well, the Greeks thought is was immutable) may, in some cases, be a shape shifter.

Contrary to some expectations in the world of nuclear physics, researchers have found that a radioactive nucleus of sulphur oscillates between two different shapes, sometimes appearing like a sphere and other times like an American football. The result, reported this month by researchers in France, is causing nuclear physicists to rethink prevailing theories about what makes some nuclei stable and others prone to splitting apart.

The Identification of the Two “Missing” Romanov Children Using DNA Analysis

I first became acquainted with the Romanovs (as historical figures, not the actual Romanovs) reading in middle school about Russian History. Later, someone turned me on to Massie’s Nicholas and Alexandra, which is quite a well known popular historical account of the last Czar of Russia and his family. Everyone knows the story of the end. The core of Czar’s family — the Czar Nicholas, his wife Alexandra, and his children — had been arrested and all of them were transported to a remote location in the Urals. A complex series of events had begun involving Czarist and Revolutionary forces. At one point, it occurred to the local revolutionary officials who were responsible for the incarceration of the Czar and his family that their execution would be a good idea, to avoid their recapture by Czarists forces in the area, and to break the loyalty of Czarist supporters still resisting the Revolution. So, on July 17th, 1918, the Czar and his family, their doctor and a nurse were escorted to an empty room in the compound in which they were being held and shot. The details are rather ghastly, as summarized by an eye witness to the event.
Continue reading The Identification of the Two “Missing” Romanov Children Using DNA Analysis

Nature and Conservation News

Pytoplankton gets some of its nutrients from the dust that settles on the ocean surface. Unfortunately, some of this dust, owing to human caused pollution, is toxic to phytoplankton.

Adina Paytan, a marine scientist at the University of California, Santa Cruz, and her colleagues have found that air samples from different areas of the world are toxic to the most common phytoplankton species, Synechococcus.

Paytan incubated seawater phytoplankton in flasks filled with different samples of aerosol-rich air. “We wanted to find out how aerosol deposition impacts the phytoplankton community,” Paytan explains. “Our hypothesis was that adding the aerosol will add nutrients to the incubation flasks and the phytoplankton will grow happily.”


Invasion of the invasive earthworms

Cindy Hale, an ecologist at the University of Minnesota, answers e-mails from a lot of distraught citizens of the Great Lakes region. The residents, it seems, have introduced certain earthworms into their gardens, she says, “and now they’ve got that ‘nothing grows here syndrome.'”

Long considered a gardener’s friend, earthworms can loosen and aerate the soil. But the story is different in the Great Lakes region. The last Ice Age wiped out native earthworms 10,000 years ago, and ever since the Northeast forest has evolved without the crawlers, Hale says. But now earthworms are back, a product of fishers who toss their worms into the forest, of off-road vehicles and lumber trucks that carry them in the treads of their tires, and of people who bring in mulch–and any worms that might be in it–from other areas.


Governor Sarah Palin and those Darn Beluga Whales. at Blogfish.

Rising sea levels subject of run-up to international climate talks at SciAm.

A 300 million year old fish brain …

ResearchBlogging.org … has been found. Inside the fish’s skull, in fact. This is from a chimaeroid fish, which today are fairly rare but during the Carboniferoius were quite common and diverse. There are really two aspects of this find that are especially interesting. One is the 3D imagery that was obtained of the ancient fossilized brain, and the other is the analysis of the fish’s ear canals. The brain is cool just because it is cool (and shows some interesting morphology). The ear canal study is interesting because it shows a pattern different than expected for a fish: This creature was probably really good at keeping track of it’s position in the horizontal plane, but not the vertical plane. That is odd for a fish.

From the abstract:

…During Carboniferous times, 358-300 million years (Myr) ago, [the chimaeroids] underwent a remarkable evolutionary radiation, with some odd and poorly understood forms, including the enigmatic iniopterygians that were known until now from poorly informative flattened impressions. Here, we report iniopterygian skulls found preserved in 3 dimensions in â??300-Myr-old concretions from Oklahoma and Kansas. The study was performed by using [ a mixture of traditional and novel technologies, fancy software, and analytical techniques] which revealed their peculiar anatomy. Iniopterygians also share unique characters with living chimaeroids, suggesting that the key chimaeroid skull features were already established 300 Myr ago. Moreover [visualization] of an articulated skull revealed a strikingly brain-shaped structure inside the endocranial cavity, which seems to be an exceptional case of soft-tissue mineralization of the brain, presumably as a result of microbially induced postmortem phosphatization. This was imaged with exceptional accuracy by using holotomography, which demonstrates its great potential to image preserved soft parts in dense fossils.


The anatomy of iniopterygians. (A) Reconstruction of Sibyrhynchus denisoni (based on ref. 5, not to scale). (B and C) Part (B) and counterpart (C) of a phosphatic nodule from the Pennsylvanian of Oklahoma (AMNH OKM38) containing the braincase and shoulder girdle of Sibyrhynchus sp. (D-F) Threedimensional reconstruction of the same specimen, obtained from conventional X-ray CT images, showing the braincase in dorsal (D), ventral (E), and lateral (F) view, with associated teeth. (G-I) Three-dimensional reconstruction of the braincase, shoulder girdle, and pectoral fin elements of a sibyrhynchid iniopterygian from the Pennsylvanian of Kansas (KUNHM 21894), based on SR- CT images. Braincase in dorsal (G), posterior (H), and ventral views, with articulated shoulder girdles and pectoral fin radials (I). (Scale bar, 5 mm; f.IX and f.X, foramina for glossopharyngeus and vagus nerves).

I quickly add that previous finds of soft tissue preserved have turned out to be something else. (See: The seductive siren of soft tissue preservation: Ancient dinosaur flesh wasn’t ancient. Or dinosaur flesh.)

Braincase anatomy and exceptional brain preservation in a sibyrhynchid iniopterygian from the Pennsylvanian of Kansas. (A and B) Articulated skull preserved in a nodule (KUNHM 22060) (see also Fig. S1) in dorsal (A) and anterior (B) view (arrow points forward). (C-Q), Three-dimensional reconstructions and putative preserved brain structures of the same specimen, obtained from SR- CT images (and holotomography for brain details). (C-H), Braincase, teeth, and lower jaw in lateral (C), anterior (D), ventral (E), posterior (F), and dorsal (G) view, showing by transparency the outline of the endocranial cavity and labyrinth (H). (I-K), Selected transverse (I and J), and horizontal (K) SR- CT (holotomography) slices through the calcite-filled endocranial cavity, showing the probably phosphatized brain at the level of the rhombencephalon (I), hypophysis (J), and roof of the optic tectum and cerebellum (K). (L-N) Reconstruction of the endocranial cavity and otic capsule in dorsal (L and M) and lateral (N) view, showing the putative brain by transparency (M and N). (O-Q), reconstruction of the putative phosphatized brain in dorsal (O), ventral (P), and lateral (Q) view. (Scale bar, 5 mm for A-N and 1 mm for I–K and O-Q. Asc, anterior semicircular canal; Cer, cerebellum; Ed, endolymphatic duct; Hsc, horizontal semicircular canal; Hyp, hypophysis; Olftr, canals for olfactory tracts; Opch, optic chiasm; Optec, optic tectum; Psc, posterior semicircular canal; II, optic nerve; III?, oculomotorius nerve?; IV?, trochlear nerve?; X?, roots of vagus nerve?).

More information:
Continue reading A 300 million year old fish brain …

Maddow Talks With SEIU’s Andy Stern about the Lying GOP

A most amazing set of spoor

Dino spoor, that is. A recently reported finding in PLoS ONE clarifies a number of questions about how certain dinosaurs held their front limbs (zombie/Frankenstein-position palm-down vs. huggie-wuggie palms-facing-each-other). This research confirms …

that early theropods, like later birds, held their palms facing medially, in contrast to … prints previously attributed to theropods that have forward-pointing digits. Both the symmetrical resting posture and the medially-facing palms therefore evolved by the Early Jurassic, much earlier in the theropod lineage than previously recognized, and may characterize all theropods.

Figure 7 from the paper. Restoration by Heather Kyoht Luterman of Early Jurassic environment preserved at the SGDS, with the theropod Dilophosaurus wetherilli in bird-like resting pose, demonstrating the manufacture of SGDS.18.T1 resting trace.

ResearchBlogging.orgThe find is from southwestern Utah. In particular, the tracks were found in the Whitmore Point Member of the Moenave Formation (WP), which in turn is one of about nine or so formations that are exposed in Zion and Kolob canyons in Zion National Park. The WP Member itself is about 100 meters thick. The Moenave Formation and together with the Kayenta formation (just above it) are considered to be Lower Jurassic in age. The base of the Moenave formation is a disconformity caused when the basin was uplifted, and thus eroded, for about ten million years. Subsequent to this shallow seas to the north of this region repeatdly expanded or shifted into this area, and the sediments of the Moenave formatoi represent lake, river, and flood plain (river-side and beyond) sediments that were part of this sea basin.

Because of the constant (in geological time) shifts between environments, the Moenave Formation possesses layers bearing fossils and traces of a wide range of sediments. Within the WP Member itself, there are plant fossils in some of the lower layers, and fish fossils throughout. Dinosaur bones have been found in the upper most layer. But in many layers, from the lowest to nearly the uppermost, there at tracks. The tracks discussed in this paper are from the lower part of the formation.


Figure 2 from the paper: Stratigraphic section of the Moenave Formation at the St. George Dinosaur Discovery Site at Johnson Farm. Resting trace and trackway SGDS.18.T1 is in the “Top Surface” of the Main Track-Bearing Sandstone Bed (indicated by the blue arrow) in the Whitmore Point Member of the Moenave Formation.

The reason that I’m pointing all of this out is to give an (accurate) impression of the significance of this basin (see this discussion). There are many hundreds of meters of sediment at Zion and other nearby locations (including the Grand Canyon) that tell the story of major changes in the landscape, and that preserve long, well represented records of life. Immense geological time is represented here, as well as the occasional brief and fleeting moments, like when some dinosaur lays down to rest and leaves behind an impression of its body, which happens, against all odds, to be preserved as a trace fossil. It is a paleontologists dream:

Twenty-five track-bearing horizons contained within a small area (1 km2) in St. George, Utah, contain a diverse, theropod-dominated ichnofauna. The most fossiliferous and diverse surface … is preserved within the St. George Dinosaur Discovery Site at Johnson Farm … museum. Mudflat, shoreline, and periodically submerged surfaces coincide on the same bedding plane as evidenced by mud cracks, ripple marks (current, symmetrical, wind-driven, interference, and wave-formed), erosive mega-ripples, load and flute casts, rill and tool marks of various sizes, raindrop impressions, and invertebrate and vertebrate ichnites. [an “ichnite” is a fossilized foot print.] This suite of sedimentary features formed on a beach or shoal along the shores of an Early Jurassic freshwater body (Lake Dixie) that underwent seasonal regressive-transgressive fluctuations. The majority of theropod trackways on this surface trend north-south, paralleling the paleoshoreline. The 22.3 m long SGDS.18.T1 trackway … includes the unique crouching traces….


Figure 4 from the paper. Eubrontes trackway with resting trace (SGDS.18.T1) in the Whitmore Point Member of the Moenave Formation, St. George, Utah. A, Overhead, slightly oblique angle photograph of SGDS.18.T1 resting trace. Note normal Eubrontes track cranial to resting traces (top center) made by track maker during first step upon getting up. Scale bar equals 10 cm. B, Schematic of SGDS.18.T1 to scale with A: first resting traces (manus, pes, and ischial callosity) in red, second (shuffling, pes only) traces in gold, final resting traces (pes and ischial callosity) in green, and tail drag marks made as track maker moved off in blue. Note long metatarsal (“heel”) impressions on pes prints. C, Direct overhead photograph and D, computerized photogrammetry with 5 mm contour lines of Eubrontes trace SGDS.18.T1. Color banding reflects topography (blue-green = lowest, purple-white = highest); a portion of the berm on which the track maker crouched is discernible. Abbreviations: ic = ischial callosity, lm = left manus, lp = left pes, rm = right manus, rp = right pes, td = tail drag marks.

Because early Jurassic dinosaurs of the type that left these tracks had relatively undifferentiated feet, it is impossible to assign these tracks to species. The tracks themselves, grouped together from different locations but looking similar, form what is called an “ichnotaxon” … a species or set of species as represented by tracks of similar morphology. Indeed, when dealing with dinosaurs, perhaps we should say that a given ichnotaxon of this type may even represent a set of genera. The paper itself provides a lengthy discussion of this issue, if you want to delve into it.

The paper concludes that …

… other ostensible theropod manus [manus = front foot] prints are either dubiously attributable to theropods, dubiously made by the manus of a pes-print [pes = back foot] maker, or uninformative with regard to the track maker’s forelimb functional morphology. Because the crouching traces in the trackway [studies here] match the architecture of known theropods, we support the alternative interpretation that most, if not all, other prints showing manus impressions instead pertain to ornithischian or other non-theropodan dinosaurs or dinosauriforms with functionally tridactyl pedes. [This trackway] therefore includes the only unambiguous theropod manus impressions recognized to date and indicates that the avian orientation of the manus, with medially-facing palms, evolved very early within the Theropoda. Less parsimoniously, this posture evolved in immediate dinosaur ancestors; absence in other dinosaurs would thus constitute reversals.

The lack of marks in [this trackway] made by the distal thoracic and pelvic limbs and the ventral portion of the pelvis indicate that, while resting, even the earliest theropods adopted a modern ratite-like [bird-like] posture with the legs folded symmetrically beneath the body such that the weight of the body was distributed between each metatarsus and pes. … The clear symmetry of [this trackway] demonstrates that even some of the oldest, basal-most theropods engaged in this additional avian-style behavior, which therefore also evolved very early in the theropod lineage or was retained in theropods from pre-dinosaurian archosaurs.

Background and references:

Continue reading A most amazing set of spoor