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Non-dinosaur papers and news items



From: Ben Creisler
bcreisler@gmail.com

Here are a number of recent non-dinosaur papers and news items that
may interest some people:


Sander W.S. Gussekloo & Jorge Cubo (2013)
Flightlessness affects cranial morphology in birds.
Zoology (advance online publication)
doi: http://dx.doi.org/10.1016/j.zool.2012.09.001
http://www.sciencedirect.com/science/article/pii/S0944200612000955


Flightless birds belonging to phylogenetically distant clades share
several morphological features in the pectoral and pelvic apparatus.
There are indications that skull morphology is also influenced by
flightlessness. In this study we used a large number of flightless
species to test whether flightlessness in modern birds does indeed
affect cranial morphology. Discriminant analyses and variation
partitioning show evidence for a relationship between skull morphology
and the flightless condition in birds. A possible explanation for the
change in cranial morphology can be linked to the reduced selective
force for light-weight skulls in flightless birds. This makes an
increase in muscle mass, and therefore an enlargement of muscle
insertion areas on the skull, possible. We also compared the
ontogenetic trajectory of Gallus with the adult morphology of a sample
of flightless species to see whether the apomorphic features
characterizing the skull of flightless birds share the same
developmental basis, which would indicate convergent evolution by
parallelism. Skull morphology (expressed as principal component
scores) of palaeognathous flightless birds (ratites) is dissimilar
(higher scores) to juvenile stages of the chicken and therefore seem
peramorphic (overdeveloped). Principal component scores of adult
neognathous flightless birds fall within the range of chicken
development, so no clear conclusions about the ontogenetic
trajectories leading to their sturdier skull morphology could be
drawn.

==

Chengmin Huang, Gregory J. Retallack, Chengshan Wang, and Qinghua Huang (2013)
Paleoatmospheric pCO2 fluctuations across the Cretaceous-Tertiary
boundary recorded from paleosol carbonates in NE China.
Palaeogeography, Palaeoclimatology, Palaeoecology (advance online publication)
http://dx.doi.org/10.1016/j.palaeo.2013.01.005
http://www.sciencedirect.com/science/article/pii/S0031018213000096

A dramatic change in atmospheric composition has been postulated
because of global carbon cycle disruption during the Cretaceous (K)
–Tertiary (T) transition following the Chicxulub impact and Deccan
Trap eruptions. Here, pedogenic carbonates were collected from
drillcore of a borehole (SK-1(N)) straddling the Late Cretaceous and
early Paleocene strata in the Songliao Basin, northeast China, to
reconstruct atmospheric CO2 concentrations using a paleosol
paleobarometer. Our estimates for atmospheric pCO2 from paleosol
carbonates range between 277 ± 115 ppmv and 837 ± 164 ppmv between
67.8 Ma and 63.1 Ma. One large ( ~ 66-65.5 Ma) and several small CO2
spikes (~ 64.7- ~ 64.2 Ma) during the latest Maastrichtian to earliest
Danian are reported here and incorporated with previously published
pCO2 estimates also estimated from paleosol carbonates. These CO2
spikes are attributed to one-million-year-long emplacement of the
large Deccan flood basalts along with the extraterrestrial impact at
the K-T boundary.

==
Abdelkbir Hminna, Sebastian Voigt, Hendrik Klein, Hafid Saber, Jörg W.
Schneider, Driss Hmich (2013)
First occurrence of tetrapod footprints from the continental Triassic
of the Sidi Said Maachou area (Western Meseta, Morocco).
Journal of African Earth Sciences 80:1-7 (publication in progress)
http://dx.doi.org/10.1016/j.jafrearsci.2012.11.003
http://www.sciencedirect.com/science/journal/1464343X

The Sidi Said Maachou area in the Moroccan western Meseta preserves a
succession, up to 400 m thick, of hitherto poorly studied continental
Triassic deposits. Recent detailed geological mapping proposes a
lithostratigraphic subdivision of the predominantly red-coloured
siliciclastic deposits into three formations. Laminated mudstones and
fine-grained sandstones in the upper part of the Oued Oum Er Rbiaa
Formation have the most interesting fossil content including plant
impressions, rhizoliths, fish scales, and invertebrate and vertebrate
traces. These biogenic remains are partially associated with tool
marks, microbially induced sedimentary structures, oscillation
ripples, desiccation cracks, and halite pseudomorphs, suggesting
sedimentation in a playa-like, fluvio-lacustrine system under semiarid
conditions. All tetrapod footprints from these beds are assigned to
Brachychirotherium parvum and indistinguishable from other occurrences
of the ichnogenus in Central Europe and North America. Supposed
trackmakers are archosaurs of the crocodile stem-group (Crurotarsi)
that were widely spread over Triassic Pangaea. Because
Brachychirotherium is only known from Late Triassic (Carnian–Rhaetian)
deposits, the same age is attributed to the footprint horizon of the
Oued Oum Er Rbiaa Formation. This is the first record of
Brachychirotherium on the African continent and the first record of
Triassic tetrapod footprints in Morocco outside of the High Atlas.

===

NEW STORY IN GERMAN WITH VIDEO

Preparation of Mosasaurus recently found in Maastricht:

http://www.aachener-zeitung.de/lokales/region/mit-dem-zahnkratzer-durch-die-kreidezeit-1.492527


===
PERMIAN STUFF

To step out of the Mesozoic for a bit, some recent articles about the
Permian and a news item in German:

Michael J. Benton & Andrew J. Newell (2012)
Impacts of global warming on Permo-Triassic terrestrial ecosystems.
Gondwana Research (advance online publication)
http://dx.doi.org/10.1016/j.gr.2012.12.010
http://www.sciencedirect.com/science/article/pii/S1342937X12004169


Geologists and palaeontologists have expressed mixed views about the
effects of the end-Permian mass extinction on continental habitats and
on terrestrial life. Current work suggests that the effects on land
were substantial, with massive erosion following the stripping of
vegetation, associated with long-term aridification and short-term
bursts of warming and acid rain. Wildfires at the Permo-Triassic
boundary contributed to the removal of forests and the prolonged
absence of forests from the Earth's surface for up to 10 Myr. These
physical crises on land impinged on the oceans, suggesting tight
interlocking of terrestrial and marine crises. Levels of extinction on
land may well have been as high as in the sea, and this is certainly
the case for tetrapods. The mass extinction seems to have been less
profound for plants and insects, but it is hard at present to
disentangle issues of data quality from reductions in abundance and
diversity. Several killing agents have been proposed, and of these
tetrapods may have succumbed primarily to acid rain, mass wasting, and
aridification. Plants may have been more affected by the sudden
effects of heating and wildfires, and the crisis for insects has yet
to be explored.


===


The pdf for the following paper is open access (free!) It has a bit
about the fossil reptiles found preserved completely intact with skin
traces and more. I have posted a few news articles in German about
these recent finds.


Ronny Rößler, Thorid Zierold, Zhuo Feng, Ralph Kretzschmar, Mathias
Merbitz, Volker Annacker, and Jörg W. Schneider (2012)
A snapshot of an Early Permian ecosystem preserved by explosive
volcanism: new results from the Chemnitz Petrified Forest, Germany.
PALAIOS 27(11):814-834
http://www.bioone.org/doi/abs/10.2110/palo.2011.p11-112r

A recently excavated locality in the Chemnitz Petrified Forest, lower
Permian in age and occurring within the Leukersdorf Formation of the
Chemnitz Basin, Germany, provides evidence for an outstanding fossil
assemblage buried in situ by pyroclastics. The environment is
interpreted as forested lowland that sheltered a dense hygrophilous
vegetation of ferns, sphenophytes, and gymnosperms, as well as a
diverse fauna of reptiles, amphibians, arthropods, and gastropods. A
detailed measured section of the outcrop documents the early volcanic
history of the Chemnitz fossil forest, including a paleosol that shows
the root systems of Psaronius tree ferns, Arthropitys calamitaleans,
and Medullosa and Cordaixylon gymnosperms in the same horizon.
Fifty-three trunks are still standing upright and rooted at their
place of growth, providing evidence that the top of the paleosol was
the land surface on which the forest grew, thereby offering insights
into the original plant community structure and density. Taphonomic
analysis of both the petrified and adpression-fossil assemblages
enable us to reconstruct the direction, estimate the violence and
extent of the volcanic events, and their effects on the entire
ecosystem. A complete dataset of three-dimensional coordinates
resulting from three and one-half years of continuing excavation and
study permits the recognition of organ connections and results in the
first reconstructions of the excavation site, the floral elements, and
the plant community as a whole.

==

Krzysztof Owocki, Grzegorz Niedźwiedzki, Andrey G. Sennikov, Valeriy
K. Golubev, Katarzyna Janiszewska, and Tomasz Sulej  (2012)
Upper Permian vertebrate coprolites from Vyazniki and Gorokhovets,
Vyatkian regional stage, Russian platform.
PALAIOS 27(12):867-877
http://www.bioone.org/doi/abs/10.2110/palo.2011.p11-112r


Numerous coprolites have been found in the Vyazniki and Gorokhovets
localities of European Russia. Five identified coprolite-bearing
horizons occur in the upper Permian deposits of the Vyatkian Regional
Stage. Coprolites were collected from mudstone with a coprolite
breccia-like layer and also from intraformational conglomerates that
were deposited in a floodplain and overbank environment. Two coprolite
morphotypes (A and B) are recognized from size and shape analysis of
32 specimens. Morphotype A has long, nonsegmented feces. Smaller,
cylindrical or tubular-shaped coprolites of morphotype B are commonly
segmented. SEM images of the coprolite matrix show spheres and
thin-walled vesicles with diameters 0.5–4 µm. Electron Micro Probe
(EMP) analyses of polished thin sections show microcrystalline
carbonate-fluoride-bearing calcium phosphate with small amounts of
calcium replaced in the crystal lattice. Optical microscopy and EMP
investigations show that iron and manganese oxides are responsible for
elevated iron and manganese concentrations in the bulk mass of
coprolites. Other metals (V, Ni) can be associated with oxides forming
spheroids with diameters 3–10 µm. REEs (rare earth elements, U, and
other trace element concentrations suggest significant eolian sediment
input to the burial environment of the coprolites. The scats contain
fish scales and bones of tetrapods (amphibians or reptiles). In one
large-sized coprolite, a small fragment of therapsid bone was also
found. Both morphotypes are matched to carnivorous taxa within the
Archosaurus rossicus zone of the Eastern Europe. The size and shape of
the best-preserved specimens suggest that they were possibly produced
by a large therapsid, anthracosaur, or early archosauromorph predator.


===

NEWS STORY IN GERMAN

Five-fingered Micromelerpeton skeletons from Permian under study

Temnospondyls typically have four digits (fingers) of their forefeet
and five toes on their hindfeet, the same as most living salamanders.
However, some specimens of the Permian temnospondyl Micromelerpeton
have five "fingers" on their forefeet. Excellent specimens with five
"fingers" are being studied at the paleontological museum in
Nierstein, Germany. Click to enlarge the photo of a specimen, although
the toes are a bit hard to count.

http://www.allgemeine-zeitung.de/region/oppenheim-nierstein-guntersblum/vg-nierstein-oppenheim/nierstein/12686092.htm