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Psittacosaurus Siberian site + more papers (non-dino)



Ben Creisler
bcreisler@gmail.com

A number of recent papers that may be of interest:

First formal description of Psittacosaurus site in Siberia:

A. V. Lopatin, E. N. Mashchenko, K. K. Tarasenko, A. V. Podlesnov, N.
V. Demidenko & E. A. Kuzmina (2015)
A unique burial site of Early Cretaceous vertebrates in Western
Siberia (the Shestakovo 3 locality, Kemerovo Province, Russia).
Doklady Biological Sciences 462(1): 148-151
DOI: 10.1134/S0012496615030102
http://link.springer.com/article/10.1134/S0012496615030102

>From the text preview:

The uniqueness of this bone-bearing lens is in the state of
preservation and abundance of the complete skeletons of
Psittacosaurus. Three monoliths and plaster jackets with bone
fragments, the preparation of which is not yet finished, were
collected in Shestakovo-3. Skeletons and fragments of skeletons of 12
individuals of Psittacosaurus of various ages were provisionally
identified in the monoliths.

===


Jun Liu, Richard Butler, Corwin Sullivan & Martin Ezcurra (20150
‘Chasmatosaurus ultimus,’ a putative proterosuchid archosauriform from
the Middle Triassic, is an indeterminate crown archosaur.
Journal of Vertebrate Paleontology (advance online publication)
DOI:10.1080/02724634.2015.965779
http://www.tandfonline.com/doi/full/10.1080/02724634.2015.965779#abstract

>From the text preview:

Here we redescribe the specimen and show that 'C. ultimus' is not a
proterosuchid but rather an indeterminate crown archosaur. An
important implication of this revision is the absence of any confirmed
record of proterosuchid archosauriforms from rocks of Middle Triassic
age or younger.

====
Free pdf:

Western Association of Vertebrate Paleontology Annual Meeting: Program
with Abstracts
PaleoBios 32(1) Supplement: 1-17
http://escholarship.org/uc/item/6fk763th

A number of dinosaur-related abstracts are included (Richardoestesia).

===


Ignacio A. Cerda, Juliana Sterli & Torsten M. Scheyer (2015)
Bone shell microstructure of Condorchelys antiqua Sterli, 2008, a stem
turtle from the Jurassic of Patagonia.
Comptes Rendus Palevol (advance online publication)
doi:10.1016/j.crpv.2015.01.004
http://www.sciencedirect.com/science/article/pii/S1631068315000329

The histology of the turtle shell has proven to be a valuable source
of characters for the study of development and shell origin, as well
as early turtles’ lifestyles and systematics. Here we describe and
discuss the shell bone microanatomy and histology of Condorchelys
antiqua, a stem turtle from the Lower Jurassic of Patagonia.
Examination of several elements (including costals, neurals,
peripherals and plastral plates) reveals that the shell bones consist
of a diploe structure in which the interior area of cancellous bone is
framed by external and internal cortices. Whereas the external cortex
is mostly composed of structural fiber bundles, histological
composition of the internal cortex is more variable, exhibiting
structural fiber bundles and/or parallel fibered bone. This
histological variation in the internal cortex allows discerning
between different types of plates. The cancellous bone is mostly well
developed and consists of fine trabeculae composed of secondary
lamellar bone tissue. Predominance of structural fiber bundles in the
shell bones suggests that metaplasia plays an important role during
the development of the shell in this taxon. Comparison with other stem
Testudines (including Proganochelys quenstedti, Proterochersis
robusta, Kayentachelys sp., Eileanchelys waldmani, and Heckerochelys
romani) reveals that the shell histology of C. antiqua resembles more
H. romani and E. waldmani than the other stem taxa. The obtained
values of compactness of C. antiqua shell bones suggest an aquatic
lifestyle for this taxon.


===
Free pdf:

Ying Cui, EnPu Gong, TieHui Wang, ChangQing Guan, YongLi Zhang &
JunHong Liang (2015)
Palynomorph assemblages and paleoclimate records from the Zhuanchengzi
Bed of the Yixian Formation, western Liaoning Province, China.
Science China Earth Sciences (advance online publication)
DOI: 10.1007/s11430-015-5147-x
free pdf:
http://earth.scichina.com:8080/sciDe/EN/abstract/abstract518118.shtml

We collected, processed, identified, and analyzed the spores and
pollen samples from the Zhuanchengzi Bed of the Yixian Formation in
the Yingwoshan area of western Liaoning. As a result, we confirm a
palynomorph assemblage of Cicatricosisporites-Protoconiferus. The
pollen was primarily from gymnosperms, dominated especially by conifer
pollen. Pteridophyte spores were less common and some questionable
angiosperm pollen occurred occasionally. The age of the palynomorph
assemblage is dated as the late Valanginian or Hauterivian-Barremian
stage, the Early Cretaceous. The study applies the concept of
Palynological Vegetation based on palynological spectra and the
paleoecological characteristics of palynological taxa for the first
time. Palynological vegetation type, climatic zone type, and humidity
type are divided quantitatively for the Zhuanchengzi Bed in the Yixian
Formation of western Liaoning. We then obtained the evolutionary
trends. The results showed that the overall climate was warm and humid
during the deposition period of the Zhuanchengzi Bed in the Yixian
Formation. Palynological vegetation types are various and include
coniferous forest, deciduous broadleaf forest, evergreen broad-leaved
forest, grass, and shrubs. The local temperature changed from warm to
much warmer and from a semi-humid to humid climate. Palynological
vegetation types are always dominated by coniferous forest. The
coexistence of deciduous broad-leaved forest, evergreen broad-leaved
forest, shrubs, grass, and some xerophytic plants indicates vertical
zonation and seasonal climate change The vertical vegetation types and
the warm humid climate may imply a large geomorphological contrast in
the Yixian Formation of western Liaoning.

==============

Victoria M. Egerton, Christopher J. Williams & Kenneth J. Lacovara (2015)
A new Late Cretaceous (Late Campanian to early Maastrichtian) wood
flora from southern Patagonia.
Palaeogeography, Palaeoclimatology, Palaeoecology (advance online publication)
doi:10.1016/j.palaeo.2015.07.011
http://www.sciencedirect.com/science/article/pii/S0031018215003715


Highlights

We report on a new Late Cretaceous flora from southern-most Argentina.
A new species of Hedycaryoxylon is described.
The wood flora is dominated by conifer wood with only a few dicot wood
specimens.

Abstract

The Cerro Fortaleza Formation, in southern-most Patagonia (Argentina),
contains a unique Late Cretaceous (Campanian) flora and fauna. This
formation is characterized by lithified fluvial sands, overbank mud
deposits, and palaeosols deposited in fluvial, fluvial-palustrine and
coastal plain environments from the northeastern margin of the Austral
(Magellanes) Basin. The overlying and underlying formations have been
dated as Campanian and Maastrichtian, respectively. Therefore, the
Cerro Fortaleza Formation putatively falls within the Late
Campanian-Maastrichtian. This formation is known for its diverse fauna
including dinosaurs, fishes, and turtles. Furthermore, poorly
preserved leaf impressions from indeterminate conifers and cycads have
also been discovered but not yet described.

Fossil wood taxa from the Cerro Fortaleza Formation yields a diverse
flora of gymnosperm wood but only two genera of angiosperm wood.
Gymnosperm genera identified in this study include Agathoxylon,
Planoxylon, Taxodioxylon, Cupressinoxylon, and Podocarpoxylon; and
angiosperm genera identified include Hedycaryoxylon and
Nothofagoxylon. This is the first record of Planoxylon, Taxodioxylon,
Cupressinoxylon and Hedycaryoxylon from Argentina. Additionally this
is the oldest occurrence of Nothofagoxylon in Argentina. Both the
angiosperm and gymnosperm wood samples possess distinct growth rings,
providing strong evidence for seasonal growth regimes in the region.
All of the wood genera from the Cerro Fortaleza Formation, except
Planoxylon, have also been described from Late Cretaceous sediments of
the Antarctic Peninsula. Thus, the presence of these taxa in both
regions supports Late Cretaceous plant dispersal between them. Despite
sharing the same taxa, the floras from the Cerro Fortaleza Formation
and the Antarctic Peninsula exhibit strikingly different relative
abundances. The ratio of gymnosperm to angiosperm wood in the Cerro
Fortaleza Formation is 75:25; whereas, coeval floras from the
Antarctic Peninsula are ~ 25:75. The floral differences between these
locations may be a relict from a widespread older flora that included
Antarctica, regional floristic variations or a result of different
depositional and/or taphonomic controls in discrete paleoenvironments.
===


Stephen E. Grasby, Benoit Beauchamp, David P.G. Bond, Paul B. Wignall
and Hamed Sane (2015)
Mercury anomalies associated with three extinction events (Capitanian
Crisis, Latest Permian Extinction and the Smithian/Spathian
Extinction) in NW Pangea.
Geological Magazine (advance online publication)
DOI: http://dx.doi.org/10.1017/S0016756815000436
http://128.232.233.5/action/displayAbstract?fromPage=online&aid=9860315&fulltextType=RA&fileId=S0016756815000436

Strata of Permian – Early Triassic age that include a record of three
major extinction events (Capitanian Crisis, Latest Permian Extinction
and the Smithian/Spathian Extinction) were examined at the Festningen
section, Spitsbergen. Over the c. 12 Ma record examined, mercury in
the sediments shows relatively constant background values of
0.005–0.010 μg g–1. However, there are notable spikes in Hg
concentration over an order of magnitude above background associated
with the three extinctions. The Hg/total organic carbon (TOC) ratio
shows similar large spikes, indicating that they represent a true
increase in Hg loading to the environment. We argue that these
represent Hg loading events associated with enhanced Hg emissions from
large igneous province (LIP) events that are synchronous with the
extinctions. The Hg anomalies are consistent across the NW margin of
Pangea, indicating that widespread mercury loading occurred. While
this provides utility as a chemostratigraphic marker the Hg spikes may
also indicate loading of toxic metals to the environment, a
contributing cause to the mass extinction events.

==


Hua Zhanga, Chang-qun Caoa, Xiao-lei Liub, Lin Mua, Quan-feng Zhengc,
Feng Liuc, Lei Xianga, Lu-jun Liua & Shu-zhong Shena (2015),
The terrestrial end-Permian mass extinction in South China.
Palaeogeography, Palaeoclimatology, Palaeoecology (advance online publication)
doi:10.1016/j.palaeo.2015.07.002
http://www.sciencedirect.com/science/article/pii/S0031018215003624

Highlights

The terrestrial end-Permian mass extinction in South China is constrained.
The time and pattern of the terrestrial and marine extinctions are consistent.
The Kayitou Formation is the witness of the terrestrial end-Permian
mass extinction.

Abstract

The end-Permian mass extinction reflects the most severe life crisis
during the Phanerozoic and was associated with major global
environmental changes. However, the consistency of the time and
pattern of the terrestrial and marine extinctions remains
controversial. In this paper, we presented detailed analyses of the
high-resolution biostratigraphical and geochemical data from
terrestrial sections in South China. Our analyses show that the
transitional Kayitou Formation actually recorded the process of
terrestrial mass extinction as evidenced by the mass disappearance of
the Gigantopteris megaflora in the lower part, the dramatic reduction
in abundance of palynomorphs in the middle, and the last occurrences
of plant remains and abundant charcoal fossils in the uppermost part.
It is associated with a distinct negative shift of δ13Corg, beginning
in the middle part of the formation, which is correlative with that in
the top of Bed 26 at the marine Meishan section. In addition, the
Kayitou Formation is characterized by a distinct shift of lithofacies
of fresh lake-swamp or river flat environment from olive/grey/black
mudstone, siltstone, fine to coarse sandstone in the lower part to
gradually increasing maroon rocks, to purely maroon mudrocks with
poorly-sorted breccia, calcic palaeosols and calcareous nodules in the
lowest part of the Dongchuan Formation, which indicates a dramatic
collapse of soil system associated with rapid deforestation and
climatic warming and drying. In the coastal area, the Kayitou
Formation contains marine beds with the typical Permian-Triassic mixed
faunas and floras which are correlative with the latest Changhsingian
marine mixed fauna 1 at Meishan. The Kayitou Formation also recorded a
distinct transgression that began in the latest Changhsingian. All
above phenomena suggest that the Kayitou Formation is actually the
witness of the terrestrial end-Permian mass extinction; and it is
mostly or entirely of latest Changhsingian (Permian), rather than
Triassic age.
==