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Jehol Biota food-web models + Middle Jurassic Daohugou plants + more papers



Ben Creisler
bcreisler@gmail.com

A number of recent mainly non-dino papers that may be of  interest:



Masaki Matsukawa, Kenichiro Shibata, Kenta Sato, Xu Xing and Martin G.
Lockley (2014)
The Early Cretaceous terrestrial ecosystems of the Jehol Biota based
on food-web and energy-flow models.
Biological Journal of the Linnean Society 113(3): 836–853
DOI: 10.1111/bij.12368
http://onlinelibrary.wiley.com/doi/10.1111/bij.12368/abstract

The ancient terrestrial ecosystems of the Lower Cretaceous Yixian
Formation and the Jiufotang Formation, consecutive components of the
Jehol Group in Northeast China were reconstructed using an energy-flow
and food-web model. This model can be used to quantitatively estimate
population densities for ancient terrestrial vertebrates based on food
webs, net primary productivity, and three categories of
energy-transfer efficiency. The results indicate that densities
reached 866 individuals km−2 and 4122 individuals km−2 in two
ecosystems, respectively. The main component of the vertebrate fauna
of the Yixian Formation consisted of large herbivorous dinosaurs,
while much smaller avians dominated the Jiufotang fauna. The model
also indicates a temporal transition in the dinosaur fauna from the
Yixian fauna to the Jiufotang fauna in which theropods decreased and
ceratopsids became more abundant. We then compared these estimates of
biodiversity with the Early Cretaceous Choyr fauna of Mongolia, and
Tetori fauna of Japan using Simpson's diversity indices. Those
indices, based on biomass, indicate that the biodiversities of the
Jehol fauna lay between those of the Choyr and Tetori faunas. This
range in biodiversity seems attributable to fundamental differences in
vegetation and the environment.

==


Yuling Naa, Steven R. Manchester, Chunlin Sun & Shuqin Zhang (2014)
The Middle Jurassic palynology of the Daohugou area, Inner Mongolia,
China, and its implications for palaeobiology and palaeogeography.
Palynology (advance online publication)
DOI:10.1080/01916122.2014.961664
http://www.tandfonline.com/doi/full/10.1080/01916122.2014.961664#.VEWJkPnF_To


Although abundant palaeontological discoveries have been documented in
the Daohugou area in Chifeng City, Inner Mongolia, China, no record of
the palynoflora has been reported previously. We collected
palynological samples from the same level as megafossil plants, and
conducted a detailed taxonomic analysis of the pollen and spores in
order to augment the megafossil record, to extend documentation of the
Middle Jurassic palynoflora, and to examine implications for
palaeogeography, palaeoecology and palaeoclimate in north China during
the Jurassic. Forty-four genera and 87 species of palynomorphs were
identified. Pollen of gymnosperms dominates numerically, followed by
spores of pteridophytes. Most taxa, including bisaccate pollen of
conifers, monosulcate pollen of Cycadales, Bennettitales or
Ginkgoales, along with Cyathidites, Deltoidospora, Granulatisporites,
Osmundacidites and Classopollis, are common elements known elsewhere
during the Jurassic. Based on comparisons with similar
palyno-assemblages in the Jurassic of China, the age of the Daohugou
locality is interpreted to be late Middle Jurassic. According to the
palaeobotanical and palaeopalynological information, the Daohugou
flora is attributed to the warm-temperate to medium temperate zone
with seasonal change. By studying the ecological and climatic
preferences of the main plant groups, five types of palaeolandscape in
the Jurassic of Daohugou are proposed: (1) mesic upland (Pinaceae,
Podocarpaceae, Czekanowskiales and Bennettitales), (2) mesic lowland
(Pinaceae, Podocarpaceae, Ginkgoales, Czekanowskiales and Cycadales,
together with some hygrophilous bryophytes, lycophytes and ferns), (3)
dry upland (Czekanowskiales), (4) dry lowland (Czekanowskiales and
Cheirolepidiaceae) and (5) waterside (plants growing along streams or
near lakes, including bryophytes, lycophytes, ferns and probably some
pteridosperms). According to the plant assemblage, the Daohugou flora
corresponds to that of the Middle Jurassic Northern Floristic Province
of China, which experienced a transition from a humid, warm climate to
a hotter climate with seasonal drought.
===

Feng-Qi Zhang, Han-Lin Chen, Geoffrey E. Batt, Zheng-Xiang Li, and
Shu-Feng Yang (2014)
Early Cretaceous Aptian charcoal from Xinchang Petrified Wood National
Geopark of Zhejiang Province, eastern South China.
PALAIOS 29(7): 325-337
doi: http://dx.doi.org/10.2110/palo.2013.130
http://www.bioone.org/doi/abs/10.2110/palo.2013.130

We report on the distribution and character of fossil charcoal found
in the Lower Cretaceous Guantou Formation in the Xinchang Petrified
Wood National Geopark, eastern South China. All charcoal fragments
studied so far exhibit well-preserved anatomical features of
Araucarioxylon, consistent with the taxonomic classification assigned
to this geopark's widely known silicified tree trunks. Homogenized
cell walls and high vitrinite reflectance values of charcoal
particles, and the synchronous presence of tuffaceous deposits within
the associated sequence, suggest that charcoal in the Xinchang Geopark
may have mainly formed under conditions of complete exclusion of air
by entombment in hot pyroclastic flows. Scattered charcoal fragments
in several sandstone beds overlying the lahar sediments and locally
high concentrations of fragments on channel-scoured surfaces are
consistent with postformation reworking and transport of charcoal
material. Zircon U–Pb SHRIMP dating of the volcanic interbeds of the
Guantou Formation and underlying units define an age of Early
Cretaceous (Aptian) for the charcoal. Both the fossil charcoal and
associated petrified wood within the Guantou Formation may have an
intimate genetic relationship with synchronous volcanism in the
Xinchang Basin, eastern South China.
===

Jeff Liston (2014)
Fossil protection legislation: Chinese issues, global problems.
Biological Journal of the Linnean Society 113(3): 694–706
DOI: 10.1111/bij.12293
http://onlinelibrary.wiley.com/doi/10.1111/bij.12293/abstract


Aspects of the legislation that affects the excavation and export of
fossils from China are reviewed in the context of the illegal removal
of material, as well as problems shared in common with fossil
protection legislation in other territories. Issues that surround a
clear definition of terminology, as well as the consequences of poor
terminology in such legislation, are highlighted, as well as the
question of the propriety of the application of cultural legislation
to palaeontological objects. Examples are given of ways in which
foreign researchers can work legally with institutions in China on
Chinese fossil material, as models of best practice to be followed.

==

Mark T. Young, Lorna Steel, Davide Foffa, Trevor Price, Darren Naish
and Jonathan P. Tennant (2014)
Marine tethysuchian crocodyliform from the ?Aptian-Albian (Lower
Cretaceous) of the Isle of Wight, UK.
Biological Journal of the Linnean Society 113(3): 854–871
DOI: 10.1111/bij.12387
http://onlinelibrary.wiley.com/doi/10.1111/bij.12387/abstract


A marine tethysuchian crocodyliform from the Isle of Wight, most
likely from the Upper Greensand Formation (upper Albian, Lower
Cretaceous), is described. However, we cannot preclude it being from
the Ferruginous Sands Formation (upper Aptian), or more remotely, the
Sandrock Formation (upper Aptian-upper Albian). The specimen consists
of the anterior region of the right dentary, from the tip of the
dentary to the incomplete fourth alveolus. This specimen increases the
known geological range of marine tethysuchians back into the late
Lower Cretaceous. Although we refer it to Tethysuchia incertae sedis,
there are seven anterior dentary characteristics that suggest a
possible relationship with the Maastrichtian-Eocene clade
Dyrosauridae. We also review ‘middle’ Cretaceous marine tethysuchians,
including putative Cenomanian dyrosaurids. We conclude that there is
insufficient evidence to be certain that any known Cenomanian specimen
can be safely referred to Dyrosauridae, as there are some cranial
similarities between basal dyrosaurids and Cenomanian–Turonian marine
‘pholidosaurids’. Future study of middle Cretaceous tethysuchians
could help unlock the origins of Dyrosauridae and improve our
understanding of tethysuchian macroevolutionary trends.

===
Final version of preprint posted earlier:


Yui Takahashi, Yasuhisa Nakajima and Tamaki Sato (2014)
An Early Triassic Ichthyopterygian Fossil from the Osawa Formation in
Minamisanriku Town, Miyagi Prefecture, Japan.
Paleontological Research 18(4): 258-262
doi: http://dx.doi.org/10.2517/2014PR023
http://www.bioone.org/doi/abs/10.2517/2014PR023

The ichthyopterygian Utatsusaurus hataii Shikama et al. 1978 is the
only valid reptilian taxon known from the Lower Triassic Osawa
Formation in Minamisanriku Town, Miyagi Prefecture, which records the
recovery of the marine ecosystem shortly after the end-Permian mass
extinction. In this paper, we describe a fragmentary specimen of an
indeterminate ichthyopterygian which is distinguished from
Utatsusaurus hataii based on rib morphology. The discovery of a
previously unknown ichthyopterygian implies that the taxonomic
diversity of the reptilian fauna of this formation is higher than
previously assumed.

====

Ingmar Werneburg, Laura A. B. Wilson, William C. H. Parr  and Walter
G. Joyce (2014)
Evolution of Neck Vertebral Shape and Neck Retraction at the
Transition to Modern Turtles: an Integrated Geometric Morphometric
Approach.
Systematic Biology (advance online publication)
doi: 10.1093/sysbio/syu072
http://sysbio.oxfordjournals.org/content/early/2014/10/09/sysbio.syu072.abstract


The unique ability of modern turtles to retract their head and neck
into the shell through a side-necked (pleurodiran) or hidden-necked
(cryptodiran) motion is thought to have evolved independently in crown
turtles. The anatomical changes that led to the vertebral shapes of
modern turtles, however, are still poorly understood. Here we present
comprehensive geometric morphometric analyses that trace turtle
vertebral evolution and reconstruct disparity across phylogeny.
Disparity of vertebral shape was high at the dawn of turtle evolution
and decreased after the modern groups evolved, reflecting a
stabilization of morphotypes that correspond to the two retraction
modes. Stem turtles, which had a very simple mode of retraction, the
lateral head tuck, show increasing flexibility of the neck through
evolution towards a pleurodiran-like morphotype. The latter was the
precondition for evolving pleurodiran and cryptodiran vertebrae. There
is no correlation between the construction of formed articulations in
the cervical centra and neck mobility. An increasing mobility between
vertebrae, associated with changes in vertebral shape, resulted in a
more advanced ability to retract the neck. In this regard, we
hypothesize that the lateral tucking retraction of stem turtles was
not only the precondition for pleurodiran but also of cryptodiran
retraction. For the former, a kink in the middle third of the neck
needed to be acquired, whereas for the latter modification was
necessary between the eighth cervical vertebra and first thoracic
vertebra. Our paper highlights the utility of 3D shape data, analyzed
in a phylogenetic framework, to examine the magnitude and mode of
evolutionary modifications to vertebral morphology. By reconstructing
and visualizing ancestral anatomical shapes we provide insight into
the anatomical features underlying neck retraction mode, which is a
salient component of extant turtle classification.

==

Adam E. Rosenblatt, Scott Zona, Michael R. Heithaus, and Frank J.
Mazzotti (2014)
Are Seeds Consumed by Crocodilians Viable? A Test of the Crocodilian
Saurochory Hypothesis.
Southeastern Naturalist  13 (3): N26-N29
doi: http://dx.doi.org/10.1656/058.013.0304
http://www.bioone.org/doi/abs/10.1656/058.013.0304


Many animal species are important dispersers of seeds; however,
relatively little attention has been paid to the seed-dispersal
capabilities of reptiles, and almost nothing is known about the
seed-dispersal capabilities of crocodilians. This lack of information
is surprising given that seeds have been found in the stomach contents
of a majority of crocodilian species. Here we present the first
experimental investigation of the seed-dispersal potential of a
crocodilian. Using a comparative germination experiment, we tested the
viability of Annona glabra (Pond-apple Tree) seeds recovered from the
stomach of an Alligator mississippiensis (American Alligator
[Alligator]) captured in the Florida Coastal Everglades. We found that
seeds from the Alligator's stomach were nonviable under ideal
germination conditions and that fresh, non-digested Pond-apple seeds
exposed to the same germination conditions were highly viable. The
seeds recovered from the Alligator’s stomach were nonviable because
they were likely destroyed by stomach acids. Thus, Alligators are
likely not dispersers of Pond-apple seeds and may instead act as seed
predators. Further research is needed to test the potential of
crocodilians as dispersers of other types of seeds from different
plant families.

====

Peter J. Wagner and George F. Estabrook (2014)
Trait-based diversification shifts reflect differential extinction
among fossil taxa.
Proceedings of the National Academy of Sciences (advance online publication)
doi: 10.1073/pnas.1406304111
http://www.pnas.org/content/early/2014/10/17/1406304111.abstract?sid=7a191a08-059b-4fb1-af50-034c7a0ae3a6

Significance

Shifts in biological diversity often are associated with particular
anatomical traits. Anatomical data from over 300 clades of
brachiopods, molluscs, arthropods, echinoderms, and chordates show
that trait-based diversification shifts are common at even fairly low
(genus and species) taxonomic levels. Cambrian taxa present the lone
major exception. Among post-Cambrian taxa, diversification shifts
correlate strongly with elevated net extinction of primitive taxa
rather than elevated net speciation of derived taxa or increased
morphological disparity among derived taxa. This finding emphasizes
the importance of extinction in shaping morphological and phylogenetic
diversity among closely related species and genera as well as suggests
another way in which Cambrian evolution was unique.

Abstract
Evolution provides many cases of apparent shifts in diversification
associated with particular anatomical traits. Three general models
connect these patterns to anatomical evolution: (i) elevated net
extinction of taxa bearing particular traits, (ii) elevated net
speciation of taxa bearing particular traits, and (iii) elevated
evolvability expanding the range of anatomies available to some
species. Trait-based diversification shifts predict elevated
hierarchical stratigraphic compatibility (i.e.,
primitive→derived→highly derived sequences) among pairs of anatomical
characters. The three specific models further predict (i) early loss
of diversity for taxa retaining primitive conditions (elevated net
extinction), (ii) increased diversification among later members of a
clade (elevated net speciation), and (iii) increased disparity among
later members in a clade (elevated evolvability). Analyses of 319
anatomical and stratigraphic datasets for fossil species and genera
show that hierarchical stratigraphic compatibility exceeds the
expectations of trait-independent diversification in the vast majority
of cases, which was expected if trait-dependent diversification shifts
are common. Excess hierarchical stratigraphic compatibility correlates
with early loss of diversity for groups retaining primitive conditions
rather than delayed bursts of diversity or disparity across entire
clades. Cambrian clades (predominantly trilobites) alone fit null
expectations well. However, it is not clear whether evolution was
unusual among Cambrian taxa or only early trilobites. At least among
post-Cambrian taxa, these results implicate models, such as
competition and extinction selectivity/resistance, as major drivers of
trait-based diversification shifts at the species and genus levels
while contradicting the predictions of elevated net speciation and
elevated evolvability models.
=====