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Dinosaurs in Brazil + Diplocynodon + non-dino papers

Ben Creisler

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

Drielli Peyerl, Carlos Roberto A. Candeiro & Silvia Fernanda Mendonça
Figueirôa (2014)
Trajectory and contribution of geoscientists (1906–1961) to dinosaur
research in the Bauru Group (Cretaceous) in the Triângulo Mineiro
region of Brazil.
Journal of South American Earth Sciences (advance online publication)

The development of paleontological research in the Triangulo Mineiro region.
The description of the trajectory of paleontologists who contributed
to the studies of the region.
The work of paleontologists in the Triângulo Mineiro region, during
twentieth century.

The present study discusses geological and paleontological research
conducted by geoscientists in the Late Cretaceous Bauru Group, of the
Triângulo Mineiro region, Brazil. This analysis based largely on
historical documentary sources focuses on the pioneering work of
geoscientists, who made numerous discoveries of dinosaur fossils. This
work contributes to a chronological survey that has been compiled on
the geological studies in the Bauru Group, and describes the
importance of the paleontological discoveries made during the
twentieth century.

Lanuze Fabielly S. Tavares, Silvina de Valais, Yuri Modesto Alves &
Carlos Roberto A. Candeiro (2014)
Amazonian Lower Cretaceous North Tocantins State (Brazil) dinosaur
track site: conservation significance.
Environmental Earth Sciences (advance online publication)
DOI: 10.1007/s12665-014-3754-z

On the left bank of the Tocantins River, near São Domingos, State of
Tocantins, northern Brazil, there are at least six vertebrate
trackways from the Barremian Corda Formation (Parnaíba Basin) first
reported by Leonardi (Buenos Aires 1:215–222, 1980) and assigned to
iguanodontid dinosaurs. Later, these trackways were reassigned as
belonging to sauropods. Until 2011, this locality was subject to river
floods during seasonal rain cycles. Since then, the amount of water on
the flatstones was substantially modified due the implantation of the
“Usina Hidroeletrica de Estreito”, which has a dam 160 km upstream
from the trackways locality. Recent fieldwork in the area has revealed
that only a part of four original trackways is still preserved. The
specimens, with poor to moderate preservation, are represented by
large semicircular pes imprints lacking digital impressions mostly
overlapping the hand print, which supports a sauropodian origin. Here,
the authors consider and suggest geotourism as an important tool to
protect and preserve the São Domingos’ footprints.


Jeremy E. Martin, Thierry Smith, France de Lapparent de Broin,
Francois Escuillié and Massimo Delfino (2014)
Late Palaeocene eusuchian remains from Mont de Berru, France, and the
origin of the alligatoroid Diplocynodon.
Zoological Journal of the Linnean Society 172(4): 867–891
DOI: 10.1111/zoj.12195

Crocodilian remains from the late Palaeocene continental locality of
Mont de Berru (Marne, France) offer the opportunity to reassess the
taxonomic identity of the oldest diplocynodontid from Europe. Owing to
significant morphological differences from previously described
species of Diplocynodon, which include the presence of a splenial
symphysis, a new species, Diplocynodon remensis sp. nov., is erected
here. Its inclusion in a phylogenetic framework for Eusuchia leads to
its positioning as a derived member of diplocynodontids.
Diplocynodontidae are viewed as a basal alligatoroid taxon, and,
because morphological affinities with the Late Cretaceous−early Eocene
North American genus Borealosuchus were mentioned in earlier studies,
a comparison amongst D. remensis sp. nov., Leidyosuchus, and
Borealosuchus spp. is presented. Although D. remensis sp. nov. is the
geologically oldest diplocynodontid, according to our results, it is
not the phylogenetically most primitive. Other morphological
discrepancies are highlighted, indicating that the topology recovered
here is only tentative. From a biogeographical point of view, the
appearance of Diplocynodon in Europe prior to the Palaeocene/Eocene
boundary indicates that it did not disperse with North American taxa
that reached Europe around the time of the Palaeocene-Eocene thermal
maximum (PETM). Therefore, a pre-PETM dispersal from North America at
the same times as other vertebrates with clear North American
affinities also occurring in the Palaeocene of Europe cannot be
excluded. The description of D. remensis sp. nov. adds substantial
new, albeit conflicting, information, highlighting the need for a
better phylogenetic framework with a revision of other critical taxa
(Menatalligator, Borealosuchus) from the Palaeocene of Europe and
North America. © 2014 The Linnean Society of London

In open access:

Vivian Allen, Julia Molnar, William Parker, Andrea Pollard, Grant
Nolan and John R. Hutchinson (2014)
Comparative architectural properties of limb muscles in Crocodylidae
and Alligatoridae and their relevance to divergent use of asymmetrical
gaits in extant Crocodylia.
Journal of Anatomy 225(6): 569–582
DOI: 10.1111/joa.12245

Crocodiles and their kin (Crocodylidae) use asymmetrical (bounding and
galloping) gaits when moving rapidly. Despite being morphologically
and ecologically similar, it seems alligators and their kin
(Alligatoridae) do not. To investigate a possible anatomical basis for
this apparent major difference in locomotor capabilities, we measured
relative masses and internal architecture (fascicle lengths and
physiological cross-sectional areas) of muscles of the pectoral and
pelvic limbs of 40 individuals from six representative species of
Crocodylidae and Alligatoridae. We found that, relative to body mass,
Crocodylidae have significantly longer muscle fascicles (increased
working range), particularly in the pectoral limb, and generally
smaller muscle physiological cross-sectional areas (decreased
force-exerting capability) than Alligatoridae. We therefore
hypothesise that the ability of some crocodylians to use asymmetrical
gaits may be limited more by the ability to make large, rapid limb
motions (especially in the pectoral limb) than the ability to exert
large limb forces. Furthermore, analysis of scaling patterns in muscle
properties shows that limb anatomy in the two clades becomes more
divergent during ontogeny. Limb muscle masses, fascicle lengths and
physiological cross-sectional areas scale with significantly larger
coefficients in Crocodylidae than Alligatoridae. This combination of
factors suggests that inter-clade disparity in maximal limb power is
highest in adult animals. Therefore, despite their apparent
morphological similarities, both mean values and scaling patterns
suggest that considerable diversity exists in the locomotor apparatus
of extant Crocodylia.


Carlo Romano, Martha B. Koot, Ilja Kogan, Arnaud Brayard, Alla V.
Minikh, Winand Brinkmann, Hugo Bucher and Jürgen Kriwet (2014)
Permian–Triassic Osteichthyes (bony fishes): diversity dynamics and
body size evolution.
Biological Reviews (advance online publication)
DOI: 10.1111/brv.12161

The Permian and Triassic were key time intervals in the history of
life on Earth. Both periods are marked by a series of biotic crises
including the most catastrophic of such events, the end-Permian mass
extinction, which eventually led to a major turnover from typical
Palaeozoic faunas and floras to those that are emblematic for the
Mesozoic and Cenozoic. Here we review patterns in Permian–Triassic
bony fishes, a group whose evolutionary dynamics are understudied.
Based on data from primary literature, we analyse changes in their
taxonomic diversity and body size (as a proxy for trophic position)
and explore their response to Permian–Triassic events. Diversity and
body size are investigated separately for different groups of
Osteichthyes (Dipnoi, Actinistia, ‘Palaeopterygii’, ‘Subholostei’,
Holostei, Teleosteomorpha), within the marine and freshwater realms
and on a global scale (total diversity) as well as across
palaeolatitudinal belts. Diversity is also measured for different
palaeogeographical provinces. Our results suggest a general trend from
low osteichthyan diversity in the Permian to higher levels in the
Triassic. Diversity dynamics in the Permian are marked by a decline in
freshwater taxa during the Cisuralian. An extinction event during the
end-Guadalupian crisis is not evident from our data, but
‘palaeopterygians’ experienced a significant body size increase across
the Guadalupian–Lopingian boundary and these fishes upheld their
position as large, top predators from the Late Permian to the Late
Triassic. Elevated turnover rates are documented at the
Permian–Triassic boundary, and two distinct diversification events are
noted in the wake of this biotic crisis, a first one during the Early
Triassic (dipnoans, actinistians, ‘palaeopterygians’, ‘subholosteans’)
and a second one during the Middle Triassic (‘subholosteans’,
neopterygians). The origination of new, small taxa predominantly among
these groups during the Middle Triassic event caused a significant
reduction in osteichthyan body size. Neopterygii, the clade that
encompasses the vast majority of extant fishes, underwent another
diversification phase in the Late Triassic. The Triassic radiation of
Osteichthyes, predominantly of Actinopterygii, which only occurred
after severe extinctions among Chondrichthyes during the Middle–Late
Permian, resulted in a profound change within global fish communities,
from chondrichthyan-rich faunas of the Permo-Carboniferous to typical
Mesozoic and Cenozoic associations dominated by actinopterygians. This
turnover was not sudden but followed a stepwise pattern, with leaps
during extinction events.


Leslie A. Rowland, Naresh C. Bal and Muthu Periasamy (2014)
The role of skeletal-muscle-based thermogenic mechanisms in vertebrate
Biological Reviews (advance online publication)
DOI: 10.1111/brv.12157

Thermogenesis is one of the most important homeostatic mechanisms that
evolved during vertebrate evolution. Despite its importance for the
survival of the organism, the mechanistic details behind various
thermogenic processes remain incompletely understood. Although heat
production from muscle has long been recognized as a thermogenic
mechanism, whether muscle can produce heat independently of
contraction remains controversial. Studies in birds and mammals
suggest that skeletal muscle can be an important site of non-shivering
thermogenesis (NST) and can be recruited during cold adaptation,
although unequivocal evidence is lacking. Much research on
thermogenesis during the last two decades has been focused on brown
adipose tissue (BAT). These studies clearly implicate BAT as an
important site of NST in mammals, in particular in newborns and
rodents. However, BAT is either absent, as in birds and pigs, or is
only a minor component, as in adult large mammals including humans,
bringing into question the BAT-centric view of thermogenesis. This
review focuses on the evolution and emergence of various thermogenic
mechanisms in vertebrates from fish to man. A careful analysis of the
existing data reveals that muscle was the earliest facultative
thermogenic organ to emerge in vertebrates, long before the appearance
of BAT in eutherian mammals. Additionally, these studies suggest that
muscle-based thermogenesis is the dominant mechanism of heat
production in many species including birds, marsupials, and certain
mammals where BAT-mediated thermogenesis is absent or limited. We
discuss the relevance of our recent findings showing that uncoupling
of sarco(endo)plasmic reticulum Ca2+-ATPase (SERCA) by sarcolipin
(SLN), resulting in futile cycling and increased heat production,
could be the basis for NST in skeletal muscle. The overall goal of
this review is to highlight the role of skeletal muscle as a
thermogenic organ and provide a balanced view of thermogenesis in