Abstract
Developmental
changes
in
salamander
skulls,
before
and
after
metamorphosis,
affect
the
feeding
capabilities
of
these
animals.
How
cranial
morphology
tissue
properties
function
skull
are
key
to
decipher
early
evolutionary
history
crown-group
salamanders.
Here,
3D
biomechanics
adult
Salamandrella
keyserlingii
were
analyzed
under
different
ossification
sequences
skeleton.
This
helped
unravel
that:
(a)
Mechanical
tissues
(as
bone,
cartilage
or
connective
tissue)
imply
a
consensus
between
stiffness
required
perform
versus
fixation
(and
displacement)
with
surrounding
skeletal
elements.
(b)
Changes
on
pattern,
producing
fontanelles
as
result
bone
loss
failure
ossify,
represent
trend
toward
simplification
potentially
helping
distribute
stress
through
skull,
but
may
also
major
destabilization
skull.
(c)
Bone
be
originated
due
biomechanical
optimization
potential
reduction
developmental
costs.
(d)
Hynobiids
excellent
models
for
reconstruction
extinct
urodeles.
Ecological
preferences
and
life
history
strategies
have
enormous
impacts
on
the
evolution
phenotypic
diversity
of
salamanders,
but
yet
established
reliable
ecological
indicators
from
bony
skeletons
hinder
investigations
into
paleobiology
early
salamanders.
Here,
we
statistically
demonstrate
by
using
time-calibrated
cladograms
geometric
morphometric
analysis
71
specimens
in
36
species,
that
both
shape
palate
many
non-shape
covariates
particularly
associated
with
vomerine
teeth
are
ecologically
informative
stem-
basal
crown-group
Disparity
patterns
within
morphospace
preferences,
strategies,
taxonomic
affiliations
were
analyzed
detail,
evolutionary
rates
ancestral
states
reconstructed.
Our
results
show
is
heavily
impacted
convergence
constrained
feeding
mechanisms
also
exhibits
clear
stepwise
alternative
configurations
to
cope
similar
functional
demand.
Salamanders
diversified
before
Middle
Jurassic
achieved
all
their
present
Early
Cretaceous.
reveal
last
common
ancestor
salamanders
share
other
modern
amphibians
a
unified
biphasic
preference,
metamorphosis
significant
expansion
ecomorphospace
Early
limb
skeletogenesis
in
salamanders
is
characterized
by
preaxial
elements,
digits
I
and
II
forming
earlier
than
their
postaxial
counterparts
(digits
III
to
V),
a
phenomenon
known
as
dominance,
whereas
amniotes
anurans,
these
developmental
sequences
are
reversed.
This
pattern
characterizes
the
late
of
zeugopodium
anamniote
tetrapods
but
remains
unknown
carpals/tarsals.
To
correct
this
gap
knowledge,
we
investigate
ossification
patterns
carpals/tarsals
six
salamander
families/clades
based
on
micro-computed
tomography
scans.
We
found
that
dominance
seen
distal
several
clades
diverse
early
tetrapods,
such
temnospondyls
amniotes.
distribution
suggests
primitive
tetrapods.
Our
results
demonstrate
developmentally
evolutionarily
independent
autopodium,
facilitates
stabilization
number
during
fin-to-limb
transition
digit
reduction
Journal of Anatomy,
Год журнала:
2020,
Номер
238(2), С. 219 - 248
Опубликована: Сен. 22, 2020
Abstract
Hynobiidae
are
a
clade
of
salamanders
that
diverged
early
within
the
crown
radiation
and
retain
considerable
number
features
plesiomorphic
for
group.
Their
evolutionary
history
is
informed
by
fossil
record
extends
to
Middle
Jurassic
Bathonian
time.
Our
understanding
evolution
total
group
has
benefited
considerably
from
recent
discoveries
stem
hynobiids
but
constrained
inadequate
anatomical
knowledge
some
extant
forms.
Pseudohynobius
derived
hynobiid
consisting
five
seven
species
living
endemic
southwestern
China.
Although
this
been
recognized
over
37
years,
osteological
details
these
remain
elusive,
which
undoubtedly
contributed
taxonomic
controversies
complex
Liua
‐
Protohynobius
.
Here
we
provide
bone‐by‐bone
study
cranium
in
(
Ps.
flavomaculatus
,
guizhouensis
jinfo
kuankuoshuiensis
shuichengensis
)
based
on
x‐ray
computer
tomography
data
18
specimens.
results
indicate
each
combination
differences
morphology,
proportions
articulation
patterns
both
dermal
endochondral
bones.
establishes
range
intraspecific
will
serve
as
organizing
hypotheses
future
studies
more
extensive
collections
become
available.
Morphological
terrestrial
ecological
adaptation
summarized.
Based
results,
also
discuss
development
several
potential
synapomorphies
Hynobiidae,
including
orbitosphenoid
articular.
Abstract
For
most
fossil
taxa,
dietary
inference
relies
primarily
on
indirect
evidence
from
jaw
morphology
and
the
dentition.
In
rare
cases,
however,
preserved
gut
contents
provide
direct
of
feeding
strategy
species
interaction.
This
is
important
in
reconstruction
food
webs
energy
flow
through
ancient
ecosystems.
The
Early
Cretaceous
Chinese
Jehol
Biota
has
yielded
several
such
examples,
with
lizards,
birds,
small
dinosaurs,
mammals
as
both
predator
prey.
Here
we
describe
an
frog
specimen,
genus
Genibatrachus
,
that
contains
adult
salamander
within
its
body
cavity.
attributed
to
hynobiid-like
Nuominerpeton
.
skeleton
complete
articulated,
suggesting
it
was
caught
swallowed
shortly
before
itself
died
buried.
Cretaceous Research,
Год журнала:
2023,
Номер
151, С. 105605 - 105605
Опубликована: Июнь 5, 2023
A
new
small-bodied
theropod
dinosaur,
Migmanychion
laiyang
gen.
et
sp.
nov.,
is
erected
based
on
appendicular
skeletal
material
from
the
Lower
Cretaceous
of
Pigeon
Hill
locality,
Inner
Mongolia,
China.
This
shows
a
peculiar
combination
features
in
hand,
part
shared
with
therizinosauroids,
oviraptorosaurs
and
enigmatic
Fukuivenator
paradoxus
Japan..
Phylogenetic
analysis
supports
closest
affinity
Fukuivenator,
yet
alternative
placements
among
Oviraptorosauria
or
non-avialan
paravians
result
suboptimal
descriptions
character
distribution.
Although
this
taxon
confidently
referred
to
Maniraptora,
uniquely
derived
hand:
only
additional
could
substantiate
its
precise
placement
bird-like
theropods.
Fragmentary
same
locality
cannot
be
unambiguously
Migmanychion.
One
specimen,
including
associated
partial
pelvis
hindlimbs,
tentatively
paravian
maniraptoran.
Atomic Spectroscopy,
Год журнала:
2022,
Номер
44(1)
Опубликована: Март 5, 2022
Salamanders
(Urodela)
are
members
of
a
clade
extant
amphibians
whose
fossil
records
extend
far
into
the
Mesozoic
Era
and
have
classic
body
model
generalized
tetrapods.The
characteristic
features
larval
ontogenetic
stages
early
salamanders
can
be
used
to
better
understand
this
group's
origins
evolutionary
history.This
study
non-destructive
micro-X-ray
fluorescence
(micro-XRF)
imaging
technology
explore
taxonomy
patterns
elemental
concentrations
Middle-Late
Jurassic
salamander
collected
from
northeastern
China.P
distribution
mapping
skeletal
structure
indicated
that
belongs
Jeholotriton
paradoxus.Further
analysis
revealed
skeleton
is
enriched
with
P,
while
soft-tissue
remains
Fe,
Mn,
Ga,
Cr.Ni
Zn
in
trunk
area
come
external
environment.The
Yanliao
biota,
which
belongs,
contains
many
fossils.Further
XRF
research
will
reveal
more
information
about
ontogenesis
taphonomy
salamanders.
