Proceedings of the National Academy of Sciences,
Год журнала:
2022,
Номер
119(47)
Опубликована: Ноя. 14, 2022
Anatomy
of
the
first
flying
feathered
dinosaurs,
modern
birds
and
crocodylians,
proposes
an
ancestral
flight
system
divided
between
shoulder
chest
muscles,
before
upstroke
muscles
migrated
beneath
body.
This
featured
dorsally
positioned
deltoids
supracoracoideus
controlling
chest-bound
pectoralis
downstroke.
Preserved
soft
anatomy
is
needed
to
contextualize
origin
system,
but
this
has
remained
elusive.
Here
we
reveal
earliest
theropod
flyers
preserved
as
residual
skin
chemistry
covering
body
delimiting
its
margins.
These
data
provide
that
independently
validate
system.
The
heavily
constructed
more
weakly
in
early
pygostylian
Confuciusornis
indicated
by
a
profile,
upstroke-enhanced
stroke.
Slender
ventral
profiles
early-diverging
Archaeopteryx
Anchiornis
suggest
habitual
use
could
not
maintain
sternum
through
bone
functional
adaptations.
Increased
wing-assisted
terrestrial
locomotion
potentially
accelerated
loss
higher
breathing
requirements.
Lower
expected
downstroke
requirements
thermal
soarer
Sapeornis
have
driven
adaption,
possibly
encouraged
demands
Confuciusornis-like
upstroke.
Both
factors
are
supported
slender
profile.
shoulder/chest
insights
into
novel
strokes
loss,
filling
important
gaps
our
understanding
appearance
flight.
Zoological Journal of the Linnean Society,
Год журнала:
2024,
Номер
202(3)
Опубликована: Фев. 16, 2024
Abstract
Oviraptorosaurs
are
among
the
most
diverse
and
best-known
extinct
theropod
groups.
Their
bizarre
anatomy
their
social
reproductive
behaviour
now
well
understood.
Among
oviraptorid
subclade,
two-fingered
Oksoko
avarsan
is
particularly
well-represented.
It
known
from
several
exquisite
skeletons,
preserving
not
only
entire
skeleton,
but
multiple
stages
through
ontogeny,
providing
an
exemplar
for
understanding
of
oviraptorids
changes
that
skeletons
experienced
over
lifetimes.
Here
I
comprehensively
describe
osteology
comment
on
its
ontogenetic
variation.
Excellent
preservation
specimens
provides
unparalleled
detail
into
oviraptorid,
valuable
context
interpreting
other
oviraptorosaurs.
Several
observed
to
occur
ontogeny
relating
robustness
bones
proportions
there
little
evidence
suggesting
discrete
features
like
cranial
crest
arose
late
in
ontogeny.
Instead,
early
development
oviraptorids,
internal
connection
with
nasal
passages
pneumatic
spaces,
argue
favour
a
role
vocalization,
perhaps
alongside
sexual
display.
Detailed
anatomical
data,
those
provided
by
avarsan,
necessary
help
underpin
ongoing
research
palaeobiology
macroevolution
Oviraptorosauria.
iScience,
Год журнала:
2024,
Номер
27(5), С. 109598 - 109598
Опубликована: Апрель 24, 2024
The
Longxiang
tracksite
(lower
Upper
Cretaceous,
Shanghang
Basin)
includes
twelve
didactyl
deinonychosaur
tracks
that
fall
into
two
morphologies,
differentiated
by
both
size
and
form.
smaller
(∼11
cm
long)
are
referable
to
the
ichnogenus
Scientific Reports,
Год журнала:
2024,
Номер
14(1)
Опубликована: Июль 25, 2024
A
new
troodontid
dinosaur,
Hypnovenator
matsubaraetoheorum
gen.
et
sp.
nov.,
is
described
based
on
an
articulated
postcranial
skeleton
recovered
from
the
fluvial
deposits
of
Albian
Ohyamashimo
Formation
Sasayama
Group
in
Tambasasayama
City,
Hyogo
Prefecture,
Japan.
distinguished
other
troodontids
by
four
autapomorphies
and
a
combination
additional
features.
Our
phylogenetic
analysis
positions
as
oldest
one
most
basal
troodontines,
forming
clade
with
Gobivenator
mongoliensis.
The
discovery
suggests
that
small-bodied
maniraptorans
sleeping
posture
were
common
not
only
environments
volcanic
eolian
events
or
alluvial
systems
but
also
systems.
Geometric
morphometric
manual
ungual
phalanges
shows
I
III
exhibit
considerable
morphological
variation
are
functionally
similar,
which
differs
those
non-troodontine
troodontids,
reflecting
transition
motion
within
Troodontinae.
has
mosaic
features
pes
related
to
cursoriality.
This
study
reveals
asymmetrical
arctometatarsus
occurred
Albian,
some
changes,
such
shorter
digit
IV
than
non-ungual
digits
roller
joints
weakly
ginglymoid
articulation,
arose
during
early
Late
Cretaceous.
PLoS ONE,
Год журнала:
2025,
Номер
20(1), С. e0308366 - e0308366
Опубликована: Янв. 30, 2025
Alvarezsauria
is
a
group
of
morphologically
distinctive,
medium-
to
small-sized
later-diverging
coelurosaurian
theropod
dinosaurs,
whose
record
ranges
from
the
Late
Jurassic
Cretaceous.
This
clade
had
widespread
distribution
in
Laurasia
what
now
Europe,
Asia,
and
North
America,
although
there
are
also
several
Cretaceous
taxa
Gondwana
Argentina
that
all
belong
family
Alvarezsauridae.
Although
alvarezsaurid
taxonomic
diversity
anatomical
knowledge
has
expanded
over
last
decade,
internal
phylogenetic
relationships
remain
highly
debated.
In
this
contribution,
we
describe
new
material
review
previously
reported
specimens
middle
Campanian—lower
Maastrichtian
Allen
Formation
discovered
at
Salitral
Ojo
de
Agua
locality
Río
Negro
province,
Patagonia,
Argentina.
these
were
collected
different
times
without
precise
original
provenance
information,
here
gathered
X-ray
diffraction
data
associated
sediments
suggests
come
same
site
stratigraphic
level
as
holotype
Bonapartenykus
ultimus
.
Based
on
information
morphological
similarity
considered
specimens,
tentatively
refer
them
genus
These
newly
referred
add
shed
light
body
plan
Patagonykinae
by
permitting
more
complete
reconstruction
neck,
pectoral
girdle,
hindlimb,
tail.
Journal of Anatomy,
Год журнала:
2025,
Номер
unknown
Опубликована: Апрель 19, 2025
Abstract
Troodontidae
is
a
family
of
small‐bodied
theropods
known
predominantly
from
Asia
but
are
comparatively
scarce
in
North
America.
In
the
Dinosaur
Park
Formation
(DPF)
Alberta,
Canada,
they
isolated
material,
precluding
taxonomic
and
ontogenetic
precision
for
this
clade.
Previously
never
sampled
histologically
within
DPF,
here
we
attempt
to
fill
gaps
our
knowledge
about
life
histories
clade
formation
by
surveying
metatarsals,
which
among
most
abundant
identifiable
troodontid
elements
DPF.
We
11
metatarsals
(three
metatarsal
IIs,
three
IIIs
five
IVs)
varying
sizes
included
pathological
individuals
describe
microanatomy
both
healthy
determine
status
each
element
graph
their
pattern
growth.
Osteohistology
reveals
that
grew
remodelled
asymmetrically
cortex,
ceasing
growth
remodelling
primarily
along
articular
surfaces
entheses.
Pathological
ranged
displaying
features
response
localised
stress
(chronic
callus
avulsion/chip
fracture)
extreme
modification
trauma
inflammation
at
distal
joint.
Only
latter
appeared
be
related
overall
growth,
suggesting
condition
either
developed
early
stunted
or
another
underlying
cause
was
responsible
resulting
observed.
Overall,
tracking
specimens
there
least
two
trajectories
DPF
differentiated
timing
major
spurts
plateaus.
Whether
represents
sexual
dimorphism,
diversity,
form
variation
warrants
further
investigation.
PeerJ,
Год журнала:
2020,
Номер
8, С. e8672 - e8672
Опубликована: Фев. 25, 2020
The
dromaeosaurid
theropod
Halszkaraptor
escuilliei
is
characterized
by
several
unusual
features
absent
in
other
paravians,
part
of
which
has
been
interpreted
as
diagnostic
a
novel
lineage
adapted
to
semiaquatic
ecology.
Recently,
these
evolutionary
and
ecological
interpretations
have
challenged,
claimed
be
transitional
form
between
non-dromaeosaurid
maniraptoriforms
dromaeosaurids:
following
that
reevaluation,
its
peculiar
body
plan
would
represent
the
retention
maniraptoran
plesiomorphies,
lost
among
dromaeosaurids,
not
an
adaptation
This
alternative
scenario
here
carefully
investigated
tested.
It
shown
most
statements
supporting
this
are
based
on
misinterpretation
anatomical
traits
bibliography.
Once
corrected,
character
state
transition
optimization
over
well-supported
phylogenetic
framework
indicates
large
majority
derived
novelties
acquired
latter
after
divergence
from
last
ancestor
shared
with
eudromaeosaurs,
thus
maniraptoriform
plesiomorphies.
At
least
seven
convergently
spinosaurids,
integrated
adaptations:
one
reported
for
first
time.
amount
morphological
Halszkaraptorinae
ancestral
condition
comparable
those
Microraptorinae
Velociraptorinae.
Among
extant
taxa,
sawbills
(Mergini,
Anseriformes)
show
closest
ecomorphological
similarity
inferred
.
halszkaraptorine
bauplan
confirmed
amphibious
specialization,
does
“transitional”
stage
along
evolution
dromaeosaurids.
Scientific Reports,
Год журнала:
2021,
Номер
11(1)
Опубликована: Март 1, 2021
Abstract
A
characteristic
fauna
of
dinosaurs
and
other
vertebrates
inhabited
the
end-Cretaceous
European
archipelago,
some
which
were
dwarves
or
had
unusual
features
likely
related
to
their
insular
habitats.
Little
is
known,
however,
about
contemporary
theropod
dinosaurs,
as
they
are
represented
mostly
by
teeth
fragmentary
fossils.
new
isolated
metatarsal
II,
from
latest
Maastrichtian
Spain
(within
200,000
years
mass
extinction)
may
represent
a
jinfengopterygine
troodontid,
first
reported
Europe.
Comparisons
with
theropods
phylogenetic
analyses
reveal
an
autapomorphic
foramen
that
distinguishes
it
all
troodontids,
supporting
its
identification
genus
species,
Tamarro
insperatus
.
Bone
histology
shows
was
actively
growing
subadult
when
died
but
have
growth
pattern
in
grew
rapidly
early
ontogeny
attained
size
quickly.
We
hypothesize
could
migrated
Asia
reach
Ibero-Armorican
island
no
later
than
Cenomanian
during
dispersal
events.
Palaeontology,
Год журнала:
2020,
Номер
63(6), С. 997 - 1006
Опубликована: Июль 25, 2020
Abstract
Establishing
hypotheses
of
relationships
is
a
critical
prerequisite
for
any
macroevolutionary
analysis,
but
different
approaches
exist
achieving
this
goal.
Amongst
palaeontologists
using
morphological
data
the
Bayesian
approach
increasingly
preferred
over
parsimony,
shift
also
alters
way
we
think
about
samples
trees.
Here
revisit
stratigraphic
congruence
as
comparator
between
and
parsimony
samples,
in
new
visual
context:
treespace.
Such
spaces
represent
an
ordination
unique
topologies
that
can
be
extended
to
create
‘landscape’
where
altitude
represents
some
comparative
measure
(here
with
stratigraphy).
By
co‐opting
existing
visualization
tools
applying
them
meta‐analysis
128
cladistic
sets
show
there
no
consistent
favouring
either
or
according
metrics,
further
empirical
treespace
visualizations
suggest
complex
variety
topological
landscapes.
We
conclude
by
arguing
treespaces
should
become
standard
exploratory
tool
phylogenetic
analysis.
Journal of Anatomy,
Год журнала:
2020,
Номер
236(5), С. 772 - 797
Опубликована: Фев. 5, 2020
Tetrapod
limbs
morphology
is
a
reliable
proxy
of
locomotor
capacities.
Beyond
this,
other
aspects
life
habits,
such
as
predation
abilities,
can
also
be
relevant
to
determine
main
morphofunctional
appendicular
properties,
which
ultimately
reflect
compromise
between
different
factors
the
biological
role.
Dromaeosauridae
dinosaur
clade
belonging
Theropoda,
group
bipedal
predators.
Dromaeosaurids
represent
an
interesting
study
case,
in
hindlimbs
have
been
proposed
involved
both
locomotion
and
activity.
A
peculiar
feature
characterizing
all
dromaeosaurids
modified
second
pedal
digit,
typically
related
predation.
This
theropod
closely
birds
diversified
during
Cretaceous
Period,
mainly
Northern
Hemisphere
(Laurasia).
However,
subclade
dromaeosaurids,
Unenlagiinae,
was
recently
recognized
for
Gondwana.
Nevertheless,
there
are
morphological
differences
derived
Laurasian
(eudromaeosaurs)
unenlagiines.
Such
observed
proportions
hindlimb
bones
presence
subarctometatarsalian
condition
unenlagiines,
characterized
by
proximally
constricted
metatarsal
III.
To
evaluate
function
these
divergent
morphologies,
we
conducted
morphometric
analyses
comparisons
qualitative
aspects,
encompassing
well
taxa
from
groups,
including
extant
birds.
The
former
approach
consisted
two
phylogenetic
principal
component
analyses,
one
based
on
measurements
hindlimb,
focused
lengths
phalanges.
first
analysis
drew
unenlagiines
close
with
long
tibiae,
slender
metatarsi.
Instead,
eudromaeosaurs
closer
shorter
wider
showed
that
similar
phalangeal
proportions,
elongation
distal
phalanx
digit
II
could
increased
force
generated
this
predatory
tool
autopodium.
This,
together
metatarsus,
marked
hinge-like
articular
surfaces
metatarsals
phalanges,
possibly
allowed
exert
great
gripping
strength
hunt
large
prey.
Conversely,
longer
subarctometatarsus,
less
well-marked
hinge
joints
gave
them
greater
cursorial
Additionally,
fast
movements
smaller
elusive
Thus,
distinctive
evolutionary
pathways
dromaeosaurid
clades
seem
influenced
particular
specializations
each
lineages.