Abstract:
Tyrannosaurs,
giant
predatory
dinosaurs
from
the
end
of
Cretaceous,
are
among
most
intensively
researched
and
best-known
groups
dinosaurs.
Despite
this,
their
relationships
systematics
highly
controversial,
number
tyrannosaur
species
occurring
in
latest
Cretaceous
North
America
is
debated.
An
ongoing
debate
concerns
status
Nanotyrannus
lancensis,
which
has
variously
been
interpreted
as
a
distinct
taxon
small-bodied
or
juvenile
coeval
Tyrannosaurus
rex.
Here,
we
review
multiple
lines
evidence
show
that
totality
strongly
supports
recognition
species:
1.
The
high
diversity
Late
tyrannosaurs
general
consistent
with
idea
more
than
one
lived
late
Maastrichtian
Western
America;
2.
shows
few
if
any
diagnostic
characters
allowing
referral
specifically
to
even
Tyrannosaurinae,
but
differentiated
T.
rex
by
at
least
77
morphological
characters,
while
intermediate
forms,
combining
characteristics
rex,
remain
unknown;
3.
Histological
individuals
previously
referred
lancensis
(i)
skeletal
fusions
maturity,
(ii)
skull
bone
textures
(iii)
slow
growth
rates
relative
(iv)
decelerating
final
years
life,
(v)
curves
predicting
adult
body
sizes
~1500
kg
less,
implying
these
animals
young
adults,
not
juveniles
Tyrannosaurus;
4.
Juveniles
other
tyrannosaurids,
including
Gorgosaurus
Tarbosaurus,
do
kinds
changes
proposed
for
Nanotyrannus-Tyrannosaurus
series,
suggesting
morphology
cannot
simply
be
explained
result
immaturity;
5.
Small
exist,
comparable
size
Nanotyrannus,
exhibit
features
Tyrannosaurus,
differ
Nanotyrannus;
6.
Phylogenetic
analysis
suggests
tyrannosaurid.
Taken
together,
rejects
tentatively
placement
outside
Tyrannosauridae
non-tyrannosaurid
member
Tyrannosauroidea.
Tyrannosaur
appears
have
higher
appreciated
before
K-Pg
extinction.
difficulties
recognizing
based
on
fossils
alone
mean
paleontologists
may
systematically
biased
towards
underestimating
ancient
ecosystems.
Cladistics,
Journal Year:
2024,
Volume and Issue:
40(3), P. 307 - 356
Published: May 21, 2024
Abstract
Gondwanan
dinosaur
faunae
during
the
20
Myr
preceding
Cretaceous–Palaeogene
(K/Pg)
extinction
included
several
lineages
that
were
absent
or
poorly
represented
in
Laurasian
landmasses.
Among
these,
South
American
fossil
record
contains
diverse
abelisaurids,
arguably
most
successful
groups
of
carnivorous
dinosaurs
from
Gondwana
Cretaceous,
reaching
their
highest
diversity
towards
end
this
period.
Here
we
describe
Koleken
inakayali
gen.
et
sp.
n.,
a
new
abelisaurid
La
Colonia
Formation
(Maastrichtian,
Upper
Cretaceous)
Patagonia.
is
known
skull
bones,
an
almost
complete
dorsal
series,
sacrum,
caudal
vertebrae,
pelvic
girdle
and
hind
limbs.
The
shows
unique
set
features
anatomical
differences
Carnotaurus
sastrei
(the
only
other
Formation).
retrieved
as
brachyrostran
abelisaurid,
clustered
with
abelisaurids
latest
Cretaceous
(Campanian–Maastrichtian),
such
Aucasaurus
,
Niebla
.
Leveraging
our
phylogeny
estimates,
explore
rates
morphological
evolution
across
ceratosaurian
lineages,
finding
them
to
be
particularly
high
for
elaphrosaurine
noasaurids
around
base
Abelisauridae,
before
Early
radiation
latter
clade.
Noasauridae
sister
clade
show
contrasting
patterns
evolution,
undergoing
early
phase
accelerated
axial
limb
skeleton
Jurassic,
exhibiting
sustained
cranial
Cretaceous.
These
results
provide
much
needed
context
evolutionary
dynamics
theropods,
contributing
broader
understanding
macroevolutionary
dinosaurs.
Fossil Studies,
Journal Year:
2024,
Volume and Issue:
2(1), P. 1 - 65
Published: Jan. 3, 2024
Tyrannosaurs
are
among
the
most
intensively
studied
and
best-known
dinosaurs.
Despite
this,
their
relationships
systematics
highly
controversial.
An
ongoing
debate
concerns
validity
of
Nanotyrannus
lancensis,
interpreted
either
as
a
distinct
genus
small-bodied
tyrannosaur
or
juvenile
Tyrannosaurus
rex.
We
examine
multiple
lines
evidence
show
that
strongly
supports
recognition
species
for
following
reasons:
1.
High
diversity
tyrannosaurs
predatory
dinosaurs
idea
tyrannosaurids
inhabited
late
Maastrichtian
Laramidia;
2.
lacks
characters
supporting
referral
to
Tyrannosaurinae
but
differs
from
T.
rex
in
>150
morphological
characters,
while
intermediate
forms
combining
features
unknown;
3.
Histology
shows
specimens
showing
(i)
skeletal
fusions,
(ii)
mature
skull
bone
textures,
(iii)
slow
growth
rates
relative
rex,
(iv)
decelerating
final
years
life,
(v)
curves
predicting
adult
masses
~1500
kg
less,
these
animals
subadults
young
adults,
not
Tyrannosaurus;
4.
series
other
tyrannosaurids,
including
Tarbosaurus
Gorgosaurus,
do
changes
proposed
Nanotyrannus–Tyrannosaurus
series,
deriving
requires
several
inconsistent
with
known
patterns
dinosaur
development;
5.
Juvenile
exist,
diagnostic
6.
Phylogenetic
analysis
suggests
may
lie
outside
Tyrannosauridae.
Tyrannosaur
before
K-Pg
extinction
is
higher
than
previously
appreciated.
The
challenges
inherent
diagnosing
based
on
fossils
mean
paleontologists
be
systematically
underestimating
ancient
ecosystems.
PeerJ,
Journal Year:
2023,
Volume and Issue:
11, P. e16236 - e16236
Published: Nov. 14, 2023
Aucasaurus
garridoi
is
an
abelisaurid
theropod
from
the
Anacleto
Formation
(lower
Campanian,
Upper
Cretaceous)
of
Patagonia,
Argentina.
The
holotype
includes
cranial
material,
axial
elements,
and
almost
complete
fore-
hind
limbs.
Here
we
present
a
detailed
description
skeleton
this
taxon,
along
with
some
paleobiological
phylogenetic
inferences.
presacral
elements
are
somewhat
fragmentary,
although
these
show
features
shared
other
abelisaurids.
caudal
series,
to
date
most
among
brachyrostran
abelisaurids,
shows
several
autapomorphic
including
presence
pneumatic
recesses
on
dorsal
surface
anterior
neural
arches,
tubercle
lateral
prezygapophysis
mid
vertebrae,
marked
protuberance
rim
transverse
process
small
ligamentous
scar
near
edge
in
anteriormost
process.
study
has
also
allowed
us
identify
characters
that
could
be
useful
for
future
studies
attempting
resolve
internal
relationships
Abelisauridae.
Computed
tomography
scans
vertebrae
traits
arches
centra,
thus
first
reported
case
taxon.
Moreover,
osteological
correlates
soft
tissues
especially
derived
brachyrostrans,
underscore
previously
proposed
increase
rigidity
within
Derbyana,
Journal Year:
2022,
Volume and Issue:
43
Published: Dec. 31, 2022
The
Bauru
Basin
bears
one
of
the
best
sampled
tetrapod
paleofaunas
Brazil,
with
about
70%
this
diversity
collected
from
its
deposits
in
São
Paulo.
Its
fossils
are
known
since
beginning
20th
century,
coming
all
stratigraphic
units
cropping-out
state,
i.e.,
Santo
Anastácio,
Araçatuba,
Adamantina
(alternatively
divided
into
Vale
do
Rio
Peixe,
Presidente
Prudente,
and
José
Preto
formations),
Marília
formations.
Identified
taxa
include
rare
anurans,
mammals,
squamates,
an
important
set
testudines,
theropods
(including
birds),
sauropods,
addition
to
most
diverse
crocodyliform
faunas
worldwide.
This
congregates
more
than
fifty
unique
taxonomic
entities,
including
42
formally
described
species.
Based
on
biostratigraphic
correlations
tetrapods),
few
absolute
ages,
other
sources
evidence,
Paulo
seem
be
chronologically
restricted
Late
Cretaceous,
but
further
investigation
is
much
needed.
Finally,
history
research
such
highlights
importance
public
funding
for
decentralization
university
education
advancement
science.
Historical Biology,
Journal Year:
2023,
Volume and Issue:
36(10), P. 2019 - 2034
Published: Aug. 8, 2023
ABSTRACTDinosaur
fossils
are
commonly
found
in
Brazilian
Mesozoic
strata,
with
teeth
being
frequently
Cretaceous
outcrops.
Many
studies
have
been
made
the
aim
of
reviewing
known
diversity
dinosaurs,
mostly
focusing
solely
on
their
palaeobiogeography.
However,
few
tried
to
typify
these
body
order
see
which
kinds
were
most
prevalent
fossil
record.
This
study
aims
count
and
identify
all
occurrences
non-avian
dinosaur
(isolated
or
situ)
unearthed
from
strata
objectively
measure
representativity
national
Our
literature
search
showed
that
almost
half
record
Brazil
is
composed
by
teeth,
those
particularly
abundant
Alcântara,
Adamantina
Marília
formations.
Theropod
more
comparison
sauropod
spinosaurids,
deinonychosaurs,
abelisaurids
amply
found.
Despite
representing
a
large
share
record,
only
recently
studied
depth,
many
specimens
reassessed
through
current
identification
methods.
Other
aspects
besides
primary
taxonomic
can
also
be
further
explored
using
latest
technologies
allowing
deeper
understanding
palaeobiology
reptiles.KEYWORDS:
TeethBrazilCretaceousDinosauriareview
AcknowledgmentsThe
authors
would
like
thank
researchers
students
who
collaborated
obtaining
articles
abstracts
used
for
this
study.
We
two
anonymous
reviewers,
Prof.
Carlos
Roberto
dos
Anjos
Candeiro
Maria
Alice
Santos
Alves
comments
suggested
improvement
manuscript.
work
was
supported
[Fundação
de
Amparo
à
Pesquisa
do
Estado
Rio
Janeiro]
under
Grants
[E
04
E-26/204.053/2022
TBR;
PDR10
E-26/201.995/2020
PVLGCP.
PMB
partially
Conselho
Nacional
Desenvolvimento
Cientifico
e
Tecnologico
[#305118/2021-8]
Fundação
Janeiro
[#E-26/201.172/2022].Disclosure
statementNo
potential
conflict
interest
reported
author(s).Supplemental
dataSupplemental
data
article
accessed
online
at
https://doi.org/10.1080/08912963.2023.2238965.Additional
informationFundingThe
Chagas
Filho
[#E-26/201.172/2022
#PDR10
E-26/201.995/2020];
[#305118/2021-8].
Journal of Systematic Palaeontology,
Journal Year:
2022,
Volume and Issue:
20(1), P. 1 - 32
Published: Sept. 22, 2022
Skorpiovenator
bustingorryi
is
a
derived
abelisaurid
theropod
represented
by
fairly
complete
skeleton
from
the
Late
Cretaceous
sedimentary
beds
of
north-western
Patagonia.
Although
some
features
were
described
in
original
paper,
mainly
related
to
skull,
appendicular
anatomy
remains
undescribed.
The
aim
present
contribution
provide
detailed
description
and
analysis
available
bones,
including
comparisons
with
other
ceratosaurian
theropods
close
Skorpiovenator.
In
this
way,
new
autapomorphies
emerged
further
distinguish
its
relatives.
Furthermore,
comprehensive
phylogenetic
was
performed
several
characteristics
hind
limb,
particular
autopodium,
resulted
identification
apomorphic
traits
for
Ceratosauria
Abelisauridae.
These
might
prove
be
useful
future
analyses
may
help
resolve
still
confusing
debated
internal
relationships
theropods.
Journal of Anatomy,
Journal Year:
2024,
Volume and Issue:
unknown
Published: July 18, 2024
Abstract
Recent
evidence
suggests
that
the
invasive
air
sac
system
evolved
at
least
three
times
independently
in
avemetatarsalians:
pterosaurs,
sauropodomorphs
and
theropods.
Data
from
showed
pneumatic
architecture
vertebrae
first
developed
camellate‐like
trabeculae
Triassic,
later
camerate
systems
Jurassic
neosauropods,
finally
camellate
tissue
Cretaceous
titanosaurs.
This
evolutionary
trajectory
has
support
a
considerable
sampling
of
sauropodomorph
taxa.
However,
evolution
bone
tissues
Theropoda
is
less
understood.
We
analyzed
computed
tomography
Majungasaurus
Rahonavis
,
using
densitometry
rendering
to
differentiate
microarchitecture
along
presacral
axial
skeleton
late
Ceratosaurians
early
Paravians.
also
compared
these
results
with
scans
other
theropod
clades.
Our
analysis
revealed
an
increase
complexity
paravians
ceratosaurians.
presents
some
apneumatic
neural
spines,
condition
observed
Allosaurus
.
features
centra
despite
presence
lateral
fossae.
raises
caution
when
evaluating
PSP
solely
based
on
external
morphology.
found
distinct
patterns
maniraptorans.
Considering
abelisaurid,
inherited
their
ceratosaurian
ancestors,
elements
such
as
spine
centra,
paravian,
took
different
toward
full
pneumatization
skeleton.
characteristic
provided
advantage
gliding
flying.
Also,
unlike
Sauropoda,
pneumaticity
apparently
by
increasing
chamber
volumes
paravians.
Similar
studies
are
needed
elucidate
better
describe
groups.
