We
describe
the
skull
of
Early
Cretaceous
(Aptian-Albian)
baenid
turtle
Trinitichelys
hiatti
using
micro-computed
tomography
to
provide
new
insights
into
cranial
anatomy
basal
baenids
and
evolution
paracryptodires.We
show
that
validity
versus
Arundelemys
dardeni
still
holds
true,
most
known
for
which
material
is
share
an
intriguing
combination
features
are
typical
either
Pleurosternidae
or
Baenidae,
carotid
system
intermediate
pleurosternids
more
advanced
baenids.Our
expanded
phylogenetic
analysis
confirms
traditional
placement
dardeni,
Lakotemys
australodakotensis,
as
baenids,
retrieves
Helochelydridae
along
stem
Baenoidea,
but
recovers
Dinochelys
whitei,
Glyptops
ornatus,
Dorsetochelys
typocardium,
Uluops
uluops
branching
Paracryptodira.
Swiss Journal of Palaeontology,
Год журнала:
2024,
Номер
143(1)
Опубликована: Март 5, 2024
The
anatomy
of
North
American
tortoises
is
poorly
understood,
despite
a
rich
fossil
record
from
the
Eocene
and
younger
strata.
Stylemys
nebrascensis
particularly
noteworthy
turtle
in
this
regard,
as
hundreds
specimens
are
known
Oligocene
deposits,
species
one
earliest
turtles
to
have
been
described
scientific
literature.
Since
its
initial
description
based
on
shell,
many
with
more
complete
material
referred
nebrascensis.
Here,
we
review
confirm
referral
an
important
historic
specimen
nebrascensis,
which
includes
non-shell
postcranial,
skull
material.
This
allows
us
document
unique
features
(e.g.,
unusual
'poststapedial
canal'
that
connects
posterior
surface
cavum
acustico-jugulare)
refer
another
well-preserved
species.
Based
computed-tomography
scanning
these
two
skulls,
provide
detailed
cranial
mandibular
osteology
has
combination
plesiomorphic
characteristics
retention
medial
jugal
process)
derived
traits
shared
extant
gopher
median
premaxillary
ridge)
suggest
it
may
be
stem-representative
tortoise
lineage.
supports
hypothesis
America
form
geographically
restricted
clade
split
Asian
relatives
during
Paleogene.
Swiss Journal of Palaeontology,
Год журнала:
2021,
Номер
140(1)
Опубликована: Окт. 6, 2021
Abstract
We
study
the
Late
Jurassic
(Tithonian)
turtle
Uluops
uluops
using
micro-computed
tomography
scans
to
investigate
cranial
anatomy
of
paracryptodires,
and
provide
new
insights
into
evolution
internal
carotid
artery
facial
nerve
systems,
as
well
phylogenetic
relationships
this
group.
demonstrate
presence
a
canalis
caroticus
lateralis
in
,
only
pleurosternid
for
which
palatine
canal
can
be
confidently
identified.
Our
analysis
retrieves
earliest
branching
pleurosternid,
Helochelydridae
within
Pleurosternidae
Compsemydidae
including
Kallokibotion
bajazidi
Baenidae
suggests
at
least
two
independent
losses
paracryptodires.
expect
future
studies
will
additional
circulation
system
clarifying
along
stem.
Swiss Journal of Palaeontology,
Год журнала:
2023,
Номер
142(1)
Опубликована: Март 16, 2023
Abstract
Trionychid
(softshell)
turtles
have
a
peculiar
bauplan,
which
includes
shell
reductions
and
cranial
elongation.
Despite
rich
fossil
record
dating
back
to
the
Early
Cretaceous,
evolutionary
origin
of
trionychid
bauplan
is
poorly
understood,
as
even
old
fossils
show
great
anatomical
similarities
extant
species.
Documenting
structural
detail
trionychids
may
help
resolve
history
group.
Here,
we
study
mandibular
anatomy
Plastomenus
thomasii
using
µCT
scanning.
belongs
Plastomenidae
,
long-lived
(Santonian–Eocene)
clade
with
uncertain
affinities
among
subclades.
The
skulls
known
plastomenids
are
characterized
by
unusual
features
otherwise
not
trionychids,
such
extremely
elongated,
spatulate
symphyses.
We
use
observations
for
updated
phylogenetic
analyses
both
parsimony
Bayesian
methods.
There
strong
support
across
methods
stem-cyclanorbine
plastomenids.
inclusion
stratigraphic
data
in
our
analysis
indicates
that
range
Cretaceous
Asian
including
Perochelys
lamadongensis
be
stem-trionychids,
suggesting
many
evolved
prior
appearance
crown
Divergence
time
estimates
from
tip-dating
Trionychia
(134.0
Ma)
Pan-Trionychidae
(123.8
constrain
span
during
has
<
11
million
years.
rate
estimation
implies
high
morphological
rates
early
softshell
turtle
evolution.
If
correct,
partially
fill
gap
results
shallow
divergence
times
cyclanorbines
late
Eocene.
Swiss Journal of Palaeontology,
Год журнала:
2024,
Номер
143(1)
Опубликована: Июль 12, 2024
Abstract
The
early
evolution
of
Pan-Chelonioidea
(sea
turtles)
is
poorly
understood.
This
in
part
due
to
the
rarity
undeformed
skulls
definitive
stem
chelonioids.
In
this
work,
we
redescribe
holotype
Nichollsemys
baieri
using
µCT
scans
and
segmentations
skull.
fossil
best
3D
preserved
skull
any
Campanian
sea
turtle,
includes
partial
“soft
tissue”
preservation.
morphologically
similar
but
clearly
distinct
from
Toxochelys
spp.,
both
show
a
mosaic
plesiomorphic
derived
chelonioid
features.
internal
cranial
anatomy
documents
presence
characters
that
are
absent
such
as
loss
epipterygoids
rod-like
shape
rostrum
basisphenoidale.
Among
numerous
splenial
bone,
which
was
unnoticed
before.
An
updated
phylogenetic
analysis
retrieves
non-protostegid
slightly
more
crownward
position
than
latiremis
.
Our
phylogeny
macrobaenids
protostegids
pan-chelonioids,
find
unorthodox
results
for
dermochelyids.
Thus,
although
provides
important
new
insights
into
morphological
turtles,
much
work
remains
be
done.
As
completely
specimen,
included
recent
landmark-based
dataset
turtles.
Morphospace
reveals
an
intermediate
between
cryptodires
crown
Based
on
these
data,
also
predict
still
capable
neck
retraction,
constraining
trait
pan-chelonioids.
Fossil record,
Год журнала:
2025,
Номер
28(1), С. 1 - 15
Опубликована: Янв. 3, 2025
Azzabaremys
moragjonesi
,
from
the
Paleocene
of
Mali,
is
a
member
Nigeremydini.
This
clade
bothremydid
pleurodiran
turtles
that
includes
large
putatively
marine
forms
which
inhabited
African
Trans-Saharian
Seaway
Maastrichtian
to
Paleocene.
work
represents
first
neuroanatomical
reconstruction
putative
sea
pleurodire.
Some
modifications
observed
for
differ
those
in
other
lineages
Bothremydidae
these
structures
have
been
documented,
corresponding
freshwater
instead
pelagic
forms.
In
fact,
primitive
condition
Pleurodira
adaptation
environments,
as
case
with
all
extant
representatives,
but
also
most
documented
extinct
The
neuroanatomy
shows
convergences
members
Pan-Cryptodira
adaptations
environments
(i.e.,
Chelonioidea,
including
Cheloniidae
and
Dermochelyidae),
clades
exclusive
fossil
record
several
Mesozoic
Palaeogene
uncertain
affiliations:
Plesiochelyidae,
Sandownidae,
Protostegidae).
Thus,
aspects
such
position
geniculate
ganglion
into
canalis
cavernosus,
absence
an
anterior
vidian
canal
piercing
pterygoid,
possession
wide
semicircular
canals
endosseous
labyrinth,
well
possible
presence
enlarged
lacrimal
glands,
are
recognized
here
convergent
developed
Cryptodira,
affiliations,
response
environments.
Fossil record,
Год журнала:
2025,
Номер
28(1), С. 1 - 15
Опубликована: Янв. 3, 2025
Azzabaremys
moragjonesi
,
from
the
Paleocene
of
Mali,
is
a
member
Nigeremydini.
This
clade
bothremydid
pleurodiran
turtles
that
includes
large
putatively
marine
forms
which
inhabited
African
Trans-Saharian
Seaway
Maastrichtian
to
Paleocene.
work
represents
first
neuroanatomical
reconstruction
putative
sea
pleurodire.
Some
modifications
observed
for
differ
those
in
other
lineages
Bothremydidae
these
structures
have
been
documented,
corresponding
freshwater
instead
pelagic
forms.
In
fact,
primitive
condition
Pleurodira
adaptation
environments,
as
case
with
all
extant
representatives,
but
also
most
documented
extinct
The
neuroanatomy
shows
convergences
members
Pan-Cryptodira
adaptations
environments
(i.e.,
Chelonioidea,
including
Cheloniidae
and
Dermochelyidae),
clades
exclusive
fossil
record
several
Mesozoic
Palaeogene
uncertain
affiliations:
Plesiochelyidae,
Sandownidae,
Protostegidae).
Thus,
aspects
such
position
geniculate
ganglion
into
canalis
cavernosus,
absence
an
anterior
vidian
canal
piercing
pterygoid,
possession
wide
semicircular
canals
endosseous
labyrinth,
well
possible
presence
enlarged
lacrimal
glands,
are
recognized
here
convergent
developed
Cryptodira,
affiliations,
response
environments.
PeerJ,
Год журнала:
2022,
Номер
10, С. e14138 - e14138
Опубликована: Ноя. 2, 2022
We
describe
the
skull
of
Early
Cretaceous
(Aptian-Albian)
baenid
turtle
Trinitichelys
hiatti
using
micro-computed
tomography
to
provide
new
insights
into
cranial
anatomy
basal
baenids
and
evolution
paracryptodires.
show
that
validity
vs
Arundelemys
dardeni
still
holds
true,
most
known
for
which
material
is
share
an
intriguing
combination
features
are
typical
either
Pleurosternidae
or
Baenidae,
carotid
system
intermediate
pleurosternids
more
advanced
baenids.
Our
expanded
phylogenetic
analysis
confirms
traditional
placement
dardeni,
Lakotemys
australodakotensis,
as
baenids,
retrieves
Helochelydridae
along
stem
Baenoidea,
but
recovers
Dinochelys
whitei,
Glyptops
ornatus,
Dorsetochelys
typocardium,
Uluops
uluops
branching
Paracryptodira.
PeerJ,
Год журнала:
2022,
Номер
10, С. e13230 - e13230
Опубликована: Апрель 12, 2022
Lakotemys
australodakotensis
is
an
Early
Cretaceous
paracryptodire
known
from
two
shells
and
a
skull
the
Lakota
Formation
of
South
Dakota,
USA.
Along
with
Arundelemys
dardeni
poorly
Trinitichelys
hiatti
,
generally
retrieved
as
early
branching
baenid,
but
more
insights
into
cranial
anatomy
these
taxa
needed
to
obtain
better
understanding
paracryptodiran
diversity
evolution.
Here,
we
describe
using
micro-computed
tomography
provide
anatomical
basis
for
future
phylogenetic
analyses
that
will
be
investigate
precisely
intrarelationships
Paracryptodira
.
Preliminary
comparisons
reveal
very
similar
Aptian-Albian
basal
baenid
both
exhibit
remarkable
combination
derived
characters
found
in
baenodds
non-baenid
paracryptodires,
particularly
Pleurosternidae
only
date
possess
canal
palatine
artery.
