Papers in Palaeontology,
Journal Year:
2023,
Volume and Issue:
9(5)
Published: Sept. 1, 2023
Abstract
Polychaetes,
echinoids
and
gastropods
have
been
proposed
as
tracemakers
for
Bolonia
Meunier,
an
elongate
positive
epirelief
trace
fossil
characterized
by
two
lobes
composed
of
biserial,
subtriangular
pads
a
mostly
heart‐shaped
cross‐section.
Here,
the
internal
structure
micromorphology
are
described
first
time
using
serial
thin
sections
from
shallow‐marine
Lower
Cretaceous
intervals
Agrio
Formation
(Neuquén
Basin,
Argentina).
In
vertical
sections,
conical
variable
width
extends
centrally
base
to
top
trace.
horizontal
grains
reoriented
reworked,
forming
central
zigzag
structure.
The
organic
matter
clays
form
grain
aggregates
representing
individual
fossil.
sediment
has
reoriented,
with
making
up
subcircular
pods.
We
interpret
collapse
medial
zone
fossil,
which
could
destroyed
drain
tubes,
especially
in
absence
early
cementation.
Studying
we
reconstruct
diagnostic
biserial
concave
structures.
These
interpreted
backfilling
structures
produced
aboral
lateral
spines
irregular
echinoids,
worked
together
compact
anteroposteriorly
moved
alternatively,
explaining
pattern
menisci.
propose
Spatangoidea
or
Cassiduloidea
(or
closely
related
group)
similar
burrowing
ability
spine
movement
these
specimens.
Ichnos/Ichnos : an international journal for plant and animal traces,
Journal Year:
2023,
Volume and Issue:
30(2), P. 157 - 171
Published: April 3, 2023
AbstractWe
report
tetrapod
traces
and
associated
ichnofauna
from
two
stratigraphic,
dominantly
terrestrial
levels
of
the
Tiout
Formation
(Valanginian-latest
Albian
to
lower
Cenomanian)
in
Laghouat
Brezina
areas,
Central
Saharan
Atlas
(Djebel
Amour),
northwestern
Algeria
discuss
their
paleoecological
implications.
The
assemblages
display
abundant
footprints
that
show
similarities
with
crocodylian
swim
assigned
Hatcherichnus
known
Jurassic–Cretaceous
deposits
North
America
Morocco.
However,
there
is
also
some
similarity
shape
attributed
swimming
pterosaurs
by
different
authors.
Because
isolated
materials
lack
distinct
trackways,
we
leave
decision
on
tracemaker
open.
majority
are
tridactyl
tetradactyl
imprints
consisting
parallel
furrows
left
claws
or
buoyant
individuals.
Tetrapod
identified,
described,
figured
herein
for
first
time
Mesozoic
Algeria.
These
vertebrate
fossil
a
low-diversity
invertebrate
marine
ichnofauna,
including
cf.
Bergaueria
isp.,
Phycodes
Sinusichnus
seilacheri,
Thalassinoides
suevicus.
Together
body
data,
fishes
non-avian
dinosaurs,
they
indicate
diverse
animal
community
populating
fluvial
system
environment
influence.
Paleoecological
paleoenvironmental
features
add
new
information
ichnoassemblages
previously
reported
'mid'-Cretaceous
Africa.Keywords:
Swim
tracesinvertebrate
ichnofaunacontinental
intercalarypaleoecologySaharan
AtlasAlgeria
AcknowledgementsWe
grateful
reviewers
Martin
Lockley
Adrian
Hunt
valuable
comments
constructive
suggestions
helped
improve
preliminary
version
typescript.Disclosure
statementNo
potential
conflict
interest
was
authors.Additional
informationFundingThis
work
supported
General
Directorate
Scientific
Research
Technological
Development
'DGRSDT'
(Algeria).
Journal of Palaeogeography,
Journal Year:
2023,
Volume and Issue:
12(4), P. 603 - 623
Published: Aug. 18, 2023
Early
Cretaceous
succession
of
the
Oued
Fodda
Formation
in
Ouarsenis
Mountains
(northwestern
Algeria)
is
mainly
composed
marl–limestone
alternations,
which
are
subdivided
into
four
informal
units
(Units
1
to
4),
based
on
distinct
lithological,
stratonomical,
and
ichnological
features.
The
analysis
reveals
a
low
diversity
trace-fossil
assemblage,
exclusively
reported
from
Units
2
3.
ichnoassemblage
contains
six
ichnotaxa
(Chondrites
intricatus,
Ophiomorpha
isp.,
Planolites
Thalassinoides
Zoophycos
brianteus,
cauda-galli),
among
Chondrites
most
common
elements
assemblage
occur
different
mud-rich
substrates
showing
bioturbation
intensities.
development
middle
part
Unit
shows
high
degree
(bioturbation
index
(BI)
=
4).
specimens
large
size,
between
45
cm
75
width,
were
interpreted
have
formed
lower
offshore
environment
where
oxygenation
amount
was
optimal,
sedimentation
rates
low,
benthic
food
abundant
seafloor.
Toward
upper
2,
Zoophycos-bearing
levels
exhibit
less
intense
(BI
2)
contrast
Planolites-
Chondrites-bearing
3
4.
At
these
levels,
displays
relatively
small,
coiled
U-shaped
spreiten,
probably
response
stressful
dysoxic
conditions
prevailing
water
bottom.
With
improved
quiet
shelf
margin
3,
organisms
recovered,
as
represented
by
medium
size
association
with
scarce
burrows,
even
if
overall
intensity
very
low.
combination
lithofacies
indicates
stable
outer
environments
below
storm
wave
base,
corresponds
classically
edge
environments,
palaeoecological
optimal
for
organisms.
