in the early 1900s very unusual teeth
were found in south america they were
loudly compressed serrated and
blade-like much like the teeth of
theropod dinosaurs especially at
tyrannosaurus
however these teeth were from cenozoic
deposits long after the non-avian
dinosaurs were thought to have gone
extinct
this brought up the possibility that
there were late surviving non-avian
dinosaurs
while this turned out to not be the case
the true owner of the teeth sebacus was
just as strange
it belonged to a clade of reptiles named
sebeka day who looked like something
straight out of the age of reptiles
many of them were very large
some far larger than any predator since
the extinction of the non-avian
dinosaurs
they primarily lived in south america
which was largely isolated from the rest
of the world for most of the cenozoic
era
the sebekets belonged to the clade
crocodile morpha the same clade of
reptiles as crocodilians
unlike their modern relatives mosta
becketts were fully terrestrial hunters
the sabekids weren't simply crocodilians
who left the water to fill the vacancy
left by the demise of the non-avian
dinosaurs
instead they were the last remnants of
something even older noto tsukiya
nodu sukiya was a very diverse clade of
fully terrestrial reptiles that evolved
before the ancestors of the true
crocodilians took to the water
as a result of their terrestrial
lifestyle cebekids differed greatly from
crocodilians
while crocodilian legs are held in a
semi-sprawling posture the long legs of
the sebekids were directly underneath
their bodies
although many crocodilians are capable
of moving at surprising speeds the
sabekids would have put them to shame
most of beckett's snouts were long but
not to the same extreme as in most
crocodilians
unlike their flat and often broad skulls
sebekit's skulls were generally deep and
narrow
the eyes of musa becketts were located
on the side of the skull instead of on
the top like in crocodilians
this allowed them a greater view of
their surroundings
on the other hand sebeked jaw muscles
were similar to those of crocodilians
but with their deeper skulls they had
even more attachment points for
additional jaw muscles
the theropod-like teeth of mossa beckets
which are called xiphodont teeth were
very well suited for carving through
flesh
this is in contrast to the conical teeth
of crocodilians which are better suited
for holding on to prey
the sebekets have been called the
ecological successors of the larger
theropod dinosaurs this is not just in
reference to their similar teeth many
subeckids such as sebekas and langstonia
were about two to three meters long
this is on par with the top predators of
south america today
and prehistoric south america's other
two major groups of large predators the
terror birds
and the mammalian sparse azodons
however the largest subekade borina
sukis was far larger
while only known from skulls these
skulls are a meter long as large as the
skull of the tyrannosaurid despitosaurus
based on comparisons with its relatives
borina sukis is estimated to have been 6
meters long or more with a weight
between one thousand and six hundred to
one thousand seven hundred and forty
kilograms
this means it was not just the largest
terrestrial predator in cenozoic south
america but potentially the largest land
predator in the entire age of mammals a
bit ironic since it was a reptile
with such great size borina sukis was
certainly worthy of being called a
successor to the dinosaurs
while barina sukis may seem like an
outlier its fossils spanned over 25
million years about half of the cenozoic
era since all of its fossils are
incomplete they probably came from
several different species of closely
related giant subekkads
the largest of beckett after barina
sukis was breasty sukis who was about
four meters long
in contrast most beckets that lived
during the dawn of the cenozoic era such
as azul masukis were much smaller
however in the aftermath of the kpg
extinction event even these small
reptiles were large enough to be apex
predators
the smallest sabekid lived during the
cretaceous period before the extinction
of the non-avian dinosaurs
named ogre sukis it was a little more
than one meter long
the earliest crocodilian morse were
endothermic or warm-blooded however the
bone histology of other nodusukians
including a possible sebekid named
ibirosukus indicates they were
ectothermic or cold-blooded
this means they relied on the external
environment to maintain their body
temperature like modern crocodilians and
most of today's other non-avian reptiles
ectotherms cannot be as active or grow
as quickly as endotherms
in general endotherms are more
competitive as large terrestrial
predators
however global temperatures were higher
during the first half of the cenozoic
era allowing cebekids to remain
competitive with endothermic predators
additionally nodus zucchinis had a
higher metabolism than most other
ectotherms
much like monitor lizards such as the
komodo dragon and the extinct megalania
this opened up ecological doors closed
to more typical ectotherms
still sebeked metabolisms were not high
enough for them to possess the endurance
needed to pursue their prey very far
instead they were ambush predators
laying in weight and then charging with
a great burst of speed
once they closed in they were able to
employ some of the best traits of
today's deadliest ectothermic hunters
most crocodilians rely on their powerful
bites
in contrast the komodo dragon relies on
its flesh cutting teeth along with the
use of head movements to inflict further
damage
close relatives of the subekids called
baurus kids employed a similar strategy
due to possessing a comparatively weak
bite force
however cebekids had both efficient
flush cutting teeth and a strong bite
combined with the sheer size of some
species the cebekids were among the
deadliest predators before humans
while most of becketts were fully
terrestrial there were a few
ecologically closer to crocodilians the
skulls of the sebekids saweti sukis and
lauro sukis are wider and flatter than
the other species which is typical of
semi-aquatic crocodilian morphs
sa itsukus is still thought to have been
primarily terrestrial
however lauro sukis seems to have been
more specialized like crocodilians its
eyes were on the top of the skull
allowing it to see while otherwise
submerged beneath the water
its teeth also lacked durations and were
not as strongly recurved as those of
other sebekids
only once a beckett ogre sukis is known
for the mesozoic era it lived on an
island in what is now europe during the
late cretaceous period
at first its small size wouldn't seem
that surprising as most land crocs were
small during that time
however this was not the case for
sobekiday's branch of nodusukia sabeko
sukiya
many mesozoic sebekosukians
such as the previously mentioned baoru
sukids were already as large as the
later medium-sized sabekits
although they were large enough to have
been among the top predators in a
cenozoic ecosystem they were outclassed
by even larger theropod dinosaurs
one exception was the sebeko sukiyan
razian andragobe who was of comparable
size to borina sukis
it is unclear how representative ogre
sukis is of other mesozoics of beckett's
it is possible they were all small
predators only later echoing their
extinct cousins
on the other hand ogre sugars lived in
europe rather than south america
since the two continents have been
isolated from each other for tens of
millions of years ogre sukis had already
diverged from the rest of sebeka day a
long time ago
either way
most of becketts from the early cenozoic
were not much larger than uger sukis so
it is unlikely that any large sabekids
were among the survivors of the kpg
extinction event
while most of becketts have been found
in south america ogre sukis's presence
in europe indicates they were once more
widespread
to have reached europe from south
america ogre sukis's ancestors would
have had to at least gone through africa
sobekosuki and fossils that could have
been from some becketts have been found
in the burqa quaran formation in egypt
notably these fossils are from the late
eocene long after the end of the
cretaceous period
this means that a second cletus of
beckets or their close relatives
independently survived into the age of
mammals
there is also evidence that some
european subukids also survived into the
cenozoic era
fragmentary fossils of two sepekosukians
and ibiro sukis have been found in rocks
from the middle eocene in europe because
of their fragmentary nature it is
unclear whether they were a basal
lineage of cebekids or their closest
known relatives
either way none of the species found in
europe were as massive as marina zucchis
iberosuccus was two meters long while
burying sukis was 1.5 meters long
they weren't the only large land crocs
in europe at the time
during the early cenozoic europe was
also home to the planeocranians
sometimes called the huffed crocodiles
the planeocranids were close relatives
of the true crocodilians who returned to
a terrestrial existence
the last fossils of the european tobacco
tsukians are from the eocene
they were likely victims of the grand
couiar an extinction event that led to
the demise of most native european
mammals between the eocene and oligocene
about 34 million years ago
the exact cause of the grand coir is
unclear but is thought to have been
connected to a period of global cooling
at around the same time
the south american subukids survived
much longer the most recent definitive
fossils are from borinosuchus and
langstonia roughly 12 million years ago
they seemed to have been one of the
casualties of local climate change
caused by the increasing elevation of
the andes mountains
as large predators they would have been
particularly vulnerable to disruptions
in their environment
an additional contributing factor in
their extinction was the likely a
continuing decline in global
temperatures which left large ectotherms
like the sepakids at a greater
disadvantage even in the tropics
however this was merely the final nail
in their coffin
in a way the sebekids were victims of
their own success
while nodusukians were very diverse
during the cretaceous period unlike
mammals only the carnivorous sabekids
survived
as the cenozoic era progressed instead
of gaining diversity they lost it
by the end of the eocene sebeka day only
consisted of medium and gargantuan
predators
a single continent can only support so
many large predators at a time
furthermore while the largest predators
were sibekids they faced competition
from the terror birds
sparse acetones
and semi-aquatic predators like the
gigantic perusaurus
since there could only be a few species
of subekids at a time it only took a few
unlucky extinctions for sebeccadae to
completely disappear from the face of
the planet
though now extinct the sabekids were
some of the most remarkable creatures
the world has ever seen
while other crocodilian wars were
adapted to terrestrial environments
during the cenozoic era none of them
were as successful or as long lived as
tobacco day
additionally in an era dominated by
mammals the reptilian sabeckids managed
to become the top predators
finally they reached sizes comparable to
the theropod dinosaurs serving as stark
reminders of the age of reptiles during
the age of mammals
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