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16.01.2016 23:18 - Encyclopedia Largest prehistoric animals Vol.1 Vertebrates part9 Reptiles ch.3 Crocodylomorpha-who"s the biggest Croc
Автор: valentint Категория: Забавление   
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Crocodiles and relatives (Crocodylomorpha) 

Crocodilians are truly iconic creatures, and throughout history have inspired stories of dragons and soul-devouring gods. Modern crocodilians are the crocodiles, alligators, caimans and gharials, all part of the crown group Crocodylia (Fig. 1). There are only 23 recognized species alive today, and of these 10 are considered to be endangered, according to the IUCN red list, due to ongoing environmental disruption and human activity. This relative lack of modern diversity stands out in stark contrast to that of their close relatives, the dinosaurs, whose modern descendants, the birds, have about 10,000 species around today! It isn’t obvious from looking at modern birds and crocodiles that they share a common ancestor. For instance, when was the last time you saw a feathered crocodile, or a pigeon sitting on a river bank waiting to ambush an unsuspecting wildebeest?
To understand why the two groups are so different, we have to use a time machine: the fossil record. Going back to the Mesozoic era, between 252 million and 66 million years ago, we find the forerunners of living crocodilians, known as crocodyliforms, which were very different to their modern counterparts. They were an incredibly successful group, with a large number of different species characterized by a range of peculiar and unique features. Some were fully equipped for swimming out to sea, while others reached phenomenal sizes, rivalling those of the biggest predatory dinosaurs!
Crocodilians and their forerunners form a group known as Pseudosuchia, literally ‘false crocodiles’, of which crocodyliforms are a major part. Pseudosuchians are closely related to dinosaurs and pterosaurs, united in a group called Archosauria, and the split between these lineages happened around 250 million years ago, in the early Triassic period. The only remnants of this ancient divergence are modern birds and crocodilians. The group Crocodylomorpha, which includes Crocodyliformes and a closely related group called Sphenosuchia, were the only major group of pseudosuchians to survive the mass-extinction event at the end of the Triassic period 201 million years ago, and around 120 million years after that, they gave rise to the group containing modern crocodiles and their kin, Crocodylia.
The earliest crocodyliforms, comprising the groups Protosuchia, Shartegosuchidae and Sphagesauridae, lived on land. They were small compared to modern species (usually no more than a metre in length), with two rows of osteoderms (a type of bony body armour) along their backs, and an upright limb posture with a slender body (Fig. 3). They were widely distributed across the globe during the Jurassic period (201 million to 145 million years ago) and the Cretaceous period (145 million to 66 million years ago), and discoveries from South Africa and North America have helped to clarify their evolutionary relationships. Some researchers consider these groups to represent a ‘grade’ — a group defined by their similar appearance rather than strictly by their evolutionary relationships — because analyses suggest that not all of their descendants share the same common ancestor, which means that they are not a monophyletic group. A diverse array of early crocodyliforms, including Zosuchus and Gobiosuchus, survived until at least the Early Cretaceous in Central Asia, where they would have lived alongside more ‘advanced’ crocs before finally going extinct.
What could be more terrifying than a 10-metre-long shark? Well, how about a 10-metre-long shark-croc? Thalattosuchians were a bizarre yet magnificent group of sea-dwelling reptiles, which were diverse during the Jurassic, but went extinct in the Early Cretaceous. They consist of two groups: the metriorhynchoids and the teleosauroids. Both of these groups could reach enormous proportions, and some evolved flipper-like limbs and tails, becoming quite shark-like.The best discoveries come from South America and Europe, and are quite similar species, suggesting that some species could travel between these two continents in the Late Jurassic. Well-preserved skulls show that metriorhynchids had salt glands, similar to those of modern sharks, turtles, some sea birds and marine iguanas, which means that they were capable of drinking sea water.
The evolutionary relationships of thalattosuchians are poorly understood. Traditionally, they were thought to be closely related to other, more advanced, marine crocodyliforms, including pholidosaurids. However, this result is likely to be due to convergent evolution between the two groups that has made them appear superficially similar, especially in their possession of longer snouts, and in fact they might belong outside of Crocodyliformes, in the broader group of Crocodylomorpha.

In early 2016, a discovery from North Africa of a 12-metre-long teleosaurid known as Teleosaurus rex showed that this group survived an extinction event at the end of the Jurassic and start of the Cretaceous, where they were previously thought to have gone extinct, and became isolated in increasingly rare lagoonal environments as the shallow seas of Europe closed off due to a major fall in sea level. The timing of extinction for thalattosuchians is quite contentious; the youngest material interpreted as their fossilized remains might actually belong to a completely different group, the plesiosaurs, instead.
The goniopholidids were relatively small-bodied at 2–4 metres long, and abundant in freshwater and non-marine brackish environments in the Northern Hemisphere throughout the Jurassic and Cretaceous. The shape of their skulls was much more like that of modern crocodiles, being relatively long and flattened. They also possessed a dual row of interlocking osteoderms on their backs and the underside of their bellies, giving them armoured protection and also bracing their bodies for movement on land.
As with many crocodyliform groups, which species belong to the group and how they are related remain fairly poorly understood, in spite of numerous discoveries. This is partly due to a failure to differentiate different species of Goniopholis based on their anatomy, but work is now showing that there is a hitherto under-appreciated diversity of goniopholidids, particularly in the Early Cretaceous of Europe.
The oldest fossil assigned to this group, Calsoyasuchus, comes from the Lower Jurassic of North America. If this species really is a goniopholidid, this has important implications because it means that we would expect other closely related crocodyliform groups to also have a Lower Jurassic record. This is because lineages ‘split’ from each other instantaneously (geologically speaking), which implies that sister groups originate at the same time. If Calsoyasuchus is truly a goniopholidid, this would mean that the radiation of this group into Europe and Asia took place between 10 million and 15 million years after the origin of the group.
Atoposaurids were typically no bigger than half a metre long, and were adapted primarily to near-shore environments such as lagoons or coastal estuaries. Because of their size, they are relatively rare in the fossil record, which has made understanding their relationships quite difficult. Analyses have found that atoposaurids were actually confined to the Late Jurassic of Europe, with different populations occupying the French and German basins; Europe at the time was like a tropical island archipelago. Weird taxa previously assigned to this group, such as Montsecosuchus or Brillanceausuchus, probably represent much more advanced groups closer to paralligatorids (see below) than atoposaurids.
Notosuchians are often described as bizarre, and you only need to take a look at some of the nicknames given to them to understand why. They were a Cretaceous group of terrestrial species primarily from the Southern Hemisphere (Gondwana), some of which looked more like an armadillo than a crocodile, while others are known informally by names like ‘boar-croc’. They were generally small-bodied and quite slender, with characteristic short and deep skulls. One genus is called Simosuchus, which translates as ‘pug-nosed crocodile’, due to its blunt snout. Another, Anatosuchus, has been dubbed a crocoduck after its wide, flattened, pancake-shaped snout.
Some taxa, such as Armadillosuchus, had features that indicate that they were good at digging, possibly to build nests or burrows. Other groups, like sphagesaurids, had complex teeth similar to those of ornithischian dinosaurs such as Iguanodon, and this has led to them sometimes being misidentified as dinosaurs. Some genera, such as Chimaerasuchus, were adapted to consuming plant matter, and others were even tusked, which suggests that they might have foraged for different food items, including molluscs, arthropods and roots. Not exactly the behaviour we associate with modern crocodiles! Others, such as baurusuchids, were well-adapted to a carnivorous lifestyle, and some such as Yacarerani even had teeth similar to what we see in mammals with complex and multi-cusped molars.
This group was generally small to medium-sized at no more than 1–1.5 metres in length, and was widely geographically distributed during the Cretaceous of North America, Asia and Europe, as well as the late Jurassic of Brazil. Some genera, such as Shamosuchus, had teeth well adapted to crushing shells, feeding predominantly on molluscs. The oldest genus, Batrachomimus, was originally identified as an early amphibian, hence the name, which refers to the Batrachia (frogs, salamanders and toads). The identification of Wannchampsus in 2014 from the Lower Cretaceous of Texas was important in showing that paralligatorids were very closely related to the group that includes modern crocodilians, Eusuchia.

Hylaeochampsids are a relatively poorly understood group, and the identity of the species that belong to this group is unclear. The group was defined on the basis of a skull from the Early Cretaceous of the United Kingdom, given the genus name Hylaeochampsus, but its evolutionary relationships, and which species belong to this group, have remained problems for crocodyliform researchers. Some studies have found that enigmatic taxa such as Pachycheilosuchus from the Early Cretaceous of Texas and Pietraroiasuchus from the Early Cretaceous of Italy might belong to this group. All of these taxa are characterized by short snouts, and might have possessed several different types of teeth. For example, Iharkutosuchus from the Late Cretaceous of Hungary had teeth adapted for crushing, similar to some notosuchians.
Pholidosaurids were known from semi-aquatic and marine environments throughout Europe, Africa and North and South America during the Cretaceous. They all had long, slender snouts, similar to the modern gharial . Some were absolute monsters — Sarcosuchus from the middle Cretaceous of the Sahara reached up to 12 metres in length (twice as long as a modern saltwater crocodile) and weighed around 8 tonnes! It probably even preyed on dinosaurs, ambushing them at the edges of river systems, in a hunting style similar to that of the modern Nile crocodile. The evolutionary relationships of pholidosaurids are currently poorly understood, although the group might be closely related to the marine dyrosaurids.

Dyrosaurids were a group of marine crocodyliforms that along with crocodylians were the only group to pass through the end-Cretaceous mass extinction. They are known from multiple places around the globe, and being geographically widespread might have made them more resilient to extinction. They were particularly common in the Trans-Saharan seaway, an epicontinental sea (a shallow sea on top of a continent) that existed when South America and Africa began to break apart. After the Cretaceous, some genera, such as Acherontisuchus, lived in shallow inland habitats in tropical environments of South America. Some, such as Rhabdognathus, had an extremely long snout, around 75% of the total skull length, indicating a strong adaptation to hunting fish (a piscivorous diet). They would have been ferocious and dangerous hunters, with mouths packed full of strong, sharp teeth. Some genera, such as Arambourgisuchus, had a skull that was around one metre long — definitely not something you’d want to encounter when out for a swim! Of note for its cool name is the Colombian species Anthracosuchus balrogus, named after the Balrog in The Lord of the Rings because it was found deep in a mine.
The origin of crocodylians is widely debated by palaeontologists. In the 1990s, taxa such as the Late Cretaceous Brachychampsa were established as being the earliest representatives of Crocodylia and all modern crocodilians. It is highly unlikely or even impossible that we’ll ever find the ancestral crocodylian that gave rise to all others, but we do know that modern crocodilians come from a stock of relatively advanced crocodyliforms called eusuchians. Many recent analyses consider hylaeochampsids and paralligatorids to be eusuchians, meaning that they could be early forerunners of modern species, but this remains hotly contested.
Part of the problem stems from what we define as a eusuchian — should we define it on the basis of features that members of the group share, or on the species that are included in the group?
In 2015, hylaeochampsids and paralligatorids were moved from their former positions as possible sister groups to Crocodylia. A new group, Allodaposuchidae, was found to have ‘filled the gap’ between Early Cretaceous hylaeochampsids and Crocodylia, providing a possible solution to some of the contention. As such, new discoveries are challenging traditional relationships between eusuchians, and casting controversy over which taxa are most closely related to modern species.

Many studies have investigated the environmental factors responsible for changes in crocodyliform diversity through time. A large-scale study of the history of pseudosuchians found that decreasing temperature over millions of years were responsible for the decline of species in the Northern Hemisphere. However, it was found that changes in sea level were more important for changes in the diversity of marine groups such as thalattosuchians and dyrosaurids; these changes controlled the availability of the shallow marine environments which the groups inhabited. Changes in sea level also seem to have been responsible for a major extinction in both marine and non-marine groups around 145 million years ago at the Jurassic–Cretaceous boundary, which might have acted as the trigger for the ecological release of new groups of marine reptiles, including turtles and plesiosaurs. Other studies have found that the diversity of marine groups seems to be correlated with changes in sea surface temperature. As a result, the exact controls on crocodyliform diversity in the geological past remain contentious.
Is it possible to predict the future of crocodiles based on what we know about their geological past? This is a difficult question to answer. Palaeontological studies focus on changes that occur over time periods of around 10 million years or longer. Translating this information to the modern scale of environmental change is very difficult, and it is hard to justify conservation projects using predictions for 10 million years in the future.
However, the fossil record does provide us with clues to modern and future diversity, by showing us the factors that crocodiles and their ancestors seem to have been most sensitive to over time. We might expect that as sea levels change in the future, which they will undoubtedly continue to do, this will control the habitable ranges of different populations. We might even see increasing contact between crocodiles and humans, and this probably wouldn’t end well for the iconic archosaurs.
Crocodiles and their predecessors have had their ups and downs over 250 million years of evolution, adopting a number of strange and wonderful lifestyles, behaviours and forms. It remains our responsibility to ensure that human actions do not put an end to their journey in the blink of a geological eye through a lack of respect for Earth and her ecosystems.

Giant  prehistoric crocodiles size


Name Time/Location Size (meters)
Deinosuchus‭ (‬alligator-like crocodile‭). Cretaceous/USA. 10-12
Gryposuchus‭ (‬gharial-like crocodile‭). Miocene/S.‭ ‬America. 10
Mourasuchus‭ (‬alligator-like crocodile‭). Miocene/Peru. 12
Purussaurus‭ (‬caiman-like crocodile‭). Miocene/S.‭ ‬America. 11-13
Rhamphosuchus‭ (‬gharial-like crocodile‭). Miocene/India‭. 8-11
Sarcosuchus‭ (‬crocodile‭). Cretaceous/Africa. 11-12
Smilosuchus‭ (‬phytosaur *not a croc‭). Triassic/USA. 12
Stomatosuchus‭ (‬crocodile‭). Cretaceous/Egypt. 10




Often argue who is the biggest crocodile ever lived. Everyone has a contender for the title between the four almost equal-sized giants - Sarcosuchus imperator, Purussaurus, Deinosuchus, and Rhamphosuchus.In fact,none of those listed in the table is not our main contender for the title of largest crocodile. There is reason to believe that we should start the review with a little-known species:

It is becoming increasingly clear that the dinosaurs were not the only large reptiles that were around in the Mesozoic, and the discovery of the partial skull of Aegisuchus is a further example of this. Although incomplete, the partial remains are from a huge skull, but at the time of writing it is not known exactly what form this skull took. Because of this, Aegisuchus has been envisioned as both a more standard crocodyloform, and a gharial-like crocodile with a longer, slender snout.
This also leads to a lot of speculation about just how big Aegisuchus was. If like a standard crocodile, it may have been between sixteen and twenty-two metres long, if gharial-like, then fifteen to twenty-one metres long. Unfortunately the only way we could be certain to the size of Aegisuchus is if elements of the post cranial skeleton were found, the more complete the better. Unfortunately again the odds are stacked against this happening as the more solid parts of crocodiles such as the skull, teeth and scutes (bony armour) are usually all that remain (though exceptions are known). If the estimates of Aegisuchus are correct however, then it will certainly have been one of the largest crocodiles of all time, and a serious contender for the largest crocodile ever. At 40 cubic centimetres, the braincase of Aegisuchus is much larger in volume than that of any other crocodyliform. Based on the ratio of braincase to skull length in other crocodilians, the total skull length of Aegisuchus is estimated to have been 2.08 to 2.86 metres (6.8 to 9.4 ft) in length. A similar ratio between braincase and body length puts Aegisuchus at 15 to 21 metres (49 to 69 ft) long when based on the proportions of long-snouted gharials, or 16 to 22 metres (52 to 72 ft) long when based on the proportions of short-snouted crocodiles.

Aegisuchus was chosen as the name of the genus because of the presence of a bony boss of bone that was on top of the skull. This is similar to designs of the Aegis shield from Ancient Greece which was a circular shield with a smaller boss (like half a sphere) in the centre. The boss on these ancient shields was often stylised into the head of the Medusa and were often seen carried by Ancient Greek gods such as Zeus, Apollo and Athena, though often it would be a breastplate instead of a shield.
The actual skull of Aegisuchus is believed to have been flat with eyes that pointed up instead of forward. If correct then Aegisuchus may have lain just below the surface of the water, while the surface glare masked its approach from any animals that may have been drinking on the shore. This would allow Aegisuchus to close in unseen until the moment it struck. Alternatively, Aegisuchus may have lain at the bottom of water systems and ambushed creatures like fish or swimming dinosaurs from below.
We do not yet know for certain what kind of animals Aegisuchus showed a preference towards hunting, if any. Future discoveries of teeth, maxilla’s and mandibles may help to determine this but these of course need to be made. Dinosaurs were certainly a viable option as many different kinds are known from the Kem Kem Beds of Morocco. If however Aegisuchus were a fish hunting species, then the large size might denote a preference for preying upon larger fish genera such as the giant sawfish Onchopristis which is also known from the Cenomanian of Morocco.


1. Sarcosuchus 2. Kaprosuchus 3. Susisuchus 4. Allodaposuchus 5. Bernissartia
Pholidosauridae is an extinct family of aquatic neosuchian mesoeucrocodylian crocodylomorphs. Fossils have been found in Europe (Denmark, England, France, Germany, Spain and Sweden), Africa (Algeria, Niger, Mali, Morocco and Tunisia), North America (Canada and the United States) and South America (Brazil and Uruguay). The pholidosaurids first appeared in the fossil record during the Bathonian stage of the Middle Jurassic and became extinct during the Late Turonian stage of the Late Cretaceous.
Pholidosauridae is usually considered to be most closely related to the Dyrosauridae. However, the relationship between these families is not fully understood. Pholidosauridae might be monophyletic,paraphyletic or even a polyphyletic in relation to Dyrosauridae.

Sarcosuchus imperator



The largest well-known crocodylomorph is likely Sarcosuchus imperator at 12 metres (39 ft) long and weighing 8 tonnes. Sarcosuchus ( meaning "flesh crocodile") is an extinctgenus of crocodyliform and distant relative of the crocodile that lived 112 million years ago. It dates from the early CretaceousPeriod of what is now Africa and South America and is one of the largest crocodile-like reptiles that ever lived. It was almost twice as long as the modern saltwater crocodile and weighed up to 8 tonnes.
The first remains were discovered during several expeditions led by the French paleontologist Albert-Fйlix de Lapparent, spanning from 1946 to 1959, in the Sahara Desert. These remains were fragments of the skull, vertebrae, teeth and scutes. In 1964, an almost complete skull was found in Niger by the French CEA, but it was not until 1997 and 2000 that most of its anatomy became known to science, when an expedition led by the American paleontologistPaul Sereno discovered 6 new specimens, including one with about half the skeleton intact and most of the spine.
Sarcosuchus was a giant relative of crocodiles, with fully grown individuals estimated up to have reached up to 11–12 metres (36–39 feet) in total length. It had somewhat telescoped eyes and a long snout compromising 75% of the length of the skull, there were 35 teeth in each side of the upper jaw while in the lower jaw there were 31 teeth in each side, the upper jaw was also noticiably longer than the lower one leaving a gap between them when the jaws were shut, creating an overbite. In young individuals the shape of the snout resembled that of the living gharial but in fully grown individuals it became considerably broader.
At the end of its snout, Sarcosuchus presented an expansion, called bulla, it has been compared to the ghara seen in gharials but unlike the ghara, though, which is only found in male gharial, the bulla is present in all Sarcosuchus skulls that have been found so far, suggesting that it was not a sexually dimorphic trait. The purpose of this structure remains enigmatic. Sereno and others asked various reptile researchers what their thoughts on this bulla were. Opinions ranged from it being an olfactory enhancer to being connected to a vocalization device.
The osteoderms, also known as dermal scutes, of Sarcosuchus were similar to those goniopholodids like Sunosuchus and Goniopholis, they formed an uninterrupted surface that started in the posterior part of the neck up to the middle of the tail like is seen in Araripesuchus and other basal crocodyliforms, different from the pattern seen in living crocodiles, which present discontinuity between the osteoderms of the neck and body.
A common method to estimate the size of crocodiles and crocodile-like reptiles is the use of the length of the skull measured in the midline from the tip of the snout to the back of the skull table, since in living crocodilians there is a strong correlation between skull length and total body length in subadult and adult individuals irrespective of their sex, this method is preferred for Sarcosuchus due to the absence of a complete enough skeleton.
Two regression equations were used to estimate the size of S. imperator, they were created based on measurements gathered from 17 captive gharial individuals from northern India and from 28 wild saltwater crocodile individuals from northern Australia, both datasets supplemented by available measurements of individuals over 1.5 metres (4.9 ft) in length found in the literature.The largest known skull of S. imperator (the type specimen) is 1.6 m (5.2 ft) long, and it was estimated that the individual it belonged to had a total body length of 11.65 m (38.2 ft), its snout-vent length of 5.7 m (19 ft) was estimated using linear equations for the saltwater crocodile and in turn this measurement was used to estimate its body weight at 8 tonnes (8.8 short tons).This shows that Sarcosuchus was able to reach a maximum body size not only greater than previously estimated but also greater than that of the MioceneRhamphosuchus,only the
Late CretaceousDeinosuchus and the MiocenePurussaurus may have achieved a comparable maximum body size.

Sarcosuchus is commonly classified as part of the clade Pholidosauridae, a group of crocodile-like reptiles (Crocodyliformes) related but outside Crocodylia (the clade containing living crocodiles, alligators and gharials).Within this group it is most closely related to the North American genus Terminonaris.Most members of Pholidosauridae had long, slender snouts and they all were aquatic, inhabiting several different environments, some forms are interpreted as marine, capable of tolerating saltwater while others, like Sarcosuchus, were freshwater forms, the most primitive members of the clade, however, were found in coastal settings, zones of mixing of freshwater and marine waters.Sarcosuchus stands out among pholidosaurids for being considered a generalist predator, different from most known members of the clade which were specialized piscivores.
During the course of several expeditions on the Sahara from 1946 to 1959, lead by the French paleontologist Albert-Fйlix de Lapparent, several fossils of a crocodyliform of large size were unearthed in the region known as the Continental intercalaire, some of them were found in Foggara Ben Draou, near the town of Aoulef, Algeria (informally named as the Aoulef Crocodile) while others came from Gara Kamboute, in the south of Tunisia, the fossils found were fragments of the skull, teeth, scutes and vertebrae. In 1957, in the region now known as the Elrhaz Formation in the north of Niger several isolated teeth of great size were found by H. Faure. The study of this material by French paleontologist France De Broin helped identify them as coming from a new long snouted crocodile.
Later, in 1964, the research team of the French CEA discovered an almost complete skull in region of Gadoufaoua, in the north of Niger, said skull was shipped to Paris for study and became the holotype of the then new genus and species Sarcosuchus imperator in 1966. The genus name comes from the Greek "sarco" meaning flesh and "suchus" meaning crocodile.
In 1977, a new species of Sarcosuchus was named, S. hartti, from remains found in the late 19th century in the Reconcavo basin of Brazil.In 1867, American naturalist Charles Hartt found two isolated teeth and sent them to the American paleontologist O. C. Marsh who erected a new species of Crocodylus for them, C. hartti,this material, along with other remains were assigned in 1907 to the genus Goniopholis as G. hartti.Now residing in the British Museum of Natural History the fragment of the lower jaw, dorsal scute and two teeth compromising the species G. hartti were reexamined and conclusively placed in the genus Sarcosuchus.
The next major findings occurred during the expeditions lead the American paleontologist Paul Sereno, in 1997 and the follow-up trip in 2000. Partial skeletons, numerous skulls and 20 tons of assorted other fossils were recovered from the deposits of the Elrhaz Formation, which has been dated as late Aptian or early Albianstages of the late Cretaceous. It took about a year to prepare the Sarcosuchus remains.
Additional fossil material was found and described in 2010, from the area of Nalut in northwestern Libya. These fossils are from the Cabao Formation, which is likely to be Hauterivian to Barremian in age.
Sereno took thin sections from trunk osteoderms of an estimated subadult individual (~80% of estimated maximum adult size).Approximately 40 lines of arrested growth (LAG) were counted in these thin sections, suggesting that S. imperator took 50 to 60 years to reach adult size.Given that extant wild crocodylians rarely reach these advanced ages, Sereno suggested that S. imperator achieved its large size by extending its period of rapid, juvenile, growth.A similar growth strategy has been suggested for the equally titanic crocodylian Deinosuchus, based on similar criteria.
Based on the broader snout of fully grown S. imperator when compared to the living gharial and other narrow-snouted crocodiles, along with a lack of interlocking of the smooth and sturdy-crowned teeth when the jaws were closed, Sereno et al. hypothesized that S. imperator had a generalized diet similar to that of the Nile crocodile. A diet that would have included large terrestrial prey such as the abundant dinosaurs that lived in the same region.
However, a 2014 analysis of a biomechanical model of its skull suggested that unlike Deinosuchus, Sarcosuchus would not have been able to perform the "death roll" maneuver used by extant crocodylians to dismember their prey.This suggests that if S. imperator did hunt big game, it probably did not dismember prey in the same fashion as extant crocodylians.
The remains of S. imperator were found in a region of the Tйnйrй Desert named Gadoufaoua, more specifically in the Elrhaz Formation of the Tegama Group, dating from the late Aptian to the early Albian of the Early Cretaceous, approximately 112 million years ago.The stratigraphy of the region and the aquatic fauna that was found therein indicates that it was an inland fluvial environment, entirely freshwater in nature with a humid tropical climate.S. imperator shared the waters with the holostean fish Lepidotus and the coelacanth Mawsonia.The dinosaur fauna was represented by the iguanodontian Lurdusaurus, which was the most common dinosaur in the region, and its relative Ouranosaurus; there were also two sauropods, Nigersaurus and a currently unnamed sauropod while the theropod fauna included the spinosaurid Suchomimus, the carcharodontosaurid Eocarcharia and the abelisaurid Kryptops.
Meanwhile, S. hartti was found in the Reconcavo basin of Brazil, specifically in the Ilhas Formation of the Bahia series, it was a shallow lacustrine environment dating from the late Aptian, similar in age to the habitat of S. imperator, with similar aquatic fauna, including Lepidotus and two species of Mawsonia. The dinosaur fauna is of a very fragmentary nature and identification does not go beyond indeterminate theropod and iguanodontid remains.




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