Named By: France de Broin & Phillipe Taquet 1966 (type).
Classification: Chordata, Reptilia, Diapsida, Archosauromorpha, Mesoeucrocodylia, Pholidosauridae.
Species: S. imperator (type).
Size: 11 - 12 meters long.
Known locations: Africa, Niger. Possibly Brazil.
Time period: Aptian to Albian of the Cretaceous.
Fossil representation: Mainly specimens are known, especially teeth and skulls. Parts of post cranial skeleton were discovered at the end of the twentieth century.
people have never heard of Sarcosuchus, but may
well know it by its
more popular name of ‘Supercroc’. This is because Sarcosuchus
remains one of the biggest crocodiles ever to live with upper size
estimates approaching twelve meters.
Initially Sarcosuchus was only known from teeth and osteoderms. In 1964 the first skull was discovered and the type species could then be established. However it was not until the closing years of the twentieth century when teams led by Paul Sereno recovered more complete material including vertebra, ribs and other parts of the post cranial skeleton. Although not complete, there is now enough material to give a more accurate estimate on the potential size of Sarcosuchus.
In terms of maximum potential size, Sarcosuchus was probably larger than Deinosuchus and at maximum estimate, could have rivalled the other giant crocodilians, Rhamphosuchus and Purussaurus. Due to lack of remains and different ways of estimating the maximum size of these prehistoric crocs, it is still not known with certainty as to which was the bigger. In contrast with sizes averaging a maximum of five to six meters, and rare individuals reaching seven meters, todays crocodiles are simply dwarfed in comparison.
Sarcosuchus was not just bigger than today’s crocodiles it was also a lot older. Most crocodiles have an average lifespan in the wild of around twenty-five years, with some individuals reaching thirty or more. Study on the growth rings present on some of the osteoderms show that Sarcosuchus was around forty years old and yet not fully grown when it died. Whereas todays crocodiles grow large and then stop when they reach adulthood, Sarcosuchus just kept getting bigger. It could be that the only limiting factor to how big it grew was when it could no longer sustain such a massive body with the available food supply.
As such a massive predator Sarcosuchus would have had to of focused its attention on hunting animals that could provide enough sustenance to keep its body going, and the two main animal groups available to it were the dinosaurs and large lobe finned fish. While the idea of Sarcosuchus shooting out of the water to drag a hadrosaur off the shoreline is a tantalising one, you need to look at the teeth and jaws of Sarcosuchus for clues.
Deinosuchus had broad jaws and strong teeth, perfect for dealing with large and powerful prey that would have been struggling as it dragged it into the water. The jaws of Sarcosuchus however had proportionately longer and thinner jaws with relatively small teeth, more suited to a fish diet. It was not until Sarcosuchus grew bigger and older that the jaws began to widen. The tip of the upper jaw also hooked downwards, another adaption seen in other fish eating crocodiles.
Predatory dinosaurs of the time and locations include Spinosaurus and Suchomimus. Both dinosaurs have long thin snouts akin to some crocodiles and their teeth are many, sharp and pointed. This has led to most palaeontologists speculating that they were fish hunters, and if true then there must have been a plentiful supply of fish of such size and sustenance to keep their numbers and massive bodies going. A large crocodile of similar size but less active lifestyle and possibly slower metabolism would have been even more suited to surviving upon a fish diet than these dinosaurs.
It may of course be that Sarcosuchus had different lifestyles and diets at different stages of its life. Fish are easy prey for small crocodiles but as they grew larger they would need more sustenance to survive and so they may have begun to incorporate dinosaurs into their diets as well. As seen in crocodiles today, they may have also left the water to scavenge the kills of the larger dinosaurs as well.
With most of the Sarcosuchus remains known from Africa, other fossils discovered in Brazil have also been attributed to it. However, these specimens may yet prove to be from another ancient crocodile.
|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|
|Smilosuchus (phytosaur *not a croc).||Triassic/USA.||12|
|3 of todays largest living crocs below|
|Alligator mississippiensis (American alligator).||Present/S. E. USA.||3.4 average - up to almost 6.|
|Crocodylus niloticus (Nile crocodile).||Present/Africa.||Average up to 5, largest up to 6.45.|
|Crocodylus porosus (Salt water crocodile).||Present/India, S. E. Asia, N. Australia.||Average 4-5.5, largest recorded 6-6.6, possibly slightly bigger.|