Named By: R. A. Long and P. A. Murray - 1995.
Synonyms: Leptosuchus gregorii.
Classification: Chordata, Reptilia, Archosauria, Phytosauria, Phytosauridae.
Species: S. gregorii (type).
Size: Up to twelve meters long.
Known locations: USA, Arizona.
Time period: Carnian to Norian of the Triassic.
Fossil representation: Several specimens.
are generally thought of as being small crocodile-like reptiles that
averaged between two and five meters in length. Smilosuchus
has been estimated at up to twelve meters long, not only making it
the apex predator of its habitat, but possibly the largest
terrestrial carnivore of the Triassic. This huge size would see
Smilosuchus capable of taking down any prey from
large fish and
possibly other aquatic reptiles in the water, to rauisuchians and
primitive dinosaurs from the water’s edge.
Smilosuchus was originally assigned as a large species of Leptosuchus and was classed as the species Leptosuchus gregorii. A key characteristic of the species was the pronounced nasal crest that supported the nostrils (the nostrils in phytosaurs were higher up the snout in front of the eyes, rather than on the end of the snout like those seen in crocodiles), and in 1995 the species was re-evaluated and considered to be distinct enough to separate it into its own genus. Thus the material became known as Smilosuchus gregorii, the gregorii part being taken from the original species classification which is standard procedure when creating a new genus from a previously established species. However since this has happened other palaeontologists have claimed that the fossil material now assigned as Smilosuchus is actually not different enough to treat it as a distinct. As such Smilosuchus faces an uncertain future at the time of writing, but future fossil discoveries may yet prove support for one theory over the other.
Regardless of what may happen with the Smilosuchus genus in the future, one bit of information which is certain is that with an upper size estimated to have been up to twelve meters long, the phytosaurs of the Triassic could grow to such sizes that they could rival the giant crocodiles that are known to have existed from the much later Cretaceous to Miocene periods. The table below presents a list that should help you to put the size of this phytosaur into perspective. You can also click the crocodile names if you would like much more detailed information on each of them.
|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.|