Named By: R. M. Dawley, J. M. Zawiskie & J. W. Cosgriff - 1979.
Classification: Chordata, Reptilia, Rauisuchia, Paracrocodylomorpha, Loricata.
Species: H. clarki (type).
Size: Skull estimated at about 65 centimetres long. Total length estimated at about 4.9-5.2 meters long.
Known locations: USA, Wyoming - Popo Agie Formation.
Time period: Carnian/Ladinian of the Triassic.
Fossil representation: Partial skull and post cranial remains of about 50% of the animal. In total fossil remains of at least four individuals are known.
is a genus of fairly large rauiscuhian
that lived in what is now
Wyoming during the mid/early late Triassic. Rauisuchians were the top
predators on land and held onto this title until the appearance of
large theropod dinosaurs. Out of these Heptasuchus
considered to be most similar to Batrachotomus
from Germany, and both
of these are usually classed as prestosuchids (Similar to
This association by classification may indicate that
Heptasuchus was primarily quadrupedal, though this
cannot yet be
confirmed because the limbs of Heptasuchus are only
known by partial
remains. By contrast another rauisuchian from the same formation as
Heptasuchus named Poposaurus
is confirmed to have been an obligate
At the time of writing all of the known Heptasuchus individuals have been found in close proximity to one another. Large rauisuchians like Heptasuchus are usually perceived to have been ambush hunters that would stake out watering holes and wait for their prey to come to them. The accumulation of the same predators around one watering hole has been used to explain the occurrence of several Heptasuchus close to one another. Here though it seems that a drought may have forced the Heptasuchus to cluster together before they themselves succumbed to death from dehydration, perhaps as a result of seasonal rains being unusually late.
- A rauisuchid thecodont from the Upper Triassic Popo Agie Formation of Wyoming. - Journal of Paleontology 53:1428-1431 - R. M. Dawley, J. M. Zawiskie & J. W. Cosgriff - 1979.
- The relationships and type locality of Heptasuchus clarki, Chugwater Group (Middle to Upper Triassic), Southeastern Big Horn Mountains, Wyoming, USA. - Journal of Vertebrate Paleontology 31 (Supp. 1): 219. - J. M. Zawiskie, R. M. Dawley & S. J. Nesbitt - 2011.