Rank Family | Class Reptilia Phylum Chordata | |
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Similar Prestosuchus, Rauisuchidae, Rauisuchia, Poposauridae, Batrachotomus | ||
Prestosuchids were a group of Triassic carnivorous archosaurs. They were large active terrestrial apex predators, ranging from around 2.5 to 7 metres (8.2 to 23.0 ft) in length. They succeeded the Erythrosuchidae as the largest archosaurs of their time. While resembling erythrosuchids in size and some features of the skull and skeleton, they were more advanced in their erect posture and crocodile-like ankle, indicating more efficient gait. Prestosuchids flourished throughout the whole of the middle, and the early part of the late Triassic, and fossils are so far known from Europe, India, Africa (Tanganyika), Argentina, and Paleorrota in Brazil. However, experts disagree regarding the phylogenetic relationships of the group, what genera should be included, and whether indeed the Prestosuchidae constitute a distinct family apart from the Rauisuchidae.
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Classification
In 1957, Alan Charig proposed a new family, the Prestosuchidae, to include genera like Mandasuchus, Prestosuchus, and Spondylosoma.
In 1967, Alfred Sherwood Romer placed Saurosuchus and Rauisuchus within Erythrosuchidae and adopted the Prestosuchidae to include Prestosuchus, Procerosuchus, and Charig's "Mandasuchus".
Prestosuchidae have often been included within Rauisuchidae, although they have sometimes considered the sister group of the aetosaurs in a monophyletic Pseudosuchia, or as a small clade intermediate between basal Crurotarsi and more advanced archosaurs such as the Aetosauridae and Rauisuchidae. J. Michael Parrish's 1993 cladistic analysis of crocodylotarsan archosaurs places the Prestosuchidae (including Prestosuchus, Ticinosuchus, and Saurosuchus) outside the crocodylomorph - poposaurid - rauisuchid - aetosaur clade. In most cladograms Prestosuchids are considered more derived than phytosaurs and ornithosuchids, but usually less derived than the poposaurids and aetosaurs.
Evolution of the group
The earliest known prestosuchid is Mandasuchus from the Anisian of Tanganyika. This was already a large animal, about 4.75 meters long. A similar but smaller form (perhaps the same genus) is Ticinosuchus of the Middle Triassic (Anisian-Ladinian) of Switzerland and Northern Italy, which was about 2.5 meters in length. The huge (6 meters long) Batrachotomus from the latest Middle Triassic (Late Ladinian) of Germany, and Prestosuchus of the early Late Triassic (Carnian) of Brazil may have been closely related animals. Yarasuchus was a lightly built animal from the Middle Triassic of India that also seems to belong to this group. Finally, Saurosuchus was a huge carnivore, 6 or 7 meters long, whose fossils are known from the Late Carnian of Argentina.