Wannaganosuchus
Wannaganosuchus | |
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Fossil of Wannaganosuchus brachymanus | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Reptilia |
Clade: | Archosauromorpha |
Clade: | Archosauriformes |
Order: | Crocodilia |
Family: | Alligatoridae |
Subfamily: | Alligatorinae |
Genus: | †Wannaganosuchus Erickson , 1982
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Type species | |
†Wannaganosuchus brachymanus Erickson, 1982
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Wannaganosuchus (meaning "Wannagan crocodile", in reference to the
.History and description
Wannaganosuchus is
The skull of SMM P76.28.247 was low, without elevated rims over the eyes, and was 159 millimetres (6.3 in) long. The snout was short and pointed compared to Cretaceous alligatorids. Its premaxillae (the bones of the tip of the snout) had five teeth each, while the maxillae (main tooth-bearing bones of the upper jaw) had thirteen teeth each, with the fourth being the largest and the last three having broad flattened crowns. The lower jaws had twenty teeth on each side, and like the upper jaws, the last five had broad crushing crowns. The forelimbs were short (hence the specific name), and the hindlimbs were long in comparison. The scutes were extensive. Most of the scutes were keeled, but did not have spikes.[2]
Erickson regarded Wannaganosuchus as a generalized early alligatorid closer to the line leading to modern alligatorids than other more specialized early alligatorids.[2] It may be the same as Allognathosuchus.[3]
Paleoecology and paleobiology
Wannaganosuchus was found in a layer with abundant plant fossils suggesting the presence of a swamp forest in the area; taxodioid logs are common. The deposit was formed under 2 to 3 metres (6.6 to 9.8 ft) of water, and grades into a shoreline deposit about 20 metres (66 ft) away. Lilies and water ferns grew along the shore and were shaded by cypress trees.[2]
SMM P76.28.247 was found in direct association with skeletons of
Phylogeny
Recent studies have consistently resolved Wannaganosuchus as a member of Alligatorinae, although its relative placement is disputed, as shown by the cladograms below.[4][5][6]
Cladogram from 2018 Bona et al. study:[4]
Alligatorinae |
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Cladogram from 2019 Massonne et al. study:[5]
Alligatorinae |
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Cladogram from 2020 Cossette & Brochu study:[6]
Alligatorinae |
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