Pakasuchus
Pakasuchus Temporal range:
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Life restoration of Pakasuchus. | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Reptilia |
Clade: | Archosauria |
Clade: | Pseudosuchia |
Clade: | Crocodylomorpha |
Clade: | Crocodyliformes |
Clade: | †Ziphosuchia |
Genus: | †Pakasuchus O’Connor et al., 2010 |
Species | |
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Pakasuchus is a genus of
Description
Pakasuchus was around 50 centimetres (20 in) long. Like all notosuchians, it was an active terrestrial animal. It probably hunted small prey such as insects. It had a short, broad skull somewhat similar in shape to a cat. Unlike living
Pakasuchus also differed from modern crocodilians, and many other crocodyliforms, in the reduction of osteoderms covering the body. Small, reduced osteoderms overlie the dorsal vertebrae, but fewer in number and are not as large as those of other notosuchians. However, caudal osteoderms still covered the tail. The loss of osteoderms on the body and retention of them on the tail is unique among crocodyliforms.[4]
Discovery
A complete skeleton of Pakasuchus was found in 2008 in southwestern Tanzania by an international research team funded by the National Science Foundation and the National Geographic Society as part of the Rukwa Rift Basin Project. Remains from six other individuals were later uncovered.[5] The specific name honors Saidi Kapilima, one of the leaders of the Rukwa Rift Basin Project and who helped in the excavation of the specimens.[6]
The most complete specimen includes a nearly complete skull. Because the jaws were closed in this specimen, some of the teeth were obscured. The describers of the specimens used
Phylogeny
Below is a cladogram modified from O’Connor et al., 2010:
Paleobiology
Pakasuchus was probably very mammal-like in behavior as well as appearance. The molariform teeth are well suited to shearing food like modern mammalian carnivores (for example, all many species of
The relative lack of osteoderms on the body may have been an adaptation for an active terrestrial lifestyle, as it would have lightened the animal. However, the retention of osteoderms on the tail is hard to explain, as they would have been quite heavy. The long legs and slender build would also have made Pakasuchus more agile.[4]
Pakasuchus was probably an herbivore; its dentition was at least as complex as those of modern herbivorous lizards.[7]
Notosuchians were widespread across Gondwana throughout the Cretaceous. Pakasuchus, as well as many other notosuchians, would have filled ecological niches in these areas that were otherwise occupied by mammals in the northern continents.[1] Mammals were relatively uncommon in Gondwana at the time, making it possible for notosuchians to occupy a similar niche.[2]
The Rukwa Rift Basin is known for a rich vertebrate fauna that existed during the Cretaceous. During the Early Cretaceous, the basin was part of a large river system with
References
- ^ S2CID 4405106.
- ^ a b Ker Than (4 August 2010). "Fossil "Cat Crocodile" Had Mammal-like Teeth". National Geographic Daily News. Archived from the original on August 5, 2010.
- ISSN 1464-343X.
- ^ .
- ^ a b "Mammal-Like Crocodile Fossil Found in East Africa, Scientists Report". ScienceDaily. August 4, 2010.
- ^ a b Young, Ed (4 August 2010). "Pakasuchus – the crocodile that's trying to be a mammal". Not Exactly Rocket Science. Discover Magazine. Retrieved 8 August 2010.
- ^ "Repeated Evolution of Herbivorous Crocodyliforms during the Age of Dinosaurs". ResearchGate. Retrieved 2019-09-01.