Kambara | |
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The skull of Kambara implexidens and the lower jaw of Kambara molnari. | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Reptilia |
Clade: | Archosauromorpha |
Clade: | Archosauriformes |
Order: | Crocodilia |
Clade: | †Mekosuchinae |
Genus: | †Kambara Willis, Molnar & Scanlon, 1993 |
Species | |
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Kambara is an extinct genus of mekosuchine crocodylian that lived during the Eocene epoch in Australia. It is generally thought to have been a semi-aquatic generalist, living a lifestyle similar to many of today's crocodiles. Four species are currently recognised, the sympatric Kambara murgonensis and Kambara implexidens from sediments near Murgon, the poorly preserved Kambara molnari from the Rundle Formation and the youngest of the four, Kambara taraina, also from the Rundle Formation. Kambara were medium-sized crocodilians, with mature specimens generally reaching lengths from 3–4 m (9.8–13.1 ft).
Species of Kambara are easiest differentiated by the different occlusal patterns of their teeth. While K. murgonensis had an overbite similar to a modern alligator, both K. implexidens and K. taraina had interlocking dentition much more similar to true crocodiles. K. molnari, although incompletely known, seems to represent an intermediate form.
Despite plentiful fossils, the ecology of Kambara is poorly understood. The general shape of the skull, which is flattened, and the environment the fossils were deposited in, all suggest that they were semi-aquatic ambush predators like modern crocodilians. However, subtle differences in the postcranial remains, especially the limb bones, suggest that Kambara may have been better adapted at walking on land than the two crocodile species still inhabiting Australia today, the saltwater and freshwater crocodile. While this could suggest that it was faster on land than living crocodilians, it does not necessarily mean that it was terrestrial like some later mekosuchines are thought to have been. Another question regarding its ecology is posed by the coexistence of K. murgonensis and K. implexidens at Murgon. It is unclear how exactly these two species differed in their niche, but they did differ notably in their anatomy, with the latter being slightly more gracile and with interlocking teeth. It is also possible that the two species didn't coexist at all, but instead were driven together by drought.
As the oldest described and named mekosuchine, Kambara is considered an important piece in understanding the evolutionary history and origin of this group. Phylogenetic analyses recover it as one of the earliest diverging mekosuchines, but recent studies have commonly found other taxa like Kalthifrons or Australosuchus to be the oldest diverging. Other studies suggest that Kambara was no mekosuchine at all, but said results are not supported by all authors.