Kambara

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Kambara is an extinct genus of mekosuchine crocodylian that lived in Australia during the Eocene epoch, about 54.6 to 29 million years ago. Four species are recognized: Kambara murgonensis, Kambara implexidens, Kambara molnari, and Kambara taraina.

Species
- Kambara murgonensis (type species), from the Tingamarra fauna near Murgon, Queensland.
- Kambara implexidens, from the Murgon area, characterized by interlocking teeth.
- Kambara molnari, from the Rundle Formation; less well known but with intermediate tooth patterns.
- Kambara taraina, the youngest species from the Rundle Formation; also shows interlocking teeth.

What Kambara looked like and how big it was
- Kambara was a medium-sized crocodylian. Adults were generally about 3 to 4 meters long; some material for K. implexidens suggests around 2.5 meters in a subadult holotype, with larger jaws indicating up to about 3.5 meters.
- The skull was broad and flat on top, with a platyrostral (relatively short and wide) snout compared with some other crocodylians.
- Teeth patterns varied among species and were the main way to tell them apart. One species (K. murgonensis) showed an overbite like an alligator, while others (K. implexidens and K. taraina) had teeth that interlocked in a crocodile-like way. K. molnari shows an intermediate condition.

Toothrow and dentition
- Across Kambara species, the upper and lower tooth rows occluded differently. K. murgonensis had an overbite, whereas K. implexidens and K. taraina interlocked teeth. K. molnari combined features, with some overlap and some interlocking teeth. The teeth themselves were slightly compressed with sharp edges, but not as blade-like as in some later crocodylians.
- The number of teeth also varied: some species had about 14 to 16 teeth in the upper jaw and 17–18 in the lower jaw, with variation among individuals.

Postcranial anatomy and movement
- Although most postcranial bones are not as well published, the available material suggests Kambara could walk well on land, possibly more adeptly than modern Australian crocodiles. The humerus (upper arm bone) shows differences from modern crocodylians, indicating a different shoulder and arm mechanics. Overall, Kambara likely combined semi-aquatic habits with notable terrestrial capabilities, which may have helped it move efficiently in variable environments.

Ecology and lifestyle
- Kambara animals resemble modern crocodilians in appearing semi-aquatic ambush predators, with a flat skull and broad snout suited for catching prey in water.
- Some postcranial features imply better terrestrial locomotion than today’s Australian crocodiles, suggesting they could spend more time on land.
- The two Murgon species (K. murgonensis and K. implexidens) appear to have coexisted at the same site, possibly occupying different ecological niches. Differences in skull and tooth structure may reflect different prey preferences or microhabitat use.

Paleobiology and diet
- The primary evidence for diet comes from tooth shape and wear, as well as fossil associations. A notably informative find is a chelid turtle plastron with bite marks at the taraina site, indicating crocodilians could and did prey on turtles, using repeated bites to reposition prey.
- Eggs and nesting materials from Kambara sites show reproductive activity. The Tingamarra and Rundle formations contain crocodilian eggshells resembling those of alligators and caimans, suggesting nesting near water and possibly seasonal nesting tied to environmental conditions.

Nesting and reproduction
- Eggshells attributed to mekosuchines like Kambara imply nesting near shorelines or shorelines/pond edges. Hatchlings likely inhabited shallow waters and fed on small prey before growing to catch larger prey. The nesting record indicates a reproductive strategy that accommodated a water-associated lifestyle.

Paleoenvironment and distribution
- Kambara lived in a network of inland water systems in eastern Australia, particularly Queensland, within lacustrine (lake-like) environments during the Eocene. The Tingamarra fauna represents a diverse semi-aquatic ecosystem, while the Rundle Formation records lagoonal mud flats.
- It is possible that Kambara was more widespread across eastern Australia than the two known sites suggest, similar to how modern freshwater crocodiles inhabit broad regions.

Discovery and taxonomy
- The first Murgon remains were described in the early 1980s, with the genus Kambara formally named in 1993 by Willis, Molnar, and Scanlon, who designated Kambara murgonensis as the type species. Subsequent species were named in 1996 (K. implexidens), 2005 (K. molnari), and 2009 (K. taraina).
- The name Kambara is rooted in an Aboriginal word for crocodile from the Queensland language region.

Phylogeny
- Kambara is placed within Mekosuchinae, a group of Australian crocodylians that diversified in isolation. Most analyses consider Kambara an early-branching member of Mekosuchinae, though exact relationships within the group have varied among studies. Some recent work places Kambara as a basal mekosuchine or closely related to other early Australian crocodylians.

Key takeaway
- Kambara was a medium-sized, semi-aquatic crocodylian of Eocene Australia with a versatile lifestyle that combined water-loving ambush predation with notable land-dwelling ability. Its four species show a variety of tooth patterns and postcranial features, illustrating an adaptive radiation within ancient Australian crocodylians and offering important clues about how these ancient crocodilians lived and evolved in isolation.