Monday, September 2, 2013

[Paleontology • 2000] Nanolania anatopretia • A new tiny rhytidosteid (Temnospondyli: Stereospondyli) from the Early Triassic of Australia and the possibility of hidden temnospondyl diversity


 Life restoration of Nanolania anatopretia.

A new genus and species of stereospondyl temnospondyl, Nanolcmia anatopretia, is described from the Early Triassic Arcadia Formation (Rewan Group) of Queensland, Australia. N. anatopretia has several character states that suggest it belongs to the group of derived trematosaurian stereospondyls that include the Rhytidosteidae and Brachyopoidea. These include the absence of a lacrimai, an untwisted quadrate ramus of the pterygoid, and a shallow otic notch. It is tentatively referred to the Rhytidosteidae. N. anatopretia is the third temnospondyl taxon from the Arcadia Formation to be represented by a skull less than 50 mm long. The others are the basal stereospondyl Lapillopsis nana, and juveniles of the capitosaurid Parotosuchus aliciae. Given that Lapillopsis nana and Nanolania anatopretia are not known from any larger specimens, and that the temnospondyl fauna from the Arcadia Formation has been well sampled, it is suggested that they are species that never grew large. It seems quite likely that a diverse array of small temnospondyls lived alongside the larger temnospondyls of the Triassic elsewhere in the world but have not been discovered due to biases working against the preservation and collection of small temnospondyl specimens.


 Yates, Adam M. 2000. A new tiny rhytidosteid (Temnospondyli: Stereospondyli) from the Early Triassic of Australia and the possibility of hidden temnospondyl diversity. Journal of Vertebrate Paleontology. 20 (3): 484–489. doi: dx.doi.org/10.1671/0272-4634(2000)020[0484:ANTRTS]2.0.CO;2

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