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Fw: Aliwalia [from Adam Yates]

Adam Yates asked me to forward this to the DML. (As an aside, I can relate from personal experience to Adam's plight regarding Brazilian visas - though our situation ended better than Adam's obviously did.)

Hi Tim,

I see there is some discussion on this taxon in the DML. Could you forward this message to the list?

Hi all,

As Scott will no doubt report I didn't make it to the IICLPV conference. The stuff-up occured when my travel agent told me that I did not need a visa for Brazil, when actually I do. So I had the very unpleasant experience of being turned away from the flight at the airport. Reading Scott's report about how good the food and the coffee is over there is just increasing the disapointment. Anyway given the discussion about the curious beast 'Aliwalia' I present here the abstract of the talk I should have presented yesterday.


Adam M. Yates
Bernard Price Institute for Palaeontological Research, University of the Witwatersrand, Private Bag 3, WITS 2050, Johannesburg, South Africa

Aliwalia rex Galton, 1985 was based on a single fragmentary femur of a large dinosaur from the lower Elliot Formation (Norian, Late Triassic) of South Africa. Originally it was described as a large herrerasaurian but later workers failed to find any derived characters that could conclusively place it closer to Herrerasauridae than to any other dinosaurs. Usually it is simply regarded as Dinosauria incertae sedis, although the hypothesis that it was a relatively basal taxon that was primitively carnivorous has persisted. This hypothesis has been bolstered by the referral of an isolated maxilla from the type locality to A. rex.
In 2003 a second Aliwalia rex femur was found in the lower Elliot Formation by a team from Bernard Price Institute, University of Witwatersrand. In this case the femur was associated with other postcranial bones that show clear sauropodomorph synapomorphies. Examination of collections at the Transvaal Museum and the Council for Geoscience in Pretoria has shown this is not the first association of Aliwalia-type femurs with sauropodomorph bones. Indeed one of these associations has been named: Eucnemosaurus fortis Van Hoepen, 1920. It is clear that these associations real and are not fortuitous taphonomic accidents. Indeed the femurs themselves display the derived sauropodomorph synapomorphy of a proximo-distally elongated, ridge-like lesser trochanter. Several prosauropod grade sauropodomorphs such as Massospondylus carinatus, Lufengosaurus huenei and Riojasaurus incertus also display the distinctive semi-pendant fourth trochanter that has been used to diagnose Aliwalia rex. These specimens represent a distinctive taxon of prosauropod-grade sauropodomorph and the forgotten Eucnemosaurus fortis is its valid name. Aliwalia rex is a junior synonym of Eucnemosaurus fortis. Amongst sauropodomorphs E. fortis shares a large posterior tubercle on the proximal femur with Riojasaurus incertus (a reversal to a non-dinosaurian character state). Cladistic analysis of basal sauropodomorph relationships finds that Riojasaurus and Eucnemosaurus are sister taxa within a large clade that also contains Massospondylidae, Yunnanosaurus, Anchisauridae, Melanorosauridae, Antetonitrus and traditional sauropods (Vulcanodontidae and Eusauropoda) to the exclusion of Plateosauridae and more basal sauropodomorphs.



[TW:] Thus, _Aliwalia rex_ is regarded by Adam as a junior synonym of _Eucnemosaurus fortis_, which is revived as a valid name. Those old prosauropod names appear to be making a comeback (_Eucnemosaurus_, _Plateosauravus_, _Gresslyosaurus_, etc). I guess the implication is that the maxilla hitherto referred (albeit provisionally) to _Aliwalia_ does not belong to _Eucnemosaurus_, since it clearly comes from a carnivore. My apologies to Mickey for throwing cold water on his suggestion in a previous post that _Aliwalia_ might be a sauropodomorph. :-) So much for giant predatory herrerasaurs! Though I wonder what the maxilla does belong to...?