Updated one day after publication. The taxa come from the Supp. Data, most not shown in the greatly simplified chronological cladogram.
In the Butler et al. (2014) tree the following purported sister taxa are all “odd bedfellows” that do not look like one another.
- Prolacerta is derived from Mesosuchus (and presumably the rhynchosaurs)
- Euparkeria is derived from Tropidosuchus and Chanaresuchus.
- Tropidosuchus and Chanaresuchus are derived from Vancleavea.
- Vancleavea is derived from Erythrosuchus.
- Pterosaurs are derived from parasuchians!!!!!!
- Lagerpeton is derived from pterosaurs.
- Ornithosuchia is derived from Lewisuchus.
- Theropoda is derived from Ornithischia.
- Ornithosuchia is a sister to Pterosauria, also derived from Parasuchia.
- Revueltosaurus is a sister to the Aetosauria and derived from Ornithosuchia
- The new Gracilisuchus clade is derived from Revueltosaurus.
- Poposaurus and the poposaurs are derived from Qianosuchus, Xilosuchus and Arizonasaurus
- Prestosuchus and the Rauisuchidae is derived from Ticinosuchus.
- Hesperosuchus and the Crocodylomorpha are derived from Rauisuchidae.
Say it ain’t so!
As you can see, many of these relationships don’t make sense. Sister taxa share very few traits with one another (pterosauria and parasuchia, is the worst such example). Many relationships are upside down with basal taxa, like theropods, derived from derived taxa, like ornithischia. (M. Mortimer also had this problem a few years ago).
What is needed is a large reptile tree in which basal taxa are basal to derived taxa and all sisters look alike (share most traits). In the large reptile tree, sister taxa look quite a bit like one another. The authors should have cast a critical eye on these results, which are very similar to those of Nesbitt (2011), who also recovered many strange bedfellows.
If I had proposed that pterosaurs arose from parasuchians,
the ridicule would be endless and justified, as it is here. Taxon exclusion seems to be the culprit again, along with the tradition of using previously published matrices, even those riddled with Red Flags and strange bedfellows.
In the large reptile tree, Gracilisuchus nests with the SMNS 12591 specimen, Saltopus and Scleromochlus at the base of the Archosauria. Turfanosuchus nests at the base of the Poposauridae, between Decuriasuchus and the base of the Archosauria, not far from Gracilisuchus. Yonghesuchus, nests between Dromicosuchus and Protosuchus.
And, because this is Science, you can repeat these experiments to see for yourself which taxa share more traits — that make sense.
Butler et al. 2014. New clade of enigmatic early archosaurs yields insights into early pseudosuchian phylogeny and the biogeography of the archosaur radiation. BMC Evolutionary Biology 14:128. doi:10.1186/1471-2148-14-128
Nesbitt SJ 2011. The early evolution of archosaurs: relationships and the origin of major clades. Bulletin of the American Museum of Natural History 352: 292 pp.