A tree topology change – turtles and pareiasaurs move from diadectids to millerettids

I spent last week adding taxa and running through potential problems with the large reptile tree. Several matrix boxes were rescored. The result shifted turtles + pareiasaurs from Diadectides + Procolophon  to Milleretta RC70 + Odontochelys (a near-turtle now, not a real turtle), which we discussed earlier.

An interesting shift. 
Moving pareiasaurs + Proganochelys back to Diadectes + Procolophon now adds 22 steps. Moving pareiasaurs + turtles to Eunotosaurus (following the results of Lyson et al. 2013) adds 28 steps.

The RC14 specimen of Milleretta is still in the same clade as Acleistorhinus + Eunotosaurus + Austraolthyris + Feeserpeton + Belebey + Bolosaurus. 

Maybe not as crazy as it sounds
It’s the “plain brown sparrows” like Milleretta, that lie at the bases of major clades, not the highly derived taxa, like Procolophon and Diadectes. Those become extinct. The various specimens of Milleretta have long been ignored, but they really are the keys to understanding the reptile family tree.

Broom R 1913. On the Structure and Affinities of Bolosaurus. Bulletin of the American Museum of Natural History 32:509-516
Broom R 1938 On the Structure of the Reptilian Tarsus: Proceedings of the Zoological Society of London, v. 133, 108, p. 535-542.
Broom R 1948. A contribution to our knowledge of the vertebrates of the Karroo beds of South Africa: Transactions of the Royal Society of Edinburgh, Endinburgh 61: 577-629.
Case EC 1907.
Description of the Skull of Bolosaurus striatus Cope. Bulletin of the American Museum of Natural History 23:653-658
Cope ED 1878
. Descriptions of extinct Batrachia and Reptilia from the Permian formations of Texas. Proceedings of the American Philosophical Society 17:505-530
Gow CE 1972. The osteology and relationships of the Millerettidae (Reptilia: Cotylosauria). Journal of Zoology, London 167:219-264.
Watson DMS 1954. On Bolosaurus and the origin and classification of reptiles.Bulletin of the Museum of Comparative Zoology at Harvard College,, v. 111, no. 9444-449.


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