Novel insights – part 1

Not much news lately,
so a bit of a review in the current storms of controversy and disparagement.

In the last four years
adding species- and specimen-based taxa to the large reptile tree and large pterosaur tree and creating reconstructions, at times using DGS, have provided a rich trove of novel insights into reptile evolution heretofore (and too often currently) unnoticed, overlooked and ignored. Of course, these all need to be tested in independent studies using similar taxon lists along with any novel list of character traits exceeding 150-200 in number.

Amniota

  1. Initial split of the Amniota into Lepidosauromorpha and Archosauromorpha clades. That means Amniota = Reptilia.
  2. Gephyrostegus bohemicus is a sister to the last common Viséan (or earlier) ancestor of all Amniotes. It lacks traditional amniote skeletal traits, but lacks posterior dorsal ribs, creating a larger volume for gravid females to hold larger eggs, a deeper pelvic opening and unfused pelvic elements.
  3. Proximal outgroup taxa to the Amniota include sisters to Silvanerpeton, Utegenia and members of the Seymouriamorpha in order of increasing distance.
  4. As in many prior studies, phylogenetic miniaturization is key to the origin of several clades.

Lepidosauromorpha

  1. Basal lepidosauromorphs include the clade of Urumqia, Brukterepeton and Thuringothyris. Some of these were formerly considered anamniotes.
  2. Captorhinomorph sister taxa include Cephalerpeton, Reiszhorhinus, Concordia and Romeria primus. Romeria texana is a basal captorhinomorph.
  3. A sister to Saurorictus is basal to all remaining lepidosauromorphs, Diadectormorpha + Millerettidae.
  4. Diadectomorphs are lepidosauromorph reptiles.
  5. Procolophon and kin are sisters to diadectomorphs like Oradectes, Silvadectes and Diadectes. A sister to Orobates is their last common ancestor.
  6. Colobomycter is a basal procolophonid.
  7. Tetraceratops is a sister to Tseajaia and Limnoscelis and these three are sisters to the Diadectes + Procolophon clade.
  8. Caseasauria are millerettids, not synapsids and caseasauria is a sister clade to Feeserpeton + Australothyris + Eunotosaurus + Acleistorhinus + Delorhynchus.
  9. Bolosaurids are also millerettids  and are basal to the Stephanospondylus clade.
  10. Stephanospondylus is basal to the pariasaur + turtle clade.
  11. Sclerosaurus is basal to the turtle clade.
  12. ElginiaMeolania nest as basalmost turtles along with Proganochelys.
  13. Odontochelys nests with Trionyx, a soft-shell turtle. Skull emargination and tooth loss was convergent in soft shell  and hard shell turtles.

More later.

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