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Re: [dinosaur] Mesosaurs (+ parareptiles as diapsids) + Coahuila State dinosaur find history + more

What I find most interesting about this abstract is that it isn't the first thing this year to find this result. Schoch and Sues (2017) found parareptiles to be diapsids in their first analysis (phrased as "araeoscelidians fell outside Eureptilia"), but they didn't really investigate this further and only showed the results of their second analysis, which found a more traditional topology.

That said, I take these results with a grain of salt. Schoch and Sues (2017) used a character list with quite a few correlated characters, and I think that any serious attempt to resolve the phylogenetic position of turtles should include more basal archosauromorphs. The new paper by Laurin and Piñeiro, with only 129 characters and 17 taxa, strikes me as also being too small for this purpose, especially if turtles are the only crown reptiles to be included.

Schoch, R. R. and H.-D. Sues. 2017. Osteology of the Middle Triassic stem-turtle Pappochelys rosinae and the early evolution of the turtle skeleton. Journal of Systematic Paleontology.

On Sun, Oct 15, 2017 at 1:09 PM Ronald Orenstein <ron.orenstein@rogers.com> wrote:
I'll be very interested to hear the rationale for including pareiasaurs among diapsids!  Not to mention exactly where among the diapsids a turtle-parareptile lineage falls out...

Ronald Orenstein 
1825 Shady Creek Court
Mississauga, ON
Canada L5L 3W2

On Oct 15, 2017, at 1:11 PM, Ben Creisler <bcreisler@gmail.com> wrote:

Ben Creisler

Some recent items

The article text has not been published online yet, but here's the  posted abstract. Among other things, it proposes that the Parareptilia is within Diapsida and turtles are parareptiles after all!

Michel Laurin and  Graciela H. Piñeiro (2017)

A reassessment of the taxonomic position of mesosaurs, and a surprising phylogeny of early amniotes.

Frontiers in Earth Sciences (article text to come)

doi: 10.3389/feart.2017.00088



We reassess the phylogenetic position of mesosaurs by using a data matrix that is updated and slightly expanded from a matrix that the first author published in 1995 with his former thesis advisor. The revised matrix, which incorporates anatomical information published in the last twenty years and observations on several mesosaur specimens (mostly from Uruguay) includes seventeen terminal taxa and 129 characters (four more taxa and five more characters than the original matrix from 1995). The new matrix also differs by incorporating more ordered characters (all morphoclines were ordered). Parsimony analyses in PAUP 4 using the branch and bound algorithm show that the new matrix supports a position of mesosaurs at the very base of Sauropsida, as suggested by the first author in 1995. The exclusion of mesosaurs from a less inclusive clade of sauropsids is supported by a Bremer (Decay) index of 4 and a bootstrap frequency of 66%, both of which suggest that this result is moderately robust. The most parsimonious trees include some unexpected results, such as placing the anapsid reptile Paleothyris near the base of diapsids, and all of parareptiles as the sister-group of younginiforms (the most crownward diapsids included in the analyses). Turtles are placed among parareptiles, as the sister-group of pareiasaurs (and in diapsids, given that parareptiles are nested within diapsids). This unexpected result offers a potential solution to the long-lasting controversy about the position of turtles because previous studies viewed a position among diapsids and among parareptiles as mutually exclusive alternatives


A short paper from last year not yet mentioned, with a free pdf:

Sven SACHS, Udo SCHEER & Márton RABI (2016)

Reste von protostegiden Meeresschildkröten aus dem Cenomanium (Oberkreide) des Kassenberges (Mülheim an der Ruhr, Westdeutschland).

[Protostegid marine turtle remains from the Cenomanian (Late Cretaceous) of the Kassenberg (Mülheim an der Ruhr, Western Germany).]

Bericht des Naturwissenschaftlichen Vereins für Bielefeld und Umgegend 54 (2016): 32 - 43

pdf download:


Postcranial remains of protostegid turtles from the lowermost Cenomanian of Mülheim an der Ruhr (Western Germany) are described. The material includes fragments from the carapace and appendicular skeleton of a taxon with a medium carapace length of approximately 20-30 cm. The turtle remains supplement the record of this group from the Cenomanian of Germany and the fossil fauna of the Kassenberg.


Newsletter for the Fundación para el Estudio de los Dinosaurios en Castilla y León

Boletín Informativo nº 68, primavera-verano 2017, with an article on Europatitan (in Spanish)

download link:




abstracts book with some dinosaur-related items






Mary Anning film crowdfunding




History of dinosaur fossils from Coahuila State in Mexico, first discovered by German geologist Erich Haarmann in 1910-1912 (in Spanish)



New wireless audio and video  technology for tablet computers enhances hadrosaur Antonio and other fossils  on display at  museum in Villaggio del Pescatore, Italy (in Italian)



Interview with paleontologist Martin Kundrát, including dinosaur finds in Iran (in Slovak)


Laiyangosaurus (in Chinese)


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