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Toremys and Perochelys, new Early Cretaceous turtles + Late Triassic tanystropheids from New Mexico



Ben Creisler
bcreisler@gmail.com

A number of recent non-dino papers:


A. Pérez-García, E. Espílez, L. Mampel & L. Alcalá (2015)
A new European Albian turtle that extends the known stratigraphic
range of the Pleurosternidae (Paracryptodira).
Cretaceous Research 55: 74–83
doi:10.1016/j.cretres.2015.02.007
http://www.sciencedirect.com/science/article/pii/S0195667115000233


Highlights

Toremys is the most recent known pleurosternid.
Toremys comes from a Spanish Albian site.
Three specimens are attributed to Toremys.

Abstract

Postcranial material corresponding to three specimens of freshwater
turtles, from the lower Albian (upper Lower Cretaceous) of Ariño
(Teruel Province, Spain), is analysed in this paper. This study allows
us to identify the presence of Pleurosternidae (Paracryptodira)
outside its known stratigraphic range, from Kimmeridgian to Barremian,
and extends its distribution to the Albian. The species from Ariño
represents a new taxon, Toremys cassiopeia gen. et sp. nov., which is
the only pleurosternid described so far in post-Berriasian levels.
Toremys cassiopeia is closely related to other taxa from Europe, to
which the Cretaceous pleurosternids are restricted. Knowledge about
the European freshwater turtle faunas distributed between the
Barremian and the uppermost Cretaceous is very limited. The new
finding provides relevant data on these poorly understood faunas.

***

Lu Li, Walter G. Joyce & Jun Liu (2015)
The first soft-shelled turtle from the Jehol Biota of China.
Vertebrate Paleontology (advance online publication)
DOI:10.1080/02724634.2014.909450
http://www.tandfonline.com/doi/full/10.1080/02724634.2014.909450#abstract

A new turtle from the Early Cretaceous (Aptian) Jiufotang Formation of
western Liaoning, China, Perochelys lamadongensis, gen. et sp. nov.,
represents the first species of soft-shelled turtle from the Jehol
Biota. The new taxon is diagnosed by the combination of the following
characters: nuchal bone about five times wider than long; preneural
absent; reversal of the orientation in the neural series at neural V;
neural series fully separates costal series; costal VIIIs reduced;
plastral callosities poorly developed and poorly sculpted; postorbital
bar narrow, around one-fourth of orbit diameter; jugal contacting
squamosal; foramen jugulare posterius separated from fenestra
postotica; neural spines weakly developed on anterior cervicals; and
phalangeal formula for pes 2-3-3-4-?. High levels of homoplasy make
the phylogenetic relationships of the new taxon difficult to assess,
and the possibility therefore exists that Perochelys lamadongensis
either represents a stem or a crown trionychid. This phylogenetic
uncertainty confirms that the skeletal morphology of trionychids has
remained virtually unchanged for the last 120 million years.

http://zoobank.org/urn:lsid:zoobank.org:pub:1FE50A16-5FE6-4DEE-B839-CE2A52038F55

==


Adam C. Pritchard, Alan H. Turner, Sterling J. Nesbitt, Randall B.
Irmis & Nathan D. Smith (2015)
Late Triassic tanystropheids (Reptilia, Archosauromorpha) from
northern New Mexico (Petrified Forest Member, Chinle Formation) and
the biogeography, functional morphology, and evolution of
Tanystropheidae.
Vertebrate Paleontology (advance online publication)
DOI:10.1080/02724634.2014.911186
http://www.tandfonline.com/doi/full/10.1080/02724634.2014.911186#abstract

We report on tanystropheids from the Late Triassic (middle Norian)
Hayden Quarry of northern New Mexico (Chinle Formation, Hayden
Quarry). These elements, consisting of isolated vertebrae and
appendicular bones, represent the first unambiguously identified
tanystropheid from western North America and likely the latest
occurrence of the group, postdating Tanytrachelos in the eastern
United States. A new phylogenetic analysis of early saurians
identifies synapomorphies of tanystropheid subclades, which are
recognized in the recovered vertebrae and a calcaneum. The femora are
consistent with referral to Tanystropheidae. There is no clear
association of the remains, however, so we refrain from erecting a new
taxon. The analysis also indicates that the Hayden Quarry
tanystropheid fossils belong to a newly recognized clade including the
Late Triassic taxa Langobardisaurus and Tanytrachelos. Because most
tanystropheid specimens are two-dimensionally crushed skeletons, the
Hayden Quarry tanystropheid fossils provide valuable insights into the
three-dimensional osteology of derived tanystropheids. The most
striking feature of the Hayden vertebrae is a rugose, flattened
expansion of the neural spines in the dorsal, sacral, and caudal
regions, probably linked to a ligamentous bracing system. These
fossils and others from Late Triassic sites in the American West
suggest that tanystropheids underwent a previously unrecognized
radiation in North America just prior to their extinction.