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Cretaceous crocodylomorph biodiversity in Teruel, Spain + Polish plesiosaur + more papers



Ben Creisler
bcreisler@gmail.com


A number of recent non-dino papers:


Eduardo Puértolas-Pascual, Raquel Rabal-Garcés, and José Ignacio Canudo (2015)
Exceptional crocodylomorph biodiversity of “La Cantalera” site (lower
Barremian; Lower Cretaceous) in Teruel, Spain.
Palaeontologia Electronica 18.2.28A: 1-16
http://palaeo-electronica.org/content/2015/1229-biodiversity-of-la-cantalera
(open access)



The palaeontological site of La Cantalera in Teruel, Spain (Blesa
Formation, Lower Cretaceous) can be characterized as the site with the
greatest biodiversity of vertebrates (32 taxa) from the lower
Barremian of the Iberian Peninsula. Remains of amphibians, lizards,
turtles, crocodiles, pterosaurs, dinosaurs and mammals have been
recovered. The most common taxa are crocodylomorphs, and their most
abundant remains are small isolated teeth. Six morphotypes have been
identified, which may correspond to at least four different sympatric
crocodylomorph taxa. This site presents a similar assemblage to other
European Lower Cretaceous sites, with morphotypes that may correspond
to the families Goniopholididae, Bernissartiidae, Atoposauridae and
multiple ziphodont crocodylomorphs. The crocodylomorph assemblage of
La Cantalera is characterized by the absence of large individuals and
presents a wide variety of dental morphologies adapted to diets
ranging from generalist to highly specialized. This rich biodiversity
could be due to concentration of vertebrates into restricted flooded
areas during dry seasons within a marsh ecosystem. Furthermore, La
Cantalera could also be close to a nesting area, which would explain
the abundance of small-sized individuals and the presence of fossil
crocodiloid eggshells.

===



Dean R. Lomax (2015)
The first plesiosaurian (Sauropterygia, Pliosauridae) remains
described from the Jurassic of Poland.
Palaeontologia Electronica 18.2.29A: 1-8
http://palaeo-electronica.org/content/2015/1230-jurassic-pliosaurid-poland
(open access)


Plesiosaur remains are rare in Poland. The first confidently
documented occurrence of the group from the Jurassic of Poland is
reported. The specimens comprise three isolated teeth of a pliosaurid
(Pliosauridae, Thalassophonea). These were found in Upper Jurassic
(lower Oxfordian) sediments and were collected from Zalas Quarry, near
Kraków, in southern Poland. Fossils from the vicinity of the Zalas
area have been collected since the 1800s, yet no report of vertebrate
remains has previously been described.


=====



Sarah Werning & Sterling J. Nesbitt (2015)
Bone histology and growth in Stenaulorhynchus stockleyi
(Archosauromorpha: Rhynchosauria) from the Middle Triassic of the
Ruhuhu Basin of Tanzania.
Comptes Rendus Palevol (advance online publication)
doi:10.1016/j.crpv.2015.03.004
http://www.sciencedirect.com/science/article/pii/S1631068315000470

The bone histology of non-archosauriform archosauromorphs is
understudied but is important for tracing the evolution of growth in
archosaurs and their closest relatives. Here, we describe the femoral
and tibial histology of a single individual of Stenaulorhynchus
stockleyi, a Middle Triassic rhynchosaur from Tanzania. Both elements
are composed largely of moderately vascularized parallel-fibered bone
tissue, which becomes avascular and more lamellar approaching the
periosteum. The spacing between growth marks in S. stockleyi strongly
attenuates with age, suggesting determinate growth for this taxon.
Whereas the bone tissue suggests slower growth compared to South
American rhynchosaurs, which have fibrolamellar bone tissue and
exhibit more anastomoses between canals, the determinate growth
pattern seems to be shared among hyperodapedontid rhynchosaurs.
Although non-archosauriform archosauromorphs vary in the rate of bone
deposition and growth in their first year, all taxa examined to date
grew relatively slowly compared to most archosauriforms.

=============

Graciela Piñeiro, Jorge Ferigolo, Ana María Ribeiro & Pablo Velozo  (2015)
Reassessing the affinities of vertebral remains from Permo-Triassic
beds of Gondwana.
Comptes Rendus Palevol (advance online publication)
doi:10.1016/j.crpv.2015.02.004
http://www.sciencedirect.com/science/article/pii/S1631068315000482



The Sanga do Cabral Formation of southern Brazil has a rich fossil
tetrapod assemblage and is suggested to have an Early Triassic age
mainly based on the presence of the parareptile Procolophon
trigoniceps. However, a Permo-Triassic age can be also suggested for
this unit taking into account the presence of putative Permian taxa
and some previous stratigraphic assessments. We describe here several
large vertebrae from the Sanga do Cabral Formation that display a
distinctive morphology that includes the presence of a transverse
distance across postzygapophyses more than twice the transverse width
of the centrum, and accessory articulation structures in the neural
arch that remind the hyposphene and hypantrum present in some basal
parareptiles and diadectomorphs. Vertebrae with a similar large size
and morphology had been previously reported from the same locality as
belonging to the genus Procolophon based on their parareptile
appearance (mainly the presence of a swollen neural arch) and the fact
that the vertebrae were collected at the same locality where a large
fragmentary skull assigned to this taxon was found. However, these
vertebrae lack a comparable consistent morphology with those of
Procolophon and basic statistical analyses demonstrate that these
vertebrae are significantly larger than those expected in the largest
known Procolophon skulls of South Africa. The morphology of these
vertebra is consistent with that present in seymouriamorphs,
pareiasaurs and diadectomorphs, but the absence of exclusive
diagnostic characters precludes an assure assignation to either of
these taxa. According to their current stratigraphic range,
seymouriamorphs are the most plausible postulation, as their younger
representatives are known from Late Permian deposits of Russia, but
the other candidates cannot be excluded. The presence of any
representative of those groups in the Sanga do Cabral Formation would
be important because: (1) they would represent the first and only
known record of seymouriamorphs or diadectomorphs in Gondwana,
regarding the characters that the described vertebrae share with these
groups; (2) they would suggest a survivorship for pareisaurs up to the
Latest Permian or through the Permian-Triassic boundary, according to
geochronological data currently available for this unit; (3) they
might also suggest a Late Permian age for at least part of the Sanga
do Cabral Formation if the intraformational conglomerates that yielded
the vertebrae resulted from the rejuvenation of older levels of the
same unit, and they do not include reworking of stratigraphically
older strata.