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Mixosaur ichthyosaur from Triassic of Norway + Large Ichthyosaurus forefin (free pdfs)



Ben Creisler
bcreisler@gmail.com

Some recent (and not so recent)  marine reptile papers with free pdfs:


Hurum, J.H., Roberts, A.J., Nakrem, H.A., Stenløkk, J.A. & Mørk, A. (2015)
The first recovered ichthyosaur from the Middle Triassic of Edgeøya, Svalbard.
Norwegian Petroleum Directorate Bulletin 11: 97–110
Stavanger 2014, ISSN Online 1894-7670, ISBN 978-82-7257-117-6.
http://www.npd.no/Global/Norsk/3-Publikasjoner/NPD-Bulletin/Bulletin-11-kap/NPD_Bulletin_Hurum_Scr.pdf


The Blanknuten Member of the Botneheia Formation preserves
ichthyopterygians of various body-sizes. Due to the fragmentary nature
of their remains, their systematic positions are controversial. The
most complete skeleton of a mixosaur from Svalbard (PMO 219.250)
described in this paper adds new data to the Phalarodon-Mixosaurus
controversy, which is directly connected to the Svalbard taxa,
starting with the description of  Ichthyosaurus nordenskioeldii by
Hulke in 1873. The ratios of the posterior dorsal vertebrae to the mid
caudal vertebrae are a mixture of what is stated to be typical for P.
callawayi, M. nordenskioeldii and M. cornalianus. We conclude that PMO
219.250 most likely should be assigned to the genus Phalarodon, but
refrain from further assignment to a species.


The same journal issue as other Triassic-related material:

http://www.npd.no/en/Publications/NPD-bulletins/Bulletin-11/

==

Massare, J. D., Lomax, D. R., and Klein, A. (2015)
A large forefin of Ichthyosaurus from the U.K., and estimates of the
size range of the genus. Paludicola 10(2): 119-135
https://www.academia.edu/12544577/A_large_forefin_of_Ichthyosaurus_from_the_U.K._and_estimates_of_the_size_of_the_genus


A large partial forefin (YORYM 2005.2411) from the Lower Jurassic of
Yorkshire is assigned to Ichthyosaurus on the basis of the humerus
shape, two digits originating from the intermedium, and an anterior
digital bifurcation. The humerus is 11.7 cm long and the forefin is
38.5 cm long, but incomplete, probably missing more than 1/3 of its
length. Regression analyses suggest that the individual had a jaw
length of 56 cm and a total length to the tail bend of almost 3 m.
This individual represents the largest Ichthyosaurus reported from the
U.K. Although interest in the reptiles of the Yorkshire coast dates
back to the early 1800s, specimens of Ichthyosaurus from the area are
rare.


==


>From last year but not yet mentioned:


Sachs, S., Schubert, S., and Kear, B. P. (2014)
Mitteilung über ein neues Skelett eines Plesiosauriers (Reptilia:
Sauropterygia) aus dem Oberen Pliensbachium (Unterjura) von Bielefeld,
Nordwestdeutschland.
[Note on a new plesiosaur (Reptilia: Sauropterygia) skeleton from the
upper Pliensbachian (Lower Jurassic) of Bielefeld, northwest Germany.]
Berichte des Naturwissenschaftlichen Vereins für Bielefeld und
Umgegend 52: 26-35
https://www.academia.edu/9200664/Note_on_a_new_plesiosaur_Reptilia_Sauropterygia_skeleton_from_the_upper_Pliensbachian_Lower_Jurassic_of_Bielefeld_northwest_Germany



This note briefly introduces a new plesiosaur specimen from the upper
Pliensbachian (Lower
Jurassic) of Bielefeld-Jöllenbeck (North Rhine-Westphalia, NW
Germany). The skeleton comprises a partial skull, sections of the
vertebral column, ribs and components of the pectoral girdle and
limbs. It belonged to an immature individual of 2-3 m length.
Important diagnostic features include a prominent notch in the caudal
border of the mandibular fossa glenoidalis, craniad cervical centra
that are higher than long, a pair of foramina subcentralia on the
cervicals separated by a broad ventral keel, and a dorsal process on
the scapula that bears a gently convex cranial margin, but no
pronounced medial thickening. The Bielefeld specimen is one of the
most complete plesiosaurs currently known from the Pliensbachian and
differs from the coeval European taxa Westphaliasaurus and Cryonectes,
but shows some similarity to unpublished material from the
Pliensbachian of England. The Bielefeld plesiosaur indicates that a
substantial diversity of taxa was present in European marine systems
during the Pliensbachian stage.
==