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Therapsid skull neutron tomography + Dinilysia, snake from Argentina + Kimbetopsalis, new multituberculate



Ben Creisler
bcreisler@gmail.com


Some new and recent non-dino items that may be of interest to some:


In open access:

Michael Laaß & Burkhard Schillinger (2015)
Reconstructing the Auditory Apparatus of Therapsids by Means of
Neutron Tomography.
Physics Procedia 69: 628–635
doi:10.1016/j.phpro.2015.07.089
http://www.sciencedirect.com/science/article/pii/S1875389215006999

The internal cranial structure of mammalian ancestors, i.e. the
therapsids or “mammal-like reptiles”, is crucial for understanding the
early mammalian evolution. In the past therapsid skulls were
investigated by mechanical sectioning or serial grinding, which was a
very time-consuming and destructive process and could only be applied
to non-valuable or poorly preserved specimens. As most therapsid
skulls are embedded in terrestrial iron-rich sediments of Late Permian
or Triassic age, i.e. so called “Red beds”, a successful investigation
with X-Rays is often not possible.

We successfully investigated therapsid skulls by means of neutron
tomography at the facility ANTARES at FRM II in Munich using cold
neutron radiation. This kind of radiation is able to penetrate
iron-rich substances in the range between 5 and 15 cm and produces a
good contrast between matrix and bones, which enables segmentation of
internal cranial structures such as bones, cavities and canals of
nerves and blood vessels. In particular, neutron tomography combined
with methods of 3D modeling was used here for the investigation and
reconstruction of the auditory apparatus of therapsids.

===


Kimbetopsalis--Paleocene rather Mesozoic, but of interest in post-K
extinction recovery story

Thomas E. Williamson, Stephen L. Brusatte, Ross Secord and Sarah Shelley (2015)
A new taeniolabidoid multituberculate (Mammalia) from the middle
Puercan of the Nacimiento Formation, New Mexico, and a revision of
taeniolabidoid systematics and phylogeny.
Zoological Journal of the Linnean Society (advance online publication)
DOI: 10.1111/zoj.12336
http://onlinelibrary.wiley.com/doi/10.1111/zoj.12336/abstract



Multituberculates were amongst the most abundant and taxonomically
diverse mammals of the late Mesozoic and the Palaeocene, reaching
their zenith in diversity and body size in the Palaeocene.
Taeniolabidoidea, the topic of this paper, includes the largest known
multituberculates, which possess highly complex cheek teeth adapted
for herbivory. A new specimen from the early Palaeocene (middle
Puercan; biochron Pu2) of the Nacimiento Formation, New Mexico
represents a new large-bodied taeniolabidoid genus and species,
Kimbetopsalis simmonsae. A phylogenetic analysis to examine the
relationships within Taeniolabidoidea that includes new information
from Kimbetopsalis gen. et sp. nov. and gen. nov. and from new
specimens of Catopsalis fissidens, first described here, and data from
all other described North American and Asian taeniolabidoids. This
analysis indicates that Catopsalis is nonmonophyletic and justifies
our transfer of the basal-most taeniolabidoid ‘Catopsalis’ joyneri to
a new genus, Valenopsalis. Kimbetopsalis and Taeniolabis form a clade
(Taeniolabididae), as do the Asian Lambdopsalis, Sphenopsalis, and
possibly also Prionessus (Lambdopsalidae). Taeniolabidoids underwent a
modest taxonomic radiation during the early Palaeocene of North
America and underwent a dramatic increase in body size, with
Taeniolabis taoensis possibly exceeding 100 kg. Taeniolabidoids appear
to have gone extinct in North America by the late Palaeocene but the
appearance of lambdopsalids in the late Palaeocene of Asia suggests
that they dispersed from North America in the early to middle
Palaeocene.


News:

http://news.unl.edu/newsrooms/unltoday/article/undergrad-discovers-new-mammal-species/

http://www.bbc.com/news/science-environment-34414923

http://in.reuters.com/article/2015/10/05/science-mammal-idINKCN0RZ08020151005


==

Dinilysia

Free pdf:

L.N. Triviño & A.M. Albino (2015).

Hallazgo de restos de la serpiente Dinilysia patagonica Smith-Woodward
1901 en una nueva localidad del Santoniano de Patagonia, Argentina.
(in Spanish)
[Record of remains of the snake Dinilysia patagonica Smith-Woodward
1901 in a new locality of the Santonian of Patagonia, Argentina.]
Estudios Geológicos 71(2): e033
http://dx.doi.org/10.3989/egeol.41858.347
http://estudiosgeol.revistas.csic.es/index.php/estudiosgeol/article/view/927/1028

Resumen



En este trabajo se describen nuevos restos de la serpiente cretácica
Dinilysia patagonica recuperados en la localidad Barreales Norte,
Formación Bajo de la Carpa (Santoniano superior), provincia del
Neuquén, Argentina. El material comprende la parte posterior de un
cráneo parcialmente conservado y articulado con un fragmento del hueso
compuesto, atlas y axis. Además, se preservaron seis secciones de
columna vertebral con vértebras precloacales. La asignación a
Dinilysia patagonica se basa en: cráneo de tamaño grande, otooccipital
con largo proceso paraoccipital adosado a un elongado supratemporal
que se extiende más allá del nivel del cóndilo occipital; cresta
sagital del parietal bien desarrollada y continua con la cresta del
supraoccipital; proótico en forma de I cursiva; vértebras anchas,
cortas y robustas; prezigapófisis largas y muy inclinadas sobre la
horizontal; canal neural pequeño y trilobulado; proceso
prezigapofisario reducido; arcos neurales aplanados con el margen
posterior recto. Este material agrega una nueva localidad al norte del
río Neuquén para la distribución de la especie en el Cretácico
superior.

**

In this study, we describe new remains of the Cretaceous snake
Dinilysia patagonica from beds of the locality Barreales Norte, Bajo
de la Carpa Formation (Upper Santonian), Neuquén Province, Argentina.
The material comprises the back of a partially preserved skull,
articulated with a fragment of the compound bone, atlas and axis.

Additionally, six fragments of precloacal vertebrae have been
preserved. The assignation to Dinilysia patagonica is based on: large
skull, otooccipital with long paraoccipital process adjacent to an
elongate supratemporal thatextends farther the level of the occipital
condyle; well developed sagital crest of parietal bone, continuously
joined with the supraoccipital crest; italics I-like prootic; wide,
short and robust vertebrae; prezygapophyses long and highly inclined
above the horizontal; triangular section of vertebral centrum; reduced
prezygapophyseal process; flattened neural arches with straight
posterior edge. This material adds a new Upper Cretaceous location for
the distribution of the species at the north of the Neuquén River.

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