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Muiscasaurus, new ichthyosaur from Early Cretaceous of Colombia + more non-dino papers



Ben Creisler
bcreisler@gmail.com



A number of new non-dino papers:



Erin E. Maxwell, Daniel Dick, Santiago Padilla and Mary Luz Parra (2015)
A new ophthalmosaurid ichthyosaur from the Early Cretaceous of Colombia.
PAPERS IN PALAEONTOLOGY (advance online publication)
DOI: 10.1002/spp2.1030
http://onlinelibrary.wiley.com/doi/10.1002/spp2.1030/abstract


Cretaceous ichthyosaurs were relatively diverse in temperate
latitudes, but few species have been described from the palaeotropics.
Here, we describe a new ophthalmosaurid ichthyosaur, Muiscasaurus
catheti gen. et sp. nov., from the Barremian–Aptian aged Paja
Formation of Colombia. This species is known only from a partial skull
and differs from all other ichthyosaurs in the unusual configuration
of the external narial opening, slender rostrum, narrow postorbital
region, and gracile dentition. It is the second ichthyosaur described
from the Paja Formation, suggesting moderate taxonomic and ecological
ichthyosaur diversity in the region during the Early Cretaceous.

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Estevan Eltink, Eliseu V. Dias, Sérgio Dias-da-Silva, Cesar L. Schultz
and Max C. Langer (2015)
The cranial morphology of the temnospondyl Australerpeton cosgriffi
(Tetrapoda: Stereospondyli) from the Middle–Late Permian of Paraná
Basin and the phylogenetic relationships of Rhinesuchidae.
Zoological Journal of the Linnean Society (advance online publication)
DOI: 10.1111/zoj.12339
http://onlinelibrary.wiley.com/journal/10.1111/(ISSN)1096-3642/earlyview

Stereospondyls are a diverse and morphologically distinctive clade of
basal tetrapods that rapidly reached a global distribution and high
abundance during the Early Triassic. Yet, the first stereospondyls
appeared in the Middle–Late Permian of Gondwana, mostly represented by
Rhinesuchidae. Australerpeton cosgriffi is a long-snouted
representative of the group and one of the most complete temnospondyls
known from the Permian of South America. The elements attributed to
Au. cosgriffi were recovered from the Middle-Late Permian deposits of
the Rio do Rasto Formation (Paraná Basin), in the Serra do Cadeado
area of Brazil. Here, we review the cranial anatomy of the species,
providing a comparative redescription, new anatomical data and
previously unrecognized characters. Australerpeton cosgriffi is nested
within Rhinesuchidae based on the anatomy of the tympanic cavity, but
its long-snouted condition is unique amongst rhinesuchids. Based on
the recovered information and new morphological data, the systematic
position of Au. cosgriffi was assessed using a new matrix of 221
characters; of which 196 were selected from previous studies and the
remaining are newly proposed. The results show Rhinesuchidae divided
into Rhinesuchinae and Australerpetinae. A unique tympanic cavity
formed by a well posteroventrally projected tabular horn, stapedial
groove, well-developed oblique crest on the pterygoid, and a dorsal
pterygoid crest (new term) characterizes the ear region of
Rhinesuchidae. Australerpeton cosgriffi is the only undisputed
Rhinesuchidae record outside southern Africa and the first
long-snouted Stereospondyli, and thus is useful in helping to
understand the diversification of the stereospondyls during the
Middle/Late Permian of Gondwana.


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Eudald Mujal, Josep Fortuny, Oriol Oms, Arnau Bolet, Àngel Galobart
and Pere Anadón (2015)
Palaeoenvironmental reconstruction and early Permian ichnoassemblage
from the NE Iberian Peninsula (Pyrenean Basin).
Geological Magazine (advance online publication)
DOI: http://dx.doi.org/10.1017/S0016756815000576
http://128.232.233.5/action/displayAbstract?fromPage=online&aid=10004460&fulltextType=RA&fileId=S0016756815000576

Recent finds of tetrapod ichnites in the red-bed and volcaniclastic
succession of the Iberian Pyrenean Basin permits an assessment of the
faunal diversity and palaeoenvironment of a late early Permian
setting. The tetrapod ichnoassemblage is inferred with the aid of
photogrammetry and constituted by Batrachichnus salamandroides,
Limnopus isp., cf. Amphisauropus (these three ichnotaxa present
associated swimming traces, assigned to Characichnos), cf.
Ichniotherium, Dromopus isp., cf. Varanopus, Hyloidichnus isp. and
Dimetropus leisnerianus. These ichnotaxa suggest the presence of
temnospondyls, seymouriamorphs, diadectomorphs, araeoscelids,
captorhinids and synapsid pelycosaurs as potential trackmakers. These
faunas correlate to the late early Permian. Two ichnoassociations
correspond to two different palaeoenvironments that were permanently
or occasionally aquatic (meandering fluvial systems and unconfined
runoff surfaces, respectively). Ichnotaxa in the fluvial system is
more diverse and abundant than in the runoff surfaces system. The
Iberian Pyrenean ichnoassemblage reveals the faunistic connection and
similarities among nearing basins (Spain, southern France and Morocco)
differing from the Central European basins (i.e. German Tambach
Formation). Based on the palaeogeography and the climate models of the
early Permian, we suggest the correlation of ichnofaunal composition
with different palaeoclimate biomes. This results in a diffuse
boundary of Gondwana–Laurasia land masses, indicating no geographic
barriers but a possible climate control on the faunal distribution.
Further studies, integrating data from distant tracksites, should
refine these biome boundaries.

====


Timothy R. Smithson, Kelly R. Richards and Jennifer A. Clack (2015)
Lungfish diversity in Romer's Gap: reaction to the end-Devonian extinction.
Palaeontology (advance online publication)
DOI: 10.1111/pala.12203
http://onlinelibrary.wiley.com/doi/10.1111/pala.12203/abstract

Romer's Gap, the interval following the end-Devonian extinction event,
has been described as a post-extinction trough for vertebrates. It is
a time roughly equivalent to the Tournaisian stage of the early
Carboniferous and has been characterized by a lull in diversity of
survivors. Lungfish typified this description. One species was known
from one locality. Recently, a diverse collection of lungfish tooth
plates, representing seven new forms, was recovered from new
Tournaisian vertebrate localities in northern Britain. They display a
range of previously unknown morphologies, with tooth shape and wear
patterns not seen in other post-Devonian forms. A comparison of tooth
ridge number and tooth ridge angle in lungfishes from the Famennian,
Tournaisian and Visean reveals marked differences between late
Devonian and early Carboniferous taxa. The most common tooth plate
shape in the Famennian is absent from our sample of Tournaisian taxa.
Two completely new shapes have evolved, one with a relatively low
tooth ridge angle, no greater than 40°, in which most of the tooth
ridges are essentially parallel, and the other with a much higher
tooth ridge angle of up to 180° where the tooth ridges are highly
divergent. This high level of morphological diversity over a narrow
time period suggests that, following the end-Devonian extinction, gaps
in ecospace left by the extinction of major groups of fishes were
exploited by a previously unrecorded radiation of lungfishes. Whilst
taxonomic diversity of lungfishes declined following the end-Devonian
extinction, recovery and diversification among tooth-plated forms was
rapid, and morphological disparity among these forms subsequently
increased. Contrary to previous assumptions, morphological disparity
among lungfish did not decline until much later in the Carboniferous.

===



Aaron M. Olsen (2015)
Exceptional avian herbivores: multiple transitions toward herbivory in
the bird order Anseriformes and its correlation with body mass.
Ecology and Evolution (advance online publication)
DOI: 10.1002/ece3.1787
http://onlinelibrary.wiley.com/doi/10.1002/ece3.1787/abstract

Free pdf:

http://onlinelibrary.wiley.com/doi/10.1002/ece3.1787/pdf



Herbivory is rare among birds and is usually thought to have evolved
predominately among large, flightless birds due to energetic
constraints or an association with increased body mass. Nearly all
members of the bird order Anseriformes, which includes ducks, geese,
and swans, are flighted and many are predominately herbivorous.
However, it is unknown whether herbivory represents a derived state
for the order and how many times a predominately herbivorous diet may
have evolved. Compiling data from over 200 published diet studies to
create a continuous character for herbivory, models of trait evolution
support at least five independent transitions toward a predominately
herbivorous diet in Anseriformes. Although a nonphylogenetic
correlation test recovers a significant positive correlation between
herbivory and body mass, this correlation is not significant when
accounting for phylogeny. These results indicate a lack of support for
the hypothesis that a larger body mass confers an advantage in the
digestion of low-quality diets but does not exclude the possibility
that shifts to a more abundant food source have driven shifts toward
herbivory in other bird lineages. The exceptional number of
transitions toward a more herbivorous diet in Anseriformes and lack of
correlation with body mass prompts a reinterpretation of the
relatively infrequent origination of herbivory among flighted birds.