[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

Fwd: Procolophonid from Spain and other non-dino papers

This posting apparently did not reach the DML the first time I tried
to send it (an on-going cyber problem).

---------- Forwarded message ----------
From: Ben Creisler <bcreisler@gmail.com>
Date: Wed, May 21, 2014 at 10:51 AM
Subject: Procolophonid from Spain and other non-dino papers
To: dinosaur@usc.edu

From: Ben Creisler

A number of recent non-dino papers that may be of interest to some:

J. Fortuny, A. Bolet, A. G. Sellés &  A. Galobart (2014)
A potential record of a procolophonid parareptile from the Triassic of
the Iberian Peninsula.
Geologica Acta 12(2), June 2014  (advance online publication)

Cranial and postcranial remains from the Middle Triassic of the
North-Eastern part of the Iberian Peninsula are reported and
tentatively assigned to Procolophonidae. The finding is the first
occurrence of a procolophonid parareptile in the Iberian Peninsula,
representing the southernmost record of the group in Europe. The
fossilbearing locality is dated as Anisian (Middle Triassic) and
includes three tooth-bearing bones, two cranial bone fragments and one
interclavicle. The mandible described herein includes nine teeth. No
cusps or complete crowns are preserved, but sections of the teeth are
available. The three anterior teeth progressively decrease in size
from front to back, while the teeth from the fourth to the eighth
position present the opposite trend. The last tooth (the ninth) is
clearly reduced in comparison to the previous ones. A close
relationship with Anomoiodon-Kapes is suggested, however, more
material is required in order to assess the exact taxonomical
determination of the Iberian remains. This finding is expected to shed
some light on the geographical distribution of procolophonines.


A. Watanabe and D. E. Slice (2014)
The utility of cranial ontogeny for phylogenetic inference: a case
study in crocodylians using geometric morphometrics.
Journal of Evolutionary Biology (advance online publication)
DOI: 10.1111/jeb.12382

The degree to which the ontogeny of organisms could facilitate our
understanding of phylogenetic relationships has long been a subject of
contention in evolutionary biology. The famed notion that ‘ontogeny
recapitulates phylogeny’ has been largely discredited, but there
remains an expectation that closely related organisms undergo similar
morphological transformations throughout ontogeny. To test this
assumption, we used three-dimensional geometric morphometric methods
to characterize the cranial morphology of 10 extant crocodylian
species and construct allometric trajectories that model the
post-natal ontogenetic shape changes. Using time-calibrated molecular
and morphological trees, we employed a suite of comparative
phylogenetic methods to assess the extent of phylogenetic signal in
these trajectories. All analyses largely demonstrated a lack of
significant phylogenetic signal, indicating that ontogenetic shape
changes contain little phylogenetic information. Notably, some Mantel
tests yielded marginally significant results when analysed with the
morphological tree, which suggest that the underlying signal in these
trajectories is correlated with similarities in the adult cranial
morphology. However, despite these instances, all other analyses,
including more powerful tests for phylogenetic signal, recovered
statistical and visual evidence against the assumption that
similarities in ontogenetic shape changes are commensurate with
phylogenetic relatedness and thus bring into question the efficacy of
using allometric trajectories for phylogenetic inference.


Jörn-Frederik Wotzlaw, Jean Guex, Annachiara Bartolini, Yves Gallet,
Leopold Krystyn, Christopher A. McRoberts, David Taylor, Blair Schoene
and Urs Schaltegger (2014)
Towards accurate numerical calibration of the Late Triassic:
High-precision U-Pb geochronology constraints on the duration of the
Geology (advance online publication)
doi: 10.1130/G35612.1

Numerical calibration of the Late Triassic stages is arguably the most
controversial issue in Mesozoic stratigraphy, despite its importance
for assessing mechanisms of environmental perturbations and associated
biologic consequences preceding the end-Triassic mass extinction. Here
we report new chemical abrasion–isotope dilution–thermal ionization
mass spectrometry zircon U-Pb dates for volcanic ash beds within the
Aramachay Formation of the Pucara Group in northern Peru that place
precise constraints on the age of the Norian-Rhaetian boundary (NRB)
and the duration of the Rhaetian. The sampled ash bed–bearing interval
is located just above the last occurrence of the bivalve Monotis
subcircularis, placing this stratigraphic sequence in the uppermost
Norian, perhaps ranging into the earliest Rhaetian. Zircon U-Pb dates
of ash beds constrain the deposition age of this interval to be
between 205.70 ± 0.15 Ma and 205.30 ± 0.14 Ma, providing precise
constraints on the age of the NRB. Combined with previously published
zircon U-Pb dates for ash beds bracketing the Triassic-Jurassic
boundary, we estimate a duration of 4.14 ± 0.39 m.y. for the Rhaetian.
This ends a prolonged controversy about the duration of this stage and
has fundamental implications for the rates of paleoenvironmental
deterioration that culminated in the end-Triassic mass extinction.


Dieter Uhl, Christoph Hartkopf-Fröder, Ralf Littke & Evelyn Kustatscher (2014)
Wildfires in the late Palaeozoic and Mesozoic of the Southern Alps—the
Anisian and Ladinian (Mid Triassic) of the Dolomites (Northern Italy).
Palaeobiodiversity and Palaeoenvironments (advance online publication)
DOI: 10.1007/s12549-014-0155-y

Based on anatomical studies of fossil charcoal fragments the first
evidence for palaeo-wildfires is presented for the Anisian and
Ladinian of the Dolomites (Northern Italy). These charcoals are from
the localities Kühwiesenkopf/Monte Prà della Vacca (middle-upper
Pelsonian, upper Anisian) and Ritberg/Ju Rit (Longobardian, upper
Ladinian), and they help to fill a gap in our current scientific
knowledge on the fossil record of Triassic wildfires worldwide.
Charcoal reflectance values from Kühwiesenkopf are surprisingly high,
indicating a palaeo-wildfire temperature of approximately 650 °C.