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Dinosaur quadrate + Allodaposuchus from France + Campanian vertebrate site in Spain
Christophe Hendrickx, Ricardo Araújo & Octávio Mateus (2015)
The non-avian theropod quadrate I: standardized terminology with an
overview of the anatomy and function.
The quadrate of reptiles and most other tetrapods plays an important
morphofunctional role by allowing the articulation of the mandible
with the cranium. In Theropoda, the morphology of the quadrate is
particularly complex and varies importantly among different clades of
non-avian theropods, therefore conferring a strong taxonomic
potential. Inconsistencies in the notation and terminology used in
discussions of the theropod quadrate anatomy have been noticed,
including at least one instance when no less than eight different
terms were given to the same structure. A standardized list of terms
and notations for each quadrate anatomical entity is proposed here,
with the goal of facilitating future descriptions of this important
cranial bone. In addition, an overview of the literature on quadrate
function and pneumaticity in non-avian theropods is presented, along
with a discussion of the inferences that could be made from this
research. Specifically, the quadrate of the large majority of
non-avian theropods is akinetic but the diagonally oriented
intercondylar sulcus of the mandibular articulation allowed both rami
of the mandible to move laterally when opening the mouth in many of
theropods. Pneumaticity of the quadrate is also present in most
averostran clades and the pneumatic chamber—invaded by the quadrate
diverticulum of the mandibular arch pneumatic system—was connected to
one or several pneumatic foramina on the medial, lateral, posterior,
anterior or ventral sides of the quadrate.
Derek D. Turner (2015)
A second look at the colors of the dinosaurs.
Studies in History and Philosophy of Science Part A (advance online publication)
Explores the conditions under which it is rational to predict what
scientific evidence will be available in the future.
Argues that epistemic betting is an important feature of historical
Diagnoses past efforts to develop armchair arguments for epistemic
optimism/pessimism about historical science.
In earlier work, I predicted that we would probably not be able to
determine the colors of the dinosaurs. I lost this epistemic bet
against science in dramatic fashion when scientists discovered that it
is possible to draw inferences about dinosaur coloration based on the
microstructure of fossil feathers (Vinther et al., 2008). This paper
is an exercise in philosophical error analysis. I examine this episode
with two questions in mind. First, does this case lend any support to
epistemic optimism about historical science? Second, under what
conditions is it rational to make predictions about what questions
scientists will or will not be able answer? In reply to the first
question, I argue that the recent work on the colors of the dinosaurs
matters less to the debate about the epistemology of historical
science than it might seem. In reply to the second question, I argue
that it is difficult to specify a policy that would rule out the
failed bet without also being too conservative.
Jeremy E. Martin, Massimo Delfino, Géraldine Garcia, Pascal Godefroit,
Stéphane Berton and Xavier Valentin (2015)
New specimens of Allodaposuchus precedens from France: intraspecific
variability and the diversity of European Late Cretaceous eusuchians.
Zoological Journal of the Linnean Society (advance online publication)
A series of cranial remains as well as a few postcranial elements
attributed to the basal eusuchian Allodaposuchus precedens are
described from Velaux-La Bastide Neuve, a Late Cretaceous continental
locality in southern France. Four skulls of different size represent
an ontogenetic series and permit an evaluation of the morphological
variability in this species. On this basis, recent proposals that
different species of Allodaposuchus inhabited the European archipelago
are questioned and A. precedens is recognized from other Late
Cretaceous deposits of France and Romania. A dentary bone is described
for the first time in A. precedens and provides a basis to reconsider
the validity of two taxa, Ischyrochampsa meridionalis and
Musturzabalsuchus buffetauti, which are interpreted as possible junior
synonyms of Allodaposuchus. These results allow the diversity of Late
Cretaceous eusuchians from Europe to be refined and recognize a basal
stock known as the Hylaeochampsidae sharing an absence of external
mandibular fenestrae. Within this family, Allodaposuchus occupies a
basal position relative to Acynodon, Iharkutosuchus and Hylaeochampsa.
A. Pérez-García, F. Ortega, A. Bolet, F. Escaso, A. Houssaye, J.
Martínez-Salanova, C. de Miguel Chaves, P. Mocho, I. Narváez, M.
Segura, A. Torices, D. Vidal & J.L. Sanz (2015)
A review of the upper Campanian vertebrate site of Armuña (Segovia
Cretaceous Research (advance online publication)
The vertebrate taxa from Armuña are studied here.
This upper Campanian site is situated in the Segovia Province (Central Spain).
A relatively high abundance and diversity of reptiles is recognized there.
New taxa, and forms previously known in the Iberoarmorican Realm, are
European clades and lineages that migrated from other continents are
The Upper Cretaceous outcrops of Armuña (Segovia Province, Spain)
yielded relatively abundant material of vertebrates during prospection
and excavation in the second half of the 1980s. However, little has
been published on these remains. A new analysis of the specimens from
this upper Campanian site reveals the presence of some clades in the
site for the first time (e.g., Dortokidae, Anguimorpha,
Mosasauroidea). Furthermore, the material of the clades previously
recognized there has been reviewed and described in more detail, with
some previous systematic attributions confirmed and others refuted.
Consequently, a relatively high local diversity has been identified.
New taxa (i.e., a member of Anguimorpha and a eusuchian crocodyliform)
are identified in Armuña, coexisting with other taxa previously
described in other sites from the Iberoarmorican Realm. The
vertebrates from Armuña confirm that the fauna from the Upper
Cretaceous of the Iberian Peninsula is composed of a mixture of
European endemic clades and lineages shared with other continents such
as North America (e.g., anguimorphs) and Africa (e.g., bothremydids).