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

Fumanya Member dinosaur environment + Clidastes from Russia + more



Ben Creisler
bcreisler@gmail.com


A number of recent papers, dino and non-dino:



O. Oms, V. Fondevilla, V. Riera, J. Marmi, E. Vicens, R. Estrada, P.
Anadón, B. Vila & À. Galobart (2015)
Transitional environments of the lower Maastrichtian South-Pyrenean
Basin (Catalonia, Spain): The Fumanya Member tidal flat.
Cretaceous Research (advance online publication)
doi:10.1016/j.cretres.2015.09.004
http://www.sciencedirect.com/science/article/pii/S0195667115300628



Sedimentological, palaeontological and geochemical data provide
detailed evidence of a marine-to-lagoon environmental succession
around the Campanian-Maastrichtian boundary in the Ibero-Armorican
domain. This regression is recorded by the succession of several
environments of the south-central Pyrenees basin: open marine mixed
shelf, marine restricted mixed shelf (both rudist-rich), tidal flat,
lagoon and fluvial dominated. The tidal flat setting belongs to the
Fumanya Member here described, which is the base of the Posa and
Massana formations (Tremp Group). The Fumanya Member is 5 m thick, is
built up of marly limestones and was an elongated tidal mudflat (100
km long, 25 km wide) developed in a foreland trough and was separated
from the Atlantic Ocean by an island-barrier system. In the lagoon
environment, marginal marine waters and continental fresh waters
alternated as documented by geochemistry and fossil molluscs. The
Fumanya Member is a dinosaur megatracksite, reporting the roaming
activity only of sauropods in tidal flats, a likely secure area
against predators. Feeding activity of these herbivores took place in
the lagoonal-lacustrine environments of the Posa Formation above the
Fumanya Member.

======

P. P. Skutschas & D. D. Vitenko (2015)
On a record of choristoderes (Diapsida, Choristodera) from the Lower
Cretaceous of Western Siberia.
Paleontological Journal 49(5): 507-511
DOI: 10.1134/S0031030115050123
http://link.springer.com/article/10.1134/S0031030115050123



Fossil remains (fragmentary dentaries and vertebrae) of Choristodera
indet. from the Lower Cretaceous Shestakovo 1 locality (Kemerovo
Region, Russia) are described. The taxon from Shestakovo is
characterized by primitive vertebral features (fused neural arches and
centra of the cervical vertebrae, elongated dorsal vertebrae) combined
with the presence of dentin folds at the tooth bases (advanced
character typical of neochoristoderes). Phylogenetic relationships of
the form from Shestakovo and other Choristodera are uncertain.

==



D. V. Grigoriev, M. S. Arkhangelsky & S. M. Merkulov (2015)
A record of Clidastes propython Cope (Squamata, Mosasauridae) in the
Upper Cretaceous of the Saratov Region, Russia.
Paleontological Journal 49(5): 512-520
DOI: 10.1134/S003103011505007X
http://link.springer.com/article/10.1134/S003103011505007X



A frontal of the mosasaur Clidastes propython from the Beloe Ozero
locality in the Saratov Region (Rybushka Formation, Campanian Stage,
Upper Cretaceous) is described. The investigated specimen differs from
the frontals of other members of the genus Clidastes in the relatively
straight lateral flanks. Reliable records of Clidastes outside America
have previously been reported only from Great Britain, Sweden, and
Germany. The new record from the Beloe Ozero locality expands the
known geographical range of the species C. propython and genus
Clidastes.

========




Final version of paper poster earlier in pre-print form:

Karl Bates, Susannah C.R. Maidment, Emma R. Schachner & Paul M. Barrett (2015)
Comments and corrections on 3D modeling studies of locomotor muscle
moment arms in archosaurs.
PeerJ 3:e1272
doi: https://dx.doi.org/10.7717/peerj.1272
https://peerj.com/articles/1272/



In a number of recent studies we used computer modeling to investigate
the evolution of muscle leverage (moment arms) and function in extant
and extinct archosaur lineages (crocodilians, dinosaurs including
birds and pterosaurs). These studies sought to quantify the level of
disparity and convergence in muscle moment arms during the evolution
of bipedal and quadrupedal posture in various independent archosaur
lineages, and in doing so further our understanding of changes in
anatomy, locomotion and ecology during the group’s >250 million year
evolutionary history. Subsequent work by others has led us to
re-evaluate our models, which revealed a methodological error that
impacted on the results obtained from the abduction–adduction and
long-axis rotation moment arms in our published studies. In this paper
we present corrected abduction–adduction and long axis rotation moment
arms for all our models, and evaluate the impact of this new data on
the conclusions of our previous studies. We find that, in general, our
newly corrected data differed only slightly from that previously
published, with very few qualitative changes in muscle moments (e.g.,
muscles originally identified as abductors remained abductors). As a
result the majority of our previous conclusions regarding the
functional evolution of key muscles in these archosaur groups are
upheld.