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Jurassic crocodylomorph eggs from Portugal (free pdf) + turtle stuff + origin of fleas
A number of recent non-dino papers that may be of interest:
J. Russo, O. Mateus, A. Balbino & M. Marzola (2014)
Crocodylomorph eggs and eggshells from the Lourinhã Fm. (Upper
Jurassic), Portugal. Comunicações Geológicas. 101, Especial I: 563-566
We here present fossil Crocodylomorpha eggshells from the Upper
Jurassic Lourinhã Formation of Portugal, recovered from five sites:
one nest from Cambelas with 13 eggs, and three partial eggs and
various fragments from, Paimogo N (I), Paimogo S (II), Casal da Rola,
and Peralta. All specimens but the nest were found in association with
dinosaur egg material. Our research reveals that on a micro- and
ultrastructural analysis, all samples present the typical characters
consistent with crocodiloid eggshell morphotype, such as the shell
unit shape, the organization of the eggshell layers, and the
triangular blocky extinction observed with crossed nicols. We assign
the material from the Lourinhã Formation to the oofamily
Krokolithidae, making it the oldest crocodylomorph eggs known so far,
as well as the best record for eggs of non- crocodylian
crocodylomorphs. Furthermore, our study indicates that the basic
structure of crocodiloid eggshells has remained stable since at least
the Upper Jurassic.
Juliana Sterli (2015)
A Review of the Fossil Record of Gondwanan Turtles of the Clade Meiolaniformes
Bulletin of the Peabody Museum of Natural History 56(1): 21-45
Gondwanan turtles of the clade Meiolaniformes have a fossil record
that reaches back to the Early Cretaceous of Patagonia (South America)
and Australia. From the Late Cretaceous to the Middle Eocene the group
is restricted to Patagonia, but appears to be extirpated afterwards.
However, the fossil record of the clade commences once again in the
Late Oligocene in Australia and surrounding islands and continues
until the Holocene. Current phylogenies recognize Meiolaniidae as a
subclade within Meiolaniformes. Early meiolaniforms show terrestrial
adaptations, but their dietary preferences remain unclear.
Meiolaniids, in contrast, show strong terrestrial adaptations, were
herbivorous and appear to have been preadapted to floating across
short to intermediate oceanic distances. A taxonomic review of the
group concludes that of the 15 named taxa, 11 are nomina valida, 3 are
nomina invalida and 1 is not recognized as a meiolaniid.
Edwin Cadena and Walter G. Joyce (2015)
A Review of the Fossil Record of Turtles of the Clades Platychelyidae
Bulletin of the Peabody Museum of Natural History 56(1): 3-20
The fossil record of platychelyid turtles expands from the Late
Jurassic (Oxfordian) of Cuba to the Early Cretaceous (Valanginian) of
Colombia. Platychelyids were adapted to freshwater to coastal
environments. Current phylogenies confidently suggest that
platychelyids are situated along the stem lineage of crown Pleurodira.
A taxonomic review of the group concludes that of six named
“platychelyid” taxa, four are valid and two are nomina nuda. Dortokids
are a poorly understood group of freshwater aquatic turtles that are
restricted to the Early Cretaceous (Barremian) to Eocene (Lutetian) of
Europe. The phylogenetic position of the group is still under debate,
but there is some evidence that these turtles are positioned along the
stem lineage of crown Pleurodira as well. A taxonomic review of the
group concludes that of four named dortokid taxa, two are valid, one
is a nomen invalidum and one a nomen nudum.
Nikolay Natchev, Nikolay Tzankov, Ingmar Werneburg & Egon Heiss (2015)
Feeding behaviour in a ‘basal’ tortoise provides insights on the
transitional feeding mode at the dawn of modern land turtle evolution.
PeerJ PrePrints 3:e1288
Almost all extant land turtles are highly associated with terrestrial
habitats and the few tortoises with high affinity to aquatic
environment are found within the genus Manouria. Manouria belongs to a
clade which forms the sister taxon to all remaining tortoises and is
suitable to be used as a model for studying evolutionary transitions
from water to land within modern turtles. We analysed the feeding
behaviour of M. emys and due to its phylogenetic position, we
hypothesise that the species might have retained some ancestral
characteristics associated to aquatic lifestyle. We tested whether M.
emys is able to feed both in aquatic and terrestrial environments as
mud turtles do. In fact, M. emys repetitively tried to reach submerged
food items in water, but always failed to grasp them and no suction
feeding mechanism was applied. When feeding on land, M. emys showed
another peculiar behaviour; it grasped food items by its jaws – a
behaviour typical for aquatic or semiaquatic turtles – and not by the
tongue as in the typical feeding mode in all tortoises studied so far.
In M. emys, the hyolingual complex remained retracted during all food
uptake sequences, but the food transport was entirely lingual based.
The kinematical profile significantly differed from those described
for other tortoises and from those proposed from the general models on
the function of the feeding systems in lower tetrapods. We conclude
that the feeding behaviour of M. emys might reflect a remnant of the
primordial condition expected in the aquatic ancestor of tortoises.
Qiyun Zhu, Michael W. Hastriter, Michael F. Whiting & Katharina Dittmar (2015)
Fleas (Siphonaptera) are Cretaceous, and Evolved with Theria.
Molecular Phylogenetics and Evolution (advance online publication)
A comprehensive phylogeny of 259 flea taxa.
Early lineage diversification started in the Cretaceous.
Most extant lineages evolved after K-Pg boundary.
Early Siphonaptera were likely associated with Theria.
Fleas likely originated on the Gondwana supercontinent.
Fleas (order Siphonaptera) are highly-specialized, diverse
blood-feeding ectoparasites of mammals and birds with an enigmatic
evolutionary history and obscure origin. We here present a molecular
phylogenetic study based on a comprehensive taxon sampling of 259 flea
taxa, representing 16 of the 18 extant families of this order. A
Bayesian phylogenetic tree with strong nodal support was recovered,
consisting of seven sequentially derived lineages with Macropsyllidae
as the earliest divergence, followed by Stephanocircidae. Divergence
times of flea lineages were estimated based on fossil records and host
specific associations to bats (Chiroptera), suggesting that the common
ancestor of extant Siphonaptera diversified during the Cretaceous.
However, most of the intraordinal divergence into extant lineages took
place after the K-Pg boundary. Ancestral states of host association
and biogeographical distribution were reconstructed, suggesting with
high likelihood that fleas originated in the southern continents
(Gondwana) and migrated from South America to their extant
distributions in a relatively short time frame. Theria (placental
mammals and marsupials) represent the most likely ancestral host group
of extant Siphonaptera, with marsupials occupying a more important
role than previously assumed. Major extant flea families evolved in
connection to post K-Pg diversification of Placentalia. The
association of fleas with monotremes and birds is likely due to later
secondary host association. These results suggest caution in casually
interpreting recently discovered Mesozoic fossil “dinosaur fleas” of
Northeast Asia as part of what we currently consider Siphonaptera.