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Flea with possible dino-blood in + amniote heart + news

Ben Creisler

I've had numerous problems posting news and blog items to the DML
lately so I hope this one gets through. This is my fourth try for this
batch. Apologies if the others show up. Here are a few recent items
not yet mentioned here....

With debate over the heaviest ever dinosaur claim this week, how about
a Mesozoic flea for contrast? Possible dino-blood sample? Free pdf of
recent paper:

Taiping Gao, Chungkun Shih, Alexandr P Rasnitsyn, Xing Xu, Shuo Wang &
Dong Ren (2014)
The first flea with fully distended abdomen from the Early Cretaceous of China.
BMC Evolutionary Biology 14: 168
DOI: 10.1186/s12862-014-0168-1


Fleas, the most notorious insect ectoparasites of human, dogs, cats,
birds, etc., have recently been traced to its basal and primitive
ancestors during the Middle Jurassic. Compared with extant fleas,
these large basal fleas have many different features. Although several
fossil species with transitional morphologies filled the evolutionary
blank, the early evolution of these ectoparasites is still poorly

Here we report a new flea with transitional characters, Pseudopulex
tanlan sp. nov., assigned to Pseudopulicidae, from the Lower
Cretaceous Yixian Formation of Liaoning Province, China. Different
from the previously described pseudopulicids, P. tanlan has relatively
smaller body size but lacking any ctenidia on the tibiae or body,
while the male with comparatively smaller and shorter genitalia. On
the other hand, P. tanlan has some characters similar to the
transitional fleas of saurophthirids, such as, a small head, short
compacted antennae, small pygidium and many stiff setae covering the

Even though other possibilities can not be ruled out, the female
specimen with extremely distended abdomen suggests that it might have
consumed its last meal before its demise. Compared with other reported
female flea fossils, we calculate and estimate that P. tanlan sp. nov.
might have consumed 0.02 milliliter (ml) of blood, which is about 15
times of the intake volume by extant fleas. These new findings further
support that fleas had evolved a broad diversity by the Early


Amniote heart evolution, including birds and crocodiles

Poelmann RE, Groot ACG-d, Vicente-Steijn R, Wisse LJ, Bartelings MM,
et al. (2014)
Evolution and Development of Ventricular Septation in the Amniote Heart.
PLoS ONE 9(9): e106569.

During cardiogenesis the epicardium, covering the surface of the
myocardial tube, has been ascribed several functions essential for
normal heart development of vertebrates from lampreys to mammals. We
investigated a novel function of the epicardium in ventricular
development in species with partial and complete septation. These
species include reptiles, birds and mammals. Adult turtles, lizards
and snakes have a complex ventricle with three cava, partially
separated by the horizontal and vertical septa. The crocodilians,
birds and mammals with origins some 100 million years apart, however,
have a left and right ventricle that are completely separated, being a
clear example of convergent evolution. In specific embryonic stages
these species show similarities in development, prompting us to
investigate the mechanisms underlying epicardial involvement. The
primitive ventricle of early embryos becomes septated by folding and
fusion of the anterior ventricular wall, trapping epicardium in its
core. This folding septum develops as the horizontal septum in
reptiles and the anterior part of the interventricular septum in the
other taxa. The mechanism of folding is confirmed using DiI tattoos of
the ventricular surface. Trapping of epicardium-derived cells is
studied by transplanting embryonic quail pro-epicardial organ into
chicken hosts. The effect of decreased epicardium involvement is
studied in knock-out mice, and pro-epicardium ablated chicken,
resulting in diminished and even absent septum formation. Proper
folding followed by diminished ventricular fusion may explain the deep
interventricular cleft observed in elephants. The vertical septum,
although indistinct in most reptiles except in crocodilians and
pythonidsis apparently homologous to the inlet septum. Eventually the
various septal components merge to form the completely septated heart.
In our attempt to discover homologies between the various septum
components we aim to elucidate the evolution and development of this
part of the vertebrate heart as well as understand the etiology of
septal defects in human congenital heart malformations.

Smuggled Alioramus fossil seized



Dinosaur bone at Dinosaur National Monument  in Utah vandalized



Theropod tooth may have come from famous 17th century collection in Oxford



Permian tetrapod tracks from Austria (in German)


pdf (in German)