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New birds from China: Eopengornis (enantiornithine genus) + Jeholornis curvipes (basal species)



Ben Creisler
bcreisler@gmail.com

In the new issue of Biological Journal of the Linnean Society devoted
to the Isle of Wight:

Ulysse Lefèvre, Dongyu Hu, François Escuillié, Gareth Dyke andPascal
Godefroit (2014)
A new long-tailed basal bird from the Lower Cretaceous of north-eastern China.
Biological Journal of the Linnean Society 113 (3): 790–804
Special Issue: Celebrating Dinosaur Island
DOI: 10.1111/bij.12343
http://onlinelibrary.wiley.com/doi/10.1111/bij.12343/abstract

A new basal Avialae, Jeholornis curvipes sp. nov., from the Yixian
Formation (Lower Cretaceous) of Liaoning Province (north-eastern
China) is described. A revision of long-tailed birds from China and a
phylogenetic analysis of basal Avialae suggest that Jeholornithiformes
were paraphyletic, with Jixiangornis orientalis being the sister-taxon
of pygostylia. The phylogenetic analysis also recovered that the tail
reduction is a unique event in the evolution of birds. Jeholornis
species were cursorial, nonperching, and seed-eating birds. © 2014 The
Linnean Society of London, Biological Journal of the Linnean Society,
2014, 113, 790–804.

***
Xiaoli Wang, Jingmai K. O'Connor, Xiaoting Zheng, Min Wang, Han Hu and
Zhonghe Zhou (2014)
Insights into the evolution of rachis dominated tail feathers from a
new basal enantiornithine (Aves: Ornithothoraces).
Biological Journal of the Linnean Society 113 (3): 805–819
Special Issue: Celebrating Dinosaur Island
DOI: 10.1111/bij.12313
http://onlinelibrary.wiley.com/doi/10.1111/bij.12313/abstract

We report on a new enantiornithine Eopengornis martini gen. et sp.
nov. from the lowest horizon of the Jehol Biota in Hebei, China; dated
at 130.7 Mya, this is the second oldest avian bearing fossil deposit
in the world, recording the First Appearance Datum of Enantiornithes.
The new specimen, only the second enantiornithine and third bird
reported from this horizon, preserves numerous synapomorphies with the
largest Lower Cretaceous enantiornithine Pengornis houi from the
Jiufotang Formation dated at 120 Mya. Together, they form a new avian
lineage that lasted over 10 Myr, which is longer than any known clade
of Lower Cretaceous enantiornithine. Eopengornis reveals new
information about basal enantiornithine morphology such as the
presence of a metatarsal V, helping to clarify the early evolution of
these dominant Cretaceous avians. Furthermore, Eopengornis preserves a
previously unrecognized tail morphology: a pair of elongate fully
pennaceous rachis dominated feathers. This discovery confirms
hypotheses proposing that the rachis dominated racket-plumes in basal
birds represent modified pennaceous feathers. We suggest that the
ornamental racket-plumes in enantiornithines and Confuciusornis
evolved independently from the basal pygostylian condition, which we
infer was a tail formed of normal flight feathers.
****

Zihui Zhang Defeng Chen, Huitao Zhang and Lianhai Hou (2014)
A large enantiornithine bird from the Lower Cretaceous of China and
its implication for lung ventilation.
Biological Journal of the Linnean Society 113 (3): 820–827
Special Issue: Celebrating Dinosaur Island
DOI: 10.1111/bij.12330
http://onlinelibrary.wiley.com/doi/10.1111/bij.12330/abstract

The Enantiornithes were the most taxonomically diverse bird group in
the Mesozoic. Most of the known taxa are from Lower Cretaceous
deposits of the Jehol Group in north-eastern China. A new specimen
from the Jiufotang Formation in Jianchang, Liaoning Province, is
described here; being a subadult individual at the time of death it
had reached a relatively large size. The presence of uncinate
processes, bicapitate and forked vertebral ribs, sternal ribs that
were all of similar length, as well as the location of parapophyses
and diapophyses on the thoracic vertebrae, may imply a rigid and
volume-constant lung, and less efficient lung ventilation in
enantiornithines.