[dinosaur] Eocene birds from Mongolia + Cretaceous turtles from Yakutia

Ben Creisler
[email protected]

Recent non-dino papers:


Sarah C. Hood, Chris R. Torres, Mark A. Norell & Julia A. Clarke (2019)
New Fossil Birds from the Earliest Eocene of Mongolia.
American Museum Novitates 3934:1-24 (2019).
doi:  https://urldefense.proofpoint.com/v2/url?u=https-3A__doi.org_10.1206_3934.1&d=DwIFaQ&c=clK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=Ry_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=tTGQAJIw90vMeHFtnD4RNABrn67dXfD-dNLip6pOGeE&s=nh3UE9iEZseroKL_3PddpgpJOpbhtSqKSR7HLoIsQeM&e= 
https://urldefense.proofpoint.com/v2/url?u=https-3A__bioone.org_journals_American-2DMuseum-2DNovitates_volume-2D2019_issue-2D3934_3934.1_New-2DFossil-2DBirds-2Dfrom-2Dthe-2DEarliest-2DEocene-2Dof-2DMongolia_10.1206_3934.1.short&d=DwIFaQ&c=clK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=Ry_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=tTGQAJIw90vMeHFtnD4RNABrn67dXfD-dNLip6pOGeE&s=QGE5O_uBvMPISBnNo7ZJFfM4JhPgI4FEyTCNPRC6w_E&e= 

NOTE: The paper should be posted in open access at the AMNH link in the
near future:

https://urldefense.proofpoint.com/v2/url?u=http-3A__digitallibrary.amnh.org_handle_2246_9&d=DwIFaQ&c=clK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=Ry_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=tTGQAJIw90vMeHFtnD4RNABrn67dXfD-dNLip6pOGeE&s=j9QxmbyyL1SUReFXcQWQyyaW35Sd4ZwNsBHMFs1FHjI&e= 


Understanding of the Asian early Paleogene avifauna is limited relative to
that of North American and European avifauna of the same period. While
major patterns of mammalian faunal exchange among these three regions
across the Paleocene/Eocene boundary have been described, much less is
known about the dynamics of bird diversity over the same time interval.
Here, we report bird fossils from the earliest Eocene Bumban Member of the
Naranbulag Formation in central Mongolia that add to the known record from
Asia from just after this boundary. Most of this material, collected by the
joint American Museum of Natural History/ Mongolia Academy of Sciences
expeditions, is referable to a previously described taxon in
Presbyornithidae (Anseriformes). However, five isolated elements are
identified as comprising at least four species from at least three other
major avian clades. While further inclusive phylogenetic analyses of each
of these clades are necessary, the new remains represent possible earliest
occurrences in Asia of these clades. The material includes a humerus and a
furcula from shorebirds (Pan-Charadriiformes), a quadrate from a stem
member of the flamingo-grebe lineage (Pan-Mirandornithes), and a coracoid
from a stem galliform (Pangalliformes). We also report a humerus with
uncertain phylogenetic affinities but with similarities to core Gruiformes.
These new fossils expand our knowledge of the Asian avifauna during this
time and have the potential to further inform our understanding of the
early biogeography of these clades. The shorebird and flamingo-grebe
material indicate that both these lineages were present in Asia by the
earliest Eocene. The pan-mirandornithine quadrate provides insight into the
early feeding ecology of the flamingo-grebe clade.


===

Pavel P. Skutschas, Valentina D. Markova, Veniamin V. Kolchanov, Alexander
O.Averianov, Thomas Martin, Rico Schellhorn, Petr N. Kolosov, Dmitry V.
Grigoriev, Dmitry D. Vitenko, Ekaterina M. Obraztsova & Igor G. Danilov
(2019)
Basal turtle material from the Lower Cretaceous of Yakutia (Russia) filling
the gap in the Asian record.
Cretaceous Research (advance online publication)
doi: https://urldefense.proofpoint.com/v2/url?u=https-3A__doi.org_10.1016_j.cretres.2019.07.016&d=DwIFaQ&c=clK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=Ry_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=tTGQAJIw90vMeHFtnD4RNABrn67dXfD-dNLip6pOGeE&s=vl-aOPhWg51v7Ysb4H838m3Rj3dQsbohDFLWyV3dQUs&e= 
https://urldefense.proofpoint.com/v2/url?u=https-3A__www.sciencedirect.com_science_article_pii_S019566711930134X&d=DwIFaQ&c=clK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=Ry_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=tTGQAJIw90vMeHFtnD4RNABrn67dXfD-dNLip6pOGeE&s=_KM_H4tKCXUg0YG4MQj9zP_1tOn-en2d68lmNpPycho&e= 

This paper describes fragmentary turtle material (isolated basisphenoid,
shell bones, humerus and ilium) from the Lower Cretaceous
(Berriasian–Barremian) Teete locality in Yakutia (Eastern Siberia, Russia).
All the material is attributed to one taxon of basal turtles (Mesochelydia
indet.), based on the morphology of the basisphenoid, shell bones and
humerus, as well as microanatomy and histology of the shell bones and
humerus. Canals and foramina of the basisphenoid of this taxon revealed by
CT scanning show an unusual pattern, which allows various interpretations
and suggests a higher diversity of carotid and/or vidian systems in basal
turtles than hitherto believed. Mesochelydia indet. from Teete fills an
Early Cretaceous gap in the record of Asian basal turtles and represents
the northernmost Asian non-marine turtle occurrence of the Mesozoic. All in
all, the record of Asian basal turtles appears to be wider geographically
and more complete temporally than previously thought. The Asian basal
turtles are represented by at least three phylogenetic lineages: primitive
Testudinata in the Late Triassic, primitive Mesochelydia from the Early
Jurassic to the Early Cretaceous and primitive Perichelydia from the Middle
Jurassic to the Late Cretaceous. The presence of such a primitive (Jurassic
level) turtle in Teete supports the hypothesis that the vast territory of
Siberia was a refugium for Jurassic vertebrate faunal elements. Details of
the external morphology and histology of the Teete turtle material as well
as its high paleolatitude occurrence argue in favor of its aquatic
lifestyle.




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