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[dinosaur] Vanolimicola, new Eocene bird from Messel + Triassic marine life + more





Ben Creisler
bcreisler@gmail.com


Some recent non-dino papers:


Vanolimicola longihallucis, gen. et sp. nov.

Gerald Mayr (2017)
A small, “wader-like” bird from the Early Eocene of Messel (Germany).
Annales de Paléontologie (advance online publication)
doi:  http://dx.doi.org/10.1016/j.annpal.2017.01.001
http://www.sciencedirect.com/science/article/pii/S0753396917300010



A small bird with a shorebird-like beak and a very long hind toe is described from the Early Eocene of Messel in Germany. Vanolimicola longihallucis, gen. et sp. nov. is one of the few candidate species for a “wading bird” from Messel, that is, a bird that may have foraged along the shoreline of the ancient lake. A few features indicate a relationship to charadriiform birds and Jacanidae (jacanas) in particular, but charadriiform affinities are only weakly supported. In the preserved skeletal elements, V. longihallucis also resembles the taxon Songzia from the Early Eocene of China, which is considered to be a representative of the Ralloidea (rails and allies). A potential biogeographic significance of the new Messel fossil is strengthened by similar fossils from the North American Green River Formation.


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N.V. Zelenkov (2016) 
Evolution of bird communities in the Neogene of Central Asia, with a review of the Neogene fossil record of Asian birds.
Paleontological Journal 50: 1421. 
doi:10.1134/S0031030116120200
http://link.springer.com/article/10.1134/S0031030116120200



A complete taxonomic review of Neogene birds of continental Asia is provided. To date, avifauna from the latter half of the Miocene and Pliocene of Central Asia (Mongolia and adjacent regions of Inner Asia) are most thoroughly investigated. Available data enable a reconstruction of successive replacement of Early and Middle Miocene avifaunas by communities of the Recent type. Middle Miocene avifaunas of Mongolia include a great number of extinct genera and species, many of which were widespread in Eurasia. Extant genera became dominant in the Late Miocene and taxa close to living species appear in the Late Pliocene fossil record. Late Pliocene communities of birds of Central Asia were complex in genesis, composed of Miocene relicts (Struthio), immigrants from the European regions of the Palearctic (phasianid Plioperdix), North American immigrants (Calcarius), and also autochthonous elements, the origin of which is apparently connected with the arid belt of Central Asia (diverse passerines).

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Free pdf:


ZHOU Changyong,  ZHANG Qiyue,  HUANG Jinyuan,  HU Shixue, WEN Wen  & XIE Tao (2017)

The first discovery of marine reptile fossils from the Early Triassic of the Nanpanjiang Basin.

Geological Bulletin of China 36(1): 168-171 (in Chinese)

http://dzhtb.cgs.cn/ch/reader/view_abstract.aspx?file_no=20170113&flag=1




Marine reptiles fossils, accompanied by abundant ammonites, brachipods, bivalves, conodonts and some other fossils, were discovered for the first time from the Lower Triassic Luolou Formation in Wangmo area of the Nanpanjiang Basin. Their age belongs to the Spathian substage of the Early Triassic Olenekian stage. This new discovery has a prominent significance for understanding the recovery of the Early Triassic marine ecosystem as well as the study of the origin and evolution of early marine reptiles in Early Triassic period.


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Free pdf:

Arnaud Brayard, L. J. Krumenacker, Joseph P. Botting, James F. Jenks, Kevin G. Bylund, Emmanuel Fara, Emmanuelle Vennin, Nicolas Olivier, Nicolas Goudemand, Thomas Saucède, Sylvain Charbonnier, Carlo Romano, Larisa Doguzhaeva, Ben Thuy, Michael Hautmann, Daniel A. Stephen, Christophe Thomazo and Gilles Escarguel (2017)
Unexpected Early Triassic marine ecosystem and the rise of the Modern evolutionary fauna.
Science Advances Vol. 3, no. 2, e1602159
DOI: 10.1126/sciadv.1602159
http://advances.sciencemag.org/content/3/2/e1602159



In the wake of the end-Permian mass extinction, the Early Triassic (~251.9 to 247 million years ago) is portrayed as an environmentally unstable interval characterized by several biotic crises and heavily depauperate marine benthic ecosystems. We describe a new fossil assemblage—the Paris Biota—from the earliest Spathian (middle Olenekian, ~250.6 million years ago) of the Bear Lake area, southeastern Idaho, USA. This highly diversified assemblage documents a remarkably complex marine ecosystem including at least seven phyla and 20 distinct metazoan orders, along with algae. Most unexpectedly, it combines early Paleozoic and middle Mesozoic taxa previously unknown from the Triassic strata, among which are primitive Cambrian-Ordovician leptomitid sponges (a 200–million year Lazarus taxon) and gladius-bearing coleoid cephalopods, a poorly documented group before the Jurassic (~50 million years after the Early Triassic). Additionally, the crinoid and ophiuroid specimens show derived anatomical characters that were thought to have evolved much later. Unlike previous works that suggested a sluggish postcrisis recovery and a low diversity for the Early Triassic benthic organisms, the unexpected composition of this exceptional assemblage points toward an early and rapid post-Permian diversification for these clades. Overall, it illustrates a phylogenetically diverse, functionally complex, and trophically multileveled marine ecosystem, from primary producers up to top predators and potential scavengers. Hence, the Paris Biota highlights the key evolutionary position of Early Triassic fossil ecosystems in the transition from the Paleozoic to the Modern marine evolutionary fauna at the dawn of the Mesozoic era.

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Free pdf:


Lawrence H. Tanner & Spencer G. Lucas (2017)
Paleosols of the Upper Paleozoic Sangre de Cristo Formation, north-central New Mexico: Record of early Permian palaeoclimate in tropical Pangaea.
Journal of Palaeogeography (advance online publication)
doi: http://dx.doi.org/10.1016/j.jop.2017.02.001
http://www.sciencedirect.com/science/article/pii/S2095383616300761


The lower Permian (Wolfcampian) Sangre de Cristo Formation of northern New Mexico consists of silty mudstones and laterally discontinuous sandstones deposited on an aggrading alluvial plain. Locally, mudstones display a variety of pedogenic features. Common mudstone fabrics vary from platy to prismatic; some beds display prominent pedogenic slickensides. Drab-colored root traces are common throughout the section, as are calcareous nodules, which vary from small bodies with diffuse boundaries to vertically stacked, discrete, cm-scale nodules (rhizocretions), and less commonly form coalescing horizons. Vertisols occur only in the lower portion of the ca. 90-m measured section. Most of the mudstone beds contain calcretes that are immature (calcic Protosols to calcic Argillisols), but the lower to middle portion of the section also contains mature calcrete horizons (argillic Calcisols and Calcisols).

Intercalated micritic limestone beds with sharp contacts containing root traces, are of laterally variable thickness and grade to nodular calcretes. These are interpreted as floodplain pond carbonates that have undergone pedogenic alteration (palustrine limestones), indicating long periods of exposure under strongly seasonal climatic conditions. The isotopic composition of the pedogenic carbonate displays a substantial range of values, but most of the range of variation in isotopic composition is accounted for by isotopically heavier carbonate (both carbon and oxygen) precipitated in shallow ponds subject to intense pedogenic reworking (palustrine carbonate).

During the early Permian, northern New Mexico was situated in a near equatorial position (ca. 4° N). The overall character of the paleosols suggests a persistent warm, semi-humid, seasonal climate throughout most of the interval of deposition during the Wolfcampian, but with episodically increased aridity during formation of the more mature calcretes. No long-term trend of climate change is evident in the stratigraphic section examined for this study.

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Mark J. MacDougall, Neil J. Tabor, Jon Woodhead, Andrew R. Daoust, Robert R. Reisz (2017)

The unique preservational environment of the Early Permian (Cisuralian) fossiliferous cave deposits of the Richards Spur locality, Oklahoma.

Palaeogeography, Palaeoclimatology, Palaeoecology (advance online publication)

doi:  http://dx.doi.org/10.1016/j.palaeo.2017.02.019

http://www.sciencedirect.com/science/article/pii/S0031018217301669

 

Highlights


Richards Spur has a preservational environment unlike any other in the Permian.

There are three main depositional modes through which animals entered the caves.

Palaeontological, geological, and geochemical evidence all support these modes.

Movement of material in the caves caused varying degrees of wear on fossils.

New absolute age for the locality obtained from dating speleothems.


Abstract


The Richards Spur locality, Oklahoma, USA, represents an Early Permian infill in a series of Ordovician limestone and dolostone karst fissures. It exhibits the most diverse terrestrial Palaeozoic community currently known, with > 40 distinct tetrapod taxa. Speleothems intimately associated with the site indicate that Richards Spur is a cave system, suggesting a preservational environment that is distinct from those of more typical Early Permian lowland deltaic/fluvial localities. Fossil material obtained from the caves is often found in disarticulation, although articulated material is not uncommon. This suggests that there were several factors that affected how animal remains became deposited within the caves. Many animals that died outside the caves were likely disarticulated on the surface and then washed in during rainfall events, resulting in mostly disarticulated remains. Alternatively, animals could be washed in before being disarticulated and some probably fell into the caves, resulting in less chance for their remains to become disarticulated. Supporting evidence for these preservational hypotheses comes in the form of wear caused by attritional processes. Disarticulated elements can exhibit high levels of wear, likely due to water transport that would carry them into the caves from the surface, as well as reworking within the caves. The partially and completely articulated remains are normally unworn, presumably due to a lesser degree of transport and reworking. X-ray diffraction and stable isotope analysis of cave infill further supports the interpretations made from fossil material. The results of this study provide a much-improved understanding of the preservational environment at Richards Spur, and will be useful in integrating information from this unique upland locality with that from the more extensively studied lowland localities of the Early Permian.


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