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[dinosaur] Protoalligator from Paleocene of China + Gastornis + Permian and Carboniferous tracks + more




Ben Creisler
bcreisler@gmail.com



Some non-dino papers:



Protoalligator



Yan-yin Wang​, Corwin Sullivan & Jun Liu  (2016)

Taxonomic revision of Eoalligator (Crocodylia, Brevirostres) and the paleogeographic origins of the Chinese alligatoroids.

PeerJ 4:e2356

doi:  https://doi.org/10.7717/peerj.2356

https://peerj.com/articles/2356/

 

 

Background. The primarily Neotropical distribution of living alligatoroids raises questions as to when and how the ancestors of Alligator sinensis migrated to China. As phylogeny provides a necessary framework for historical biogeographic issues, determining the phylogenetic positions of the Chinese alligatoroids is a crucial step towards understanding global alligatoroid paleobiogeography. Besides the unnamed alligatoroids from the Eocene of Guangdong Province, three Chinese fossil taxa have been referred to Alligatoroidea: Alligator luicus, Eoalligator chunyii and Eoalligator huiningensis. However, none of these fossil taxa has been included in a phylogenetic analysis. The genus Eoalligator was established to accommodate E. chunyii from Guangdong Province. E. huiningensis from Anhui Province was later erected as a second species, despite no distinctive similarities with E. chunyii. By contrast, the putative crocodyline Asiatosuchus nanlingensis was established based on material from Guangdong Province, close to the E. chunyii specimens geographically and stratigraphically. Furthermore, specimens of A. nanlingensis and E. chunyii share four distinctive characters, but display no evident differences. As a result, the taxonomic relationships of these three species require restudy.

 

Methods. In this paper, all specimens of E. chunyii and E. huiningensis are reassessed in detail, and compared to specimens of A. nanlingensis. Detailed re-descriptions and revised diagnoses are provided, and a cladistic analysis is carried out to assess the phylogenetic positions of E. chunyii, E. huiningensis and A. nanlingensis.

 

Results. The analysis recovers E. chunyii and A. nanlingensis as sister taxa among basal Crocodylidae, while P. huiningensis is posited as an alligatoroid. Two key characters support the monophyly E. chunyii + A. nanlingensis: sulcus within surangular, and anteroposteriorly oriented surangular-articular suture. The former character is unique to E. chunyii and A. nanlingensis among crocodyloids, although a smaller and more posteriorly positioned surangular fossa is known in Diplocynodon. Detailed comparisons show the two species to be synonymous, with E. chunyii as the junior synonym of A. nanlingensis based on page priority. Because E. chunyii was erected as the type species of Eoalligator, the genus is now invalid. We establish the new genus Protoalligator to accommodate “Eoalligator” huiningensis, an alligatoroid whose exact phylogenetic position is uncertain. In particular, P. huiningensis retains primitive characters such as a lacrimal that extends further anteriorly than the prefrontal, and a notch at the premaxilla-maxilla suture. However, P. huiningensis also appears to share one important derived character, a complete nasal bar, with alligators. Our taxonomic revisions imply that four alligatoroids are currently known from China, and these species must have dispersed from North America to Asia in more than one event.

 

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Cécile Mourer-Chauviré & Estelle Bourdon (2016)

The Gastornis (Aves, Gastornithidae) from the Late Paleocene of Louvois (Marne, France).

Swiss Journal of Palaeontology 135(2): 327–341

DOI: 10.1007/s13358-015-0097-7

http://link.springer.com/article/10.1007/s13358-015-0097-7




The Late Paleocene locality of Louvois is located about 20 km south of Reims, in the department of Marne (France). These marly sediments have yielded numerous vertebrate remains. The Louvois fauna is coeval with those of the localities of Cernay-lès-Reims and Berru and is dated as reference-level MP6, late Thanetian. Here we provide a detailed description of the remains of giant flightless gastornithids that were preliminarily reported in a study of the vertebrate fauna from Louvois. These fragmentary gastornithid remains mainly include a carpometacarpus, several tarsometatarsi, and numerous pedal phalanges. These new avian fossils add to the fossil record of Gastornis, which has been reported from various Early Paleogene localities in the Northern Hemisphere. Tarsometatarsi and pedal phalanges show large differences in size, which may be interpreted as sexual size dimorphism. The specimens from Louvois are morphologically different from those of Gastornis parisiensis and G. russelli, from Cernay and Berru. The Louvois carpometacarpus is also different from that of the North American G. giganteus, and the Louvois pedal phalanges are shorter and stouter than in other species of Gastornis. Moreover, the Louvois tarsometatarsi are more similar to that of the much younger G. sarasini, from Monthelon, reference-level MP 10, late Ypresian. We refrain from assigning the Louvois specimens to a new species of Gastornis and we designate it as Gastornis sp., owing to the fragmentary nature of the material. However, the morphological features of the Louvois material are sufficiently distinct for us to propose that three different forms of Gastornis were present in the Late Paleocene of North-eastern France.



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Gerald Mayr (2016)

On the taxonomy and osteology of the Early Eocene North American Geranoididae (Aves, Gruoidea).

Swiss Journal of Palaeontology 135(2): 315–325

DOI: 10.1007/s13358-016-0117-2

http://link.springer.com/article/10.1007/s13358-016-0117-2



Whereas our knowledge of small arboreal Paleogene birds has greatly increased in the past years, that of the larger birds coexisting with them is far less detailed. Particularly poorly known and, hence, widely ignored are the North American Geranoididae, of which six species were described from the Early Eocene Willwood Formation. The published material of all of these consists only of incomplete leg elements, and previous descriptions and comparisons mainly focused on selected bones. Here, a revision of some geranoidids from the Willwood Formation is undertaken, and it is concluded that the taxon Geranoides Wetmore, 1933, the type genus of the Geranoididae, is a junior synonym of Palaeophasianus Shufeldt, 1913. Eogeranoides campivagus Cracraft, 1969 is poorly differentiated from Paragrus prentici (Loomis, 1906), and a synonymy of both species also seems likely. Complete leg bones of a large Eogeranoides/Paragrus-like species are reported, which constitute the most substantial record of a geranoidid from the Willwood Formation. It is detailed that geranoidids are likely to be stem group representatives of the Gruoidea, the clade including trumpeters, cranes, and allies, and the potential occurrence of geranoidids in the Eocene of Europe is discussed.


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Grzegorz Pieńkowski, Marta Hodbod & Clemens V. Ullmann (2016)

Fungal decomposition of terrestrial organic matter accelerated Early Jurassic climate warming.

Scientific Reports 6, Article number: 31930

doi:10.1038/srep31930

http://www.nature.com/articles/srep31930

 

Soils – constituting the largest terrestrial carbon pool - are vulnerable to climatic warming. Currently existing uncertainties regarding carbon fluxes within terrestrial systems can be addressed by studies of past carbon cycle dynamics and related climate change recorded in sedimentary successions. Here we show an example from the Early Jurassic (early Toarcian, c. 183 mya) marginal-marine strata from Poland, tracking the hinterland response to climatic changes through a super-greenhouse event. In contrast to anoxia-related enhanced carbon storage in coeval open marine environments, Total Organic Carbon (TOC) concentrations in the Polish successions are substantially reduced during this event. Increasing temperature favoured fungal-mediated decomposition of plant litter – specifically of normally resistant woody tissues. The associated injection of oxidized organic matter into the atmosphere corresponds to abrupt changes in standing vegetation and may have contributed significantly to the amplified greenhouse climate on Earth. The characteristic Toarcian signature of multiple warm pulses coinciding with rapidly decreasing carbon isotope ratios may in part be the result of a radical reduction of the terrestrial carbon pool as a response to climate change.


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Adriana Cecilia Mancuso, Veronica Krapovickas, Claudia Marsicano, Cecilia Benavente, Dario Benedito, Marcelo de la Fuente, and Eduardo G. Ottone (2016)

Tetrapod tracks taphonomy in eolian facies from the Permian of Argentina.

PALAIOS 31(8): 374-388

doi: http://dx.doi.org/10.2110/palo.2015.077

http://palaios.geoscienceworld.org/content/31/8/374

http://www.bioone.org/doi/abs/10.2110/palo.2015.077

 

Ancient desert deposits preserve a copious ichnofossil record, particularly Permian-age deposits where the record of tetrapod footprints is present and abundant in almost all desert settings. We propose to analyze, from a taphonomic perspective, Permian footprints preserved in eolian deposits from Argentina with a detailed sedimentological study of the trackway-bearing levels, in order to find evidence of processes that may have enhanced their preservation. We defined four taphonomic modes based on preservation quality, and the morphological and extra-morphological features of the footprints. Mode 1 includes footprints with detailed impressions of the palm, digits and claws. Mode 2 includes tracks with palm and digit impressions associated with small bulbous-shape marginal rims. Mode 3 includes tracks characterized by large, bulbous, marginal rims and randomly preserved palm impressions. Mode 4 includes footprints with shallow digit and palm impressions associated with sand-crescent marginal rims. The Los Reyunos footprints suggest preservation in: (1) dry sand, evidenced by sediment slipping down-slope structures and (2) subsurface damp sand, evidenced by digit impressions and claw drag traces. Also, we found vertical water content variations along the dune foresets, evidenced by a varying amount of sediment slipping down-slope in the same trackway. Moreover, differences in the time of entombment are suggested by the morphology of rims (bulbous-shape or sand-crescent). The stratigraphic genetic framework resulting from the Los Reyunos taphonomic analysis supports changes in the interstitial subsurface water and rapid entombment of the tracking surface due to a high rate of sediment supply as the main factor for footprint preservation.


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Free pdf:


Jesper Milàn, Hendrik Klein, Sebastian Voigt & Lars Stemmerik (2016) 

First record of tetrapod footprints from the Carboniferous Mesters Vig Formation in East

Greenland. 

Bulletin of the Geological Society of Denmark 64:  69-76

http://2dgf.dk/publikationer/bulletin/188bull64.html#3




A single slab with Late Palaeozoic tetrapod footprints from East Greenland has been housed at the Natural History Museum of Denmark for decades without scientific notice. The specimen comes from the Mesters Vig Formation of northern Scoresby Land in East Greenland and contains a monospecific assemblage of tetrapod footprints that we assign to Limnopus Marsh 1894.

 

As there is no significant morphological difference from other records of this ichnogenus from North America, Europe and North Africa, the described tetrapod footprints can be referred to eryopoid temnospondyl trackmakers. Limnopus is well-known from Upper Carboniferous and Lower Permian continental deposits of palaeoequatorial Pangea. Identification of Limnopus tracks is in agreement with the supposed Late Carboniferous age of the Mesters Vig Formation and thereby also the first evidence of Carboniferous tetrapods from Greenland.


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