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[dinosaur] Sinemys + Triassic tetrapod teeth from Germany + Wealden + crocodile color change + more papers






Ben Creisler
bcreisler@gmail.com

Some recent mainly non-dino papers:


Free pdf:

Sinemys chabuensis sp. nov.

JI Shuâan & CHEN Xiaoyun (2018)
A New Early Cretaceous Turtle from Otog Qi, Inner Mongolia, China.
Acta Geologica Sinica 92(4): 629-637
http://www.geojournals.cn/dzxbe/ch/reader/view_abstract.aspx?file_no=2017089&flag=1
pdf:
http://www.geojournals.cn/dzxbe/ch/reader/create_pdf.aspx?file_no=2017089&flag=1&journal_id=dzxbe&year_id=2018


Abundant fossil turtles have been known from the Early Cretaceous deposits of the Ordos region,Inner Mongolia. A new species of Sinemys, S. chabuensis sp. nov, is erected based on a nearly complete turtle carapace that was excavated from the Jingchuan Formation of Otog Qi, Ordos. This species is characterized by its very wide third vertebral scute with its width doubling its length and its length of anterior lateral margin 1.7 times the length of posterior lateral margin, the contact between the paired eighth pleural plates at midline, very broad first suprapygal plate, and the very developed lateral spine from the seventh peripheral plate. At least two turtle species have been reported from the Early Cretaceous Jingchuan Formation and other two taxa from the underlying Luohandong Formation from Ordos region, respectively. There appear some successions and differences of the turtles between the two formations.




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Rainer R. Schoch, Frank Ullmann, Brigitte Rozynek, Reinhard Ziegler, Dieter Seegis & Hans-Dieter Sues (2018)
Tetrapod diversity and palaeoecology in the German Middle Triassic (Lower Keuper) documented by tooth morphotypes.
Palaeobiodiversity and Palaeoenvironments (advance online publication)
DOI: https://doi.org/10.1007/s12549-018-0327-2
https://link.springer.com/article/10.1007/s12549-018-0327-2



Continued excavations during the last decade have yielded large quantities of tetrapod remains from the Middle Triassic (Ladinian) Erfurt Formation (Lower Keuper) in Germany. The temnospondyl dental morphotypes are highly variable but represent low taxonomic diversity. This is in contrast to the reptilian tooth morphotypes, which comprise a minimum of 26 distinct types, only some of which can be referred to taxa based on diagnostic skeletal material. The assemblage includes a taxonomically diverse range of semi-aquatic or aquatic faunivores, in addition to large terrestrial carnivores and many smaller-sized forms that may have subsisted on invertebrates and small vertebrates. With only two taxa known to date, tetrapods with dentitions suitable for oral processing of plant material form the least common faunal element. The Lower Keuper assemblages are dominated by diapsid reptiles, especially archosauriforms. Unlike in the more or less coeval tetrapod communities from Gondwana, gomphodont cynodonts are represented only by a single molariform tooth to date, whereas avemetatarsalian archosaurs are entirely absent. Most remarkable is the virtually total absence of medium- to large-sized herbivores (rhynchosaurs, dicynodont synapsids).

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Peter A. Austen & David J. Batten (2018)
English Wealden fossils: an update.
Proceedings of the Geologists' Association (advance online publication)
doi: https://doi.org/10.1016/j.pgeola.2018.02.007
https://www.sciencedirect.com/science/article/pii/S0016787818300270


The non-marine Wealden succession of southern England contains a great variety of fossils, new finds of which continue to reveal novel insights into the animals and plants that inhabited this part of the world during much of the Early Cretaceous. Although seldom common, careful searching during the past few years has yielded megafossils that add to previous knowledge of occurrences of taxa and palaeoenvironmental conditions. Particularly significant in this respect has been the recovery of a large number of new insect species, but there have also been numerous finds of vertebrate bones and other body parts, such as teeth, skulls, a claw and a cranial endocast. In addition, the taxonomy of some of these groups and, in the case of dinosaurs, the ichnotaxonomy of their footprints and trackways, has been reviewed and/or reassessed. In this paper, we provide an illustrated account of the research that has been published on Wealden geology and the fossils that have been recovered from the succession since a field guide to English Wealden fossils was issued by the Palaeontological Association in 2011. It is aimed at providing the reader with a document of first resort for fossil identification purposes and a lead into the literature for further information.

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Free pdf:

Rudah Ruano Cavalcanti Duque & Alcina MagnÃlia Franca Barreto (2018)
Novos SÃtios FossilÃferos da FormaÃÃo Romualdo, CretÃceo Inferior, Bacia do Araripe, Exu, Pernambuco, Nordeste do Brasil.
[New Fossiliferous Sites of the Romualdo Formation, Lower Cretaceous, Araripe Basin, Exu, Pernambuco, Northeast of Brazil.]
AnuÃrio do Instituto de GeociÃncias 41(1): 5-14
http://www.anuario.igeo.ufrj.br/2018_01/2018_1_05_14.pdf



Here are new and old inventory of fossiliferous sites in the Romualdo Formation, Albian of the Araripe Basin, in the municipality of Exu, Pernambuco, Northeast of Brazil, with the survey of its fossiliferous diversity, with emphasis on paleovertebrates. Seven localities were studied, and 16 taxa of paleovertebrates were identified, including fishes: Vinctifer comptoni, Rhacolepis buccalis, Calamopleurus cylindricus, Cladocyclus gardneri, Neoproscinetes penalvai, Paraelops cearenses, Tharrhias araripis, Notelops brama, Araripelepdotes temnurus, Brannerion sp. e Beurlenichthys ouricuriensis; new occurrences of pterosaurs Anhangueridae and; chelonians (Araripemys barretoi). The Romualdo Formation has been studied since 1800 and it is internationally recognized as FossillagerstÃtte. However, the Pernambuco region of the Araripe Basin lacks systematic studies when compared to the region of CearÃ, which indicates the need to register the occurrence of fossiliferous sites and diversity, contributing to the knowledge of vertebrate paleontology in the southwest portion of the Araripe Basin and expanding the paleontological collections of the state of Pernambuco.Â


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Cenozoic...


Gerald Mayr (2018)
New data on the anatomy and palaeobiology of sandcoleid mousebirds (Aves, Coliiformes) from the early Eocene of Messel.
Palaeobiodiversity and Palaeoenvironments (advance online publication)
DOI: https://doi.org/10.1007/s12549-018-0328-1
https://link.springer.com/article/10.1007/s12549-018-0328-1



The Sandcoleidae are stem group representatives of the Coliiformes (mousebirds). These birds are among the most abundant medium-sized arboreal birds in some early and middle Eocene fossil sites of Europe and North America, and they are particularly well represented in the German locality Messel. Here, new sandcoleid fossils from Messel are reported. Most of these are tentatively assigned to Eoglaucidium pallas, which is the only named European sandcoleid species, but one specimen is likely to represent a new, unnamed species. Another fossil exhibits exceptionally well-preserved feather remains, which show that the tail of sandcoleids was not as greatly elongated and stiffened as that of extant mousebirds (Coliidae). It is hypothesised that these differences in the tail morphology of sandcoleids and coliids may have been due to changes in the habitual perching posture, which occurred early in the evolutionary history of the Coliidae.


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Mark Merchant, Amber Hale, Jen Brueggen, Curt Harbsmeier & Colette Adams (2018)
Crocodiles Alter Skin Color in Response to Environmental Color Conditions.
Scientific Reports 8, Article number: 6174 (2018)
doi:10.1038/s41598-018-24579-6
https://www.nature.com/articles/s41598-018-24579-6

Free pdf:

https://www.nature.com/articles/s41598-018-24579-6.pdf

Many species alter skin color to varying degrees and by different mechanisms. Here, we show that some crocodylians modify skin coloration in response to changing light and environmental conditions. Within the Family, Crocodylidae, all members of the genus Crocodylus lightened substantially when transitioned from dark enclosure to white enclosures, whereas Mecistops and Osteolaemus showed little/no change. The two members of the Family Gavialidae showed an opposite response, lightening under darker conditions, while all member of the Family Alligatoridae showed no changes. Observed color changes were rapid and reversible, occurring within 60â90âminutes. The response is visually-mediated and modulated by serum Î-melanocyte-stimulating hormone (Î-MSH), resulting in redistribution of melanosomes within melanophores. Injection of crocodiles with Î-MSH caused the skin to lighten. These results represent a novel description of color change in crocodylians, and have important phylogenetic implications. The data support the inclusion of the Malayan gharial in the Family Gavialidae, and the shift of the African slender-snouted crocodile from the genus Crocodylus to the monophyletic genus Mecistops.