Ben Creisler
Some recent non-dino papers not yet mentioned:
Shitienfenia completus sp. nov.
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Wang Junyou, Yi Jian & Liu Jun (2019)
The first complete pareiasaur skull from China.
Acta Palaeontologica Sinica 58(2): 216â221
http://113.31.19.23/Qikan/Article/Detail?id=7002558706&from=Qikan_Search_Indexor
http://gswxb.cnjournals.cn/ch/reader/view_abstract.aspx?file_no=20190207&flag=1(No free pdf link that I can find, though...)
Although seven pareiasaur species have been named from China, none of them is represented by well-preserved cranial material. Here we briefly describe a new material from Ordos Basin, it includes a nearly complete skull with occluding mandibles. This specimen can be referred to Elginiidae by dermal bosses of cranial bones that have a long and pointed horn, cheek ornamentation in the form of prominent conical horns, supratemporal horn projecting posterolaterally from corner of skull table, slender parabasisphenoid with median, ventral groove, and enlarged tabulars (supernumerary bones) that contact each other medially, thereby excluding the postparietals from the caudal margin of the skull roof. It shares the following features with Sanchuansaurus pygmaeus: a small boss on the maxillary anterodorsal process posterior to the naris, maxillary teeth with fan-shaped crown, 9~11 cusps; and differs from the latter by two exits for the infraorbital canal on the lateral surface are closer and more ventrally (close to the alveoli margin), crown nearly not overlapped, only 14 alveoli (tooth sockets). It shares unique features on the mandible with Huanghesaurus liulinensis for the ventral margin of the mandible nearly straight, the angular with a boss towards the posterior end, dentary teeth with ~17 cusps, the midline bulge ascends the medial face of the crown. The previous cladistics analyses do not support a closely relationship of Huanghesaurus with Elgiidae, but the new specimen supports a closely relationship between Sanchuansaurus and Huanghesaurus, and both should be a member of Elginiidae. The new specimen is referred to Shitienfenia as a new species, S. completus. However, it is also possibly belonged to Shitienfenia permica while Sanchuansaurus pygmaeus and Huanghesaurus liulinensis are valid species. Recently, many skeletons have been collected from the same locality, they will help to resolve the interrelationships of Shitienfenia, Huanghesaurus, and Sanchuansaurus.
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Masaya Iijima, Takehisa Tsubamoto, Khishigjav Tsogtbaatar, Tsogtbaatar Chinzorig, and Soyol Baasankhuu (2019)
Discovery of a crocodyliform tooth from the upper Eocene Ergilin Dzo Formation, Mongolia.
Acta Palaeontologica Polonica (in press)
doi:
https://doi.org/10.4202/app.00633.2019http://app.pan.pl/article/item/app006332019.htmlFree pdf:
http://app.pan.pl/archive/published/app64/app006332019.pdfAlthough the distribution of Asian crocodyliforms was extended northwards during the PaleoceneâEocene greenhouse world, the fossil record in northern Asia becomes scarce towards the end of the Eocene. We here report the first crocodyliform (an isolated tooth) from the upper Eocene Ergilin Dzo Formation of southeastern Mongolia, the mammalian fauna of which defines the Ergilian Asian Land Mammal Age. The conical non-recurved crown, the near complete root with the central resorption facet, and its late Eocene age suggest the crocodyliform affinity of the tooth. The current finding represents one of the northernmost occurrences of crocodyliforms in the upper Eocene of Asia (paleolatitude ca. 49Â30â N), and demonstrates that SE Mongolia probably met thermal requirements of crocodyliforms during the late Eocene.
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Jamile M BubaduÃ, Carla D Hendges, Jorge J Cherem, Felipe O Cerezer, Tania P FalconÃ, MaurÃcio E Graipel, Nilton C CÃceres (2019)
Marsupial versus placental: assessing the evolutionary changes in the scapula of didelphids and sigmodontines.
Biological Journal of the Linnean Society, blz134
doi:
https://doi.org/10.1093/biolinnean/blz134https://academic.oup.com/biolinnean/advance-article-abstract/doi/10.1093/biolinnean/blz134/5585926It is not a new concept that marsupials and placentals are distant and distinct clades among mammals. In South America, these animals coexist, occupy similar niches and, in some cases, are similar in appearance. This is especially true with respect to the locomotor categories of smaller rodents belonging to the family Cricetidae or, more specifically, the subfamily Sigmodontinae, compared with the marsupials of the Didelphidae family. In this study, we have investigated both the similarities and the differences between the two clades by examining locomotion-dependent adaptation, a crucial survival mechanism that has affected the morphology of both clades. We applied geometric morphometrics to quantify the shape of the scapula, which is a very adaptable structure. We found similar morphological adaptations between the clades, especially with respect to adaptation to life in trees. Moreover, Didelphidae are influenced by phylogenetic history to a greater extent than Sigmodontinae with regard to variation of scapula shape and allometry. These differences can be explained by the greater degree of body size variation that exists within the Didelphidae. Didelphidae have an ancient evolutionary history in South America compared with the Sigmodontinae, which have undergone a very successful and rapid diversification more recently.
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Anurans are extremely diverse amphibians with a unique Bauplan, whose origin, early ecomorphological diversification, and adaptive significance remain elusive. Their early fossil record is improving at an accelerated pace worldwide, but its contribution to these issues is still wanting. Here we explore ecomorphological diversity among Early Cretaceous (Barremian) frogs that inhabited a large subtropical wetland from Iberia by inferring locomotor abilities with a phylogenetic flexible discriminant analysis on data from limb proportions, which strongly correlate with locomotion. The results show a remarkable diversity among these frogs when compared with the extant diversity from this region and from tropical and subtropical wetland assemblages worldwide, encompassing miniature to medium-size jumpers and dedicated swimmers with more extreme proportions than extant 'archeobatrachians,' but also more generalized jumping and/or swimming forms. This agrees with the inferred wetland paleoenvironment and the hypothesis regarding early frogs as small poor jumpers or swimmers that evolved their peculiar Bauplan in aquatic environments.
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Joerg W. Schneider, Spencer G. Lucas, Frank Scholze, SebastianVoigt, Lorenzo Marchetti, Hendrik Klein, Stanislav OpluÅtil, Ralf Werneburg, Valeriy K. Golubev, James E. Barrick, Tamara Nemyrovska, Ausonio Ronchi, Michael O. Day, Vladimir V. Silantiev, Ronny RÃÃler, Hafid Saber, Ulf Linnemann, Veronika Zharinova & Shu-Zhong Shen (2019)
Late Paleozoicâearly Mesozoic continental biostratigraphy â links to the Standard Global Chronostratigraphic Scale.
Palaeoworld (advance online publication)
doi:
https://doi.org/10.1016/j.palwor.2019.09.001 https://www.sciencedirect.com/science/article/pii/S1871174X19300976?dgcid=rss_sd_allNonmarine biostratigraphic/biochronologic schemes have been created for all or parts of the late CarboniferousâMiddle Triassic using palynomorphs, megafossil plants, conchostracans, blattoid insects, tetrapod footprints and tetrapod body fossils, and these provide varied temporal resolution. Cross correlation of the nonmarine biochronologies to the Standard Global Chronostratigraphic Scale has been achieved in some parts of the late CarboniferousâMiddle Triassic in locations where nonmarine and marine strata are intercalated, the nonmarine strata produce biochronologically significant fossils and the marine strata yield fusulinids, conodonts and/or ammonoids. Other cross correlations have been aided by magnetostratigraphy, chemostratigraphy and a growing database of radioisotopic ages. A synthetic nonmarine biochronology for the late CarboniferousâMiddle Triassic based on all available nonmarine index fossils, integrated with the Standard Global Chronostratigraphic Scale, is presented here. The focus is on the nonmarine biostratigraphy/biochronology of blattoid insects, conchostracans, branchiosaurid amphibians, tetrapod footprints and tetrapod body fossils within the biochronological framework of land-vertebrate faunachrons. Correlation to the Standard Global Chronostratigraphic Scale presented here is divided into seven time intervals: Pennsylvanian, CarboniferousâPermian boundary, Cisuralian, Guadalupian, Lopingian, PermianâTriassic boundary and Early to Middle Triassic. The insects, conchostracans and branchiosaurs provide robust nonmarine correlations in the PennsylvanianâCisuralian, and the footprints and tetrapod body fossils provide robust correlations of varied precision within the entire PennsylvanianâMiddle Triassic. Radioisotopic ages are currently the strongest basis for cross correlation of the nonmarine biostratigraphy/biochronology to the Standard Global Chronostratigraphic Scale, particularly for the PennsylvanianâCisuralian. Chemostratigraphy and magnetostratigraphy thus far provide only limited links of nomarine and marine chronologies. Improvements in the nonmarine-marine correlations of late PaleozoicâTriassic Pangea require better alpha taxonomy and stratigraphic precision for the nonmarine fossil record integrated with more reliable radioisotopic ages and more extensive chemostratigraphic and magnetostratigraphic datasets.