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[dinosaur] Ornithomimosaur ungual phalanges morphology + Susisuchus (Eusuchia) palate + ichnology (free pdfs)





Ben Creisler
bcreisler@gmail.com


New papers with free pdfs:

Bradley McFeeters, Michael J. Ryan & Thomas M. Cullen (2018)
Morphology and variation in ungual phalanges of North American ornithomimosaurs (DINOSAURIA, THEROPODA): implications for interpreting isolated elements.
Vertebrate Anatomy Morphology Palaeontology 6: 60-67
DOI: http://dx.doi.org/10.18435/vamp29283
https://journals.library.ualberta.ca/vamp/index.php/VAMP/article/view/29283



Characters of isolated ungual phalanges were previously cited as supporting the occurrence of two distinct ornithomimosaur taxa in the Arundel Clay of Maryland, USA, and the co-occurrence of basal and more derived ornithomimosaurs in North America in the Early Cretaceous. However, these conclusions are based on misconceptions of the morphology and variability of ornithomimosaur unguals. Some characters previously cited as diagnostic of ornithomimosaur unguals are not actually observed in this clade, or are more homoplastically distributed among theropods. Claims of multiple distinct ornithomimosaur taxa in the Arundel Clay are premature, and the two pedal ungual morphotypes may instead represent positional variation in a single taxon. Positional variation is documented in ornithomimid pedal unguals from the Dinosaur Park and Horseshoe Canyon formations of Alberta, Canada, and characters for identifying the position of isolated ornithomimosaur pedal unguals are discussed. A small theropod pes from the Dinosaur Park Formation, previously referred to the oviraptorosaur Leptorhynchos, is reidentified here as ornithomimid.


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Karla J. Leiteââ & Daniel C. Fortier (2018)
The palate and choanae structure of the cf. Susisuchus (Crocodyliformes, Eusuchia): phylogenetic implications.Â
PeerJ Preprints 6:e26956v1
doi:Â https://doi.org/10.7287/peerj.preprints.26956v1
https://peerj.com/preprints/26956/



Crocodyliformes have undergone few modifications in their morphology since they have emerged. The change in the position of the choana was important during the evolutionary history of this group. Such character is relevant in the phylogenetic position of many crocodyliforms. The Susisuchidae clade has been placed in different phylogenetic positions: as a sister group of Eusuchia, advanced Neosuchia and in Eusuchia. In Isisfordia there are reports that the choana of this taxon is or not fully enclosed by pterygoid. A new skull of cf. Susisuchus from the Crato Formation of the Santana Group (Lower Cretaceous) is described and we recover Susisuchidae in a new phylogenetic position within Eusuchia. The preservation in the ventral view of FPH-243-V allows character encoding not yet observed for the species. The new specimen shows a typical eusuchian palate for Susisuchus, in which the choana is fully enclosed by the pterygoid. The encoding of the ventral characters of Susisuchus places Susisuchidae in Eusuchia. However, this position must be further studied, since the matrices showed fragility in the reconstitution of the Neosuchia-Eusuchia transition.


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Now with free pdf:

Peter L. Falkingham, Karl T. Bates, Marco Avanzini, Matthew Bennett, Emese M. Bordy , Brent H. Breithaupt, Diego Castanera, Paolo Citton, Ignacio DÃazâMartÃnez, Jim O. Farlow , Anthony R. Fiorillo, Stephen M. Gatesy, Patrick Getty, Kevin G. Hatala, Jahn J. Hornung, James A. Hyatt , Hendrik Klein, Jens N. Lallensack, Anthony J. Martin, Daniel Marty, Neffra A. Matthews , Christian A. Meyer, Jesper MilÃn, Nicholas J. Minter, Novella L. Razzolini, Anthony Romilio , Steven W. Salisbury, Lara Sciscio, Ikuko Tanaka, Ashleigh L. A. Wiseman, L. D. Xing & Matteo Belvedere (2018)Â
A standard protocol for documenting modern and fossil ichnological data.
Palaeontology (advance online publication)
doi: https://doi.org/10.1111/pala.12373
https://onlinelibrary.wiley.com/doi/abs/10.1111/pala.12373
https://onlinelibrary.wiley.com/doi/pdf/10.1111/pala.12373



The collection and dissemination of vertebrate ichnological data is struggling to keep up with techniques that are becoming commonplace in the wider palaeontological field. A standard protocol is required to ensure that data is recorded, presented and archived in a manner that will be useful both to contemporary researchers, and to future generations. Primarily, our aim is to make the 3D capture of ichnological data standard practice, and to provide guidance on how such 3D data can be communicated effectively (both via the literature and other means) and archived openly and in perpetuity. We recommend capture of 3D data, and the presentation of said data in the form of photographs, falseâcolour images, and interpretive drawings. Raw data (3D models of traces) should always be provided in a form usable by other researchers (i.e. in an open format). If adopted by the field as a whole, the result will be a more robust and uniform literature, supplemented by unparalleled availability of datasets for future workers.

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